diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/Kconfig | 64 | ||||
| -rw-r--r-- | kernel/trace/Makefile | 4 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 275 | ||||
| -rw-r--r-- | kernel/trace/ring_buffer.c | 2014 | ||||
| -rw-r--r-- | kernel/trace/trace.c | 1845 | ||||
| -rw-r--r-- | kernel/trace/trace.h | 211 | ||||
| -rw-r--r-- | kernel/trace/trace_boot.c | 126 | ||||
| -rw-r--r-- | kernel/trace/trace_functions.c | 2 | ||||
| -rw-r--r-- | kernel/trace/trace_irqsoff.c | 19 | ||||
| -rw-r--r-- | kernel/trace/trace_mmiotrace.c | 116 | ||||
| -rw-r--r-- | kernel/trace/trace_nop.c | 64 | ||||
| -rw-r--r-- | kernel/trace/trace_sched_switch.c | 137 | ||||
| -rw-r--r-- | kernel/trace/trace_sched_wakeup.c | 148 | ||||
| -rw-r--r-- | kernel/trace/trace_selftest.c | 83 | ||||
| -rw-r--r-- | kernel/trace/trace_stack.c | 310 | ||||
| -rw-r--r-- | kernel/trace/trace_sysprof.c | 2 |
16 files changed, 4102 insertions, 1318 deletions
diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 263e9e6bbd60..1cb3e1f616af 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -1,23 +1,37 @@ # # Architectures that offer an FTRACE implementation should select HAVE_FTRACE: # + +config NOP_TRACER + bool + config HAVE_FTRACE bool + select NOP_TRACER config HAVE_DYNAMIC_FTRACE bool +config HAVE_FTRACE_MCOUNT_RECORD + bool + config TRACER_MAX_TRACE bool +config RING_BUFFER + bool + config TRACING bool select DEBUG_FS + select RING_BUFFER select STACKTRACE + select TRACEPOINTS config FTRACE bool "Kernel Function Tracer" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select FRAME_POINTER select TRACING select CONTEXT_SWITCH_TRACER @@ -36,6 +50,7 @@ config IRQSOFF_TRACER depends on TRACE_IRQFLAGS_SUPPORT depends on GENERIC_TIME depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACE_IRQFLAGS select TRACING select TRACER_MAX_TRACE @@ -59,6 +74,7 @@ config PREEMPT_TRACER depends on GENERIC_TIME depends on PREEMPT depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACING select TRACER_MAX_TRACE help @@ -86,6 +102,7 @@ config SYSPROF_TRACER config SCHED_TRACER bool "Scheduling Latency Tracer" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACING select CONTEXT_SWITCH_TRACER select TRACER_MAX_TRACE @@ -96,16 +113,56 @@ config SCHED_TRACER config CONTEXT_SWITCH_TRACER bool "Trace process context switches" depends on HAVE_FTRACE + depends on DEBUG_KERNEL select TRACING select MARKERS help This tracer gets called from the context switch and records all switching of tasks. +config BOOT_TRACER + bool "Trace boot initcalls" + depends on HAVE_FTRACE + depends on DEBUG_KERNEL + select TRACING + help + This tracer helps developers to optimize boot times: it records + the timings of the initcalls and traces key events and the identity + of tasks that can cause boot delays, such as context-switches. + + Its aim is to be parsed by the /scripts/bootgraph.pl tool to + produce pretty graphics about boot inefficiencies, giving a visual + representation of the delays during initcalls - but the raw + /debug/tracing/trace text output is readable too. + + ( Note that tracing self tests can't be enabled if this tracer is + selected, because the self-tests are an initcall as well and that + would invalidate the boot trace. ) + +config STACK_TRACER + bool "Trace max stack" + depends on HAVE_FTRACE + depends on DEBUG_KERNEL + select FTRACE + select STACKTRACE + help + This special tracer records the maximum stack footprint of the + kernel and displays it in debugfs/tracing/stack_trace. + + This tracer works by hooking into every function call that the + kernel executes, and keeping a maximum stack depth value and + stack-trace saved. Because this logic has to execute in every + kernel function, all the time, this option can slow down the + kernel measurably and is generally intended for kernel + developers only. + + Say N if unsure. + config DYNAMIC_FTRACE bool "enable/disable ftrace tracepoints dynamically" depends on FTRACE depends on HAVE_DYNAMIC_FTRACE + depends on DEBUG_KERNEL default y help This option will modify all the calls to ftrace dynamically @@ -121,12 +178,17 @@ config DYNAMIC_FTRACE were made. If so, it runs stop_machine (stops all CPUS) and modifies the code to jump over the call to ftrace. +config FTRACE_MCOUNT_RECORD + def_bool y + depends on DYNAMIC_FTRACE + depends on HAVE_FTRACE_MCOUNT_RECORD + config FTRACE_SELFTEST bool config FTRACE_STARTUP_TEST bool "Perform a startup test on ftrace" - depends on TRACING + depends on TRACING && DEBUG_KERNEL && !BOOT_TRACER select FTRACE_SELFTEST help This option performs a series of startup tests on ftrace. On bootup diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 71d17de17288..a85dfba88ba0 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -11,6 +11,7 @@ obj-y += trace_selftest_dynamic.o endif obj-$(CONFIG_FTRACE) += libftrace.o +obj-$(CONFIG_RING_BUFFER) += ring_buffer.o obj-$(CONFIG_TRACING) += trace.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o @@ -19,6 +20,9 @@ obj-$(CONFIG_FTRACE) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o obj-$(CONFIG_PREEMPT_TRACER) += trace_irqsoff.o obj-$(CONFIG_SCHED_TRACER) += trace_sched_wakeup.o +obj-$(CONFIG_NOP_TRACER) += trace_nop.o +obj-$(CONFIG_STACK_TRACER) += trace_stack.o obj-$(CONFIG_MMIOTRACE) += trace_mmiotrace.o +obj-$(CONFIG_BOOT_TRACER) += trace_boot.o libftrace-y := ftrace.o diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index f6e3af31b403..4dda4f60a2a9 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -81,7 +81,7 @@ void clear_ftrace_function(void) static int __register_ftrace_function(struct ftrace_ops *ops) { - /* Should never be called by interrupts */ + /* should not be called from interrupt context */ spin_lock(&ftrace_lock); ops->next = ftrace_list; @@ -115,6 +115,7 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) struct ftrace_ops **p; int ret = 0; + /* should not be called from interrupt context */ spin_lock(&ftrace_lock); /* @@ -153,6 +154,30 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) #ifdef CONFIG_DYNAMIC_FTRACE +#ifndef CONFIG_FTRACE_MCOUNT_RECORD +/* + * The hash lock is only needed when the recording of the mcount + * callers are dynamic. That is, by the caller themselves and + * not recorded via the compilation. + */ +static DEFINE_SPINLOCK(ftrace_hash_lock); +#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags) +#define ftrace_hash_unlock(flags) \ + spin_unlock_irqrestore(&ftrace_hash_lock, flags) +#else +/* This is protected via the ftrace_lock with MCOUNT_RECORD. */ +#define ftrace_hash_lock(flags) do { (void)(flags); } while (0) +#define ftrace_hash_unlock(flags) do { } while(0) +#endif + +/* + * Since MCOUNT_ADDR may point to mcount itself, we do not want + * to get it confused by reading a reference in the code as we + * are parsing on objcopy output of text. Use a variable for + * it instead. + */ +static unsigned long mcount_addr = MCOUNT_ADDR; + static struct task_struct *ftraced_task; enum { @@ -171,7 +196,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE]; static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu); -static DEFINE_SPINLOCK(ftrace_shutdown_lock); static DEFINE_MUTEX(ftraced_lock); static DEFINE_MUTEX(ftrace_regex_lock); @@ -294,13 +318,37 @@ static inline void ftrace_del_hash(struct dyn_ftrace *node) static void ftrace_free_rec(struct dyn_ftrace *rec) { - /* no locking, only called from kstop_machine */ - rec->ip = (unsigned long)ftrace_free_records; ftrace_free_records = rec; rec->flags |= FTRACE_FL_FREE; } +void ftrace_release(void *start, unsigned long size) +{ + struct dyn_ftrace *rec; + struct ftrace_page *pg; + unsigned long s = (unsigned long)start; + unsigned long e = s + size; + int i; + + if (ftrace_disabled || !start) + return; + + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); + + for (pg = ftrace_pages_start; pg; pg = pg->next) { + for (i = 0; i < pg->index; i++) { + rec = &pg->records[i]; + + if ((rec->ip >= s) && (rec->ip < e)) + ftrace_free_rec(rec); + } + } + spin_unlock(&ftrace_lock); + +} + static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip) { struct dyn_ftrace *rec; @@ -338,7 +386,6 @@ ftrace_record_ip(unsigned long ip) unsigned long flags; unsigned long key; int resched; - int atomic; int cpu; if (!ftrace_enabled || ftrace_disabled) @@ -368,9 +415,7 @@ ftrace_record_ip(unsigned long ip) if (ftrace_ip_in_hash(ip, key)) goto out; - atomic = irqs_disabled(); - - spin_lock_irqsave(&ftrace_shutdown_lock, flags); + ftrace_hash_lock(flags); /* This ip may have hit the hash before the lock */ if (ftrace_ip_in_hash(ip, key)) @@ -387,7 +432,7 @@ ftrace_record_ip(unsigned long ip) ftraced_trigger = 1; out_unlock: - spin_unlock_irqrestore(&ftrace_shutdown_lock, flags); + ftrace_hash_unlock(flags); out: per_cpu(ftrace_shutdown_disable_cpu, cpu)--; @@ -531,6 +576,16 @@ static void ftrace_shutdown_replenish(void) ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL); } +static void print_ip_ins(const char *fmt, unsigned char *p) +{ + int i; + + printk(KERN_CONT "%s", fmt); + + for (i = 0; i < MCOUNT_INSN_SIZE; i++) + printk(KERN_CONT "%s%02x", i ? ":" : "", p[i]); +} + static int ftrace_code_disable(struct dyn_ftrace *rec) { @@ -541,10 +596,27 @@ ftrace_code_disable(struct dyn_ftrace *rec) ip = rec->ip; nop = ftrace_nop_replace(); - call = ftrace_call_replace(ip, MCOUNT_ADDR); + call = ftrace_call_replace(ip, mcount_addr); failed = ftrace_modify_code(ip, call, nop); if (failed) { + switch (failed) { + case 1: + WARN_ON_ONCE(1); + pr_info("ftrace faulted on modifying "); + print_ip_sym(ip); + break; + case 2: + WARN_ON_ONCE(1); + pr_info("ftrace failed to modify "); + print_ip_sym(ip); + print_ip_ins(" expected: ", call); + print_ip_ins(" actual: ", (unsigned char *)ip); + print_ip_ins(" replace: ", nop); + printk(KERN_CONT "\n"); + break; + } + rec->flags |= FTRACE_FL_FAILED; return 0; } @@ -792,47 +864,7 @@ static int ftrace_update_code(void) return 1; } -static int ftraced(void *ignore) -{ - unsigned long usecs; - - while (!kthread_should_stop()) { - - set_current_state(TASK_INTERRUPTIBLE); - - /* check once a second */ - schedule_timeout(HZ); - - if (unlikely(ftrace_disabled)) - continue; - - mutex_lock(&ftrace_sysctl_lock); - mutex_lock(&ftraced_lock); - if (!ftraced_suspend && !ftraced_stop && - ftrace_update_code()) { - usecs = nsecs_to_usecs(ftrace_update_time); - if (ftrace_update_tot_cnt > 100000) { - ftrace_update_tot_cnt = 0; - pr_info("hm, dftrace overflow: %lu change%s" - " (%lu total) in %lu usec%s\n", - ftrace_update_cnt, - ftrace_update_cnt != 1 ? "s" : "", - ftrace_update_tot_cnt, - usecs, usecs != 1 ? "s" : ""); - ftrace_disabled = 1; - WARN_ON_ONCE(1); - } - } - mutex_unlock(&ftraced_lock); - mutex_unlock(&ftrace_sysctl_lock); - - ftrace_shutdown_replenish(); - } - __set_current_state(TASK_RUNNING); - return 0; -} - -static int __init ftrace_dyn_table_alloc(void) +static int __init ftrace_dyn_table_alloc(unsigned long num_to_init) { struct ftrace_page *pg; int cnt; @@ -859,7 +891,9 @@ static int __init ftrace_dyn_table_alloc(void) pg = ftrace_pages = ftrace_pages_start; - cnt = NR_TO_INIT / ENTRIES_PER_PAGE; + cnt = num_to_init / ENTRIES_PER_PAGE; + pr_info("ftrace: allocating %ld hash entries in %d pages\n", + num_to_init, cnt); for (i = 0; i < cnt; i++) { pg->next = (void *)get_zeroed_page(GFP_KERNEL); @@ -901,6 +935,8 @@ t_next(struct seq_file *m, void *v, loff_t *pos) (*pos)++; + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); retry: if (iter->idx >= iter->pg->index) { if (iter->pg->next) { @@ -910,15 +946,13 @@ t_next(struct seq_file *m, void *v, loff_t *pos) } } else { rec = &iter->pg->records[iter->idx++]; - if ((!(iter->flags & FTRACE_ITER_FAILURES) && + if ((rec->flags & FTRACE_FL_FREE) || + + (!(iter->flags & FTRACE_ITER_FAILURES) && (rec->flags & FTRACE_FL_FAILED)) || ((iter->flags & FTRACE_ITER_FAILURES) && - (!(rec->flags & FTRACE_FL_FAILED) || - (rec->flags & FTRACE_FL_FREE))) || - - ((iter->flags & FTRACE_ITER_FILTER) && - !(rec->flags & FTRACE_FL_FILTER)) || + !(rec->flags & FTRACE_FL_FAILED)) || ((iter->flags & FTRACE_ITER_NOTRACE) && !(rec->flags & FTRACE_FL_NOTRACE))) { @@ -926,6 +960,7 @@ t_next(struct seq_file *m, void *v, loff_t *pos) goto retry; } } + spin_unlock(&ftrace_lock); iter->pos = *pos; @@ -1039,8 +1074,8 @@ static void ftrace_filter_reset(int enable) unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE; unsigned i; - /* keep kstop machine from running */ - preempt_disable(); + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); if (enable) ftrace_filtered = 0; pg = ftrace_pages_start; @@ -1053,7 +1088,7 @@ static void ftrace_filter_reset(int enable) } pg = pg->next; } - preempt_enable(); + spin_unlock(&ftrace_lock); } static int @@ -1165,8 +1200,8 @@ ftrace_match(unsigned char *buff, int len, int enable) } } - /* keep kstop machine from running */ - preempt_disable(); + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); if (enable) ftrace_filtered = 1; pg = ftrace_pages_start; @@ -1203,7 +1238,7 @@ ftrace_match(unsigned char *buff, int len, int enable) } pg = pg->next; } - preempt_enable(); + spin_unlock(&ftrace_lock); } static ssize_t @@ -1556,6 +1591,114 @@ static __init int ftrace_init_debugfs(void) fs_initcall(ftrace_init_debugfs); +#ifdef CONFIG_FTRACE_MCOUNT_RECORD +static int ftrace_convert_nops(unsigned long *start, + unsigned long *end) +{ + unsigned long *p; + unsigned long addr; + unsigned long flags; + + p = start; + while (p < end) { + addr = ftrace_call_adjust(*p++); + /* should not be called from interrupt context */ + spin_lock(&ftrace_lock); + ftrace_record_ip(addr); + spin_unlock(&ftrace_lock); + ftrace_shutdown_replenish(); + } + + /* p is ignored */ + local_irq_save(flags); + __ftrace_update_code(p); + local_irq_restore(flags); + + return 0; +} + +void ftrace_init_module(unsigned long *start, unsigned long *end) +{ + if (ftrace_disabled || start == end) + return; + ftrace_convert_nops(start, end); +} + +extern unsigned long __start_mcount_loc[]; +extern unsigned long __stop_mcount_loc[]; + +void __init ftrace_init(void) +{ + unsigned long count, addr, flags; + int ret; + + /* Keep the ftrace pointer to the stub */ + addr = (unsigned long)ftrace_stub; + + local_irq_save(flags); + ftrace_dyn_arch_init(&addr); + local_irq_restore(flags); + + /* ftrace_dyn_arch_init places the return code in addr */ + if (addr) + goto failed; + + count = __stop_mcount_loc - __start_mcount_loc; + + ret = ftrace_dyn_table_alloc(count); + if (ret) + goto failed; + + last_ftrace_enabled = ftrace_enabled = 1; + + ret = ftrace_convert_nops(__start_mcount_loc, + __stop_mcount_loc); + + return; + failed: + ftrace_disabled = 1; +} +#else /* CONFIG_FTRACE_MCOUNT_RECORD */ +static int ftraced(void *ignore) +{ + unsigned long usecs; + + while (!kthread_should_stop()) { + + set_current_state(TASK_INTERRUPTIBLE); + + /* check once a second */ + schedule_timeout(HZ); + + if (unlikely(ftrace_disabled)) + continue; + + mutex_lock(&ftrace_sysctl_lock); + mutex_lock(&ftraced_lock); + if (!ftraced_suspend && !ftraced_stop && + ftrace_update_code()) { + usecs = nsecs_to_usecs(ftrace_update_time); + if (ftrace_update_tot_cnt > 100000) { + ftrace_update_tot_cnt = 0; + pr_info("hm, dftrace overflow: %lu change%s" + " (%lu total) in %lu usec%s\n", + ftrace_update_cnt, + ftrace_update_cnt != 1 ? "s" : "", + ftrace_update_tot_cnt, + usecs, usecs != 1 ? "s" : ""); + ftrace_disabled = 1; + WARN_ON_ONCE(1); + } + } + mutex_unlock(&ftraced_lock); + mutex_unlock(&ftrace_sysctl_lock); + + ftrace_shutdown_replenish(); + } + __set_current_state(TASK_RUNNING); + return 0; +} + static int __init ftrace_dynamic_init(void) { struct task_struct *p; @@ -1572,7 +1715,7 @@ static int __init ftrace_dynamic_init(void) goto failed; } - ret = ftrace_dyn_table_alloc(); + ret = ftrace_dyn_table_alloc(NR_TO_INIT); if (ret) goto failed; @@ -1593,6 +1736,8 @@ static int __init ftrace_dynamic_init(void) } core_initcall(ftrace_dynamic_init); +#endif /* CONFIG_FTRACE_MCOUNT_RECORD */ + #else # define ftrace_startup() do { } while (0) # define ftrace_shutdown() do { } while (0) diff --git a/kernel/trace/ring_buffer.c b/kernel/trace/ring_buffer.c new file mode 100644 index 000000000000..94af1fe56bb4 --- /dev/null +++ b/kernel/trace/ring_buffer.c @@ -0,0 +1,2014 @@ +/* + * Generic ring buffer + * + * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com> + */ +#include <linux/ring_buffer.h> +#include <linux/spinlock.h> +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/module.h> +#include <linux/percpu.h> +#include <linux/mutex.h> +#include <linux/sched.h> /* used for sched_clock() (for now) */ +#include <linux/init.h> +#include <linux/hash.h> +#include <linux/list.h> +#include <linux/fs.h> + +/* Up this if you want to test the TIME_EXTENTS and normalization */ +#define DEBUG_SHIFT 0 + +/* FIXME!!! */ +u64 ring_buffer_time_stamp(int cpu) +{ + /* shift to debug/test normalization and TIME_EXTENTS */ + return sched_clock() << DEBUG_SHIFT; +} + +void ring_buffer_normalize_time_stamp(int cpu, u64 *ts) +{ + /* Just stupid testing the normalize function and deltas */ + *ts >>= DEBUG_SHIFT; +} + +#define RB_EVNT_HDR_SIZE (sizeof(struct ring_buffer_event)) +#define RB_ALIGNMENT_SHIFT 2 +#define RB_ALIGNMENT (1 << RB_ALIGNMENT_SHIFT) +#define RB_MAX_SMALL_DATA 28 + +enum { + RB_LEN_TIME_EXTEND = 8, + RB_LEN_TIME_STAMP = 16, +}; + +/* inline for ring buffer fast paths */ +static inline unsigned +rb_event_length(struct ring_buffer_event *event) +{ + unsigned length; + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + /* undefined */ + return -1; + + case RINGBUF_TYPE_TIME_EXTEND: + return RB_LEN_TIME_EXTEND; + + case RINGBUF_TYPE_TIME_STAMP: + return RB_LEN_TIME_STAMP; + + case RINGBUF_TYPE_DATA: + if (event->len) + length = event->len << RB_ALIGNMENT_SHIFT; + else + length = event->array[0]; + return length + RB_EVNT_HDR_SIZE; + default: + BUG(); + } + /* not hit */ + return 0; +} + +/** + * ring_buffer_event_length - return the length of the event + * @event: the event to get the length of + */ +unsigned ring_buffer_event_length(struct ring_buffer_event *event) +{ + return rb_event_length(event); +} + +/* inline for ring buffer fast paths */ +static inline void * +rb_event_data(struct ring_buffer_event *event) +{ + BUG_ON(event->type != RINGBUF_TYPE_DATA); + /* If length is in len field, then array[0] has the data */ + if (event->len) + return (void *)&event->array[0]; + /* Otherwise length is in array[0] and array[1] has the data */ + return (void *)&event->array[1]; +} + +/** + * ring_buffer_event_data - return the data of the event + * @event: the event to get the data from + */ +void *ring_buffer_event_data(struct ring_buffer_event *event) +{ + return rb_event_data(event); +} + +#define for_each_buffer_cpu(buffer, cpu) \ + for_each_cpu_mask(cpu, buffer->cpumask) + +#define TS_SHIFT 27 +#define TS_MASK ((1ULL << TS_SHIFT) - 1) +#define TS_DELTA_TEST (~TS_MASK) + +/* + * This hack stolen from mm/slob.c. + * We can store per page timing information in the page frame of the page. + * Thanks to Peter Zijlstra for suggesting this idea. + */ +struct buffer_page { + u64 time_stamp; /* page time stamp */ + local_t write; /* index for next write */ + local_t commit; /* write commited index */ + unsigned read; /* index for next read */ + struct list_head list; /* list of free pages */ + void *page; /* Actual data page */ +}; + +/* + * Also stolen from mm/slob.c. Thanks to Mathieu Desnoyers for pointing + * this issue out. + */ +static inline void free_buffer_page(struct buffer_page *bpage) +{ + if (bpage->page) + __free_page(bpage->page); + kfree(bpage); +} + +/* + * We need to fit the time_stamp delta into 27 bits. + */ +static inline int test_time_stamp(u64 delta) +{ + if (delta & TS_DELTA_TEST) + return 1; + return 0; +} + +#define BUF_PAGE_SIZE PAGE_SIZE + +/* + * head_page == tail_page && head == tail then buffer is empty. + */ +struct ring_buffer_per_cpu { + int cpu; + struct ring_buffer *buffer; + spinlock_t lock; + struct lock_class_key lock_key; + struct list_head pages; + struct buffer_page *head_page; /* read from head */ + struct buffer_page *tail_page; /* write to tail */ + struct buffer_page *commit_page; /* commited pages */ + struct buffer_page *reader_page; + unsigned long overrun; + unsigned long entries; + u64 write_stamp; + u64 read_stamp; + atomic_t record_disabled; +}; + +struct ring_buffer { + unsigned long size; + unsigned pages; + unsigned flags; + int cpus; + cpumask_t cpumask; + atomic_t record_disabled; + + struct mutex mutex; + + struct ring_buffer_per_cpu **buffers; +}; + +struct ring_buffer_iter { + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long head; + struct buffer_page *head_page; + u64 read_stamp; +}; + +#define RB_WARN_ON(buffer, cond) \ + do { \ + if (unlikely(cond)) { \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + } \ + } while (0) + +#define RB_WARN_ON_RET(buffer, cond) \ + do { \ + if (unlikely(cond)) { \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + return -1; \ + } \ + } while (0) + +#define RB_WARN_ON_ONCE(buffer, cond) \ + do { \ + static int once; \ + if (unlikely(cond) && !once) { \ + once++; \ + atomic_inc(&buffer->record_disabled); \ + WARN_ON(1); \ + } \ + } while (0) + +/** + * check_pages - integrity check of buffer pages + * @cpu_buffer: CPU buffer with pages to test + * + * As a safty measure we check to make sure the data pages have not + * been corrupted. + */ +static int rb_check_pages(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct list_head *head = &cpu_buffer->pages; + struct buffer_page *page, *tmp; + + RB_WARN_ON_RET(cpu_buffer, head->next->prev != head); + RB_WARN_ON_RET(cpu_buffer, head->prev->next != head); + + list_for_each_entry_safe(page, tmp, head, list) { + RB_WARN_ON_RET(cpu_buffer, + page->list.next->prev != &page->list); + RB_WARN_ON_RET(cpu_buffer, + page->list.prev->next != &page->list); + } + + return 0; +} + +static int rb_allocate_pages(struct ring_buffer_per_cpu *cpu_buffer, + unsigned nr_pages) +{ + struct list_head *head = &cpu_buffer->pages; + struct buffer_page *page, *tmp; + unsigned long addr; + LIST_HEAD(pages); + unsigned