diff options
| -rw-r--r-- | kernel/trace/fgraph.c | 360 | ||||
| -rw-r--r-- | kernel/trace/ftrace.c | 368 |
2 files changed, 366 insertions, 362 deletions
diff --git a/kernel/trace/fgraph.c b/kernel/trace/fgraph.c index de887a983ac7..374f3e42e29e 100644 --- a/kernel/trace/fgraph.c +++ b/kernel/trace/fgraph.c @@ -7,11 +7,27 @@ * * Highly modified by Steven Rostedt (VMware). */ +#include <linux/suspend.h> #include <linux/ftrace.h> +#include <linux/slab.h> -#include "trace.h" +#include <trace/events/sched.h> + +#include "ftrace_internal.h" + +#ifdef CONFIG_DYNAMIC_FTRACE +#define ASSIGN_OPS_HASH(opsname, val) \ + .func_hash = val, \ + .local_hash.regex_lock = __MUTEX_INITIALIZER(opsname.local_hash.regex_lock), +#else +#define ASSIGN_OPS_HASH(opsname, val) +#endif static bool kill_ftrace_graph; +int ftrace_graph_active; + +/* Both enabled by default (can be cleared by function_graph tracer flags */ +static bool fgraph_sleep_time = true; /** * ftrace_graph_is_dead - returns true if ftrace_graph_stop() was called @@ -162,6 +178,31 @@ ftrace_pop_return_trace(struct ftrace_graph_ret *trace, unsigned long *ret, } /* + * Hibernation protection. + * The state of the current task is too much unstable during + * suspend/restore to disk. We want to protect against that. + */ +static int +ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, + void *unused) +{ + switch (state) { + case PM_HIBERNATION_PREPARE: + pause_graph_tracing(); + break; + + case PM_POST_HIBERNATION: + unpause_graph_tracing(); + break; + } + return NOTIFY_DONE; +} + +static struct notifier_block ftrace_suspend_notifier = { + .notifier_call = ftrace_suspend_notifier_call, +}; + +/* * Send the trace to the ring-buffer. * @return the original return address. */ @@ -190,3 +231,320 @@ unsigned long ftrace_return_to_handler(unsigned long frame_pointer) return ret; } + +static struct ftrace_ops graph_ops = { + .func = ftrace_stub, + .flags = FTRACE_OPS_FL_RECURSION_SAFE | + FTRACE_OPS_FL_INITIALIZED | + FTRACE_OPS_FL_PID | + FTRACE_OPS_FL_STUB, +#ifdef FTRACE_GRAPH_TRAMP_ADDR + .trampoline = FTRACE_GRAPH_TRAMP_ADDR, + /* trampoline_size is only needed for dynamically allocated tramps */ +#endif + ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) +}; + +void ftrace_graph_sleep_time_control(bool enable) +{ + fgraph_sleep_time = enable; +} + +int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) +{ + return 0; +} + +/* The callbacks that hook a function */ +trace_func_graph_ret_t ftrace_graph_return = + (trace_func_graph_ret_t)ftrace_stub; +trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; +static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; + +/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ +static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) +{ + int i; + int ret = 0; + int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; + struct task_struct *g, *t; + + for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { + ret_stack_list[i] = + kmalloc_array(FTRACE_RETFUNC_DEPTH, + sizeof(struct ftrace_ret_stack), + GFP_KERNEL); + if (!ret_stack_list[i]) { + start = 0; + end = i; + ret = -ENOMEM; + goto free; + } + } + + read_lock(&tasklist_lock); + do_each_thread(g, t) { + if (start == end) { + ret = -EAGAIN; + goto unlock; + } + + if (t->ret_stack == NULL) { + atomic_set(&t->tracing_graph_pause, 0); + atomic_set(&t->trace_overrun, 0); + t->curr_ret_stack = -1; + t->curr_ret_depth = -1; + /* Make sure the tasks see the -1 first: */ + smp_wmb(); + t->ret_stack = ret_stack_list[start++]; + } + } while_each_thread(g, t); + +unlock: + read_unlock(&tasklist_lock); +free: + for (i = start; i < end; i++) + kfree(ret_stack_list[i]); + return ret; +} + +static void +ftrace_graph_probe_sched_switch(void *ignore, bool preempt, + struct task_struct *prev, struct task_struct *next) +{ + unsigned long long timestamp; + int index; + + /* + * Does the user want to count the time a function was asleep. + * If so, do