i; + + for (i = 0; i < nr_pages; i++) { + page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu_buffer->cpu)); + if (!page) + goto free_pages; + list_add(&page->list, &pages); + + addr = __get_free_page(GFP_KERNEL); + if (!addr) + goto free_pages; + page->page = (void *)addr; + } + + list_splice(&pages, head); + + rb_check_pages(cpu_buffer); + + return 0; + + free_pages: + list_for_each_entry_safe(page, tmp, &pages, list) { + list_del_init(&page->list); + free_buffer_page(page); + } + return -ENOMEM; +} + +static struct ring_buffer_per_cpu * +rb_allocate_cpu_buffer(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct buffer_page *page; + unsigned long addr; + int ret; + + cpu_buffer = kzalloc_node(ALIGN(sizeof(*cpu_buffer), cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!cpu_buffer) + return NULL; + + cpu_buffer->cpu = cpu; + cpu_buffer->buffer = buffer; + spin_lock_init(&cpu_buffer->lock); + INIT_LIST_HEAD(&cpu_buffer->pages); + + page = kzalloc_node(ALIGN(sizeof(*page), cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!page) + goto fail_free_buffer; + + cpu_buffer->reader_page = page; + addr = __get_free_page(GFP_KERNEL); + if (!addr) + goto fail_free_reader; + page->page = (void *)addr; + + INIT_LIST_HEAD(&cpu_buffer->reader_page->list); + + ret = rb_allocate_pages(cpu_buffer, buffer->pages); + if (ret < 0) + goto fail_free_reader; + + cpu_buffer->head_page + = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + cpu_buffer->tail_page = cpu_buffer->commit_page = cpu_buffer->head_page; + + return cpu_buffer; + + fail_free_reader: + free_buffer_page(cpu_buffer->reader_page); + + fail_free_buffer: + kfree(cpu_buffer); + return NULL; +} + +static void rb_free_cpu_buffer(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct list_head *head = &cpu_buffer->pages; + struct buffer_page *page, *tmp; + + list_del_init(&cpu_buffer->reader_page->list); + free_buffer_page(cpu_buffer->reader_page); + + list_for_each_entry_safe(page, tmp, head, list) { + list_del_init(&page->list); + free_buffer_page(page); + } + kfree(cpu_buffer); +} + +/* + * Causes compile errors if the struct buffer_page gets bigger + * than the struct page. + */ +extern int ring_buffer_page_too_big(void); + +/** + * ring_buffer_alloc - allocate a new ring_buffer + * @size: the size in bytes that is needed. + * @flags: attributes to set for the ring buffer. + * + * Currently the only flag that is available is the RB_FL_OVERWRITE + * flag. This flag means that the buffer will overwrite old data + * when the buffer wraps. If this flag is not set, the buffer will + * drop data when the tail hits the head. + */ +struct ring_buffer *ring_buffer_alloc(unsigned long size, unsigned flags) +{ + struct ring_buffer *buffer; + int bsize; + int cpu; + + /* Paranoid! Optimizes out when all is well */ + if (sizeof(struct buffer_page) > sizeof(struct page)) + ring_buffer_page_too_big(); + + + /* keep it in its own cache line */ + buffer = kzalloc(ALIGN(sizeof(*buffer), cache_line_size()), + GFP_KERNEL); + if (!buffer) + return NULL; + + buffer->pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + buffer->flags = flags; + + /* need at least two pages */ + if (buffer->pages == 1) + buffer->pages++; + + buffer->cpumask = cpu_possible_map; + buffer->cpus = nr_cpu_ids; + + bsize = sizeof(void *) * nr_cpu_ids; + buffer->buffers = kzalloc(ALIGN(bsize, cache_line_size()), + GFP_KERNEL); + if (!buffer->buffers) + goto fail_free_buffer; + + for_each_buffer_cpu(buffer, cpu) { + buffer->buffers[cpu] = + rb_allocate_cpu_buffer(buffer, cpu); + if (!buffer->buffers[cpu]) + goto fail_free_buffers; + } + + mutex_init(&buffer->mutex); + + return buffer; + + fail_free_buffers: + for_each_buffer_cpu(buffer, cpu) { + if (buffer->buffers[cpu]) + rb_free_cpu_buffer(buffer->buffers[cpu]); + } + kfree(buffer->buffers); + + fail_free_buffer: + kfree(buffer); + return NULL; +} + +/** + * ring_buffer_free - free a ring buffer. + * @buffer: the buffer to free. + */ +void +ring_buffer_free(struct ring_buffer *buffer) +{ + int cpu; + + for_each_buffer_cpu(buffer, cpu) + rb_free_cpu_buffer(buffer->buffers[cpu]); + + kfree(buffer); +} + +static void rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer); + +static void +rb_remove_pages(struct ring_buffer_per_cpu *cpu_buffer, unsigned nr_pages) +{ + struct buffer_page *page; + struct list_head *p; + unsigned i; + + atomic_inc(&cpu_buffer->record_disabled); + synchronize_sched(); + + for (i = 0; i < nr_pages; i++) { + BUG_ON(list_empty(&cpu_buffer->pages)); + p = cpu_buffer->pages.next; + page = list_entry(p, struct buffer_page, list); + list_del_init(&page->list); + free_buffer_page(page); + } + BUG_ON(list_empty(&cpu_buffer->pages)); + + rb_reset_cpu(cpu_buffer); + + rb_check_pages(cpu_buffer); + + atomic_dec(&cpu_buffer->record_disabled); + +} + +static void +rb_insert_pages(struct ring_buffer_per_cpu *cpu_buffer, + struct list_head *pages, unsigned nr_pages) +{ + struct buffer_page *page; + struct list_head *p; + unsigned i; + + atomic_inc(&cpu_buffer->record_disabled); + synchronize_sched(); + + for (i = 0; i < nr_pages; i++) { + BUG_ON(list_empty(pages)); + p = pages->next; + page = list_entry(p, struct buffer_page, list); + list_del_init(&page->list); + list_add_tail(&page->list, &cpu_buffer->pages); + } + rb_reset_cpu(cpu_buffer); + + rb_check_pages(cpu_buffer); + + atomic_dec(&cpu_buffer->record_disabled); +} + +/** + * ring_buffer_resize - resize the ring buffer + * @buffer: the buffer to resize. + * @size: the new size. + * + * The tracer is responsible for making sure that the buffer is + * not being used while changing the size. + * Note: We may be able to change the above requirement by using + * RCU synchronizations. + * + * Minimum size is 2 * BUF_PAGE_SIZE. + * + * Returns -1 on failure. + */ +int ring_buffer_resize(struct ring_buffer *buffer, unsigned long size) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned nr_pages, rm_pages, new_pages; + struct buffer_page *page, *tmp; + unsigned long buffer_size; + unsigned long addr; + LIST_HEAD(pages); + int i, cpu; + + size = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + size *= BUF_PAGE_SIZE; + buffer_size = buffer->pages * BUF_PAGE_SIZE; + + /* we need a minimum of two pages */ + if (size < BUF_PAGE_SIZE * 2) + size = BUF_PAGE_SIZE * 2; + + if (size == buffer_size) + return size; + + mutex_lock(&buffer->mutex); + + nr_pages = DIV_ROUND_UP(size, BUF_PAGE_SIZE); + + if (size < buffer_size) { + + /* easy case, just free pages */ + BUG_ON(nr_pages >= buffer->pages); + + rm_pages = buffer->pages - nr_pages; + + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + rb_remove_pages(cpu_buffer, rm_pages); + } + goto out; + } + + /* + * This is a bit more difficult. We only want to add pages + * when we can allocate enough for all CPUs. We do this + * by allocating all the pages and storing them on a local + * link list. If we succeed in our allocation, then we + * add these pages to the cpu_buffers. Otherwise we just free + * them all and return -ENOMEM; + */ + BUG_ON(nr_pages <= buffer->pages); + new_pages = nr_pages - buffer->pages; + + for_each_buffer_cpu(buffer, cpu) { + for (i = 0; i < new_pages; i++) { + page = kzalloc_node(ALIGN(sizeof(*page), + cache_line_size()), + GFP_KERNEL, cpu_to_node(cpu)); + if (!page) + goto free_pages; + list_add(&page->list, &pages); + addr = __get_free_page(GFP_KERNEL); + if (!addr) + goto free_pages; + page->page = (void *)addr; + } + } + + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + rb_insert_pages(cpu_buffer, &pages, new_pages); + } + + BUG_ON(!list_empty(&pages)); + + out: + buffer->pages = nr_pages; + mutex_unlock(&buffer->mutex); + + return size; + + free_pages: + list_for_each_entry_safe(page, tmp, &pages, list) { + list_del_init(&page->list); + free_buffer_page(page); + } + return -ENOMEM; +} + +static inline int rb_null_event(struct ring_buffer_event *event) +{ + return event->type == RINGBUF_TYPE_PADDING; +} + +static inline void *__rb_page_index(struct buffer_page *page, unsigned index) +{ + return page->page + index; +} + +static inline struct ring_buffer_event * +rb_reader_event(struct ring_buffer_per_cpu *cpu_buffer) +{ + return __rb_page_index(cpu_buffer->reader_page, + cpu_buffer->reader_page->read); +} + +static inline struct ring_buffer_event * +rb_head_event(struct ring_buffer_per_cpu *cpu_buffer) +{ + return __rb_page_index(cpu_buffer->head_page, + cpu_buffer->head_page->read); +} + +static inline struct ring_buffer_event * +rb_iter_head_event(struct ring_buffer_iter *iter) +{ + return __rb_page_index(iter->head_page, iter->head); +} + +static inline unsigned rb_page_write(struct buffer_page *bpage) +{ + return local_read(&bpage->write); +} + +static inline unsigned rb_page_commit(struct buffer_page *bpage) +{ + return local_read(&bpage->commit); +} + +/* Size is determined by what has been commited */ +static inline unsigned rb_page_size(struct buffer_page *bpage) +{ + return rb_page_commit(bpage); +} + +static inline unsigned +rb_commit_index(struct ring_buffer_per_cpu *cpu_buffer) +{ + return rb_page_commit(cpu_buffer->commit_page); +} + +static inline unsigned rb_head_size(struct ring_buffer_per_cpu *cpu_buffer) +{ + return rb_page_commit(cpu_buffer->head_page); +} + +/* + * When the tail hits the head and the buffer is in overwrite mode, + * the head jumps to the next page and all content on the previous + * page is discarded. But before doing so, we update the overrun + * variable of the buffer. + */ +static void rb_update_overflow(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct ring_buffer_event *event; + unsigned long head; + + for (head = 0; head < rb_head_size(cpu_buffer); + head += rb_event_length(event)) { + + event = __rb_page_index(cpu_buffer->head_page, head); + BUG_ON(rb_null_event(event)); + /* Only count data entries */ + if (event->type != RINGBUF_TYPE_DATA) + continue; + cpu_buffer->overrun++; + cpu_buffer->entries--; + } +} + +static inline void rb_inc_page(struct ring_buffer_per_cpu *cpu_buffer, + struct buffer_page **page) +{ + struct list_head *p = (*page)->list.next; + + if (p == &cpu_buffer->pages) + p = p->next; + + *page = list_entry(p, struct buffer_page, list); +} + +static inline unsigned +rb_event_index(struct ring_buffer_event *event) +{ + unsigned long addr = (unsigned long)event; + + return (addr & ~PAGE_MASK) - (PAGE_SIZE - BUF_PAGE_SIZE); +} + +static inline int +rb_is_commit(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + unsigned long addr = (unsigned long)event; + unsigned long index; + + index = rb_event_index(event); + addr &= PAGE_MASK; + + return cpu_buffer->commit_page->page == (void *)addr && + rb_commit_index(cpu_buffer) == index; +} + +static inline void +rb_set_commit_event(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + unsigned long addr = (unsigned long)event; + unsigned long index; + + index = rb_event_index(event); + addr &= PAGE_MASK; + + while (cpu_buffer->commit_page->page != (void *)addr) { + RB_WARN_ON(cpu_buffer, + cpu_buffer->commit_page == cpu_buffer->tail_page); + cpu_buffer->commit_page->commit = + cpu_buffer->commit_page->write; + rb_inc_page(cpu_buffer, &cpu_buffer->commit_page); + cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp; + } + + /* Now set the commit to the event's index */ + local_set(&cpu_buffer->commit_page->commit, index); +} + +static inline void +rb_set_commit_to_write(struct ring_buffer_per_cpu *cpu_buffer) +{ + /* + * We only race with interrupts and NMIs on this CPU. + * If we own the commit event, then we can commit + * all others that interrupted us, since the interruptions + * are in stack format (they finish before they come + * back to us). This allows us to do a simple loop to + * assign the commit to the tail. + */ + while (cpu_buffer->commit_page != cpu_buffer->tail_page) { + cpu_buffer->commit_page->commit = + cpu_buffer->commit_page->write; + rb_inc_page(cpu_buffer, &cpu_buffer->commit_page); + cpu_buffer->write_stamp = cpu_buffer->commit_page->time_stamp; + /* add barrier to keep gcc from optimizing too much */ + barrier(); + } + while (rb_commit_index(cpu_buffer) != + rb_page_write(cpu_buffer->commit_page)) { + cpu_buffer->commit_page->commit = + cpu_buffer->commit_page->write; + barrier(); + } +} + +static void rb_reset_reader_page(struct ring_buffer_per_cpu *cpu_buffer) +{ + cpu_buffer->read_stamp = cpu_buffer->reader_page->time_stamp; + cpu_buffer->reader_page->read = 0; +} + +static inline void rb_inc_iter(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; + + /* + * The iterator could be on the reader page (it starts there). + * But the head could have moved, since the reader was + * found. Check for this case and assign the iterator + * to the head page instead of next. + */ + if (iter->head_page == cpu_buffer->reader_page) + iter->head_page = cpu_buffer->head_page; + else + rb_inc_page(cpu_buffer, &iter->head_page); + + iter->read_stamp = iter->head_page->time_stamp; + iter->head = 0; +} + +/** + * ring_buffer_update_event - update event type and data + * @event: the even to update + * @type: the type of event + * @length: the size of the event field in the ring buffer + * + * Update the type and data fields of the event. The length + * is the actual size that is written to the ring buffer, + * and with this, we can determine what to place into the + * data field. + */ +static inline void +rb_update_event(struct ring_buffer_event *event, + unsigned type, unsigned length) +{ + event->type = type; + + switch (type) { + + case RINGBUF_TYPE_PADDING: + break; + + case RINGBUF_TYPE_TIME_EXTEND: + event->len = + (RB_LEN_TIME_EXTEND + (RB_ALIGNMENT-1)) + >> RB_ALIGNMENT_SHIFT; + break; + + case RINGBUF_TYPE_TIME_STAMP: + event->len = + (RB_LEN_TIME_STAMP + (RB_ALIGNMENT-1)) + >> RB_ALIGNMENT_SHIFT; + break; + + case RINGBUF_TYPE_DATA: + length -= RB_EVNT_HDR_SIZE; + if (length > RB_MAX_SMALL_DATA) { + event->len = 0; + event->array[0] = length; + } else + event->len = + (length + (RB_ALIGNMENT-1)) + >> RB_ALIGNMENT_SHIFT; + break; + default: + BUG(); + } +} + +static inline unsigned rb_calculate_event_length(unsigned length) +{ + struct ring_buffer_event event; /* Used only for sizeof array */ + + /* zero length can cause confusions */ + if (!length) + length = 1; + + if (length > RB_MAX_SMALL_DATA) + length += sizeof(event.array[0]); + + length += RB_EVNT_HDR_SIZE; + length = ALIGN(length, RB_ALIGNMENT); + + return length; +} + +static struct ring_buffer_event * +__rb_reserve_next(struct ring_buffer_per_cpu *cpu_buffer, + unsigned type, unsigned long length, u64 *ts) +{ + struct buffer_page *tail_page, *head_page, *reader_page; + unsigned long tail, write; + struct ring_buffer *buffer = cpu_buffer->buffer; + struct ring_buffer_event *event; + unsigned long flags; + + tail_page = cpu_buffer->tail_page; + write = local_add_return(length, &tail_page->write); + tail = write - length; + + /* See if we shot pass the end of this buffer page */ + if (write > BUF_PAGE_SIZE) { + struct buffer_page *next_page = tail_page; + + spin_lock_irqsave(&cpu_buffer->lock, flags); + + rb_inc_page(cpu_buffer, &next_page); + + head_page = cpu_buffer->head_page; + reader_page = cpu_buffer->reader_page; + + /* we grabbed the lock before incrementing */ + RB_WARN_ON(cpu_buffer, next_page == reader_page); + + /* + * If for some reason, we had an interrupt storm that made + * it all the way around the buffer, bail, and warn + * about it. + */ + if (unlikely(next_page == cpu_buffer->commit_page)) { + WARN_ON_ONCE(1); + goto out_unlock; + } + + if (next_page == head_page) { + if (!(buffer->flags & RB_FL_OVERWRITE)) { + /* reset write */ + if (tail <= BUF_PAGE_SIZE) + local_set(&tail_page->write, tail); + goto out_unlock; + } + + /* tail_page has not moved yet? */ + if (tail_page == cpu_buffer->tail_page) { + /* count overflows */ + rb_update_overflow(cpu_buffer); + + rb_inc_page(cpu_buffer, &head_page); + cpu_buffer->head_page = head_page; + cpu_buffer->head_page->read = 0; + } + } + + /* + * If the tail page is still the same as what we think + * it is, then it is up to us to update the tail + * pointer. + */ + if (tail_page == cpu_buffer->tail_page) { + local_set(&next_page->write, 0); + local_set(&next_page->commit, 0); + cpu_buffer->tail_page = next_page; + + /* reread the time stamp */ + *ts = ring_buffer_time_stamp(cpu_buffer->cpu); + cpu_buffer->tail_page->time_stamp = *ts; + } + + /* + * The actual tail page has moved forward. + */ + if (tail < BUF_PAGE_SIZE) { + /* Mark the rest of the page with padding */ + event = __rb_page_index(tail_page, tail); + event->type = RINGBUF_TYPE_PADDING; + } + + if (tail <= BUF_PAGE_SIZE) + /* Set the write back to the previous setting */ + local_set(&tail_page->write, tail); + + /* + * If this was a commit entry that failed, + * increment that too + */ + if (tail_page == cpu_buffer->commit_page && + tail == rb_commit_index(cpu_buffer)) { + rb_set_commit_to_write(cpu_buffer); + } + + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + + /* fail and let the caller try again */ + return ERR_PTR(-EAGAIN); + } + + /* We reserved something on the buffer */ + + BUG_ON(write > BUF_PAGE_SIZE); + + event = __rb_page_index(tail_page, tail); + rb_update_event(event, type, length); + + /* + * If this is a commit and the tail is zero, then update + * this page's time stamp. + */ + if (!tail && rb_is_commit(cpu_buffer, event)) + cpu_buffer->commit_page->time_stamp = *ts; + + return event; + + out_unlock: + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + return NULL; +} + +static int +rb_add_time_stamp(struct ring_buffer_per_cpu *cpu_buffer, + u64 *ts, u64 *delta) +{ + struct ring_buffer_event *event; + static int once; + int ret; + + if (unlikely(*delta > (1ULL << 59) && !once++)) { + printk(KERN_WARNING "Delta way too big! %llu" + " ts=%llu write stamp = %llu\n", + *delta, *ts, cpu_buffer->write_stamp); + WARN_ON(1); + } + + /* + * The delta is too big, we to add a + * new timestamp. + */ + event = __rb_reserve_next(cpu_buffer, + RINGBUF_TYPE_TIME_EXTEND, + RB_LEN_TIME_EXTEND, + ts); + if (!event) + return -EBUSY; + + if (PTR_ERR(event) == -EAGAIN) + return -EAGAIN; + + /* Only a commited time event can update the write stamp */ + if (rb_is_commit(cpu_buffer, event)) { + /* + * If this is the first on the page, then we need to + * update the page itself, and just put in a zero. + */ + if (rb_event_index(event)) { + event->time_delta = *delta & TS_MASK; + event->array[0] = *delta >> TS_SHIFT; + } else { + cpu_buffer->commit_page->time_stamp = *ts; + event->time_delta = 0; + event->array[0] = 0; + } + cpu_buffer->write_stamp = *ts; + /* let the caller know this was the commit */ + ret = 1; + } else { + /* Darn, this is just wasted space */ + event->time_delta = 0; + event->array[0] = 0; + ret = 0; + } + + *delta = 0; + + return ret; +} + +static struct ring_buffer_event * +rb_reserve_next_event(struct ring_buffer_per_cpu *cpu_buffer, + unsigned type, unsigned long length) +{ + struct ring_buffer_event *event; + u64 ts, delta; + int commit = 0; + + again: + ts = ring_buffer_time_stamp(cpu_buffer->cpu); + + /* + * Only the first commit can update the timestamp. + * Yes there is a race here. If an interrupt comes in + * just after the conditional and it traces too, then it + * will also check the deltas. More than one timestamp may + * also be made. But only the entry that did the actual + * commit will be something other than zero. + */ + if (cpu_buffer->tail_page == cpu_buffer->commit_page && + rb_page_write(cpu_buffer->tail_page) == + rb_commit_index(cpu_buffer)) { + + delta = ts - cpu_buffer->write_stamp; + + /* make sure this delta is calculated here */ + barrier(); + + /* Did the write stamp get updated already? */ + if (unlikely(ts < cpu_buffer->write_stamp)) + goto again; + + if (test_time_stamp(delta)) { + + commit = rb_add_time_stamp(cpu_buffer, &ts, &delta); + + if (commit == -EBUSY) + return NULL; + + if (commit == -EAGAIN) + goto again; + + RB_WARN_ON(cpu_buffer, commit < 0); + } + } else + /* Non commits have zero deltas */ + delta = 0; + + event = __rb_reserve_next(cpu_buffer, type, length, &ts); + if (PTR_ERR(event) == -EAGAIN) + goto again; + + if (!event) { + if (unlikely(commit)) + /* + * Ouch! We needed a timestamp and it was commited. But + * we didn't get our event reserved. + */ + rb_set_commit_to_write(cpu_buffer); + return NULL; + } + + /* + * If the timestamp was commited, make the commit our entry + * now so that we will update it when needed. + */ + if (commit) + rb_set_commit_event(cpu_buffer, event); + else if (!rb_is_commit(cpu_buffer, event)) + delta = 0; + + event->time_delta = delta; + + return event; +} + +static DEFINE_PER_CPU(int, rb_need_resched); + +/** + * ring_buffer_lock_reserve - reserve a part of the buffer + * @buffer: the ring buffer to reserve from + * @length: the length of the data to reserve (excluding event header) + * @flags: a pointer to save the interrupt flags + * + * Returns a reseverd event on the ring buffer to copy directly to. + * The user of this interface will need to get the body to write into + * and can use the ring_buffer_event_data() interface. + * + * The length is the length of the data needed, not the event length + * which also includes the event header. + * + * Must be paired with ring_buffer_unlock_commit, unless NULL is returned. + * If NULL is returned, then nothing has been allocated or locked. + */ +struct ring_buffer_event * +ring_buffer_lock_reserve(struct ring_buffer *buffer, + unsigned long length, + unsigned long *flags) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + int cpu, resched; + + if (atomic_read(&buffer->record_disabled)) + return NULL; + + /* If we are tracing schedule, we don't want to recurse */ + resched = need_resched(); + preempt_disable_notrace(); + + cpu = raw_smp_processor_id(); + + if (!cpu_isset(cpu, buffer->cpumask)) + goto out; + + cpu_buffer = buffer->buffers[cpu]; + + if (atomic_read(&cpu_buffer->record_disabled)) + goto out; + + length = rb_calculate_event_length(length); + if (length > BUF_PAGE_SIZE) + goto out; + + event = rb_reserve_next_event(cpu_buffer, RINGBUF_TYPE_DATA, length); + if (!event) + goto out; + + /* + * Need to store resched state on this cpu. + * Only the first needs to. + */ + + if (preempt_count() == 1) + per_cpu(rb_need_resched, cpu) = resched; + + return event; + + out: + if (resched) + preempt_enable_notrace(); + else + preempt_enable_notrace(); + return NULL; +} + +static void rb_commit(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + cpu_buffer->entries++; + + /* Only process further if we own the commit */ + if (!rb_is_commit(cpu_buffer, event)) + return; + + cpu_buffer->write_stamp += event->time_delta; + + rb_set_commit_to_write(cpu_buffer); +} + +/** + * ring_buffer_unlock_commit - commit a reserved + * @buffer: The buffer to commit to + * @event: The event pointer to commit. + * @flags: the interrupt flags received from ring_buffer_lock_reserve. + * + * This commits the data to the ring buffer, and releases any locks held. + * + * Must be paired with ring_buffer_lock_reserve. + */ +int ring_buffer_unlock_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu = raw_smp_processor_id(); + + cpu_buffer = buffer->buffers[cpu]; + + rb_commit(cpu_buffer, event); + + /* + * Only the last preempt count needs to restore preemption. + */ + if (preempt_count() == 1) { + if (per_cpu(rb_need_resched, cpu)) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); + } else + preempt_enable_no_resched_notrace(); + + return 0; +} + +/** + * ring_buffer_write - write data to the buffer without reserving + * @buffer: The ring buffer to write to. + * @length: The length of the data being written (excluding the event header) + * @data: The data to write to the buffer. + * + * This is like ring_buffer_lock_reserve and ring_buffer_unlock_commit as + * one function. If you already have the data to write to the buffer, it + * may be easier to simply call this function. + * + * Note, like ring_buffer_lock_reserve, the length is the length of the data + * and not the length of the event which would hold the header. + */ +int ring_buffer_write(struct ring_buffer *buffer, + unsigned long length, + void *data) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + unsigned long event_length; + void *body; + int ret = -EBUSY; + int cpu, resched; + + if (atomic_read(&buffer->record_disabled)) + return -EBUSY; + + resched = need_resched(); + preempt_disable_notrace(); + + cpu = raw_smp_processor_id(); + + if (!cpu_isset(cpu, buffer->cpumask)) + goto out; + + cpu_buffer = buffer->buffers[cpu]; + + if (atomic_read(&cpu_buffer->record_disabled)) + goto out; + + event_length = rb_calculate_event_length(length); + event = rb_reserve_next_event(cpu_buffer, + RINGBUF_TYPE_DATA, event_length); + if (!event) + goto out; + + body = rb_event_data(event); + + memcpy(body, data, length); + + rb_commit(cpu_buffer, event); + + ret = 0; + out: + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); + + return ret; +} + +static inline int rb_per_cpu_empty(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct buffer_page *reader = cpu_buffer->reader_page; + struct buffer_page *head = cpu_buffer->head_page; + struct buffer_page *commit = cpu_buffer->commit_page; + + return reader->read == rb_page_commit(reader) && + (commit == reader || + (commit == head && + head->read == rb_page_commit(commit))); +} + +/** + * ring_buffer_record_disable - stop all writes into the buffer + * @buffer: The ring buffer to stop writes to. + * + * This prevents all writes to the buffer. Any attempt to write + * to the buffer after this will fail and return NULL. + * + * The caller should call synchronize_sched() after this. + */ +void ring_buffer_record_disable(struct ring_buffer *buffer) +{ + atomic_inc(&buffer->record_disabled); +} + +/** + * ring_buffer_record_enable - enable writes to the buffer + * @buffer: The ring buffer to enable writes + * + * Note, multiple disables will need the same number of enables + * to truely enable the writing (much like preempt_disable). + */ +void ring_buffer_record_enable(struct ring_buffer *buffer) +{ + atomic_dec(&buffer->record_disabled); +} + +/** + * ring_buffer_record_disable_cpu - stop all writes into the cpu_buffer + * @buffer: The ring buffer to stop writes to. + * @cpu: The CPU buffer to stop + * + * This prevents all writes to the buffer. Any attempt to write + * to the buffer after this will fail and return NULL. + * + * The caller should call synchronize_sched() after this. + */ +void ring_buffer_record_disable_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return; + + cpu_buffer = buffer->buffers[cpu]; + atomic_inc(&cpu_buffer->record_disabled); +} + +/** + * ring_buffer_record_enable_cpu - enable writes to the buffer + * @buffer: The ring buffer to enable writes + * @cpu: The CPU to enable. + * + * Note, multiple disables will need the same number of enables + * to truely enable the writing (much like preempt_disable). + */ +void ring_buffer_record_enable_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return; + + cpu_buffer = buffer->buffers[cpu]; + atomic_dec(&cpu_buffer->record_disabled); +} + +/** + * ring_buffer_entries_cpu - get the number of entries in a cpu buffer + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the entries from. + */ +unsigned long ring_buffer_entries_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + return cpu_buffer->entries; +} + +/** + * ring_buffer_overrun_cpu - get the number of overruns in a cpu_buffer + * @buffer: The ring buffer + * @cpu: The per CPU buffer to get the number of overruns from + */ +unsigned long ring_buffer_overrun_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return 0; + + cpu_buffer = buffer->buffers[cpu]; + return cpu_buffer->overrun; +} + +/** + * ring_buffer_entries - get the number of entries in a buffer + * @buffer: The ring buffer + * + * Returns the total number of entries in the ring buffer + * (all CPU entries) + */ +unsigned long ring_buffer_entries(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long entries = 0; + int cpu; + + /* if you care about this being correct, lock the buffer */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + entries += cpu_buffer->entries; + } + + return entries; +} + +/** + * ring_buffer_overrun_cpu - get the number of overruns in buffer + * @buffer: The ring buffer + * + * Returns the total number of overruns in the ring buffer + * (all CPU entries) + */ +unsigned long ring_buffer_overruns(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + unsigned long overruns = 0; + int cpu; + + /* if you care about this being correct, lock the buffer */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + overruns += cpu_buffer->overrun; + } + + return overruns; +} + +/** + * ring_buffer_iter_reset - reset an iterator + * @iter: The iterator to reset + * + * Resets the iterator, so that it will start from the beginning + * again. + */ +void ring_buffer_iter_reset(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; + + /* Iterator usage is expected to have record disabled */ + if (list_empty(&cpu_buffer->reader_page->list)) { + iter->head_page = cpu_buffer->head_page; + iter->head = cpu_buffer->head_page->read; + } else { + iter->head_page = cpu_buffer->reader_page; + iter->head = cpu_buffer->reader_page->read; + } + if (iter->head) + iter->read_stamp = cpu_buffer->read_stamp; + else + iter->read_stamp = iter->head_page->time_stamp; +} + +/** + * ring_buffer_iter_empty - check if an iterator has no more to read + * @iter: The iterator to check + */ +int ring_buffer_iter_empty(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + cpu_buffer = iter->cpu_buffer; + + return iter->head_page == cpu_buffer->commit_page && + iter->head == rb_commit_index(cpu_buffer); +} + +static void +rb_update_read_stamp(struct ring_buffer_per_cpu *cpu_buffer, + struct ring_buffer_event *event) +{ + u64 delta; + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + return; + + case RINGBUF_TYPE_TIME_EXTEND: + delta = event->array[0]; + delta <<= TS_SHIFT; + delta += event->time_delta; + cpu_buffer->read_stamp += delta; + return; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + return; + + case RINGBUF_TYPE_DATA: + cpu_buffer->read_stamp += event->time_delta; + return; + + default: + BUG(); + } + return; +} + +static void +rb_update_iter_read_stamp(struct ring_buffer_iter *iter, + struct ring_buffer_event *event) +{ + u64 delta; + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + return; + + case RINGBUF_TYPE_TIME_EXTEND: + delta = event->array[0]; + delta <<= TS_SHIFT; + delta += event->time_delta; + iter->read_stamp += delta; + return; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + return; + + case RINGBUF_TYPE_DATA: + iter->read_stamp += event->time_delta; + return; + + default: + BUG(); + } + return; +} + +static struct buffer_page * +rb_get_reader_page(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct buffer_page *reader = NULL; + unsigned long flags; + + spin_lock_irqsave(&cpu_buffer->lock, flags); + + again: + reader = cpu_buffer->reader_page; + + /* If there's more to read, return this page */ + if (cpu_buffer->reader_page->read < rb_page_size(reader)) + goto out; + + /* Never should we have an index greater than the size */ + RB_WARN_ON(cpu_buffer, + cpu_buffer->reader_page->read > rb_page_size(reader)); + + /* check if we caught up to the tail */ + reader = NULL; + if (cpu_buffer->commit_page == cpu_buffer->reader_page) + goto out; + + /* + * Splice the empty reader page into the list around the head. + * Reset the reader page to size zero. + */ + + reader = cpu_buffer->head_page; + cpu_buffer->reader_page->list.next = reader->list.next; + cpu_buffer->reader_page->list.prev = reader->list.prev; + + local_set(&cpu_buffer->reader_page->write, 0); + local_set(&cpu_buffer->reader_page->commit, 0); + + /* Make the reader page now replace the head */ + reader->list.prev->next = &cpu_buffer->reader_page->list; + reader->list.next->prev = &cpu_buffer->reader_page->list; + + /* + * If the tail is on the reader, then we must set the head + * to the inserted page, otherwise we set it one before. + */ + cpu_buffer->head_page = cpu_buffer->reader_page; + + if (cpu_buffer->commit_page != reader) + rb_inc_page(cpu_buffer, &cpu_buffer->head_page); + + /* Finally update the reader page to the new head */ + cpu_buffer->reader_page = reader; + rb_reset_reader_page(cpu_buffer); + + goto again; + + out: + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + + return reader; +} + +static void rb_advance_reader(struct ring_buffer_per_cpu *cpu_buffer) +{ + struct ring_buffer_event *event; + struct buffer_page *reader; + unsigned length; + + reader = rb_get_reader_page(cpu_buffer); + + /* This function should not be called when buffer is empty */ + BUG_ON(!reader); + + event = rb_reader_event(cpu_buffer); + + if (event->type == RINGBUF_TYPE_DATA) + cpu_buffer->entries--; + + rb_update_read_stamp(cpu_buffer, event); + + length = rb_event_length(event); + cpu_buffer->reader_page->read += length; +} + +static void rb_advance_iter(struct ring_buffer_iter *iter) +{ + struct ring_buffer *buffer; + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + unsigned length; + + cpu_buffer = iter->cpu_buffer; + buffer = cpu_buffer->buffer; + + /* + * Check if we are at the end of the buffer. + */ + if (iter->head >= rb_page_size(iter->head_page)) { + BUG_ON(iter->head_page == cpu_buffer->commit_page); + rb_inc_iter(iter); + return; + } + + event = rb_iter_head_event(iter); + + length = rb_event_length(event); + + /* + * This should not be called to advance the header if we are + * at the tail of the buffer. + */ + BUG_ON((iter->head_page == cpu_buffer->commit_page) && + (iter->head + length > rb_commit_index(cpu_buffer))); + + rb_update_iter_read_stamp(iter, event); + + iter->head += length; + + /* check for end of page padding */ + if ((iter->head >= rb_page_size(iter->head_page)) && + (iter->head_page != cpu_buffer->commit_page)) + rb_advance_iter(iter); +} + +/** + * ring_buffer_peek - peek at the next event to be read + * @buffer: The ring buffer to read + * @cpu: The cpu to peak at + * @ts: The timestamp counter of this event. + * + * This will return the event that will be read next, but does + * not consume the data. + */ +struct ring_buffer_event * +ring_buffer_peek(struct ring_buffer *buffer, int cpu, u64 *ts) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + struct buffer_page *reader; + + if (!cpu_isset(cpu, buffer->cpumask)) + return NULL; + + cpu_buffer = buffer->buffers[cpu]; + + again: + reader = rb_get_reader_page(cpu_buffer); + if (!reader) + return NULL; + + event = rb_reader_event(cpu_buffer); + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + RB_WARN_ON(cpu_buffer, 1); + rb_advance_reader(cpu_buffer); + return NULL; + + case RINGBUF_TYPE_TIME_EXTEND: + /* Internal data, OK to advance */ + rb_advance_reader(cpu_buffer); + goto again; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + rb_advance_reader(cpu_buffer); + goto again; + + case RINGBUF_TYPE_DATA: + if (ts) { + *ts = cpu_buffer->read_stamp + event->time_delta; + ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts); + } + return event; + + default: + BUG(); + } + + return NULL; +} + +/** + * ring_buffer_iter_peek - peek at the next event to be read + * @iter: The ring buffer iterator + * @ts: The timestamp counter of this event. + * + * This will return the event that will be read next, but does + * not increment the iterator. + */ +struct ring_buffer_event * +ring_buffer_iter_peek(struct ring_buffer_iter *iter, u64 *ts) +{ + struct ring_buffer *buffer; + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + + if (ring_buffer_iter_empty(iter)) + return NULL; + + cpu_buffer = iter->cpu_buffer; + buffer = cpu_buffer->buffer; + + again: + if (rb_per_cpu_empty(cpu_buffer)) + return NULL; + + event = rb_iter_head_event(iter); + + switch (event->type) { + case RINGBUF_TYPE_PADDING: + rb_inc_iter(iter); + goto again; + + case RINGBUF_TYPE_TIME_EXTEND: + /* Internal data, OK to advance */ + rb_advance_iter(iter); + goto again; + + case RINGBUF_TYPE_TIME_STAMP: + /* FIXME: not implemented */ + rb_advance_iter(iter); + goto again; + + case RINGBUF_TYPE_DATA: + if (ts) { + *ts = iter->read_stamp + event->time_delta; + ring_buffer_normalize_time_stamp(cpu_buffer->cpu, ts); + } + return event; + + default: + BUG(); + } + + return NULL; +} + +/** + * ring_buffer_consume - return an event and consume it + * @buffer: The ring buffer to get the next event from + * + * Returns the next event in the ring buffer, and that event is consumed. + * Meaning, that sequential reads will keep returning a different event, + * and eventually empty the ring buffer if the producer is slower. + */ +struct ring_buffer_event * +ring_buffer_consume(struct ring_buffer *buffer, int cpu, u64 *ts) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_event *event; + + if (!cpu_isset(cpu, buffer->cpumask)) + return NULL; + + event = ring_buffer_peek(buffer, cpu, ts); + if (!event) + return NULL; + + cpu_buffer = buffer->buffers[cpu]; + rb_advance_reader(cpu_buffer); + + return event; +} + +/** + * ring_buffer_read_start - start a non consuming read of the buffer + * @buffer: The ring buffer to read from + * @cpu: The cpu buffer to iterate over + * + * This starts up an iteration through the buffer. It also disables + * the recording to the buffer until the reading is finished. + * This prevents the reading from being corrupted. This is not + * a consuming read, so a producer is not expected. + * + * Must be paired with ring_buffer_finish. + */ +struct ring_buffer_iter * +ring_buffer_read_start(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + struct ring_buffer_iter *iter; + unsigned long flags; + + if (!cpu_isset(cpu, buffer->cpumask)) + return NULL; + + iter = kmalloc(sizeof(*iter), GFP_KERNEL); + if (!iter) + return NULL; + + cpu_buffer = buffer->buffers[cpu]; + + iter->cpu_buffer = cpu_buffer; + + atomic_inc(&cpu_buffer->record_disabled); + synchronize_sched(); + + spin_lock_irqsave(&cpu_buffer->lock, flags); + ring_buffer_iter_reset(iter); + spin_unlock_irqrestore(&cpu_buffer->lock, flags); + + return iter; +} + +/** + * ring_buffer_finish - finish reading the iterator of the buffer + * @iter: The iterator retrieved by ring_buffer_start + * + * This re-enables the recording to the buffer, and frees the + * iterator. + */ +void +ring_buffer_read_finish(struct ring_buffer_iter *iter) +{ + struct ring_buffer_per_cpu *cpu_buffer = iter->cpu_buffer; + + atomic_dec(&cpu_buffer->record_disabled); + kfree(iter); +} + +/** + * ring_buffer_read - read the next item in the ring buffer by the iterator + * @iter: The ring buffer iterator + * @ts: The time stamp of the event read. + * + * This reads the next event in the ring buffer and increments the iterator. + */ +struct ring_buffer_event * +ring_buffer_read(struct ring_buffer_iter *iter, u64 *ts) +{ + struct ring_buffer_event *event; + + event = ring_buffer_iter_peek(iter, ts); + if (!event) + return NULL; + + rb_advance_iter(iter); + + return event; +} + +/** + * ring_buffer_size - return the size of the ring buffer (in bytes) + * @buffer: The ring buffer. + */ +unsigned long ring_buffer_size(struct ring_buffer *buffer) +{ + return BUF_PAGE_SIZE * buffer->pages; +} + +static void +rb_reset_cpu(struct ring_buffer_per_cpu *cpu_buffer) +{ + cpu_buffer->head_page + = list_entry(cpu_buffer->pages.next, struct buffer_page, list); + local_set(&cpu_buffer->head_page->write, 0); + local_set(&cpu_buffer->head_page->commit, 0); + + cpu_buffer->head_page->read = 0; + + cpu_buffer->tail_page = cpu_buffer->head_page; + cpu_buffer->commit_page = cpu_buffer->head_page; + + INIT_LIST_HEAD(&cpu_buffer->reader_page->list); + local_set(&cpu_buffer->reader_page->write, 0); + local_set(&cpu_buffer->reader_page->commit, 0); + cpu_buffer->reader_page->read = 0; + + cpu_buffer->overrun = 0; + cpu_buffer->entries = 0; +} + +/** + * ring_buffer_reset_cpu - reset a ring buffer per CPU buffer + * @buffer: The ring buffer to reset a per cpu buffer of + * @cpu: The CPU buffer to be reset + */ +void ring_buffer_reset_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer = buffer->buffers[cpu]; + unsigned long flags; + + if (!cpu_isset(cpu, buffer->cpumask)) + return; + + spin_lock_irqsave(&cpu_buffer->lock, flags); + + rb_reset_cpu(cpu_buffer); + + spin_unlock_irqrestore(&cpu_buffer->lock, flags); +} + +/** + * ring_buffer_reset - reset a ring buffer + * @buffer: The ring buffer to reset all cpu buffers + */ +void ring_buffer_reset(struct ring_buffer *buffer) +{ + int cpu; + + for_each_buffer_cpu(buffer, cpu) + ring_buffer_reset_cpu(buffer, cpu); +} + +/** + * rind_buffer_empty - is the ring buffer empty? + * @buffer: The ring buffer to test + */ +int ring_buffer_empty(struct ring_buffer *buffer) +{ + struct ring_buffer_per_cpu *cpu_buffer; + int cpu; + + /* yes this is racy, but if you don't like the race, lock the buffer */ + for_each_buffer_cpu(buffer, cpu) { + cpu_buffer = buffer->buffers[cpu]; + if (!rb_per_cpu_empty(cpu_buffer)) + return 0; + } + return 1; +} + +/** + * ring_buffer_empty_cpu - is a cpu buffer of a ring buffer empty? + * @buffer: The ring buffer + * @cpu: The CPU buffer to test + */ +int ring_buffer_empty_cpu(struct ring_buffer *buffer, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer; + + if (!cpu_isset(cpu, buffer->cpumask)) + return 1; + + cpu_buffer = buffer->buffers[cpu]; + return rb_per_cpu_empty(cpu_buffer); +} + +/** + * ring_buffer_swap_cpu - swap a CPU buffer between two ring buffers + * @buffer_a: One buffer to swap with + * @buffer_b: The other buffer to swap with + * + * This function is useful for tracers that want to take a "snapshot" + * of a CPU buffer and has another back up buffer lying around. + * it is expected that the tracer handles the cpu buffer not being + * used at the moment. + */ +int ring_buffer_swap_cpu(struct ring_buffer *buffer_a, + struct ring_buffer *buffer_b, int cpu) +{ + struct ring_buffer_per_cpu *cpu_buffer_a; + struct ring_buffer_per_cpu *cpu_buffer_b; + + if (!cpu_isset(cpu, buffer_a->cpumask) || + !cpu_isset(cpu, buffer_b->cpumask)) + return -EINVAL; + + /* At least make sure the two buffers are somewhat the same */ + if (buffer_a->size != buffer_b->size || + buffer_a->pages != buffer_b->pages) + return -EINVAL; + + cpu_buffer_a = buffer_a->buffers[cpu]; + cpu_buffer_b = buffer_b->buffers[cpu]; + + /* + * We can't do a synchronize_sched here because this + * function can be called in atomic context. + * Normally this will be called from the same CPU as cpu. + * If not it's up to the caller to protect this. + */ + atomic_inc(&cpu_buffer_a->record_disabled); + atomic_inc(&cpu_buffer_b->record_disabled); + + buffer_a->buffers[cpu] = cpu_buffer_b; + buffer_b->buffers[cpu] = cpu_buffer_a; + + cpu_buffer_b->buffer = buffer_a; + cpu_buffer_a->buffer = buffer_b; + + atomic_dec(&cpu_buffer_a->record_disabled); + atomic_dec(&cpu_buffer_b->record_disabled); + + return 0; +} + diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8f3fb3db61c3..d345d649d073 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -14,6 +14,7 @@ #include <linux/utsrelease.h> #include <linux/kallsyms.h> #include <linux/seq_file.h> +#include <linux/notifier.h> #include <linux/debugfs.h> #include <linux/pagemap.h> #include <linux/hardirq.h> @@ -22,6 +23,7 @@ #include <linux/ftrace.h> #include <linux/module.h> #include <linux/percpu.h> +#include <linux/kdebug.h> #include <linux/ctype.h> #include <linux/init.h> #include <linux/poll.h> @@ -31,25 +33,36 @@ #include <linux/writeback.h> #include <linux/stacktrace.h> +#include <linux/ring_buffer.h> #include "trace.h" +#define TRACE_BUFFER_FLAGS (RB_FL_OVERWRITE) + unsigned long __read_mostly tracing_max_latency = (cycle_t)ULONG_MAX; unsigned long __read_mostly tracing_thresh; -static unsigned long __read_mostly tracing_nr_buffers; +static DEFINE_PER_CPU(local_t, ftrace_cpu_disabled); + +static inline void ftrace_disable_cpu(void) +{ + preempt_disable(); + local_inc(&__get_cpu_var(ftrace_cpu_disabled)); +} + +static inline void ftrace_enable_cpu(void) +{ + local_dec(&__get_cpu_var(ftrace_cpu_disabled)); + preempt_enable(); +} + static cpumask_t __read_mostly