not update the time stamps. + */ + if (fgraph_sleep_time) + return; + + timestamp = trace_clock_local(); + + prev->ftrace_timestamp = timestamp; + + /* only process tasks that we timestamped */ + if (!next->ftrace_timestamp) + return; + + /* + * Update all the counters in next to make up for the + * time next was sleeping. + */ + timestamp -= next->ftrace_timestamp; + + for (index = next->curr_ret_stack; index >= 0; index--) + next->ret_stack[index].calltime += timestamp; +} + +static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) +{ + if (!ftrace_ops_test(&global_ops, trace->func, NULL)) + return 0; + return __ftrace_graph_entry(trace); +} + +/* + * The function graph tracer should only trace the functions defined + * by set_ftrace_filter and set_ftrace_notrace. If another function + * tracer ops is registered, the graph tracer requires testing the + * function against the global ops, and not just trace any function + * that any ftrace_ops registered. + */ +void update_function_graph_func(void) +{ + struct ftrace_ops *op; + bool do_test = false; + + /* + * The graph and global ops share the same set of functions + * to test. If any other ops is on the list, then + * the graph tracing needs to test if its the function + * it should call. + */ + do_for_each_ftrace_op(op, ftrace_ops_list) { + if (op != &global_ops && op != &graph_ops && + op != &ftrace_list_end) { + do_test = true; + /* in double loop, break out with goto */ + goto out; + } + } while_for_each_ftrace_op(op); + out: + if (do_test) + ftrace_graph_entry = ftrace_graph_entry_test; + else + ftrace_graph_entry = __ftrace_graph_entry; +} + +static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); + +static void +graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) +{ + atomic_set(&t->tracing_graph_pause, 0); + atomic_set(&t->trace_overrun, 0); + t->ftrace_timestamp = 0; + /* make curr_ret_stack visible before we add the ret_stack */ + smp_wmb(); + t->ret_stack = ret_stack; +} + +/* + * Allocate a return stack for the idle task. May be the first + * time through, or it may be done by CPU hotplug online. + */ +void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) +{ + t->curr_ret_stack = -1; + t->curr_ret_depth = -1; + /* + * The idle task has no parent, it either has its own + * stack or no stack at all. + */ + if (t->ret_stack) + WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); + + if (ftrace_graph_active) { + struct ftrace_ret_stack *ret_stack; + + ret_stack = per_cpu(idle_ret_stack, cpu); + if (!ret_stack) { + ret_stack = + kmalloc_array(FTRACE_RETFUNC_DEPTH, + sizeof(struct ftrace_ret_stack), + GFP_KERNEL); + if (!ret_stack) + return; + per_cpu(idle_ret_stack, cpu) = ret_stack; + } + graph_init_task(t, ret_stack); + } +} + +/* Allocate a return stack for newly created task */ +void ftrace_graph_init_task(struct task_struct *t) +{ + /* Make sure we do not use the parent ret_stack */ + t->ret_stack = NULL; + t->curr_ret_stack = -1; + t->curr_ret_depth = -1; + + if (ftrace_graph_active) { + struct ftrace_ret_stack *ret_stack; + + ret_stack = kmalloc_array(FTRACE_RETFUNC_DEPTH, + sizeof(struct ftrace_ret_stack), + GFP_KERNEL); + if (!ret_stack) + return; + graph_init_task(t, ret_stack); + } +} + +void ftrace_graph_exit_task(struct task_struct *t) +{ + struct ftrace_ret_stack *ret_stack = t->ret_stack; + + t->ret_stack = NULL; + /* NULL must become visible to IRQs before we free it: */ + barrier(); + + kfree(ret_stack); +} + +/* Allocate a return stack for each task */ +static int start_graph_tracing(void) +{ + struct ftrace_ret_stack **ret_stack_list; + int ret, cpu; + + ret_stack_list = kmalloc_array(FTRACE_RETSTACK_ALLOC_SIZE, + sizeof(struct ftrace_ret_stack *), + GFP_KERNEL); + + if (!ret_stack_list) + return -ENOMEM; + + /* The cpu_boot init_task->ret_stack will never be freed */ + for_each_online_cpu(cpu) { + if (!idle_task(cpu)->ret_stack) + ftrace_graph_init_idle_task(idle_task(cpu), cpu); + } + + do { + ret = alloc_retstack_tasklist(ret_stack_list); + } while (ret == -EAGAIN); + + if (!ret) { + ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); + if (ret) + pr_info("ftrace_graph: Couldn't activate tracepoint" + " probe to kernel_sched_switch\n"); + } + + kfree(ret_stack_list); + return ret; +} + +int register_ftrace_graph(trace_func_graph_ret_t retfunc, + trace_func_graph_ent_t entryfunc) +{ + int ret = 0; + + mutex_lock(&ftrace_lock); + + /* we currently allow only one tracer registered at a time */ + if (ftrace_graph_active) { + ret = -EBUSY; + goto out; + } + + register_pm_notifier(&ftrace_suspend_notifier); + + ftrace_graph_active++; + ret = start_graph_tracing(); + if (ret) { + ftrace_graph_active--; + goto out; + } + + ftrace_graph_return = retfunc; + + /* + * Update the indirect function to the entryfunc, and the + * function that gets called to the entry_test first. Then + * call the update fgraph entry function to determine if + * the entryfunc should be called directly or not. + */ + __ftrace_graph_entry = entryfunc; + ftrace_graph_entry = ftrace_graph_entry_test; + update_function_graph_func(); + + ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); +out: + mutex_unlock(&ftrace_lock); + return ret; +} + +void unregister_ftrace_graph(void) +{ + mutex_lock(&ftrace_lock); + + if (unlikely(!ftrace_graph_active)) + goto out; + + ftrace_graph_active--; + ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; + ftrace_graph_entry = ftrace_graph_entry_stub; + __ftrace_graph_entry = ftrace_graph_entry_stub; + ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); + unregister_pm_notifier(&ftrace_suspend_notifier); + unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); + + out: + mutex_unlock(&ftrace_lock); +} diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 52c89428b0db..c53533b833cf 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -19,7 +19,6 @@ #include <linux/sched/task.h> #include <linux/kallsyms.h> #include <linux/seq_file.h> -#include <linux/suspend.h> #include <linux/tracefs.h> #include <linux/hardirq.h> #include <linux/kthread.h> @@ -167,12 +166,6 @@ static void ftrace_sync_ipi(void *data) smp_rmb(); } -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -/* Both enabled by default (can be cleared by function_graph tracer flags */ -static bool fgraph_sleep_time = true; -static bool fgraph_graph_time = true; -#endif - static ftrace_func_t ftrace_ops_get_list_func(struct ftrace_ops *ops) { /* @@ -790,6 +783,13 @@ function_profile_call(unsigned long ip, unsigned long parent_ip, } #ifdef CONFIG_FUNCTION_GRAPH_TRACER +static bool fgraph_graph_time = true; + +void ftrace_graph_graph_time_control(bool enable) +{ + fgraph_graph_time = enable; +} + static int profile_graph_entry(struct ftrace_graph_ent *trace) { int index = current->curr_ret_stack; @@ -996,10 +996,6 @@ static __init void ftrace_profile_tracefs(struct dentry *d_tracer) } #endif /* CONFIG_FUNCTION_PROFILER */ -#ifdef CONFIG_FUNCTION_GRAPH_TRACER -int ftrace_graph_active; -#endif - #ifdef CONFIG_DYNAMIC_FTRACE static struct ftrace_ops *removed_ops; @@ -6697,353 +6693,3 @@ ftrace_enable_sysctl(struct ctl_table *table, int write, mutex_unlock(&ftrace_lock); return ret; } - -#ifdef CONFIG_FUNCTION_GRAPH_TRACER - -static struct ftrace_ops graph_ops = { - .func = ftrace_stub, - .flags = FTRACE_OPS_FL_RECURSION_SAFE | - FTRACE_OPS_FL_INITIALIZED | - FTRACE_OPS_FL_PID | - FTRACE_OPS_FL_STUB, -#ifdef FTRACE_GRAPH_TRAMP_ADDR - .trampoline = FTRACE_GRAPH_TRAMP_ADDR, - /* trampoline_size is only needed for dynamically allocated tramps */ -#endif - ASSIGN_OPS_HASH(graph_ops, &global_ops.local_hash) -}; - -void ftrace_graph_sleep_time_control(bool enable) -{ - fgraph_sleep_time = enable; -} - -void ftrace_graph_graph_time_control(bool enable) -{ - fgraph_graph_time = enable; -} - -int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) -{ - return 0; -} - -/* The callbacks that hook a function */ -trace_func_graph_ret_t ftrace_graph_return = - (trace_func_graph_ret_t)ftrace_stub; -trace_func_graph_ent_t ftrace_graph_entry = ftrace_graph_entry_stub; -static trace_func_graph_ent_t __ftrace_graph_entry = ftrace_graph_entry_stub; - -/* Try to assign a return stack array on FTRACE_RETSTACK_ALLOC_SIZE tasks. */ -static int alloc_retstack_tasklist(struct ftrace_ret_stack **ret_stack_list) -{ - int i; - int ret = 0; - int start = 0, end = FTRACE_RETSTACK_ALLOC_SIZE; - struct task_struct *g, *t; - - for (i = 0; i < FTRACE_RETSTACK_ALLOC_SIZE; i++) { - ret_stack_list[i] = - kmalloc_array(FTRACE_RETFUNC_DEPTH, - sizeof(struct ftrace_ret_stack), - GFP_KERNEL); - if (!ret_stack_list[i]) { - start = 0; - end = i; - ret = -ENOMEM; - goto free; - } - } - - read_lock(&tasklist_lock); - do_each_thread(g, t) { - if (start == end) { - ret = -EAGAIN; - goto unlock; - } - - if (t->ret_stack == NULL) { - atomic_set(&t->tracing_graph_pause, 0); - atomic_set(&t->trace_overrun, 0); - t->curr_ret_stack = -1; - t->curr_ret_depth = -1; - /* Make sure the tasks see the -1 first: */ - smp_wmb(); - t->ret_stack = ret_stack_list[start++]; - } - } while_each_thread(g, t); - -unlock: - read_unlock(&tasklist_lock); -free: - for (i = start; i < end; i++) - kfree(ret_stack_list[i]); - return ret; -} - -static void -ftrace_graph_probe_sched_switch(void *ignore, bool preempt, - struct task_struct *prev, struct task_struct *next) -{ - unsigned long long timestamp; - int index; - - /* - * Does the user want to count the time a function was asleep. - * If so, do not update the time stamps. - */ - if (fgraph_sleep_time) - return; - - timestamp = trace_clock_local(); - - prev->ftrace_timestamp = timestamp; - - /* only process tasks that we timestamped */ - if (!next->ftrace_timestamp) - return; - - /* - * Update all the counters in next to make up for the - * time next was sleeping. - */ - timestamp -= next->ftrace_timestamp; - - for (index = next->curr_ret_stack; index >= 0; index--) - next->ret_stack[index].calltime += timestamp; -} - -/* Allocate a return stack for each task */ -static int start_graph_tracing(void) -{ - struct ftrace_ret_stack **ret_stack_list; - int ret, cpu; - - ret_stack_list = kmalloc_array(FTRACE_RETSTACK_ALLOC_SIZE, - sizeof(struct ftrace_ret_stack *), - GFP_KERNEL); - - if (!ret_stack_list) - return -ENOMEM; - - /* The cpu_boot init_task->ret_stack will never be freed */ - for_each_online_cpu(cpu) { - if (!idle_task(cpu)->ret_stack) - ftrace_graph_init_idle_task(idle_task(cpu), cpu); - } - - do { - ret = alloc_retstack_tasklist(ret_stack_list); - } while (ret == -EAGAIN); - - if (!ret) { - ret = register_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); - if (ret) - pr_info("ftrace_graph: Couldn't activate tracepoint" - " probe to kernel_sched_switch\n"); - } - - kfree(ret_stack_list); - return ret; -} - -/* - * Hibernation protection. - * The state of the current task is too much unstable during - * suspend/restore to disk. We want to protect against that. - */ -static int -ftrace_suspend_notifier_call(struct notifier_block *bl, unsigned long state, - void *unused) -{ - switch (state) { - case PM_HIBERNATION_PREPARE: - pause_graph_tracing(); - break; - - case PM_POST_HIBERNATION: - unpause_graph_tracing(); - break; - } - return NOTIFY_DONE; -} - -static int ftrace_graph_entry_test(struct ftrace_graph_ent *trace) -{ - if (!ftrace_ops_test(&global_ops, trace->func, NULL)) - return 0; - return __ftrace_graph_entry(trace); -} - -/* - * The function graph tracer should only trace the functions defined - * by set_ftrace_filter and set_ftrace_notrace. If another function - * tracer ops is registered, the graph tracer requires testing the - * function against the global ops, and not just trace any function - * that any ftrace_ops registered. - */ -void update_function_graph_func(void) -{ - struct ftrace_ops *op; - bool do_test = false; - - /* - * The graph and global ops share the same set of functions - * to test. If any other ops is on the list, then - * the graph tracing needs to test if its the function - * it should call. - */ - do_for_each_ftrace_op(op, ftrace_ops_list) { - if (op != &global_ops && op != &graph_ops && - op != &ftrace_list_end) { - do_test = true; - /* in double loop, break out with goto */ - goto out; - } - } while_for_each_ftrace_op(op); - out: - if (do_test) - ftrace_graph_entry = ftrace_graph_entry_test; - else - ftrace_graph_entry = __ftrace_graph_entry; -} - -static struct notifier_block ftrace_suspend_notifier = { - .notifier_call = ftrace_suspend_notifier_call, -}; - -int register_ftrace_graph(trace_func_graph_ret_t retfunc, - trace_func_graph_ent_t entryfunc) -{ - int ret = 0; - - mutex_lock(&ftrace_lock); - - /* we currently allow only one tracer registered at a time */ - if (ftrace_graph_active) { - ret = -EBUSY; - goto out; - } - - register_pm_notifier(&ftrace_suspend_notifier); - - ftrace_graph_active++; - ret = start_graph_tracing(); - if (ret) { - ftrace_graph_active--; - goto out; - } - - ftrace_graph_return = retfunc; - - /* - * Update the indirect function to the entryfunc, and the - * function that gets called to the entry_test first. Then - * call the update fgraph entry function to determine if - * the entryfunc should be called directly or not. - */ - __ftrace_graph_entry = entryfunc; - ftrace_graph_entry = ftrace_graph_entry_test; - update_function_graph_func(); - - ret = ftrace_startup(&graph_ops, FTRACE_START_FUNC_RET); -out: - mutex_unlock(&ftrace_lock); - return ret; -} - -void unregister_ftrace_graph(void) -{ - mutex_lock(&ftrace_lock); - - if (unlikely(!ftrace_graph_active)) - goto out; - - ftrace_graph_active--; - ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; - ftrace_graph_entry = ftrace_graph_entry_stub; - __ftrace_graph_entry = ftrace_graph_entry_stub; - ftrace_shutdown(&graph_ops, FTRACE_STOP_FUNC_RET); - unregister_pm_notifier(&ftrace_suspend_notifier); - unregister_trace_sched_switch(ftrace_graph_probe_sched_switch, NULL); - - out: - mutex_unlock(&ftrace_lock); -} - -static DEFINE_PER_CPU(struct ftrace_ret_stack *, idle_ret_stack); - -static void -graph_init_task(struct task_struct *t, struct ftrace_ret_stack *ret_stack) -{ - atomic_set(&t->tracing_graph_pause, 0); - atomic_set(&t->trace_overrun, 0); - t->ftrace_timestamp = 0; - /* make curr_ret_stack visible before we add the ret_stack */ - smp_wmb(); - t->ret_stack = ret_stack; -} - -/* - * Allocate a return stack for the idle task. May be the first - * time through, or it may be done by CPU hotplug online. - */ -void ftrace_graph_init_idle_task(struct task_struct *t, int cpu) -{ - t->curr_ret_stack = -1; - t->curr_ret_depth = -1; - /* - * The idle task has no parent, it either has its own - * stack or no stack at all. - */ - if (t->ret_stack) - WARN_ON(t->ret_stack != per_cpu(idle_ret_stack, cpu)); - - if (ftrace_graph_active) { - struct ftrace_ret_stack *ret_stack; - - ret_stack = per_cpu(idle_ret_stack, cpu); - if (!ret_stack) { - ret_stack = - kmalloc_array(FTRACE_RETFUNC_DEPTH, - sizeof(struct ftrace_ret_stack), - GFP_KERNEL); - if (!ret_stack) - return; - per_cpu(idle_ret_stack, cpu) = ret_stack; - } - graph_init_task(t, ret_stack); - } -} - -/* Allocate a return stack for newly created task */ -void ftrace_graph_init_task(struct task_struct *t) -{ - /* Make sure we do not use the parent ret_stack */ - t->ret_stack = NULL; - t->curr_ret_stack = -1; - t->curr_ret_depth = -1; - - if (ftrace_graph_active) { - struct ftrace_ret_stack *ret_stack; - - ret_stack = kmalloc_array(FTRACE_RETFUNC_DEPTH, - sizeof(struct ftrace_ret_stack), - GFP_KERNEL); - if (!ret_stack) - return; - graph_init_task(t, ret_stack); - } -} - -void ftrace_graph_exit_task(struct task_struct *t) -{ - struct ftrace_ret_stack *ret_stack = t->ret_stack; - - t->ret_stack = NULL; - /* NULL must become visible to IRQs before we free it: */ - barrier(); - - kfree(ret_stack); -} -#endif |