tracing_buffer_mask; #define for_each_tracing_cpu(cpu) \ for_each_cpu_mask(cpu, tracing_buffer_mask) -static int trace_alloc_page(void); -static int trace_free_page(void); - static int tracing_disabled = 1; -static unsigned long tracing_pages_allocated; - long ns2usecs(cycle_t nsec) { @@ -60,7 +73,9 @@ ns2usecs(cycle_t nsec) cycle_t ftrace_now(int cpu) { - return cpu_clock(cpu); + u64 ts = ring_buffer_time_stamp(cpu); + ring_buffer_normalize_time_stamp(cpu, &ts); + return ts; } /* @@ -100,11 +115,18 @@ static int tracer_enabled = 1; int ftrace_function_enabled; /* - * trace_nr_entries is the number of entries that is allocated - * for a buffer. Note, the number of entries is always rounded - * to ENTRIES_PER_PAGE. + * trace_buf_size is the size in bytes that is allocated + * for a buffer. Note, the number of bytes is always rounded + * to page size. + * + * This number is purposely set to a low number of 16384. + * If the dump on oops happens, it will be much appreciated + * to not have to wait for all that output. Anyway this can be + * boot time and run time configurable. */ -static unsigned long trace_nr_entries = 65536UL; +#define TRACE_BUF_SIZE_DEFAULT 1441792UL /* 16384 * 88 (sizeof(entry)) */ + +static unsigned long trace_buf_size = TRACE_BUF_SIZE_DEFAULT; /* trace_types holds a link list of available tracers. */ static struct tracer *trace_types __read_mostly; @@ -133,24 +155,6 @@ static DECLARE_WAIT_QUEUE_HEAD(trace_wait); /* trace_flags holds iter_ctrl options */ unsigned long trace_flags = TRACE_ITER_PRINT_PARENT; -static notrace void no_trace_init(struct trace_array *tr) -{ - int cpu; - - ftrace_function_enabled = 0; - if(tr->ctrl) - for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); - tracer_enabled = 0; -} - -/* dummy trace to disable tracing */ -static struct tracer no_tracer __read_mostly = { - .name = "none", - .init = no_trace_init -}; - - /** * trace_wake_up - wake up tasks waiting for trace input * @@ -167,23 +171,21 @@ void trace_wake_up(void) wake_up(&trace_wait); } -#define ENTRIES_PER_PAGE (PAGE_SIZE / sizeof(struct trace_entry)) - -static int __init set_nr_entries(char *str) +static int __init set_buf_size(char *str) { - unsigned long nr_entries; + unsigned long buf_size; int ret; if (!str) return 0; - ret = strict_strtoul(str, 0, &nr_entries); + ret = strict_strtoul(str, 0, &buf_size); /* nr_entries can not be zero */ - if (ret < 0 || nr_entries == 0) + if (ret < 0 || buf_size == 0) return 0; - trace_nr_entries = nr_entries; + trace_buf_size = buf_size; return 1; } -__setup("trace_entries=", set_nr_entries); +__setup("trace_buf_size=", set_buf_size); unsigned long nsecs_to_usecs(unsigned long nsecs) { @@ -191,21 +193,6 @@ unsigned long nsecs_to_usecs(unsigned long nsecs) } /* - * trace_flag_type is an enumeration that holds different - * states when a trace occurs. These are: - * IRQS_OFF - interrupts were disabled - * NEED_RESCED - reschedule is requested - * HARDIRQ - inside an interrupt handler - * SOFTIRQ - inside a softirq handler - */ -enum trace_flag_type { - TRACE_FLAG_IRQS_OFF = 0x01, - TRACE_FLAG_NEED_RESCHED = 0x02, - TRACE_FLAG_HARDIRQ = 0x04, - TRACE_FLAG_SOFTIRQ = 0x08, -}; - -/* * TRACE_ITER_SYM_MASK masks the options in trace_flags that * control the output of kernel symbols. */ @@ -224,6 +211,7 @@ static const char *trace_options[] = { "block", "stacktrace", "sched-tree", + "ftrace_printk", NULL }; @@ -266,54 +254,6 @@ __update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) tracing_record_cmdline(current); } -#define CHECK_COND(cond) \ - if (unlikely(cond)) { \ - tracing_disabled = 1; \ - WARN_ON(1); \ - return -1; \ - } - -/** - * check_pages - integrity check of trace buffers - * - * As a safty measure we check to make sure the data pages have not - * been corrupted. - */ -int check_pages(struct trace_array_cpu *data) -{ - struct page *page, *tmp; - - CHECK_COND(data->trace_pages.next->prev != &data->trace_pages); - CHECK_COND(data->trace_pages.prev->next != &data->trace_pages); - - list_for_each_entry_safe(page, tmp, &data->trace_pages, lru) { - CHECK_COND(page->lru.next->prev != &page->lru); - CHECK_COND(page->lru.prev->next != &page->lru); - } - - return 0; -} - -/** - * head_page - page address of the first page in per_cpu buffer. - * - * head_page returns the page address of the first page in - * a per_cpu buffer. This also preforms various consistency - * checks to make sure the buffer has not been corrupted. - */ -void *head_page(struct trace_array_cpu *data) -{ - struct page *page; - - if (list_empty(&data->trace_pages)) - return NULL; - - page = list_entry(data->trace_pages.next, struct page, lru); - BUG_ON(&page->lru == &data->trace_pages); - - return page_address(page); -} - /** * trace_seq_printf - sequence printing of trace information * @s: trace sequence descriptor @@ -395,28 +335,23 @@ trace_seq_putmem(struct trace_seq *s, void *mem, size_t len) return len; } -#define HEX_CHARS 17 -static const char hex2asc[] = "0123456789abcdef"; +#define MAX_MEMHEX_BYTES 8 +#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1) static int trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len) { unsigned char hex[HEX_CHARS]; unsigned char *data = mem; - unsigned char byte; int i, j; - BUG_ON(len >= HEX_CHARS); - #ifdef __BIG_ENDIAN for (i = 0, j = 0; i < len; i++) { #else for (i = len-1, j = 0; i >= 0; i--) { #endif - byte = data[i]; - - hex[j++] = hex2asc[byte & 0x0f]; - hex[j++] = hex2asc[byte >> 4]; + hex[j++] = hex_asc_hi(data[i]); + hex[j++] = hex_asc_lo(data[i]); } hex[j++] = ' '; @@ -460,34 +395,6 @@ trace_print_seq(struct seq_file *m, struct trace_seq *s) trace_seq_reset(s); } -/* - * flip the trace buffers between two trace descriptors. - * This usually is the buffers between the global_trace and - * the max_tr to record a snapshot of a current trace. - * - * The ftrace_max_lock must be held. - */ -static void -flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) -{ - struct list_head flip_pages; - - INIT_LIST_HEAD(&flip_pages); - - memcpy(&tr1->trace_head_idx, &tr2->trace_head_idx, - sizeof(struct trace_array_cpu) - - offsetof(struct trace_array_cpu, trace_head_idx)); - - check_pages(tr1); - check_pages(tr2); - list_splice_init(&tr1->trace_pages, &flip_pages); - list_splice_init(&tr2->trace_pages, &tr1->trace_pages); - list_splice_init(&flip_pages, &tr2->trace_pages); - BUG_ON(!list_empty(&flip_pages)); - check_pages(tr1); - check_pages(tr2); -} - /** * update_max_tr - snapshot all trace buffers from global_trace to max_tr * @tr: tracer @@ -500,17 +407,17 @@ flip_trace(struct trace_array_cpu *tr1, struct trace_array_cpu *tr2) void update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct trace_array_cpu *data; - int i; + struct ring_buffer *buf = tr->buffer; WARN_ON_ONCE(!irqs_disabled()); __raw_spin_lock(&ftrace_max_lock); - /* clear out all the previous traces */ - for_each_tracing_cpu(i) { - data = tr->data[i]; - flip_trace(max_tr.data[i], data); - tracing_reset(data); - } + + tr->buffer = max_tr.buffer; + max_tr.buffer = buf; + + ftrace_disable_cpu(); + ring_buffer_reset(tr->buffer); + ftrace_enable_cpu(); __update_max_tr(tr, tsk, cpu); __raw_spin_unlock(&ftrace_max_lock); @@ -527,16 +434,19 @@ update_max_tr(struct trace_array *tr, struct task_struct *tsk, int cpu) void update_max_tr_single(struct trace_array *tr, struct task_struct *tsk, int cpu) { - struct trace_array_cpu *data = tr->data[cpu]; - int i; + int ret; WARN_ON_ONCE(!irqs_disabled()); __raw_spin_lock(&ftrace_max_lock); - for_each_tracing_cpu(i) - tracing_reset(max_tr.data[i]); - flip_trace(max_tr.data[cpu], data); - tracing_reset(data); + ftrace_disable_cpu(); + + ring_buffer_reset(max_tr.buffer); + ret = ring_buffer_swap_cpu(max_tr.buffer, tr->buffer, cpu); + + ftrace_enable_cpu(); + + WARN_ON_ONCE(ret); __update_max_tr(tr, tsk, cpu); __raw_spin_unlock(&ftrace_max_lock); @@ -573,7 +483,6 @@ int register_tracer(struct tracer *type) #ifdef CONFIG_FTRACE_STARTUP_TEST if (type->selftest) { struct tracer *saved_tracer = current_trace; - struct trace_array_cpu *data; struct trace_array *tr = &global_trace; int saved_ctrl = tr->ctrl; int i; @@ -585,10 +494,7 @@ int register_tracer(struct tracer *type) * If we fail, we do not register this tracer. */ for_each_tracing_cpu(i) { - data = tr->data[i]; - if (!head_page(data)) - continue; - tracing_reset(data); + tracing_reset(tr, i); } current_trace = type; tr->ctrl = 0; @@ -604,10 +510,7 @@ int register_tracer(struct tracer *type) } /* Only reset on passing, to avoid touching corrupted buffers */ for_each_tracing_cpu(i) { - data = tr->data[i]; - if (!head_page(data)) - continue; - tracing_reset(data); + tracing_reset(tr, i); } printk(KERN_CONT "PASSED\n"); } @@ -653,13 +556,11 @@ void unregister_tracer(struct tracer *type) mutex_unlock(&trace_types_lock); } -void tracing_reset(struct trace_array_cpu *data) +void tracing_reset(struct trace_array *tr, int cpu) { - data->trace_idx = 0; - data->overrun = 0; - data->trace_head = data->trace_tail = head_page(data); - data->trace_head_idx = 0; - data->trace_tail_idx = 0; + ftrace_disable_cpu(); + ring_buffer_reset_cpu(tr->buffer, cpu); + ftrace_enable_cpu(); } #define SAVED_CMDLINES 128 @@ -745,82 +646,16 @@ void tracing_record_cmdline(struct task_struct *tsk) trace_save_cmdline(tsk); } -static inline struct list_head * -trace_next_list(struct trace_array_cpu *data, struct list_head *next) -{ - /* - * Roundrobin - but skip the head (which is not a real page): - */ - next = next->next; - if (unlikely(next == &data->trace_pages)) - next = next->next; - BUG_ON(next == &data->trace_pages); - - return next; -} - -static inline void * -trace_next_page(struct trace_array_cpu *data, void *addr) -{ - struct list_head *next; - struct page *page; - - page = virt_to_page(addr); - - next = trace_next_list(data, &page->lru); - page = list_entry(next, struct page, lru); - - return page_address(page); -} - -static inline struct trace_entry * -tracing_get_trace_entry(struct trace_array *tr, struct trace_array_cpu *data) -{ - unsigned long idx, idx_next; - struct trace_entry *entry; - - data->trace_idx++; - idx = data->trace_head_idx; - idx_next = idx + 1; - - BUG_ON(idx * TRACE_ENTRY_SIZE >= PAGE_SIZE); - - entry = data->trace_head + idx * TRACE_ENTRY_SIZE; - - if (unlikely(idx_next >= ENTRIES_PER_PAGE)) { - data->trace_head = trace_next_page(data, data->trace_head); - idx_next = 0; - } - - if (data->trace_head == data->trace_tail && - idx_next == data->trace_tail_idx) { - /* overrun */ - data->overrun++; - data->trace_tail_idx++; - if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { - data->trace_tail = - trace_next_page(data, data->trace_tail); - data->trace_tail_idx = 0; - } - } - - data->trace_head_idx = idx_next; - - return entry; -} - -static inline void -tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) +void +tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, + int pc) { struct task_struct *tsk = current; - unsigned long pc; - - pc = preempt_count(); - entry->preempt_count = pc & 0xff; - entry->pid = (tsk) ? tsk->pid : 0; - entry->t = ftrace_now(raw_smp_processor_id()); - entry->flags = (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | + entry->preempt_count = pc & 0xff; + entry->pid = (tsk) ? tsk->pid : 0; + entry->flags = + (irqs_disabled_flags(flags) ? TRACE_FLAG_IRQS_OFF : 0) | ((pc & HARDIRQ_MASK) ? TRACE_FLAG_HARDIRQ : 0) | ((pc & SOFTIRQ_MASK) ? TRACE_FLAG_SOFTIRQ : 0) | (need_resched() ? TRACE_FLAG_NEED_RESCHED : 0); @@ -828,145 +663,139 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags) void trace_function(struct trace_array *tr, struct trace_array_cpu *data, - unsigned long ip, unsigned long parent_ip, unsigned long flags) + unsigned long ip, unsigned long parent_ip, unsigned long flags, + int pc) { - struct trace_entry *entry; + struct ring_buffer_event *event; + struct ftrace_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_FN; - entry->fn.ip = ip; - entry->fn.parent_ip = parent_ip; - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + /* If we are reading the ring buffer, don't trace */ + if (unlikely(local_read(&__get_cpu_var(ftrace_cpu_disabled)))) + return; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_FN; + entry->ip = ip; + entry->parent_ip = parent_ip; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } void ftrace(struct trace_array *tr, struct trace_array_cpu *data, - unsigned long ip, unsigned long parent_ip, unsigned long flags) + unsigned long ip, unsigned long parent_ip, unsigned long flags, + int pc) { if (likely(!atomic_read(&data->disabled))) - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, pc); } -#ifdef CONFIG_MMIOTRACE -void __trace_mmiotrace_rw(struct trace_array *tr, struct trace_array_cpu *data, - struct mmiotrace_rw *rw) +static void ftrace_trace_stack(struct trace_array *tr, + struct trace_array_cpu *data, + unsigned long flags, + int skip, int pc) { - struct trace_entry *entry; + struct ring_buffer_event *event; + struct stack_entry *entry; + struct stack_trace trace; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_RW; - entry->mmiorw = *rw; - - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); - - trace_wake_up(); -} - -void __trace_mmiotrace_map(struct trace_array *tr, struct trace_array_cpu *data, - struct mmiotrace_map *map) -{ - struct trace_entry *entry; - unsigned long irq_flags; + if (!(trace_flags & TRACE_ITER_STACKTRACE)) + return; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_STACK; - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_MMIO_MAP; - entry->mmiomap = *map; + memset(&entry->caller, 0, sizeof(entry->caller)); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + trace.nr_entries = 0; + trace.max_entries = FTRACE_STACK_ENTRIES; + trace.skip = skip; + trace.entries = entry->caller; - trace_wake_up(); + save_stack_trace(&trace); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); } -#endif void __trace_stack(struct trace_array *tr, struct trace_array_cpu *data, unsigned long flags, int skip) { - struct trace_entry *entry; - struct stack_trace trace; - - if (!(trace_flags & TRACE_ITER_STACKTRACE)) - return; - - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_STACK; - - memset(&entry->stack, 0, sizeof(entry->stack)); - - trace.nr_entries = 0; - trace.max_entries = FTRACE_STACK_ENTRIES; - trace.skip = skip; - trace.entries = entry->stack.caller; - - save_stack_trace(&trace); + ftrace_trace_stack(tr, data, flags, skip, preempt_count()); } -void -__trace_special(void *__tr, void *__data, - unsigned long arg1, unsigned long arg2, unsigned long arg3) +static void +ftrace_trace_special(void *__tr, void *__data, + unsigned long arg1, unsigned long arg2, unsigned long arg3, + int pc) { + struct ring_buffer_event *event; struct trace_array_cpu *data = __data; struct trace_array *tr = __tr; - struct trace_entry *entry; + struct special_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, 0); - entry->type = TRACE_SPECIAL; - entry->special.arg1 = arg1; - entry->special.arg2 = arg2; - entry->special.arg3 = arg3; - __trace_stack(tr, data, irq_flags, 4); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, pc); + entry->ent.type = TRACE_SPECIAL; + entry->arg1 = arg1; + entry->arg2 = arg2; + entry->arg3 = arg3; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + ftrace_trace_stack(tr, data, irq_flags, 4, pc); trace_wake_up(); } void +__trace_special(void *__tr, void *__data, + unsigned long arg1, unsigned long arg2, unsigned long arg3) +{ + ftrace_trace_special(__tr, __data, arg1, arg2, arg3, preempt_count()); +} + +void tracing_sched_switch_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *prev, struct task_struct *next, - unsigned long flags) + unsigned long flags, int pc) { - struct trace_entry *entry; + struct ring_buffer_event *event; + struct ctx_switch_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_CTX; - entry->ctx.prev_pid = prev->pid; - entry->ctx.prev_prio = prev->prio; - entry->ctx.prev_state = prev->state; - entry->ctx.next_pid = next->pid; - entry->ctx.next_prio = next->prio; - entry->ctx.next_state = next->state; - __trace_stack(tr, data, flags, 5); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_CTX; + entry->prev_pid = prev->pid; + entry->prev_prio = prev->prio; + entry->prev_state = prev->state; + entry->next_pid = next->pid; + entry->next_prio = next->prio; + entry->next_state = next->state; + entry->next_cpu = task_cpu(next); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + ftrace_trace_stack(tr, data, flags, 5, pc); } void @@ -974,25 +803,28 @@ tracing_sched_wakeup_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *wakee, struct task_struct *curr, - unsigned long flags) + unsigned long flags, int pc) { - struct trace_entry *entry; + struct ring_buffer_event *event; + struct ctx_switch_entry *entry; unsigned long irq_flags; - raw_local_irq_save(irq_flags); - __raw_spin_lock(&data->lock); - entry = tracing_get_trace_entry(tr, data); - tracing_generic_entry_update(entry, flags); - entry->type = TRACE_WAKE; - entry->ctx.prev_pid = curr->pid; - entry->ctx.prev_prio = curr->prio; - entry->ctx.prev_state = curr->state; - entry->ctx.next_pid = wakee->pid; - entry->ctx.next_prio = wakee->prio; - entry->ctx.next_state = wakee->state; - __trace_stack(tr, data, flags, 6); - __raw_spin_unlock(&data->lock); - raw_local_irq_restore(irq_flags); + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_WAKE; + entry->prev_pid = curr->pid; + entry->prev_prio = curr->prio; + entry->prev_state = curr->state; + entry->next_pid = wakee->pid; + entry->next_prio = wakee->prio; + entry->next_state = wakee->state; + entry->next_cpu = task_cpu(wakee); + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + ftrace_trace_stack(tr, data, flags, 6, pc); trace_wake_up(); } @@ -1002,23 +834,21 @@ ftrace_special(unsigned long arg1, unsigned long arg2, unsigned long arg3) { struct trace_array *tr = &global_trace; struct trace_array_cpu *data; - unsigned long flags; - long disabled; int cpu; + int pc; - if (tracing_disabled || current_trace == &no_tracer || !tr->ctrl) + if (tracing_disabled || !tr->ctrl) return; - local_irq_save(flags); + pc = preempt_count(); + preempt_disable_notrace(); cpu = raw_smp_processor_id(); data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); - if (likely(disabled == 1)) - __trace_special(tr, data, arg1, arg2, arg3); + if (likely(!atomic_read(&data->disabled))) + ftrace_trace_special(tr, data, arg1, arg2, arg3, pc); - atomic_dec(&data->disabled); - local_irq_restore(flags); + preempt_enable_notrace(); } #ifdef CONFIG_FTRACE @@ -1029,7 +859,8 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) struct trace_array_cpu *data; unsigned long flags; long disabled; - int cpu; + int cpu, resched; + int pc; if (unlikely(!ftrace_function_enabled)) return; @@ -1037,16 +868,22 @@ function_trace_call(unsigned long ip, unsigned long parent_ip) if (skip_trace(ip)) return; - local_irq_save(flags); + pc = preempt_count(); + resched = need_resched(); + preempt_disable_notrace(); + local_save_flags(flags); cpu = raw_smp_processor_id(); data = tr->data[cpu]; disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, pc); atomic_dec(&data->disabled); - local_irq_restore(flags); + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); } static struct ftrace_ops trace_ops __read_mostly = @@ -1073,111 +910,96 @@ enum trace_file_type { TRACE_FILE_LAT_FMT = 1, }; -static struct trace_entry * -trace_entry_idx(struct trace_array *tr, struct trace_array_cpu *data, - struct trace_iterator *iter, int cpu) +static void trace_iterator_increment(struct trace_iterator *iter, int cpu) { - struct page *page; - struct trace_entry *array; + /* Don't allow ftrace to trace into the ring buffers */ + ftrace_disable_cpu(); - if (iter->next_idx[cpu] >= tr->entries || - iter->next_idx[cpu] >= data->trace_idx || - (data->trace_head == data->trace_tail && - data->trace_head_idx == data->trace_tail_idx)) - return NULL; + iter->idx++; + if (iter->buffer_iter[iter->cpu]) + ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); - if (!iter->next_page[cpu]) { - /* Initialize the iterator for this cpu trace buffer */ - WARN_ON(!data->trace_tail); - page = virt_to_page(data->trace_tail); - iter->next_page[cpu] = &page->lru; - iter->next_page_idx[cpu] = data->trace_tail_idx; - } + ftrace_enable_cpu(); +} + +static struct trace_entry * +peek_next_entry(struct trace_iterator *iter, int cpu, u64 *ts) +{ + struct ring_buffer_event *event; + struct ring_buffer_iter *buf_iter = iter->buffer_iter[cpu]; - page = list_entry(iter->next_page[cpu], struct page, lru); - BUG_ON(&data->trace_pages == &page->lru); + /* Don't allow ftrace to trace into the ring buffers */ + ftrace_disable_cpu(); + + if (buf_iter) + event = ring_buffer_iter_peek(buf_iter, ts); + else + event = ring_buffer_peek(iter->tr->buffer, cpu, ts); - array = page_address(page); + ftrace_enable_cpu(); - WARN_ON(iter->next_page_idx[cpu] >= ENTRIES_PER_PAGE); - return &array[iter->next_page_idx[cpu]]; + return event ? ring_buffer_event_data(event) : NULL; } static struct trace_entry * -find_next_entry(struct trace_iterator *iter, int *ent_cpu) +__find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) { - struct trace_array *tr = iter->tr; + struct ring_buffer *buffer = iter->tr->buffer; struct trace_entry *ent, *next = NULL; + u64 next_ts = 0, ts; int next_cpu = -1; int cpu; for_each_tracing_cpu(cpu) { - if (!head_page(tr->data[cpu])) + + if (ring_buffer_empty_cpu(buffer, cpu)) continue; - ent = trace_entry_idx(tr, tr->data[cpu], iter, cpu); + + ent = peek_next_entry(iter, cpu, &ts); + /* * Pick the entry with the smallest timestamp: */ - if (ent && (!next || ent->t < next->t)) { + if (ent && (!next || ts < next_ts)) { next = ent; next_cpu = cpu; + next_ts = ts; } } if (ent_cpu) *ent_cpu = next_cpu; + if (ent_ts) + *ent_ts = next_ts; + return next; } -static void trace_iterator_increment(struct trace_iterator *iter) +/* Find the next real entry, without updating the iterator itself */ +static struct trace_entry * +find_next_entry(struct trace_iterator *iter, int *ent_cpu, u64 *ent_ts) { - iter->idx++; - iter->next_idx[iter->cpu]++; - iter->next_page_idx[iter->cpu]++; - - if (iter->next_page_idx[iter->cpu] >= ENTRIES_PER_PAGE) { - struct trace_array_cpu *data = iter->tr->data[iter->cpu]; - - iter->next_page_idx[iter->cpu] = 0; - iter->next_page[iter->cpu] = - trace_next_list(data, iter->next_page[iter->cpu]); - } + return __find_next_entry(iter, ent_cpu, ent_ts); } -static void trace_consume(struct trace_iterator *iter) +/* Find the next real entry, and increment the iterator to the next entry */ +static void *find_next_entry_inc(struct trace_iterator *iter) { - struct trace_array_cpu *data = iter->tr->data[iter->cpu]; + iter->ent = __find_next_entry(iter, &iter->cpu, &iter->ts); - data->trace_tail_idx++; - if (data->trace_tail_idx >= ENTRIES_PER_PAGE) { - data->trace_tail = trace_next_page(data, data->trace_tail); - data->trace_tail_idx = 0; - } + if (iter->ent) + trace_iterator_increment(iter, iter->cpu); - /* Check if we empty it, then reset the index */ - if (data->trace_head == data->trace_tail && - data->trace_head_idx == data->trace_tail_idx) - data->trace_idx = 0; + return iter->ent ? iter : NULL; } -static void *find_next_entry_inc(struct trace_iterator *iter) +static void trace_consume(struct trace_iterator *iter) { - struct trace_entry *next; - int next_cpu = -1; - - next = find_next_entry(iter, &next_cpu); - - iter->prev_ent = iter->ent; - iter->prev_cpu = iter->cpu; - - iter->ent = next; - iter->cpu = next_cpu; - - if (next) - trace_iterator_increment(iter); - - return next ? iter : NULL; + /* Don't allow ftrace to trace into the ring buffers */ + ftrace_disable_cpu(); + ring_buffer_consume(iter->tr->buffer, iter->cpu, &iter->ts); + ftrace_enable_cpu(); } static void *s_next(struct seq_file *m, void *v, loff_t *pos) @@ -1210,7 +1032,7 @@ static void *s_start(struct seq_file *m, loff_t *pos) struct trace_iterator *iter = m->private; void *p = NULL; loff_t l = 0; - int i; + int cpu; mutex_lock(&trace_types_lock); @@ -1229,14 +1051,15 @@ static void *s_start(struct seq_file *m, loff_t *pos) iter->ent = NULL; iter->cpu = 0; iter->idx = -1; - iter->prev_ent = NULL; - iter->prev_cpu = -1; - for_each_tracing_cpu(i) { - iter->next_idx[i] = 0; - iter->next_page[i] = NULL; + ftrace_disable_cpu(); + + for_each_tracing_cpu(cpu) { + ring_buffer_iter_reset(iter->buffer_iter[cpu]); } + ftrace_enable_cpu(); + for (p = iter; p && l < *pos; p = s_next(m, p, &l)) ; @@ -1330,21 +1153,21 @@ seq_print_ip_sym(struct trace_seq *s, unsigned long ip, unsigned long sym_flags) static void print_lat_help_header(struct seq_file *m) { - seq_puts(m, "# _------=> CPU# \n"); - seq_puts(m, "# / _-----=> irqs-off \n"); - seq_puts(m, "# | / _----=> need-resched \n"); - seq_puts(m, "# || / _---=> hardirq/softirq \n"); - seq_puts(m, "# ||| / _--=> preempt-depth \n"); - seq_puts(m, "# |||| / \n"); - seq_puts(m, "# ||||| delay \n"); - seq_puts(m, "# cmd pid ||||| time | caller \n"); - seq_puts(m, "# \\ / ||||| \\ | / \n"); + seq_puts(m, "# _------=> CPU# \n"); + seq_puts(m, "# / _-----=> irqs-off \n"); + seq_puts(m, "# | / _----=> need-resched \n"); + seq_puts(m, "# || / _---=> hardirq/softirq \n"); + seq_puts(m, "# ||| / _--=> preempt-depth \n"); + seq_puts(m, "# |||| / \n"); + seq_puts(m, "# ||||| delay \n"); + seq_puts(m, "# cmd pid ||||| time | caller \n"); + seq_puts(m, "# \\ / ||||| \\ | / \n"); } static void print_func_help_header(struct seq_file *m) { - seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); - seq_puts(m, "# | | | | |\n"); + seq_puts(m, "# TASK-PID CPU# TIMESTAMP FUNCTION\n"); + seq_puts(m, "# | | | | |\n"); } @@ -1355,23 +1178,16 @@ print_trace_header(struct seq_file *m, struct trace_iterator *iter) struct trace_array *tr = iter->tr; struct trace_array_cpu *data = tr->data[tr->cpu]; struct tracer *type = current_trace; - unsigned long total = 0; - unsigned long entries = 0; - int cpu; + unsigned long total; + unsigned long entries; const char *name = "preemption"; if (type) name = type->name; - for_each_tracing_cpu(cpu) { - if (head_page(tr->data[cpu])) { - total += tr->data[cpu]->trace_idx; - if (tr->data[cpu]->trace_idx > tr->entries) - entries += tr->entries; - else - entries += tr->data[cpu]->trace_idx; - } - } + entries = ring_buffer_entries(iter->tr->buffer); + total = entries + + ring_buffer_overruns(iter->tr->buffer); seq_printf(m, "%s latency trace v1.1.5 on %s\n", name, UTS_RELEASE); @@ -1428,7 +1244,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) comm = trace_find_cmdline(entry->pid); trace_seq_printf(s, "%8.8s-%-5d ", comm, entry->pid); - trace_seq_printf(s, "%d", cpu); + trace_seq_printf(s, "%3d", cpu); trace_seq_printf(s, "%c%c", (entry->flags & TRACE_FLAG_IRQS_OFF) ? 'd' : '.', ((entry->flags & TRACE_FLAG_NEED_RESCHED) ? 'N' : '.')); @@ -1457,7 +1273,7 @@ lat_print_generic(struct trace_seq *s, struct trace_entry *entry, int cpu) unsigned long preempt_mark_thresh = 100; static void -lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, +lat_print_timestamp(struct trace_seq *s, u64 abs_usecs, unsigned long rel_usecs) { trace_seq_printf(s, " %4lldus", abs_usecs); @@ -1471,34 +1287,76 @@ lat_print_timestamp(struct trace_seq *s, unsigned long long abs_usecs, static const char state_to_char[] = TASK_STATE_TO_CHAR_STR; -static int +/* + * The message is supposed to contain an ending newline. + * If the printing stops prematurely, try to add a newline of our own. + */ +void trace_seq_print_cont(struct trace_seq *s, struct trace_iterator *iter) +{ + struct trace_entry *ent; + struct trace_field_cont *cont; + bool ok = true; + + ent = peek_next_entry(iter, iter->cpu, NULL); + if (!ent || ent->type != TRACE_CONT) { + trace_seq_putc(s, '\n'); + return; + } + + do { + cont = (struct trace_field_cont *)ent; + if (ok) + ok = (trace_seq_printf(s, "%s", cont->buf) > 0); + + ftrace_disable_cpu(); + + if (iter->buffer_iter[iter->cpu]) + ring_buffer_read(iter->buffer_iter[iter->cpu], NULL); + else + ring_buffer_consume(iter->tr->buffer, iter->cpu, NULL); + + ftrace_enable_cpu(); + + ent = peek_next_entry(iter, iter->cpu, NULL); + } while (ent && ent->type == TRACE_CONT); + + if (!ok) + trace_seq_putc(s, '\n'); +} + +static enum print_line_t print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) { struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); - struct trace_entry *next_entry = find_next_entry(iter, NULL); + struct trace_entry *next_entry; unsigned long verbose = (trace_flags & TRACE_ITER_VERBOSE); struct trace_entry *entry = iter->ent; unsigned long abs_usecs; unsigned long rel_usecs; + u64 next_ts; char *comm; int S, T; int i; unsigned state; + if (entry->type == TRACE_CONT) + return TRACE_TYPE_HANDLED; + + next_entry = find_next_entry(iter, NULL, &next_ts); if (!next_entry) - next_entry = entry; - rel_usecs = ns2usecs(next_entry->t - entry->t); - abs_usecs = ns2usecs(entry->t - iter->tr->time_start); + next_ts = iter->ts; + rel_usecs = ns2usecs(next_ts - iter->ts); + abs_usecs = ns2usecs(iter->ts - iter->tr->time_start); if (verbose) { comm = trace_find_cmdline(entry->pid); - trace_seq_printf(s, "%16s %5d %d %d %08x %08x [%08lx]" + trace_seq_printf(s, "%16s %5d %3d %d %08x %08x [%08lx]" " %ld.%03ldms (+%ld.%03ldms): ", comm, entry->pid, cpu, entry->flags, entry->preempt_count, trace_idx, - ns2usecs(entry->t), + ns2usecs(iter->ts), abs_usecs/1000, abs_usecs % 1000, rel_usecs/1000, rel_usecs % 1000); @@ -1507,52 +1365,85 @@ print_lat_fmt(struct trace_iterator *iter, unsigned int trace_idx, int cpu) lat_print_timestamp(s, abs_usecs, rel_usecs); } switch (entry->type) { - case TRACE_FN: - seq_print_ip_sym(s, entry->fn.ip, sym_flags); + case TRACE_FN: { + struct ftrace_entry *field; + + trace_assign_type(field, entry); + + seq_print_ip_sym(s, field->ip, sym_flags); trace_seq_puts(s, " ("); - if (kretprobed(entry->fn.parent_ip)) + if (kretprobed(field->parent_ip)) trace_seq_puts(s, KRETPROBE_MSG); else - seq_print_ip_sym(s, entry->fn.parent_ip, sym_flags); + seq_print_ip_sym(s, field->parent_ip, sym_flags); trace_seq_puts(s, ")\n"); break; + } case TRACE_CTX: - case TRACE_WAKE: - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); + + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; - state = entry->ctx.prev_state ? __ffs(entry->ctx.prev_state) + 1 : 0; + state = field->prev_state ? + __ffs(field->prev_state) + 1 : 0; S = state < sizeof(state_to_char) - 1 ? state_to_char[state] : 'X'; - comm = trace_find_cmdline(entry->ctx.next_pid); - trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c %s\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, + comm = trace_find_cmdline(field->next_pid); + trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c %s\n", + field->prev_pid, + field->prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", - entry->ctx.next_pid, - entry->ctx.next_prio, + field->next_cpu, + field->next_pid, + field->next_prio, T, comm); break; - case TRACE_SPECIAL: + } + case TRACE_SPECIAL: { + struct special_entry *field; + + trace_assign_type(field, entry); + trace_seq_printf(s, "# %ld %ld %ld\n", - entry->special.arg1, - entry->special.arg2, - entry->special.arg3); + field->arg1, + field->arg2, + field->arg3); break; - case TRACE_STACK: + } + case TRACE_STACK: { + struct stack_entry *field; + + trace_assign_type(field, entry); + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) trace_seq_puts(s, " <= "); - seq_print_ip_sym(s, entry->stack.caller[i], sym_flags); + seq_print_ip_sym(s, field->caller[i], sym_flags); } trace_seq_puts(s, "\n"); break; + } + case TRACE_PRINT: { + struct print_entry *field; + + trace_assign_type(field, entry); + + seq_print_ip_sym(s, field->ip, sym_flags); + trace_seq_printf(s, ": %s", field->buf); + if (entry->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; + } default: trace_seq_printf(s, "Unknown type %d\n", entry->type); } - return 1; + return TRACE_TYPE_HANDLED; } -static int print_trace_fmt(struct trace_iterator *iter) +static enum print_line_t print_trace_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; unsigned long sym_flags = (trace_flags & TRACE_ITER_SYM_MASK); @@ -1567,90 +1458,126 @@ static int print_trace_fmt(struct trace_iterator *iter) entry = iter->ent; + if (entry->type == TRACE_CONT) + return TRACE_TYPE_HANDLED; + comm = trace_find_cmdline(iter->ent->pid); - t = ns2usecs(entry->t); + t = ns2usecs(iter->ts); usec_rem = do_div(t, 1000000ULL); secs = (unsigned long)t; ret = trace_seq_printf(s, "%16s-%-5d ", comm, entry->pid); if (!ret) - return 0; - ret = trace_seq_printf(s, "[%02d] ", iter->cpu); + return TRACE_TYPE_PARTIAL_LINE; + ret = trace_seq_printf(s, "[%03d] ", iter->cpu); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; ret = trace_seq_printf(s, "%5lu.%06lu: ", secs, usec_rem); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; switch (entry->type) { - case TRACE_FN: - ret = seq_print_ip_sym(s, entry->fn.ip, sym_flags); + case TRACE_FN: { + struct ftrace_entry *field; + + trace_assign_type(field, entry); + + ret = seq_print_ip_sym(s, field->ip, sym_flags); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; if ((sym_flags & TRACE_ITER_PRINT_PARENT) && - entry->fn.parent_ip) { + field->parent_ip) { ret = trace_seq_printf(s, " <-"); if (!ret) - return 0; - if (kretprobed(entry->fn.parent_ip)) + return TRACE_TYPE_PARTIAL_LINE; + if (kretprobed(field->parent_ip)) ret = trace_seq_puts(s, KRETPROBE_MSG); else - ret = seq_print_ip_sym(s, entry->fn.parent_ip, + ret = seq_print_ip_sym(s, + field->parent_ip, sym_flags); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; } ret = trace_seq_printf(s, "\n"); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; + } case TRACE_CTX: - case TRACE_WAKE: - S = entry->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.prev_state] : 'X'; - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; - ret = trace_seq_printf(s, " %5d:%3d:%c %s %5d:%3d:%c\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, + case TRACE_WAKE: { + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); + + S = field->prev_state < sizeof(state_to_char) ? + state_to_char[field->prev_state] : 'X'; + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; + ret = trace_seq_printf(s, " %5d:%3d:%c %s [%03d] %5d:%3d:%c\n", + field->prev_pid, + field->prev_prio, S, entry->type == TRACE_CTX ? "==>" : " +", - entry->ctx.next_pid, - entry->ctx.next_prio, + field->next_cpu, + field->next_pid, + field->next_prio, T); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; - case TRACE_SPECIAL: + } + case TRACE_SPECIAL: { + struct special_entry *field; + + trace_assign_type(field, entry); + ret = trace_seq_printf(s, "# %ld %ld %ld\n", - entry->special.arg1, - entry->special.arg2, - entry->special.arg3); + field->arg1, + field->arg2, + field->arg3); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; - case TRACE_STACK: + } + case TRACE_STACK: { + struct stack_entry *field; + + trace_assign_type(field, entry); + for (i = 0; i < FTRACE_STACK_ENTRIES; i++) { if (i) { ret = trace_seq_puts(s, " <= "); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; } - ret = seq_print_ip_sym(s, entry->stack.caller[i], + ret = seq_print_ip_sym(s, field->caller[i], sym_flags); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; } ret = trace_seq_puts(s, "\n"); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } - return 1; + case TRACE_PRINT: { + struct print_entry *field; + + trace_assign_type(field, entry); + + seq_print_ip_sym(s, field->ip, sym_flags); + trace_seq_printf(s, ": %s", field->buf); + if (entry->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; + } + } + return TRACE_TYPE_HANDLED; } -static int print_raw_fmt(struct trace_iterator *iter) +static enum print_line_t print_raw_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; @@ -1659,47 +1586,77 @@ static int print_raw_fmt(struct trace_iterator *iter) entry = iter->ent; + if (entry->type == TRACE_CONT) + return TRACE_TYPE_HANDLED; + ret = trace_seq_printf(s, "%d %d %llu ", - entry->pid, iter->cpu, entry->t); + entry->pid, iter->cpu, iter->ts); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; switch (entry->type) { - case TRACE_FN: + case TRACE_FN: { + struct ftrace_entry *field; + + trace_assign_type(field, entry); + ret = trace_seq_printf(s, "%x %x\n", - entry->fn.ip, entry->fn.parent_ip); + field->ip, + field->parent_ip); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; + } case TRACE_CTX: - case TRACE_WAKE: - S = entry->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.prev_state] : 'X'; - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); + + S = field->prev_state < sizeof(state_to_char) ? + state_to_char[field->prev_state] : 'X'; + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; - ret = trace_seq_printf(s, "%d %d %c %d %d %c\n", - entry->ctx.prev_pid, - entry->ctx.prev_prio, + ret = trace_seq_printf(s, "%d %d %c %d %d %d %c\n", + field->prev_pid, + field->prev_prio, S, - entry->ctx.next_pid, - entry->ctx.next_prio, + field->next_cpu, + field->next_pid, + field->next_prio, T); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; + } case TRACE_SPECIAL: - case TRACE_STACK: + case TRACE_STACK: { + struct special_entry *field; + + trace_assign_type(field, entry); + ret = trace_seq_printf(s, "# %ld %ld %ld\n", - entry->special.arg1, - entry->special.arg2, - entry->special.arg3); + field->arg1, + field->arg2, + field->arg3); if (!ret) - return 0; + return TRACE_TYPE_PARTIAL_LINE; break; } - return 1; + case TRACE_PRINT: { + struct print_entry *field; + + trace_assign_type(field, entry); + + trace_seq_printf(s, "# %lx %s", field->ip, field->buf); + if (entry->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + break; + } + } + return TRACE_TYPE_HANDLED; } #define SEQ_PUT_FIELD_RET(s, x) \ @@ -1710,11 +1667,12 @@ do { \ #define SEQ_PUT_HEX_FIELD_RET(s, x) \ do { \ + BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \ if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \ return 0; \ } while (0) -static int print_hex_fmt(struct trace_iterator *iter) +static enum print_line_t print_hex_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; unsigned char newline = '\n'; @@ -1723,97 +1681,139 @@ static int print_hex_fmt(struct trace_iterator *iter) entry = iter->ent; + if (entry->type == TRACE_CONT) + return TRACE_TYPE_HANDLED; + SEQ_PUT_HEX_FIELD_RET(s, entry->pid); SEQ_PUT_HEX_FIELD_RET(s, iter->cpu); - SEQ_PUT_HEX_FIELD_RET(s, entry->t); + SEQ_PUT_HEX_FIELD_RET(s, iter->ts); switch (entry->type) { - case TRACE_FN: - SEQ_PUT_HEX_FIELD_RET(s, entry->fn.ip); - SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); + case TRACE_FN: { + struct ftrace_entry *field; + + trace_assign_type(field, entry); + + SEQ_PUT_HEX_FIELD_RET(s, field->ip); + SEQ_PUT_HEX_FIELD_RET(s, field->parent_ip); break; + } case TRACE_CTX: - case TRACE_WAKE: - S = entry->ctx.prev_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.prev_state] : 'X'; - T = entry->ctx.next_state < sizeof(state_to_char) ? - state_to_char[entry->ctx.next_state] : 'X'; + case TRACE_WAKE: { + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); + + S = field->prev_state < sizeof(state_to_char) ? + state_to_char[field->prev_state] : 'X'; + T = field->next_state < sizeof(state_to_char) ? + state_to_char[field->next_state] : 'X'; if (entry->type == TRACE_WAKE) S = '+'; - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_pid); - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.prev_prio); + SEQ_PUT_HEX_FIELD_RET(s, field->prev_pid); + SEQ_PUT_HEX_FIELD_RET(s, field->prev_prio); SEQ_PUT_HEX_FIELD_RET(s, S); - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_pid); - SEQ_PUT_HEX_FIELD_RET(s, entry->ctx.next_prio); - SEQ_PUT_HEX_FIELD_RET(s, entry->fn.parent_ip); + SEQ_PUT_HEX_FIELD_RET(s, field->next_cpu); + SEQ_PUT_HEX_FIELD_RET(s, field->next_pid); + SEQ_PUT_HEX_FIELD_RET(s, field->next_prio); SEQ_PUT_HEX_FIELD_RET(s, T); break; + } case TRACE_SPECIAL: - case TRACE_STACK: - SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg1); - SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg2); - SEQ_PUT_HEX_FIELD_RET(s, entry->special.arg3); + case TRACE_STACK: { + struct special_entry *field; + + trace_assign_type(field, entry); + + SEQ_PUT_HEX_FIELD_RET(s, field->arg1); + SEQ_PUT_HEX_FIELD_RET(s, field->arg2); + SEQ_PUT_HEX_FIELD_RET(s, field->arg3); break; } + } SEQ_PUT_FIELD_RET(s, newline); - return 1; + return TRACE_TYPE_HANDLED; } -static int print_bin_fmt(struct trace_iterator *iter) +static enum print_line_t print_bin_fmt(struct trace_iterator *iter) { struct trace_seq *s = &iter->seq; struct trace_entry *entry; entry = iter->ent; + if (entry->type == TRACE_CONT) + return TRACE_TYPE_HANDLED; + SEQ_PUT_FIELD_RET(s, entry->pid); - SEQ_PUT_FIELD_RET(s, entry->cpu); - SEQ_PUT_FIELD_RET(s, entry->t); + SEQ_PUT_FIELD_RET(s, iter->cpu); + SEQ_PUT_FIELD_RET(s, iter->ts); switch (entry->type) { - case TRACE_FN: - SEQ_PUT_FIELD_RET(s, entry->fn.ip); - SEQ_PUT_FIELD_RET(s, entry->fn.parent_ip); + case TRACE_FN: { + struct ftrace_entry *field; + + trace_assign_type(field, entry); + + SEQ_PUT_FIELD_RET(s, field->ip); + SEQ_PUT_FIELD_RET(s, field->parent_ip); break; - case TRACE_CTX: - SEQ_PUT_FIELD_RET(s, entry->ctx.prev_pid); - SEQ_PUT_FIELD_RET(s, entry->ctx.prev_prio); - SEQ_PUT_FIELD_RET(s, entry->ctx.prev_state); - SEQ_PUT_FIELD_RET(s, entry->ctx.next_pid); - SEQ_PUT_FIELD_RET(s, entry->ctx.next_prio); - SEQ_PUT_FIELD_RET(s, entry->ctx.next_state); + } + case TRACE_CTX: { + struct ctx_switch_entry *field; + + trace_assign_type(field, entry); + + SEQ_PUT_FIELD_RET(s, field->prev_pid); + SEQ_PUT_FIELD_RET(s, field->prev_prio); + SEQ_PUT_FIELD_RET(s, field->prev_state); + SEQ_PUT_FIELD_RET(s, field->next_pid); + SEQ_PUT_FIELD_RET(s, field->next_prio); + SEQ_PUT_FIELD_RET(s, field->next_state); break; + } case TRACE_SPECIAL: - case TRACE_STACK: - SEQ_PUT_FIELD_RET(s, entry->special.arg1); - SEQ_PUT_FIELD_RET(s, entry->special.arg2); - SEQ_PUT_FIELD_RET(s, entry->special.arg3); + case TRACE_STACK: { + struct special_entry *field; + + trace_assign_type(field, entry); + + SEQ_PUT_FIELD_RET(s, field->arg1); + SEQ_PUT_FIELD_RET(s, field->arg2); + SEQ_PUT_FIELD_RET(s, field->arg3); break; } + } return 1; } static int trace_empty(struct trace_iterator *iter) { - struct trace_array_cpu *data; int cpu; for_each_tracing_cpu(cpu) { - data = iter->tr->data[cpu]; - - if (head_page(data) && data->trace_idx && - (data->trace_tail != data->trace_head || - data->trace_tail_idx != data->trace_head_idx)) - return 0; + if (iter->buffer_iter[cpu]) { + if (!ring_buffer_iter_empty(iter->buffer_iter[cpu])) + return 0; + } else { + if (!ring_buffer_empty_cpu(iter->tr->buffer, cpu)) + return 0; + } } + return 1; } -static int print_trace_line(struct trace_iterator *iter) +static enum print_line_t print_trace_line(struct trace_iterator *iter) { - if (iter->trace && iter->trace->print_line) - return iter->trace->print_line(iter); + enum print_line_t ret; + + if (iter->trace && iter->trace->print_line) { + ret = iter->trace->print_line(iter); + if (ret != TRACE_TYPE_UNHANDLED) + return ret; + } if (trace_flags & TRACE_ITER_BIN) return print_bin_fmt(iter); @@ -1869,6 +1869,8 @@ static struct trace_iterator * __tracing_open(struct inode *inode, struct file *file, int *ret) { struct trace_iterator *iter; + struct seq_file *m; + int cpu; if (tracing_disabled) { *ret = -ENODEV; @@ -1889,28 +1891,45 @@ __tracing_open(struct inode *inode, struct file *file, int *ret) iter->trace = current_trace; iter->pos = -1; + for_each_tracing_cpu(cpu) { + + iter->buffer_iter[cpu] = + ring_buffer_read_start(iter->tr->buffer, cpu); + + if (!iter->buffer_iter[cpu]) + goto fail_buffer; + } + /* TODO stop tracer */ *ret = seq_open(file, &tracer_seq_ops); - if (!*ret) { - struct seq_file *m = file->private_data; - m->private = iter; + if (*ret) + goto fail_buffer; - /* stop the trace while dumping */ - if (iter->tr->ctrl) { - tracer_enabled = 0; - ftrace_function_enabled = 0; - } + m = file->private_data; + m->private = iter; - if (iter->trace && iter->trace->open) - iter->trace->open(iter); - } else { - kfree(iter); - iter = NULL; + /* stop the trace while dumping */ + if (iter->tr->ctrl) { + tracer_enabled = 0; + ftrace_function_enabled = 0; } + + if (iter->trace && iter->trace->open) + iter->trace->open(iter); + mutex_unlock(&trace_types_lock); out: return iter; + + fail_buffer: + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } + mutex_unlock(&trace_types_lock); + + return ERR_PTR(-ENOMEM); } int tracing_open_generic(struct inode *inode, struct file *filp) @@ -1926,8 +1945,14 @@ int tracing_release(struct inode *inode, struct file *file) { struct seq_file *m = (struct seq_file *)file->private_data; struct trace_iterator *iter = m->private; + int cpu; mutex_lock(&trace_types_lock); + for_each_tracing_cpu(cpu) { + if (iter->buffer_iter[cpu]) + ring_buffer_read_finish(iter->buffer_iter[cpu]); + } + if (iter->trace && iter->trace->close) iter->trace->close(iter); @@ -2352,9 +2377,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, struct tracer *t; char buf[max_tracer_type_len+1]; int i; + size_t ret; if (cnt > max_tracer_type_len) cnt = max_tracer_type_len; + ret = cnt; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; @@ -2370,7 +2397,11 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, if (strcmp(t->name, buf) == 0) break; } - if (!t || t == current_trace) + if (!t) { + ret = -EINVAL; + goto out; + } + if (t == current_trace) goto out; if (current_trace && current_trace->reset) @@ -2383,9 +2414,10 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, out: mutex_unlock(&trace_types_lock); - filp->f_pos += cnt; + if (ret == cnt) + filp->f_pos += cnt; - return cnt; + return ret; } static ssize_t @@ -2500,20 +2532,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) { struct trace_iterator *iter = filp->private_data; - struct trace_array_cpu *data; - static cpumask_t mask; - unsigned long flags; -#ifdef CONFIG_FTRACE - int ftrace_save; -#endif - int cpu; ssize_t sret; /* return any leftover data */ sret = trace_seq_to_user(&iter->seq, ubuf, cnt); if (sret != -EBUSY) return sret; - sret = 0; trace_seq_reset(&iter->seq); @@ -2524,6 +2548,8 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, goto out; } +waitagain: + sret = 0; while (trace_empty(iter)) { if ((filp->f_flags & O_NONBLOCK)) { @@ -2588,46 +2614,12 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, offsetof(struct trace_iterator, seq)); iter->pos = -1; - /* - * We need to stop all tracing on all CPUS to read the - * the next buffer. This is a bit expensive, but is - * not done often. We fill all what we can read, - * and then release the locks again. - */ - - cpus_clear(mask); - local_irq_save(flags); -#ifdef CONFIG_FTRACE - ftrace_save = ftrace_enabled; - ftrace_enabled = 0; -#endif - smp_wmb(); - for_each_tracing_cpu(cpu) { - data = iter->tr->data[cpu]; - - if (!head_page(data) || !data->trace_idx) - continue; - - atomic_inc(&data->disabled); - cpu_set(cpu, mask); - } - - for_each_cpu_mask(cpu, mask) { - data = iter->tr->data[cpu]; - __raw_spin_lock(&data->lock); - - if (data->overrun > iter->last_overrun[cpu]) - iter->overrun[cpu] += - data->overrun - iter->last_overrun[cpu]; - iter->last_overrun[cpu] = data->overrun; - } - while (find_next_entry_inc(iter) != NULL) { - int ret; + enum print_line_t ret; int len = iter->seq.len; ret = print_trace_line(iter); - if (!ret) { + if (ret == TRACE_TYPE_PARTIAL_LINE) { /* don't print partial lines */ iter->seq.len = len; break; @@ -2639,26 +2631,17 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, break; } - for_each_cpu_mask(cpu, mask) { - data = iter->tr->data[cpu]; - __raw_spin_unlock(&data->lock); - } - - for_each_cpu_mask(cpu, mask) { - data = iter->tr->data[cpu]; - atomic_dec(&data->disabled); - } -#ifdef CONFIG_FTRACE - ftrace_enabled = ftrace_save; -#endif - local_irq_restore(flags); - /* Now copy what we have to the user */ sret = trace_seq_to_user(&iter->seq, ubuf, cnt); if (iter->seq.readpos >= iter->seq.len) trace_seq_reset(&iter->seq); + + /* + * If there was nothing to send to user, inspite of consuming trace + * entries, go back to wait for more entries. + */ if (sret == -EBUSY) - sret = 0; + goto waitagain; out: mutex_unlock(&trace_types_lock); @@ -2684,7 +2667,8 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, { unsigned long val; char buf[64]; - int i, ret; + int ret; + struct trace_array *tr = filp->private_data; if (cnt >= sizeof(buf)) return -EINVAL; @@ -2704,59 +2688,38 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, mutex_lock(&trace_types_lock); - if (current_trace != &no_tracer) { + if (tr->ctrl) { cnt = -EBUSY; - pr_info("ftrace: set current_tracer to none" + pr_info("ftrace: please disable tracing" " before modifying buffer size\n"); goto out; } - if (val > global_trace.entries) { - long pages_requested; - unsigned long freeable_pages; - - /* make sure we have enough memory before mapping */ - pages_requested = - (val + (ENTRIES_PER_PAGE-1)) / ENTRIES_PER_PAGE; - - /* account for each buffer (and max_tr) */ - pages_requested *= tracing_nr_buffers * 2; - - /* Check for overflow */ - if (pages_requested < 0) { - cnt = -ENOMEM; - goto out; - } - - freeable_pages = determine_dirtyable_memory(); - - /* we only allow to request 1/4 of useable memory */ - if (pages_requested > - ((freeable_pages + tracing_pages_allocated) / 4)) { - cnt = -ENOMEM; + if (val != global_trace.entries) { + ret = ring_buffer_resize(global_trace.buffer, val); + if (ret < 0) { + cnt = ret; goto out; } - while (global_trace.entries < val) { - if (trace_alloc_page()) { - cnt = -ENOMEM; - goto out; + ret = ring_buffer_resize(max_tr.buffer, val); + if (ret < 0) { + int r; + cnt = ret; + r = ring_buffer_resize(global_trace.buffer, + global_trace.entries); + if (r < 0) { + /* AARGH! We are left with different + * size max buffer!!!! */ + WARN_ON(1); + tracing_disabled = 1; } - /* double check that we don't go over the known pages */ - if (tracing_pages_allocated > pages_requested) - break; + goto out; } - } else { - /* include the number of entries in val (inc of page entries) */ - while (global_trace.entries > val + (ENTRIES_PER_PAGE - 1)) - trace_free_page(); + global_trace.entries = val; } - /* check integrity */ - for_each_tracing_cpu(i) - check_pages(global_trace.data[i]); - filp->f_pos += cnt; /* If check pages failed, return ENOMEM */ @@ -2769,6 +2732,52 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } +static int mark_printk(const char *fmt, ...) +{ + int ret; + va_list args; + va_start(args, fmt); + ret = trace_vprintk(0, fmt, args); + va_end(args); + return ret; +} + +static ssize_t +tracing_mark_write(struct file *filp, const char __user *ubuf, + size_t cnt, loff_t *fpos) +{ + char *buf; + char *end; + struct trace_array *tr = &global_trace; + + if (!tr->ctrl || tracing_disabled) + return -EINVAL; + + if (cnt > TRACE_BUF_SIZE) + cnt = TRACE_BUF_SIZE; + + buf = kmalloc(cnt + 1, GFP_KERNEL); + if (buf == NULL) + return -ENOMEM; + + if (copy_from_user(buf, ubuf, cnt)) { + kfree(buf); + return -EFAULT; + } + + /* Cut from the first nil or newline. */ + buf[cnt] = '\0'; + end = strchr(buf, '\n'); + if (end) + *end = '\0'; + + cnt = mark_printk("%s\n", buf); + kfree(buf); + *fpos += cnt; + + return cnt; +} + static struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -2800,6 +2809,11 @@ static struct file_operations tracing_entries_fops = { .write = tracing_entries_write, }; +static struct file_operations tracing_mark_fops = { + .open = tracing_open_generic, + .write = tracing_mark_write, +}; + #ifdef CONFIG_DYNAMIC_FTRACE static ssize_t @@ -2846,7 +2860,7 @@ struct dentry *tracing_init_dentry(void) #include "trace_selftest.c" #endif -static __init void tracer_init_debugfs(void) +static __init int tracer_init_debugfs(void) { struct dentry *d_tracer; struct dentry *entry; @@ -2881,12 +2895,12 @@ static __init void tracer_init_debugfs(void) entry = debugfs_create_file("available_tracers", 0444, d_tracer, &global_trace, &show_traces_fops); if (!entry) - pr_warning("Could not create debugfs 'trace' entry\n"); + pr_warning("Could not create debugfs 'available_tracers' entry\n"); entry = debugfs_create_file("current_tracer", 0444, d_tracer, &global_trace, &set_tracer_fops); if (!entry) - pr_warning("Could not create debugfs 'trace' entry\n"); + pr_warning("Could not create debugfs 'current_tracer' entry\n"); entry = debugfs_create_file("tracing_max_latency", 0644, d_tracer, &tracing_max_latency, @@ -2899,7 +2913,7 @@ static __init void tracer_init_debugfs(void) &tracing_thresh, &tracing_max_lat_fops); if (!entry) pr_warning("Could not create debugfs " - "'tracing_threash' entry\n"); + "'tracing_thresh' entry\n"); entry = debugfs_create_file("README", 0644, d_tracer, NULL, &tracing_readme_fops); if (!entry) @@ -2909,13 +2923,19 @@ static __init void tracer_init_debugfs(void) NULL, &tracing_pipe_fops); if (!entry) pr_warning("Could not create debugfs " - "'tracing_threash' entry\n"); + "'trace_pipe' entry\n"); entry = debugfs_create_file("trace_entries", 0644, d_tracer, &global_trace, &tracing_entries_fops); if (!entry) pr_warning("Could not create debugfs " - "'tracing_threash' entry\n"); + "'trace_entries' entry\n"); + + entry = debugfs_create_file("trace_marker", 0220, d_tracer, + NULL, &tracing_mark_fops); + if (!entry) + pr_warning("Could not create debugfs " + "'trace_marker' entry\n"); #ifdef CONFIG_DYNAMIC_FTRACE entry = debugfs_create_file("dyn_ftrace_total_info", 0444, d_tracer, @@ -2928,230 +2948,263 @@ static __init void tracer_init_debugfs(void) #ifdef CONFIG_SYSPROF_TRACER init_tracer_sysprof_debugfs(d_tracer); #endif + return 0; } -static int trace_alloc_page(void) +int trace_vprintk(unsigned long ip, const char *fmt, va_list args) { + static DEFINE_SPINLOCK(trace_buf_lock); + static char trace_buf[TRACE_BUF_SIZE]; + + struct ring_buffer_event *event; + struct trace_array *tr = &global_trace; struct trace_array_cpu *data; - struct page *page, *tmp; - LIST_HEAD(pages); - void *array; - unsigned pages_allocated = 0; - int i; + struct print_entry *entry; + unsigned long flags, irq_flags; + int cpu, len = 0, size, pc; - /* first allocate a page for each CPU */ - for_each_tracing_cpu(i) { - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_pages; - } + if (!tr->ctrl || tracing_disabled) + return 0; - pages_allocated++; - page = virt_to_page(array); - list_add(&page->lru, &pages); + pc = preempt_count(); + preempt_disable_notrace(); + cpu = raw_smp_processor_id(); + data = tr->data[cpu]; -/* Only allocate if we are actually using the max trace */ -#ifdef CONFIG_TRACER_MAX_TRACE - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_pages; - } - pages_allocated++; - page = virt_to_page(array); - list_add(&page->lru, &pages); -#endif - } + if (unlikely(atomic_read(&data->disabled))) + goto out; - /* Now that we successfully allocate a page per CPU, add them */ - for_each_tracing_cpu(i) { - data = global_trace.data[i]; - page = list_entry(pages.next, struct page, lru); - list_del_init(&page->lru); - list_add_tail(&page->lru, &data->trace_pages); - ClearPageLRU(page); + spin_lock_irqsave(&trace_buf_lock, flags); + len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args); -#ifdef CONFIG_TRACER_MAX_TRACE - data = max_tr.data[i]; - page = list_entry(pages.next, struct page, lru); - list_del_init(&page->lru); - list_add_tail(&page->lru, &data->trace_pages); - SetPageLRU(page); -#endif - } - tracing_pages_allocated += pages_allocated; - global_trace.entries += ENTRIES_PER_PAGE; + len = min(len, TRACE_BUF_SIZE-1); + trace_buf[len] = 0; - return 0; + size = sizeof(*entry) + len + 1; + event = ring_buffer_lock_reserve(tr->buffer, size, &irq_flags); + if (!event) + goto out_unlock; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, flags, pc); + entry->ent.type = TRACE_PRINT; + entry->ip = ip; - free_pages: - list_for_each_entry_safe(page, tmp, &pages, lru) { - list_del_init(&page->lru); - __free_page(page); - } - return -ENOMEM; + memcpy(&entry->buf, trace_buf, len); + entry->buf[len] = 0; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + out_unlock: + spin_unlock_irqrestore(&trace_buf_lock, flags); + + out: + preempt_enable_notrace(); + + return len; } +EXPORT_SYMBOL_GPL(trace_vprintk); -static int trace_free_page(void) +int __ftrace_printk(unsigned long ip, const char *fmt, ...) { - struct trace_array_cpu *data; - struct page *page; - struct list_head *p; - int i; - int ret = 0; + int ret; + va_list ap; - /* free one page from each buffer */ - for_each_tracing_cpu(i) { - data = global_trace.data[i]; - p = data->trace_pages.next; - if (p == &data->trace_pages) { - /* should never happen */ - WARN_ON(1); - tracing_disabled = 1; - ret = -1; - break; - } - page = list_entry(p, struct page, lru); - ClearPageLRU(page); - list_del(&page->lru); - tracing_pages_allocated--; - tracing_pages_allocated--; - __free_page(page); + if (!(trace_flags & TRACE_ITER_PRINTK)) + return 0; - tracing_reset(data); + va_start(ap, fmt); + ret = trace_vprintk(ip, fmt, ap); + va_end(ap); + return ret; +} +EXPORT_SYMBOL_GPL(__ftrace_printk); -#ifdef CONFIG_TRACER_MAX_TRACE - data = max_tr.data[i]; - p = data->trace_pages.next; - if (p == &data->trace_pages) { - /* should never happen */ - WARN_ON(1); - tracing_disabled = 1; - ret = -1; - break; - } - page = list_entry(p, struct page, lru); - ClearPageLRU(page); - list_del(&page->lru); - __free_page(page); +static int trace_panic_handler(struct notifier_block *this, + unsigned long event, void *unused) +{ + ftrace_dump(); + return NOTIFY_OK; +} - tracing_reset(data); -#endif - } - global_trace.entries -= ENTRIES_PER_PAGE; +static struct notifier_block trace_panic_notifier = { + .notifier_call = trace_panic_handler, + .next = NULL, + .priority = 150 /* priority: INT_MAX >= x >= 0 */ +}; - return ret; +static int trace_die_handler(struct notifier_block *self, + unsigned long val, + void *data) +{ + switch (val) { + case DIE_OOPS: + ftrace_dump(); + break; + default: + break; + } + return NOTIFY_OK; } -__init static int tracer_alloc_buffers(void) +static struct notifier_block trace_die_notifier = { + .notifier_call = trace_die_handler, + .priority = 200 +}; + +/* + * printk is set to max of 1024, we really don't need it that big. + * Nothing should be printing 1000 characters anyway. + */ +#define TRACE_MAX_PRINT 1000 + +/* + * Define here KERN_TRACE so that we have one place to modify + * it if we decide to change what log level the ftrace dump + * should be at. + */ +#define KERN_TRACE KERN_INFO + +static void +trace_printk_seq(struct trace_seq *s) { - struct trace_array_cpu *data; - void *array; - struct page *page; - int pages = 0; - int ret = -ENOMEM; - int i; + /* Probably should print a warning here. */ + if (s->len >= 1000) + s->len = 1000; - /* TODO: make the number of buffers hot pluggable with CPUS */ - tracing_nr_buffers = num_possible_cpus(); - tracing_buffer_mask = cpu_possible_map; + /* should be zero ended, but we are paranoid. */ + s->buffer[s->len] = 0; - /* Allocate the first page for all buffers */ - for_each_tracing_cpu(i) { - data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); - max_tr.data[i] = &per_cpu(max_data, i); + printk(KERN_TRACE "%s", s->buffer); - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_buffers; - } + trace_seq_reset(s); +} + + +void ftrace_dump(void) +{ + static DEFINE_SPINLOCK(ftrace_dump_lock); + /* use static because iter can be a bit big for the stack */ + static struct trace_iterator iter; + static cpumask_t mask; + static int dump_ran; + unsigned long flags; + int cnt = 0, cpu; - /* set the array to the list */ - INIT_LIST_HEAD(&data->trace_pages); - page = virt_to_page(array); - list_add(&page->lru, &data->trace_pages); - /* use the LRU flag to differentiate the two buffers */ - ClearPageLRU(page); + /* only one dump */ + spin_lock_irqsave(&ftrace_dump_lock, flags); + if (dump_ran) + goto out; - data->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; - max_tr.data[i]->lock = (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + dump_ran = 1; -/* Only allocate if we are actually using the max trace */ -#ifdef CONFIG_TRACER_MAX_TRACE - array = (void *)__get_free_page(GFP_KERNEL); - if (array == NULL) { - printk(KERN_ERR "tracer: failed to allocate page" - "for trace buffer!\n"); - goto free_buffers; - } + /* No turning back! */ + ftrace_kill_atomic(); - INIT_LIST_HEAD(&max_tr.data[i]->trace_pages); - page = virt_to_page(array); - list_add(&page->lru, &max_tr.data[i]->trace_pages); - SetPageLRU(page); -#endif + for_each_tracing_cpu(cpu) { + atomic_inc(&global_trace.data[cpu]->disabled); } + printk(KERN_TRACE "Dumping ftrace buffer:\n"); + + iter.tr = &global_trace; + iter.trace = current_trace; + /* - * Since we allocate by orders of pages, we may be able to - * round up a bit. + * We need to stop all tracing on all CPUS to read the + * the next buffer. This is a bit expensive, but is + * not done often. We fill all what we can read, + * and then release the locks again. */ - global_trace.entries = ENTRIES_PER_PAGE; - pages++; - while (global_trace.entries < trace_nr_entries) { - if (trace_alloc_page()) - break; - pages++; + cpus_clear(mask); + + while (!trace_empty(&iter)) { + + if (!cnt) + printk(KERN_TRACE "---------------------------------\n"); + + cnt++; + + /* reset all but tr, trace, and overruns */ + memset(&iter.seq, 0, + sizeof(struct trace_iterator) - + offsetof(struct trace_iterator, seq)); + iter.iter_flags |= TRACE_FILE_LAT_FMT; + iter.pos = -1; + + if (find_next_entry_inc(&iter) != NULL) { + print_trace_line(&iter); + trace_consume(&iter); + } + + trace_printk_seq(&iter.seq); } - max_tr.entries = global_trace.entries; - pr_info("tracer: %d pages allocated for %ld entries of %ld bytes\n", - pages, trace_nr_entries, (long)TRACE_ENTRY_SIZE); - pr_info(" actual entries %ld\n", global_trace.entries); + if (!cnt) + printk(KERN_TRACE " (ftrace buffer empty)\n"); + else + printk(KERN_TRACE "---------------------------------\n"); + + out: + spin_unlock_irqrestore(&ftrace_dump_lock, flags); +} + +__init static int tracer_alloc_buffers(void) +{ + struct trace_array_cpu *data; + int i; + + /* TODO: make the number of buffers hot pluggable with CPUS */ + tracing_buffer_mask = cpu_possible_map; + + global_trace.buffer = ring_buffer_alloc(trace_buf_size, + TRACE_BUFFER_FLAGS); + if (!global_trace.buffer) { + printk(KERN_ERR "tracer: failed to allocate ring buffer!\n"); + WARN_ON(1); + return 0; + } + global_trace.entries = ring_buffer_size(global_trace.buffer); - tracer_init_debugfs(); +#ifdef CONFIG_TRACER_MAX_TRACE + max_tr.buffer = ring_buffer_alloc(trace_buf_size, + TRACE_BUFFER_FLAGS); + if (!max_tr.buffer) { + printk(KERN_ERR "tracer: failed to allocate max ring buffer!\n"); + WARN_ON(1); + ring_buffer_free(global_trace.buffer); + return 0; + } + max_tr.entries = ring_buffer_size(max_tr.buffer); + WARN_ON(max_tr.entries != global_trace.entries); +#endif + + /* Allocate the first page for all buffers */ + for_each_tracing_cpu(i) { + data = global_trace.data[i] = &per_cpu(global_trace_cpu, i); + max_tr.data[i] = &per_cpu(max_data, i); + } trace_init_cmdlines(); - register_tracer(&no_tracer); - current_trace = &no_tracer; + register_tracer(&nop_trace); +#ifdef CONFIG_BOOT_TRACER + register_tracer(&boot_tracer); + current_trace = &boot_tracer; + current_trace->init(&global_trace); +#else + current_trace = &nop_trace; +#endif /* All seems OK, enable tracing */ global_trace.ctrl = tracer_enabled; tracing_disabled = 0; - return 0; + atomic_notifier_chain_register(&panic_notifier_list, + &trace_panic_notifier); - free_buffers: - for (i-- ; i >= 0; i--) { - struct page *page, *tmp; - struct trace_array_cpu *data = global_trace.data[i]; + register_die_notifier(&trace_die_notifier); - if (data) { - list_for_each_entry_safe(page, tmp, - &data->trace_pages, lru) { - list_del_init(&page->lru); - __free_page(page); - } - } - -#ifdef CONFIG_TRACER_MAX_TRACE - data = max_tr.data[i]; - if (data) { - list_for_each_entry_safe(page, tmp, - &data->trace_pages, lru) { - list_del_init(&page->lru); - __free_page(page); - } - } -#endif - } - return ret; + return 0; } -fs_initcall(tracer_alloc_buffers); +early_initcall(tracer_alloc_buffers); +fs_initcall(tracer_init_debugfs); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index f69f86788c2b..f1f99572cde7 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -5,7 +5,9 @@ #include <asm/atomic.h> #include <linux/sched.h> #include <linux/clocksource.h> +#include <linux/ring_buffer.h> #include <linux/mmiotrace.h> +#include <linux/ftrace.h> enum trace_type { __TRACE_FIRST_TYPE = 0, @@ -13,38 +15,60 @@ enum trace_type { TRACE_FN, TRACE_CTX, TRACE_WAKE, + TRACE_CONT, TRACE_STACK, + TRACE_PRINT, TRACE_SPECIAL, TRACE_MMIO_RW, TRACE_MMIO_MAP, + TRACE_BOOT, __TRACE_LAST_TYPE }; /* + * The trace entry - the most basic unit of tracing. This is what + * is printed in the end as a single line in the trace output, such as: + * + * bash-15816 [01] 235.197585: idle_cpu <- irq_enter + */ +struct trace_entry { + unsigned char type; + unsigned char cpu; + unsigned char flags; + unsigned char preempt_count; + int pid; +}; + +/* * Function trace entry - function address and parent function addres: */ struct ftrace_entry { + struct trace_entry ent; unsigned long ip; unsigned long parent_ip; }; +extern struct tracer boot_tracer; /* * Context switch trace entry - which task (and prio) we switched from/to: */ struct ctx_switch_entry { + struct trace_entry ent; unsigned int prev_pid; unsigned char prev_prio; unsigned char prev_state; unsigned int next_pid; unsigned char next_prio; unsigned char next_state; + unsigned int next_cpu; }; /* * Special (free-form) trace entry: */ struct special_entry { + struct trace_entry ent; unsigned long arg1; unsigned long arg2; unsigned long arg3; @@ -57,33 +81,60 @@ struct special_entry { #define FTRACE_STACK_ENTRIES 8 struct stack_entry { + struct trace_entry ent; unsigned long caller[FTRACE_STACK_ENTRIES]; }; /* - * The trace entry - the most basic unit of tracing. This is what - * is printed in the end as a single line in the trace output, such as: - * - * bash-15816 [01] 235.197585: idle_cpu <- irq_enter + * ftrace_printk entry: */ -struct trace_entry { - char type; - char cpu; - char flags; - char preempt_count; - int pid; - cycle_t t; - union { - struct ftrace_entry fn; - struct ctx_switch_entry ctx; - struct special_entry special; - struct stack_entry stack; - struct mmiotrace_rw mmiorw; - struct mmiotrace_map mmiomap; - }; +struct print_entry { + struct trace_entry ent; + unsigned long ip; + char buf[]; +}; + +#define TRACE_OLD_SIZE 88 + +struct trace_field_cont { + unsigned char type; + /* Temporary till we get rid of this completely */ + char buf[TRACE_OLD_SIZE - 1]; +}; + +struct trace_mmiotrace_rw { + struct trace_entry ent; + struct mmiotrace_rw rw; }; -#define TRACE_ENTRY_SIZE sizeof(struct trace_entry) +struct trace_mmiotrace_map { + struct trace_entry ent; + struct mmiotrace_map map; +}; + +struct trace_boot { + struct trace_entry ent; + struct boot_trace initcall; +}; + +/* + * trace_flag_type is an enumeration that holds different + * states when a trace occurs. These are: + * IRQS_OFF - interrupts were disabled + * NEED_RESCED - reschedule is requested + * HARDIRQ - inside an interrupt handler + * SOFTIRQ - inside a softirq handler + * CONT - multiple entries hold the trace item + */ +enum trace_flag_type { + TRACE_FLAG_IRQS_OFF = 0x01, + TRACE_FLAG_NEED_RESCHED = 0x02, + TRACE_FLAG_HARDIRQ = 0x04, + TRACE_FLAG_SOFTIRQ = 0x08, + TRACE_FLAG_CONT = 0x10, +}; + +#define TRACE_BUF_SIZE 1024 /* * The CPU trace array - it consists of thousands of trace entries @@ -91,16 +142,9 @@ struct trace_entry { * the trace, etc.) */ struct trace_array_cpu { - struct list_head trace_pages; atomic_t disabled; - raw_spinlock_t lock; - struct lock_class_key lock_key; /* these fields get copied into max-trace: */ - unsigned trace_head_idx; - unsigned trace_tail_idx; - void *trace_head; /* producer */ - void *trace_tail; /* consumer */ unsigned long trace_idx; unsigned long overrun; unsigned long saved_latency; @@ -124,6 +168,7 @@ struct trace_iterator; * They have on/off state as well: */ struct trace_array { + struct ring_buffer *buffer; unsigned long entries; long ctrl; int cpu; @@ -132,6 +177,56 @@ struct trace_array { struct trace_array_cpu *data[NR_CPUS]; }; +#define FTRACE_CMP_TYPE(var, type) \ + __builtin_types_compatible_p(typeof(var), type *) + +#undef IF_ASSIGN +#define IF_ASSIGN(var, entry, etype, id) \ + if (FTRACE_CMP_TYPE(var, etype)) { \ + var = (typeof(var))(entry); \ + WARN_ON(id && (entry)->type != id); \ + break; \ + } + +/* Will cause compile errors if type is not found. */ +extern void __ftrace_bad_type(void); + +/* + * The trace_assign_type is a verifier that the entry type is + * the same as the type being assigned. To add new types simply + * add a line with the following format: + * + * IF_ASSIGN(var, ent, type, id); + * + * Where "type" is the trace type that includes the trace_entry + * as the "ent" item. And "id" is the trace identifier that is + * used in the trace_type enum. + * + * If the type can have more than one id, then use zero. + */ +#define trace_assign_type(var, ent) \ + do { \ + IF_ASSIGN(var, ent, struct ftrace_entry, TRACE_FN); \ + IF_ASSIGN(var, ent, struct ctx_switch_entry, 0); \ + IF_ASSIGN(var, ent, struct trace_field_cont, TRACE_CONT); \ + IF_ASSIGN(var, ent, struct stack_entry, TRACE_STACK); \ + IF_ASSIGN(var, ent, struct print_entry, TRACE_PRINT); \ + IF_ASSIGN(var, ent, struct special_entry, 0); \ + IF_ASSIGN(var, ent, struct trace_mmiotrace_rw, \ + TRACE_MMIO_RW); \ + IF_ASSIGN(var, ent, struct trace_mmiotrace_map, \ + TRACE_MMIO_MAP); \ + IF_ASSIGN(var, ent, struct trace_boot, TRACE_BOOT); \ + __ftrace_bad_type(); \ + } while (0) + +/* Return values for print_line callback */ +enum print_line_t { + TRACE_TYPE_PARTIAL_LINE = 0, /* Retry after flushing the seq */ + TRACE_TYPE_HANDLED = 1, + TRACE_TYPE_UNHANDLED = 2 /* Relay to other output functions */ +}; + /* * A specific tracer, represented by methods that operate on a trace array: */ @@ -152,7 +247,7 @@ struct tracer { int (*selftest)(struct tracer *trace, struct trace_array *tr); #endif - int (*print_line)(struct trace_iterator *iter); + enum print_line_t (*print_line)(struct trace_iterator *iter); struct tracer *next; int print_max; }; @@ -171,57 +266,58 @@ struct trace_iterator { struct trace_array *tr; struct tracer *trace; void *private; - long last_overrun[NR_CPUS]; - long overrun[NR_CPUS]; + struct ring_buffer_iter *buffer_iter[NR_CPUS]; /* The below is zeroed out in pipe_read */ struct trace_seq seq; struct trace_entry *ent; int cpu; - - struct trace_entry *prev_ent; - int prev_cpu; + u64 ts; unsigned long iter_flags; loff_t pos; - unsigned long next_idx[NR_CPUS]; - struct list_head *next_page[NR_CPUS]; - unsigned next_page_idx[NR_CPUS]; long idx; }; -void tracing_reset(struct trace_array_cpu *data); +void trace_wake_up(void); +void tracing_reset(struct trace_array *tr, int cpu); int tracing_open_generic(struct inode *inode, struct file *filp); struct dentry *tracing_init_dentry(void); void init_tracer_sysprof_debugfs(struct dentry *d_tracer); +struct trace_entry *tracing_get_trace_entry(struct trace_array *tr, + struct trace_array_cpu *data); +void tracing_generic_entry_update(struct trace_entry *entry, + unsigned long flags, + int pc); + void ftrace(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, - unsigned long flags); + unsigned long flags, int pc); void tracing_sched_switch_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *prev, struct task_struct *next, - unsigned long flags); + unsigned long flags, int pc); void tracing_record_cmdline(struct task_struct *tsk); void tracing_sched_wakeup_trace(struct trace_array *tr, struct trace_array_cpu *data, struct task_struct *wakee, struct task_struct *cur, - unsigned long flags); + unsigned long flags, int pc); void trace_special(struct trace_array *tr, struct trace_array_cpu *data, unsigned long arg1, unsigned long arg2, - unsigned long arg3); + unsigned long arg3, int pc); void trace_function(struct trace_array *tr, struct trace_array_cpu *data, unsigned long ip, unsigned long parent_ip, - unsigned long flags); + unsigned long flags, int pc); void tracing_start_cmdline_record(void); void tracing_stop_cmdline_record(void); @@ -268,51 +364,33 @@ extern unsigned long ftrace_update_tot_cnt; extern int DYN_FTRACE_TEST_NAME(void); #endif -#ifdef CONFIG_MMIOTRACE -extern void __trace_mmiotrace_rw(struct trace_array *tr, - struct trace_array_cpu *data, - struct mmiotrace_rw *rw); -extern void __trace_mmiotrace_map(struct trace_array *tr, - struct trace_array_cpu *data, - struct mmiotrace_map *map); -#endif - #ifdef CONFIG_FTRACE_STARTUP_TEST -#ifdef CONFIG_FTRACE extern int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_IRQSOFF_TRACER extern int trace_selftest_startup_irqsoff(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_PREEMPT_TRACER extern int trace_selftest_startup_preemptoff(struct tracer *trace, struct trace_array *tr); -#endif -#if defined(CONFIG_IRQSOFF_TRACER) && defined(CONFIG_PREEMPT_TRACER) extern int trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_SCHED_TRACER extern int trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_CONTEXT_SWITCH_TRACER +extern int trace_selftest_startup_nop(struct tracer *trace, + struct trace_array *tr); extern int trace_selftest_startup_sched_switch(struct tracer *trace, struct trace_array *tr); -#endif -#ifdef CONFIG_SYSPROF_TRACER extern int trace_selftest_startup_sysprof(struct tracer *trace, struct trace_array *tr); -#endif #endif /* CONFIG_FTRACE_STARTUP_TEST */ extern void *head_page(struct trace_array_cpu *data); extern int trace_seq_printf(struct trace_seq *s, const char *fmt, ...); +extern void trace_seq_print_cont(struct trace_seq *s, + struct trace_iterator *iter); extern ssize_t trace_seq_to_user(struct trace_seq *s, char __user *ubuf, size_t cnt); extern long ns2usecs(cycle_t nsec); +extern int trace_vprintk(unsigned long ip, const char *fmt, va_list args); extern unsigned long trace_flags; @@ -334,6 +412,9 @@ enum trace_iterator_flags { TRACE_ITER_BLOCK = 0x80, TRACE_ITER_STACKTRACE = 0x100, TRACE_ITER_SCHED_TREE = 0x200, + TRACE_ITER_PRINTK = 0x400, }; +extern struct tracer nop_trace; + #endif /* _LINUX_KERNEL_TRACE_H */ diff --git a/kernel/trace/trace_boot.c b/kernel/trace/trace_boot.c new file mode 100644 index 000000000000..d0a5e50eeff2 --- /dev/null +++ b/kernel/trace/trace_boot.c @@ -0,0 +1,126 @@ +/* + * ring buffer based initcalls tracer + * + * Copyright (C) 2008 Frederic Weisbecker <fweisbec@gmail.com> + * + */ + +#include <linux/init.h> +#include <linux/debugfs.h> +#include <linux/ftrace.h> +#include <linux/kallsyms.h> + +#include "trace.h" + +static struct trace_array *boot_trace; +static int trace_boot_enabled; + + +/* Should be started after do_pre_smp_initcalls() in init/main.c */ +void start_boot_trace(void) +{ + trace_boot_enabled = 1; +} + +void stop_boot_trace(void) +{ + trace_boot_enabled = 0; +} + +void reset_boot_trace(struct trace_array *tr) +{ + stop_boot_trace(); +} + +static void boot_trace_init(struct trace_array *tr) +{ + int cpu; + boot_trace = tr; + + trace_boot_enabled = 0; + + for_each_cpu_mask(cpu, cpu_possible_map) + tracing_reset(tr, cpu); +} + +static void boot_trace_ctrl_update(struct trace_array *tr) +{ + if (tr->ctrl) + start_boot_trace(); + else + stop_boot_trace(); +} + +static enum print_line_t initcall_print_line(struct trace_iterator *iter) +{ + int ret; + struct trace_entry *entry = iter->ent; + struct trace_boot *field = (struct trace_boot *)entry; + struct boot_trace *it = &field->initcall; + struct trace_seq *s = &iter->seq; + struct timespec calltime = ktime_to_timespec(it->calltime); + struct timespec rettime = ktime_to_timespec(it->rettime); + + if (entry->type == TRACE_BOOT) { + ret = trace_seq_printf(s, "[%5ld.%09ld] calling %s @ %i\n", + calltime.tv_sec, + calltime.tv_nsec, + it->func, it->caller); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + ret = trace_seq_printf(s, "[%5ld.%09ld] initcall %s " + "returned %d after %lld msecs\n", + rettime.tv_sec, + rettime.tv_nsec, + it->func, it->result, it->duration); + + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + return TRACE_TYPE_HANDLED; + } + return TRACE_TYPE_UNHANDLED; +} + +struct tracer boot_tracer __read_mostly = +{ + .name = "initcall", + .init = boot_trace_init, + .reset = reset_boot_trace, + .ctrl_update = boot_trace_ctrl_update, + .print_line = initcall_print_line, +}; + +void trace_boot(struct boot_trace *it, initcall_t fn) +{ + struct ring_buffer_event *event; + struct trace_boot *entry; + struct trace_array_cpu *data; + unsigned long irq_flags; + struct trace_array *tr = boot_trace; + + if (!trace_boot_enabled) + return; + + /* Get its name now since this function could + * disappear because it is in the .init section. + */ + sprint_symbol(it->func, (unsigned long)fn); + preempt_disable(); + data = tr->data[smp_processor_id()]; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + goto out; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, 0); + entry->ent.type = TRACE_BOOT; + entry->initcall = *it; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + trace_wake_up(); + + out: + preempt_enable(); +} diff --git a/kernel/trace/trace_functions.c b/kernel/trace/trace_functions.c index 312144897970..e90eb0c2c56c 100644 --- a/kernel/trace/trace_functions.c +++ b/kernel/trace/trace_functions.c @@ -23,7 +23,7 @@ static void function_reset(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void start_function_trace(struct trace_array *tr) diff --git a/kernel/trace/trace_irqsoff.c b/kernel/trace/trace_irqsoff.c index ece6cfb649fa..a7db7f040ae0 100644 --- a/kernel/trace/trace_irqsoff.c +++ b/kernel/trace/trace_irqsoff.c @@ -95,7 +95,7 @@ irqsoff_tracer_call(unsigned long ip, unsigned long parent_ip) disabled = atomic_inc_return(&data->disabled); if (likely(disabled == 1)) - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, preempt_count()); atomic_dec(&data->disabled); } @@ -130,6 +130,7 @@ check_critical_timing(struct trace_array *tr, unsigned long latency, t0, t1; cycle_t T0, T1, delta; unsigned long flags; + int pc; /* * usecs conversion is slow so we try to delay the conversion @@ -141,6 +142,8 @@ check_critical_timing(struct trace_array *tr, local_save_flags(flags); + pc = preempt_count(); + if (!report_latency(delta)) goto out; @@ -150,7 +153,7 @@ check_critical_timing(struct trace_array *tr, if (!report_latency(delta)) goto out_unlock; - trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); + trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc); latency = nsecs_to_usecs(delta); @@ -173,8 +176,8 @@ out_unlock: out: data->critical_sequence = max_sequence; data->preempt_timestamp = ftrace_now(cpu); - tracing_reset(data); - trace_function(tr, data, CALLER_ADDR0, parent_ip, flags); + tracing_reset(tr, cpu); + trace_function(tr, data, CALLER_ADDR0, parent_ip, flags, pc); } static inline void @@ -203,11 +206,11 @@ start_critical_timing(unsigned long ip, unsigned long parent_ip) data->critical_sequence = max_sequence; data->preempt_timestamp = ftrace_now(cpu); data->critical_start = parent_ip ? : ip; - tracing_reset(data); + tracing_reset(tr, cpu); local_save_flags(flags); - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, preempt_count()); per_cpu(tracing_cpu, cpu) = 1; @@ -234,14 +237,14 @@ stop_critical_timing(unsigned long ip, unsigned long parent_ip) data = tr->data[cpu]; - if (unlikely(!data) || unlikely(!head_page(data)) || + if (unlikely(!data) || !data->critical_start || atomic_read(&data->disabled)) return; atomic_inc(&data->disabled); local_save_flags(flags); - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, preempt_count()); check_critical_timing(tr, data, parent_ip ? : ip, cpu); data->critical_start = 0; atomic_dec(&data->disabled); diff --git a/kernel/trace/trace_mmiotrace.c b/kernel/trace/trace_mmiotrace.c index b13dc19dcbb4..f28484618ff0 100644 --- a/kernel/trace/trace_mmiotrace.c +++ b/kernel/trace/trace_mmiotrace.c @@ -27,7 +27,7 @@ static void mmio_reset_data(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void mmio_trace_init(struct trace_array *tr) @@ -130,10 +130,14 @@ static unsigned long count_overruns(struct trace_iterator *iter) { int cpu; unsigned long cnt = 0; +/* FIXME: */ +#if 0 for_each_online_cpu(cpu) { cnt += iter->overrun[cpu]; iter->overrun[cpu] = 0; } +#endif + (void)cpu; return cnt; } @@ -171,17 +175,21 @@ print_out: return (ret == -EBUSY) ? 0 : ret; } -static int mmio_print_rw(struct trace_iterator *iter) +static enum print_line_t mmio_print_rw(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_rw *rw = &entry->mmiorw; + struct trace_mmiotrace_rw *field; + struct mmiotrace_rw *rw; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->t); + unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; int ret = 1; - switch (entry->mmiorw.opcode) { + trace_assign_type(field, entry); + rw = &field->rw; + + switch (rw->opcode) { case MMIO_READ: ret = trace_seq_printf(s, "R %d %lu.%06lu %d 0x%llx 0x%lx 0x%lx %d\n", @@ -209,21 +217,25 @@ static int mmio_print_rw(struct trace_iterator *iter) break; } if (ret) - return 1; - return 0; + return TRACE_TYPE_HANDLED; + return TRACE_TYPE_PARTIAL_LINE; } -static int mmio_print_map(struct trace_iterator *iter) +static enum print_line_t mmio_print_map(struct trace_iterator *iter) { struct trace_entry *entry = iter->ent; - struct mmiotrace_map *m = &entry->mmiomap; + struct trace_mmiotrace_map *field; + struct mmiotrace_map *m; struct trace_seq *s = &iter->seq; - unsigned long long t = ns2usecs(entry->t); + unsigned long long t = ns2usecs(iter->ts); unsigned long usec_rem = do_div(t, 1000000ULL); unsigned secs = (unsigned long)t; - int ret = 1; + int ret; - switch (entry->mmiorw.opcode) { + trace_assign_type(field, entry); + m = &field->map; + + switch (m->opcode) { case MMIO_PROBE: ret = trace_seq_printf(s, "MAP %lu.%06lu %d 0x%llx 0x%lx 0x%lx 0x%lx %d\n", @@ -241,20 +253,43 @@ static int mmio_print_map(struct trace_iterator *iter) break; } if (ret) - return 1; - return 0; + return TRACE_TYPE_HANDLED; + return TRACE_TYPE_PARTIAL_LINE; +} + +static enum print_line_t mmio_print_mark(struct trace_iterator *iter) +{ + struct trace_entry *entry = iter->ent; + struct print_entry *print = (struct print_entry *)entry; + const char *msg = print->buf; + struct trace_seq *s = &iter->seq; + unsigned long long t = ns2usecs(iter->ts); + unsigned long usec_rem = do_div(t, 1000000ULL); + unsigned secs = (unsigned long)t; + int ret; + + /* The trailing newline must be in the message. */ + ret = trace_seq_printf(s, "MARK %lu.%06lu %s", secs, usec_rem, msg); + if (!ret) + return TRACE_TYPE_PARTIAL_LINE; + + if (entry->flags & TRACE_FLAG_CONT) + trace_seq_print_cont(s, iter); + + return TRACE_TYPE_HANDLED; } -/* return 0 to abort printing without consuming current entry in pipe mode */ -static int mmio_print_line(struct trace_iterator *iter) +static enum print_line_t mmio_print_line(struct trace_iterator *iter) { switch (iter->ent->type) { case TRACE_MMIO_RW: return mmio_print_rw(iter); case TRACE_MMIO_MAP: return mmio_print_map(iter); + case TRACE_PRINT: + return mmio_print_mark(iter); default: - return 1; /* ignore unknown entries */ + return TRACE_TYPE_HANDLED; /* ignore unknown entries */ } } @@ -276,6 +311,27 @@ __init static int init_mmio_trace(void) } device_initcall(init_mmio_trace); +static void __trace_mmiotrace_rw(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_rw *rw) +{ + struct ring_buffer_event *event; + struct trace_mmiotrace_rw *entry; + unsigned long irq_flags; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, preempt_count()); + entry->ent.type = TRACE_MMIO_RW; + entry->rw = *rw; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + trace_wake_up(); +} + void mmio_trace_rw(struct mmiotrace_rw *rw) { struct trace_array *tr = mmio_trace_array; @@ -283,6 +339,27 @@ void mmio_trace_rw(struct mmiotrace_rw *rw) __trace_mmiotrace_rw(tr, data, rw); } +static void __trace_mmiotrace_map(struct trace_array *tr, + struct trace_array_cpu *data, + struct mmiotrace_map *map) +{ + struct ring_buffer_event *event; + struct trace_mmiotrace_map *entry; + unsigned long irq_flags; + + event = ring_buffer_lock_reserve(tr->buffer, sizeof(*entry), + &irq_flags); + if (!event) + return; + entry = ring_buffer_event_data(event); + tracing_generic_entry_update(&entry->ent, 0, preempt_count()); + entry->ent.type = TRACE_MMIO_MAP; + entry->map = *map; + ring_buffer_unlock_commit(tr->buffer, event, irq_flags); + + trace_wake_up(); +} + void mmio_trace_mapping(struct mmiotrace_map *map) { struct trace_array *tr = mmio_trace_array; @@ -293,3 +370,8 @@ void mmio_trace_mapping(struct mmiotrace_map *map) __trace_mmiotrace_map(tr, data, map); preempt_enable(); } + +int mmio_trace_printk(const char *fmt, va_list args) +{ + return trace_vprintk(0, fmt, args); +} diff --git a/kernel/trace/trace_nop.c b/kernel/trace/trace_nop.c new file mode 100644 index 000000000000..4592b4862515 --- /dev/null +++ b/kernel/trace/trace_nop.c @@ -0,0 +1,64 @@ +/* + * nop tracer + * + * Copyright (C) 2008 Steven Noonan <steven@uplinklabs.net> + * + */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <linux/debugfs.h> +#include <linux/ftrace.h> + +#include "trace.h" + +static struct trace_array *ctx_trace; + +static void start_nop_trace(struct trace_array *tr) +{ + /* Nothing to do! */ +} + +static void stop_nop_trace(struct trace_array *tr) +{ + /* Nothing to do! */ +} + +static void nop_trace_init(struct trace_array *tr) +{ + int cpu; + ctx_trace = tr; + + for_each_online_cpu(cpu) + tracing_reset(tr, cpu); + + if (tr->ctrl) + start_nop_trace(tr); +} + +static void nop_trace_reset(struct trace_array *tr) +{ + if (tr->ctrl) + stop_nop_trace(tr); +} + +static void nop_trace_ctrl_update(struct trace_array *tr) +{ + /* When starting a new trace, reset the buffers */ + if (tr->ctrl) + start_nop_trace(tr); + else + stop_nop_trace(tr); +} + +struct tracer nop_trace __read_mostly = +{ + .name = "nop", + .init = nop_trace_init, + .reset = nop_trace_reset, + .ctrl_update = nop_trace_ctrl_update, +#ifdef CONFIG_FTRACE_SELFTEST + .selftest = trace_selftest_startup_nop, +#endif +}; + diff --git a/kernel/trace/trace_sched_switch.c b/kernel/trace/trace_sched_switch.c index cb817a209aa0..b8f56beb1a62 100644 --- a/kernel/trace/trace_sched_switch.c +++ b/kernel/trace/trace_sched_switch.c @@ -9,8 +9,8 @@ #include <linux/debugfs.h> #include <linux/kallsyms.h> #include <linux/uaccess.h> -#include <linux/marker.h> #include <linux/ftrace.h> +#include <trace/sched.h> #include "trace.h" @@ -19,15 +19,16 @@ static int __read_mostly tracer_enabled; static atomic_t sched_ref; static void -sched_switch_func(void *private, void *__rq, struct task_struct *prev, +probe_sched_switch(struct rq *__rq, struct task_struct *prev, struct task_struct *next) { - struct trace_array **ptr = private; - struct trace_array *tr = *ptr; struct trace_array_cpu *data; unsigned long flags; - long disabled; int cpu; + int pc; + + if (!atomic_read(&sched_ref)) + return; tracing_record_cmdline(prev); tracing_record_cmdline(next); @@ -35,97 +36,41 @@ sched_switch_func(void *private, void *__rq, struct task_struct *prev, if (!tracer_enabled) return; + pc = preempt_count(); local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); + data = ctx_trace->data[cpu]; - if (likely(disabled == 1)) - tracing_sched_switch_trace(tr, data, prev, next, flags); + if (likely(!atomic_read(&data->disabled))) + tracing_sched_switch_trace(ctx_trace, data, prev, next, flags, pc); - atomic_dec(&data->disabled); local_irq_restore(flags); } -static notrace void -sched_switch_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct task_struct *prev; - struct task_struct *next; - struct rq *__rq; - - if (!atomic_read(&sched_ref)) - return; - - /* skip prev_pid %d next_pid %d prev_state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, int); - (void)va_arg(*args, long); - __rq = va_arg(*args, typeof(__rq)); - prev = va_arg(*args, typeof(prev)); - next = va_arg(*args, typeof(next)); - - /* - * If tracer_switch_func only points to the local - * switch func, it still needs the ptr passed to it. - */ - sched_switch_func(probe_data, __rq, prev, next); -} - static void -wakeup_func(void *private, void *__rq, struct task_struct *wakee, struct - task_struct *curr) +probe_sched_wakeup(struct rq *__rq, struct task_struct *wakee) { - struct trace_array **ptr = private; - struct trace_array *tr = *ptr; struct trace_array_cpu *data; unsigned long flags; - long disabled; - int cpu; + int cpu, pc; - if (!tracer_enabled) + if (!likely(tracer_enabled)) return; - tracing_record_cmdline(curr); + pc = preempt_count(); + tracing_record_cmdline(current); local_irq_save(flags); cpu = raw_smp_processor_id(); - data = tr->data[cpu]; - disabled = atomic_inc_return(&data->disabled); + data = ctx_trace->data[cpu]; - if (likely(disabled == 1)) - tracing_sched_wakeup_trace(tr, data, wakee, curr, flags); + if (likely(!atomic_read(&data->disabled))) + tracing_sched_wakeup_trace(ctx_trace, data, wakee, current, + flags, pc); - atomic_dec(&data->disabled); local_irq_restore(flags); } -static notrace void -wake_up_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct task_struct *curr; - struct task_struct *task; - struct rq *__rq; - - if (likely(!tracer_enabled)) - return; - - /* Skip pid %d state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, long); - /* now get the meat: "rq %p task %p rq->curr %p" */ - __rq = va_arg(*args, typeof(__rq)); - task = va_arg(*args, typeof(task)); - curr = va_arg(*args, typeof(curr)); - - tracing_record_cmdline(task); - tracing_record_cmdline(curr); - - wakeup_func(probe_data, __rq, task, curr); -} - static void sched_switch_reset(struct trace_array *tr) { int cpu; @@ -133,67 +78,47 @@ static void sched_switch_reset(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static int tracing_sched_register(void) { int ret; - ret = marker_probe_register("kernel_sched_wakeup", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &ctx_trace); + ret = register_trace_sched_wakeup(probe_sched_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup\n"); return ret; } - ret = marker_probe_register("kernel_sched_wakeup_new", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &ctx_trace); + ret = register_trace_sched_wakeup_new(probe_sched_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup_new\n"); goto fail_deprobe; } - ret = marker_probe_register("kernel_sched_schedule", - "prev_pid %d next_pid %d prev_state %ld " - "## rq %p prev %p next %p", - sched_switch_callback, - &ctx_trace); + ret = register_trace_sched_switch(probe_sched_switch); if (ret) { - pr_info("sched trace: Couldn't add marker" + pr_info("sched trace: Couldn't activate tracepoint" " probe to kernel_sched_schedule\n"); goto fail_deprobe_wake_new; } return ret; fail_deprobe_wake_new: - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &ctx_trace); + unregister_trace_sched_wakeup_new(probe_sched_wakeup); fail_deprobe: - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &ctx_trace); + unregister_trace_sched_wakeup(probe_sched_wakeup); return ret; } static void tracing_sched_unregister(void) { - marker_probe_unregister("kernel_sched_schedule", - sched_switch_callback, - &ctx_trace); - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &ctx_trace); - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &ctx_trace); + unregister_trace_sched_switch(probe_sched_switch); + unregister_trace_sched_wakeup_new(probe_sched_wakeup); + unregister_trace_sched_wakeup(probe_sched_wakeup); } static void tracing_start_sched_switch(void) diff --git a/kernel/trace/trace_sched_wakeup.c b/kernel/trace/trace_sched_wakeup.c index e303ccb62cdf..fe4a252c2363 100644 --- a/kernel/trace/trace_sched_wakeup.c +++ b/kernel/trace/trace_sched_wakeup.c @@ -15,7 +15,7 @@ #include <linux/kallsyms.h> #include <linux/uaccess.h> #include <linux/ftrace.h> -#include <linux/marker.h> +#include <trace/sched.h> #include "trace.h" @@ -44,10 +44,12 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) long disabled; int resched; int cpu; + int pc; if (likely(!wakeup_task)) return; + pc = preempt_count(); resched = need_resched(); preempt_disable_notrace(); @@ -70,7 +72,7 @@ wakeup_tracer_call(unsigned long ip, unsigned long parent_ip) if (task_cpu(wakeup_task) != cpu) goto unlock; - trace_function(tr, data, ip, parent_ip, flags); + trace_function(tr, data, ip, parent_ip, flags, pc); unlock: __raw_spin_unlock(&wakeup_lock); @@ -112,17 +114,18 @@ static int report_latency(cycle_t delta) } static void notrace -wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, +probe_wakeup_sched_switch(struct rq *rq, struct task_struct *prev, struct task_struct *next) { unsigned long latency = 0, t0 = 0, t1 = 0; - struct trace_array **ptr = private; - struct trace_array *tr = *ptr; struct trace_array_cpu *data; cycle_t T0, T1, delta; unsigned long flags; long disabled; int cpu; + int pc; + + tracing_record_cmdline(prev); if (unlikely(!tracer_enabled)) return; @@ -139,12 +142,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, if (next != wakeup_task) return; + pc = preempt_count(); + /* The task we are waiting for is waking up */ - data = tr->data[wakeup_cpu]; + data = wakeup_trace->data[wakeup_cpu]; /* disable local data, not wakeup_cpu data */ cpu = raw_smp_processor_id(); - disabled = atomic_inc_return(&tr->data[cpu]->disabled); + disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); if (likely(disabled != 1)) goto out; @@ -155,7 +160,7 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, if (unlikely(!tracer_enabled || next != wakeup_task)) goto out_unlock; - trace_function(tr, data, CALLER_ADDR1, CALLER_ADDR2, flags); + trace_function(wakeup_trace, data, CALLER_ADDR1, CALLER_ADDR2, flags, pc); /* * usecs conversion is slow so we try to delay the conversion @@ -174,39 +179,14 @@ wakeup_sched_switch(void *private, void *rq, struct task_struct *prev, t0 = nsecs_to_usecs(T0); t1 = nsecs_to_usecs(T1); - update_max_tr(tr, wakeup_task, wakeup_cpu); + update_max_tr(wakeup_trace, wakeup_task, wakeup_cpu); out_unlock: - __wakeup_reset(tr); + __wakeup_reset(wakeup_trace); __raw_spin_unlock(&wakeup_lock); local_irq_restore(flags); out: - atomic_dec(&tr->data[cpu]->disabled); -} - -static notrace void -sched_switch_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct task_struct *prev; - struct task_struct *next; - struct rq *__rq; - - /* skip prev_pid %d next_pid %d prev_state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, int); - (void)va_arg(*args, long); - __rq = va_arg(*args, typeof(__rq)); - prev = va_arg(*args, typeof(prev)); - next = va_arg(*args, typeof(next)); - - tracing_record_cmdline(prev); - - /* - * If tracer_switch_func only points to the local - * switch func, it still needs the ptr passed to it. - */ - wakeup_sched_switch(probe_data, __rq, prev, next); + atomic_dec(&wakeup_trace->data[cpu]->disabled); } static void __wakeup_reset(struct trace_array *tr) @@ -216,7 +196,7 @@ static void __wakeup_reset(struct trace_array *tr) for_each_possible_cpu(cpu) { data = tr->data[cpu]; - tracing_reset(data); + tracing_reset(tr, cpu); } wakeup_cpu = -1; @@ -240,19 +220,26 @@ static void wakeup_reset(struct trace_array *tr) } static void -wakeup_check_start(struct trace_array *tr, struct task_struct *p, - struct task_struct *curr) +probe_wakeup(struct rq *rq, struct task_struct *p) { int cpu = smp_processor_id(); unsigned long flags; long disabled; + int pc; + + if (likely(!tracer_enabled)) + return; + + tracing_record_cmdline(p); + tracing_record_cmdline(current); if (likely(!rt_task(p)) || p->prio >= wakeup_prio || - p->prio >= curr->prio) + p->prio >= current->prio) return; - disabled = atomic_inc_return(&tr->data[cpu]->disabled); + pc = preempt_count(); + disabled = atomic_inc_return(&wakeup_trace->data[cpu]->disabled); if (unlikely(disabled != 1)) goto out; @@ -264,7 +251,7 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p, goto out_locked; /* reset the trace */ - __wakeup_reset(tr); + __wakeup_reset(wakeup_trace); wakeup_cpu = task_cpu(p); wakeup_prio = p->prio; @@ -274,74 +261,37 @@ wakeup_check_start(struct trace_array *tr, struct task_struct *p, local_save_flags(flags); - tr->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); - trace_function(tr, tr->data[wakeup_cpu], - CALLER_ADDR1, CALLER_ADDR2, flags); + wakeup_trace->data[wakeup_cpu]->preempt_timestamp = ftrace_now(cpu); + trace_function(wakeup_trace, wakeup_trace->data[wakeup_cpu], + CALLER_ADDR1, CALLER_ADDR2, flags, pc); out_locked: __raw_spin_unlock(&wakeup_lock); out: - atomic_dec(&tr->data[cpu]->disabled); -} - -static notrace void -wake_up_callback(void *probe_data, void *call_data, - const char *format, va_list *args) -{ - struct trace_array **ptr = probe_data; - struct trace_array *tr = *ptr; - struct task_struct *curr; - struct task_struct *task; - struct rq *__rq; - - if (likely(!tracer_enabled)) - return; - - /* Skip pid %d state %ld */ - (void)va_arg(*args, int); - (void)va_arg(*args, long); - /* now get the meat: "rq %p task %p rq->curr %p" */ - __rq = va_arg(*args, typeof(__rq)); - task = va_arg(*args, typeof(task)); - curr = va_arg(*args, typeof(curr)); - - tracing_record_cmdline(task); - tracing_record_cmdline(curr); - - wakeup_check_start(tr, task, curr); + atomic_dec(&wakeup_trace->data[cpu]->disabled); } static void start_wakeup_tracer(struct trace_array *tr) { int ret; - ret = marker_probe_register("kernel_sched_wakeup", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &wakeup_trace); + ret = register_trace_sched_wakeup(probe_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup\n"); return; } - ret = marker_probe_register("kernel_sched_wakeup_new", - "pid %d state %ld ## rq %p task %p rq->curr %p", - wake_up_callback, - &wakeup_trace); + ret = register_trace_sched_wakeup_new(probe_wakeup); if (ret) { - pr_info("wakeup trace: Couldn't add marker" + pr_info("wakeup trace: Couldn't activate tracepoint" " probe to kernel_sched_wakeup_new\n"); goto fail_deprobe; } - ret = marker_probe_register("kernel_sched_schedule", - "prev_pid %d next_pid %d prev_state %ld " - "## rq %p prev %p next %p", - sched_switch_callback, - &wakeup_trace); + ret = register_trace_sched_switch(probe_wakeup_sched_switch); if (ret) { - pr_info("sched trace: Couldn't add marker" + pr_info("sched trace: Couldn't activate tracepoint" " probe to kernel_sched_schedule\n"); goto fail_deprobe_wake_new; } @@ -363,28 +313,18 @@ static void start_wakeup_tracer(struct trace_array *tr) return; fail_deprobe_wake_new: - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &wakeup_trace); + unregister_trace_sched_wakeup_new(probe_wakeup); fail_deprobe: - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &wakeup_trace); + unregister_trace_sched_wakeup(probe_wakeup); } static void stop_wakeup_tracer(struct trace_array *tr) { tracer_enabled = 0; unregister_ftrace_function(&trace_ops); - marker_probe_unregister("kernel_sched_schedule", - sched_switch_callback, - &wakeup_trace); - marker_probe_unregister("kernel_sched_wakeup_new", - wake_up_callback, - &wakeup_trace); - marker_probe_unregister("kernel_sched_wakeup", - wake_up_callback, - &wakeup_trace); + unregister_trace_sched_switch(probe_wakeup_sched_switch); + unregister_trace_sched_wakeup_new(probe_wakeup); + unregister_trace_sched_wakeup(probe_wakeup); } static void wakeup_tracer_init(struct trace_array *tr) diff --git a/kernel/trace/trace_selftest.c b/kernel/trace/trace_selftest.c index 0911b7e073bf..09cf230d7eca 100644 --- a/kernel/trace/trace_selftest.c +++ b/kernel/trace/trace_selftest.c @@ -9,65 +9,29 @@ static inline int trace_valid_entry(struct trace_entry *entry) case TRACE_FN: case TRACE_CTX: case TRACE_WAKE: + case TRACE_CONT: case TRACE_STACK: + case TRACE_PRINT: case TRACE_SPECIAL: return 1; } return 0; } -static int -trace_test_buffer_cpu(struct trace_array *tr, struct trace_array_cpu *data) +static int trace_test_buffer_cpu(struct trace_array *tr, int cpu) { - struct trace_entry *entries; - struct page *page; - int idx = 0; - int i; + struct ring_buffer_event *event; + struct trace_entry *entry; - BUG_ON(list_empty(&data->trace_pages)); - page = list_entry(data->trace_pages.next, struct page, lru); - entries = page_address(page); + while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) { + entry = ring_buffer_event_data(event); - check_pages(data); - if (head_page(data) != entries) - goto failed; - - /* - * The starting trace buffer always has valid elements, - * if any element exists. - */ - entries = head_page(data); - - for (i = 0; i < tr->entries; i++) { - - if (i < data->trace_idx && !trace_valid_entry(&entries[idx])) { + if (!trace_valid_entry(entry)) { printk(KERN_CONT ".. invalid entry %d ", - entries[idx].type); + entry->type); goto failed; } - - idx++; - if (idx >= ENTRIES_PER_PAGE) { - page = virt_to_page(entries); - if (page->lru.next == &data->trace_pages) { - if (i != tr->entries - 1) { - printk(KERN_CONT ".. entries buffer mismatch"); - goto failed; - } - } else { - page = list_entry(page->lru.next, struct page, lru); - entries = page_address(page); - } - idx = 0; - } } - - page = virt_to_page(entries); - if (page->lru.next != &data->trace_pages) { - printk(KERN_CONT ".. too many entries"); - goto failed; - } - return 0; failed: @@ -89,13 +53,11 @@ static int trace_test_buffer(struct trace_array *tr, unsigned long *count) /* Don't allow flipping of max traces now */ raw_local_irq_save(flags); __raw_spin_lock(&ftrace_max_lock); - for_each_possible_cpu(cpu) { - if (!head_page(tr->data[cpu])) - continue; - cnt += tr->data[cpu]->trace_idx; + cnt = ring_buffer_entries(tr->buffer); - ret = trace_test_buffer_cpu(tr, tr->data[cpu]); + for_each_possible_cpu(cpu) { + ret = trace_test_buffer_cpu(tr, cpu); if (ret) break; } @@ -120,11 +82,11 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, struct trace_array *tr, int (*func)(void)) { - unsigned long count; - int ret; int save_ftrace_enabled = ftrace_enabled; int save_tracer_enabled = tracer_enabled; + unsigned long count; char *func_name; + int ret; /* The ftrace test PASSED */ printk(KERN_CONT "PASSED\n"); @@ -157,6 +119,7 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, /* enable tracing */ tr->ctrl = 1; trace->init(tr); + /* Sleep for a 1/10 of a second */ msleep(100); @@ -212,10 +175,10 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace, int trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr) { - unsigned long count; - int ret; int save_ftrace_enabled = ftrace_enabled; int save_tracer_enabled = tracer_enabled; + unsigned long count; + int ret; /* make sure msleep has been recorded */ msleep(1); @@ -415,6 +378,15 @@ trace_selftest_startup_preemptirqsoff(struct tracer *trace, struct trace_array * } #endif /* CONFIG_IRQSOFF_TRACER && CONFIG_PREEMPT_TRACER */ +#ifdef CONFIG_NOP_TRACER +int +trace_selftest_startup_nop(struct tracer *trace, struct trace_array *tr) +{ + /* What could possibly go wrong? */ + return 0; +} +#endif + #ifdef CONFIG_SCHED_TRACER static int trace_wakeup_test_thread(void *data) { @@ -486,6 +458,9 @@ trace_selftest_startup_wakeup(struct tracer *trace, struct trace_array *tr) wake_up_process(p); + /* give a little time to let the thread wake up */ + msleep(100); + /* stop the tracing. */ tr->ctrl = 0; trace->ctrl_update(tr); diff --git a/kernel/trace/trace_stack.c b/kernel/trace/trace_stack.c new file mode 100644 index 000000000000..74c5d9a3afae --- /dev/null +++ b/kernel/trace/trace_stack.c @@ -0,0 +1,310 @@ +/* + * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com> + * + */ +#include <linux/stacktrace.h> +#include <linux/kallsyms.h> +#include <linux/seq_file.h> +#include <linux/spinlock.h> +#include <linux/uaccess.h> +#include <linux/debugfs.h> +#include <linux/ftrace.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/fs.h> +#include "trace.h" + +#define STACK_TRACE_ENTRIES 500 + +static unsigned long stack_dump_trace[STACK_TRACE_ENTRIES+1] = + { [0 ... (STACK_TRACE_ENTRIES)] = ULONG_MAX }; +static unsigned stack_dump_index[STACK_TRACE_ENTRIES]; + +static struct stack_trace max_stack_trace = { + .max_entries = STACK_TRACE_ENTRIES, + .entries = stack_dump_trace, +}; + +static unsigned long max_stack_size; +static raw_spinlock_t max_stack_lock = + (raw_spinlock_t)__RAW_SPIN_LOCK_UNLOCKED; + +static int stack_trace_disabled __read_mostly; +static DEFINE_PER_CPU(int, trace_active); + +static inline void check_stack(void) +{ + unsigned long this_size, flags; + unsigned long *p, *top, *start; + int i; + + this_size = ((unsigned long)&this_size) & (THREAD_SIZE-1); + this_size = THREAD_SIZE - this_size; + + if (this_size <= max_stack_size) + return; + + raw_local_irq_save(flags); + __raw_spin_lock(&max_stack_lock); + + /* a race could have already updated it */ + if (this_size <= max_stack_size) + goto out; + + max_stack_size = this_size; + + max_stack_trace.nr_entries = 0; + max_stack_trace.skip = 3; + + save_stack_trace(&max_stack_trace); + + /* + * Now find where in the stack these are. + */ + i = 0; + start = &this_size; + top = (unsigned long *) + (((unsigned long)start & ~(THREAD_SIZE-1)) + THREAD_SIZE); + + /* + * Loop through all the entries. One of the entries may + * for some reason be missed on the stack, so we may + * have to account for them. If they are all there, this + * loop will only happen once. This code only takes place + * on a new max, so it is far from a fast path. + */ + while (i < max_stack_trace.nr_entries) { + + stack_dump_index[i] = this_size; + p = start; + + for (; p < top && i < max_stack_trace.nr_entries; p++) { + if (*p == stack_dump_trace[i]) { + this_size = stack_dump_index[i++] = + (top - p) * sizeof(unsigned long); + /* Start the search from here */ + start = p + 1; + } + } + + i++; + } + + out: + __raw_spin_unlock(&max_stack_lock); + raw_local_irq_restore(flags); +} + +static void +stack_trace_call(unsigned long ip, unsigned long parent_ip) +{ + int cpu, resched; + + if (unlikely(!ftrace_enabled || stack_trace_disabled)) + return; + + resched = need_resched(); + preempt_disable_notrace(); + + cpu = raw_smp_processor_id(); + /* no atomic needed, we only modify this variable by this cpu */ + if (per_cpu(trace_active, cpu)++ != 0) + goto out; + + check_stack(); + + out: + per_cpu(trace_active, cpu)--; + /* prevent recursion in schedule */ + if (resched) + preempt_enable_no_resched_notrace(); + else + preempt_enable_notrace(); +} + +static struct ftrace_ops trace_ops __read_mostly = +{ + .func = stack_trace_call, +}; + +static ssize_t +stack_max_size_read(struct file *filp, char __user *ubuf, + size_t count, loff_t *ppos) +{ + unsigned long *ptr = filp->private_data; + char buf[64]; + int r; + + r = snprintf(buf, sizeof(buf), "%ld\n", *ptr); + if (r > sizeof(buf)) + r = sizeof(buf); + return simple_read_from_buffer(ubuf, count, ppos, buf, r); +} + +static ssize_t +stack_max_size_write(struct file *filp, const char __user *ubuf, + size_t count, loff_t *ppos) +{ + long *ptr = filp->private_data; + unsigned long val, flags; + char buf[64]; + int ret; + + if (count >= sizeof(buf)) + return -EINVAL; + + if (copy_from_user(&buf, ubuf, count)) + return -EFAULT; + + buf[count] = 0; + + ret = strict_strtoul(buf, 10, &val); + if (ret < 0) + return ret; + + raw_local_irq_save(flags); + __raw_spin_lock(&max_stack_lock); + *ptr = val; + __raw_spin_unlock(&max_stack_lock); + raw_local_irq_restore(flags); + + return count; +} + +static struct file_operations stack_max_size_fops = { + .open = tracing_open_generic, + .read = stack_max_size_read, + .write = stack_max_size_write, +}; + +static void * +t_next(struct seq_file *m, void *v, loff_t *pos) +{ + long i = (long)m->private; + + (*pos)++; + + i++; + + if (i >= max_stack_trace.nr_entries || + stack_dump_trace[i] == ULONG_MAX) + return NULL; + + m->private = (void *)i; + + return &m->private; +} + +static void *t_start(struct seq_file *m, loff_t *pos) +{ + void *t = &m->private; + loff_t l = 0; + + local_irq_disable(); + __raw_spin_lock(&max_stack_lock); + + for (; t && l < *pos; t = t_next(m, t, &l)) + ; + + return t; +} + +static void t_stop(struct seq_file *m, void *p) +{ + __raw_spin_unlock(&max_stack_lock); + local_irq_enable(); +} + +static int trace_lookup_stack(struct seq_file *m, long i) +{ + unsigned long addr = stack_dump_trace[i]; +#ifdef CONFIG_KALLSYMS + char str[KSYM_SYMBOL_LEN]; + + sprint_symbol(str, addr); + + return seq_printf(m, "%s\n", str); +#else + return seq_printf(m, "%p\n", (void*)addr); +#endif +} + +static int t_show(struct seq_file *m, void *v) +{ + long i = *(long *)v; + int size; + + if (i < 0) { + seq_printf(m, " Depth Size Location" + " (%d entries)\n" + " ----- ---- --------\n", + max_stack_trace.nr_entries); + return 0; + } + + if (i >= max_stack_trace.nr_entries || + stack_dump_trace[i] == ULONG_MAX) + return 0; + + if (i+1 == max_stack_trace.nr_entries || + stack_dump_trace[i+1] == ULONG_MAX) + size = stack_dump_index[i]; + else + size = stack_dump_index[i] - stack_dump_index[i+1]; + + seq_printf(m, "%3ld) %8d %5d ", i, stack_dump_index[i], size); + + trace_lookup_stack(m, i); + + return 0; +} + +static struct seq_operations stack_trace_seq_ops = { + .start = t_start, + .next = t_next, + .stop = t_stop, + .show = t_show, +}; + +static int stack_trace_open(struct inode *inode, struct file *file) +{ + int ret; + + ret = seq_open(file, &stack_trace_seq_ops); + if (!ret) { + struct seq_file *m = file->private_data; + m->private = (void *)-1; + } + + return ret; +} + +static struct file_operations stack_trace_fops = { + .open = stack_trace_open, + .read = seq_read, + .llseek = seq_lseek, +}; + +static __init int stack_trace_init(void) +{ + struct dentry *d_tracer; + struct dentry *entry; + + d_tracer = tracing_init_dentry(); + + entry = debugfs_create_file("stack_max_size", 0644, d_tracer, + &max_stack_size, &stack_max_size_fops); + if (!entry) + pr_warning("Could not create debugfs 'stack_max_size' entry\n"); + + entry = debugfs_create_file("stack_trace", 0444, d_tracer, + NULL, &stack_trace_fops); + if (!entry) + pr_warning("Could not create debugfs 'stack_trace' entry\n"); + + register_ftrace_function(&trace_ops); + + return 0; +} + +device_initcall(stack_trace_init); diff --git a/kernel/trace/trace_sysprof.c b/kernel/trace/trace_sysprof.c index db58fb66a135..9587d3bcba55 100644 --- a/kernel/trace/trace_sysprof.c +++ b/kernel/trace/trace_sysprof.c @@ -241,7 +241,7 @@ static void stack_reset(struct trace_array *tr) tr->time_start = ftrace_now(tr->cpu); for_each_online_cpu(cpu) - tracing_reset(tr->data[cpu]); + tracing_reset(tr, cpu); } static void start_stack_trace(struct trace_array *tr) |