diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/pstore/Kconfig | 1 | ||||
| -rw-r--r-- | fs/pstore/ftrace.c | 96 | ||||
| -rw-r--r-- | fs/pstore/internal.h | 6 | ||||
| -rw-r--r-- | fs/pstore/platform.c | 9 | ||||
| -rw-r--r-- | fs/pstore/ram.c | 28 |
5 files changed, 125 insertions, 15 deletions
diff --git a/fs/pstore/Kconfig b/fs/pstore/Kconfig index d39bb5cce883..ca71db69da07 100644 --- a/fs/pstore/Kconfig +++ b/fs/pstore/Kconfig @@ -23,6 +23,7 @@ config PSTORE_FTRACE bool "Persistent function tracer" depends on PSTORE depends on FUNCTION_TRACER + depends on DEBUG_FS help With this option kernel traces function calls into a persistent ram buffer that can be decoded and dumped after reboot through diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index a130d484b7d3..2d57e1ac0115 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -17,19 +17,113 @@ #include <linux/percpu.h> #include <linux/smp.h> #include <linux/atomic.h> +#include <linux/types.h> +#include <linux/mutex.h> +#include <linux/ftrace.h> +#include <linux/fs.h> +#include <linux/debugfs.h> +#include <linux/err.h> +#include <linux/cache.h> #include <asm/barrier.h> #include "internal.h" -void notrace pstore_ftrace_call(unsigned long ip, unsigned long parent_ip) +static void notrace pstore_ftrace_call(unsigned long ip, + unsigned long parent_ip) { + unsigned long flags; struct pstore_ftrace_record rec = {}; if (unlikely(oops_in_progress)) return; + local_irq_save(flags); + rec.ip = ip; rec.parent_ip = parent_ip; pstore_ftrace_encode_cpu(&rec, raw_smp_processor_id()); psinfo->write_buf(PSTORE_TYPE_FTRACE, 0, NULL, 0, (void *)&rec, sizeof(rec), psinfo); + + local_irq_restore(flags); +} + +static struct ftrace_ops pstore_ftrace_ops __read_mostly = { + .func = pstore_ftrace_call, +}; + +static DEFINE_MUTEX(pstore_ftrace_lock); +static bool pstore_ftrace_enabled; + +static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf, + size_t count, loff_t *ppos) +{ + u8 on; + ssize_t ret; + + ret = kstrtou8_from_user(buf, count, 2, &on); + if (ret) + return ret; + + mutex_lock(&pstore_ftrace_lock); + + if (!on ^ pstore_ftrace_enabled) + goto out; + + if (on) + ret = register_ftrace_function(&pstore_ftrace_ops); + else + ret = unregister_ftrace_function(&pstore_ftrace_ops); + if (ret) { + pr_err("%s: unable to %sregister ftrace ops: %zd\n", + __func__, on ? "" : "un", ret); + goto err; + } + + pstore_ftrace_enabled = on; +out: + ret = count; +err: + mutex_unlock(&pstore_ftrace_lock); + + return ret; +} + +static ssize_t pstore_ftrace_knob_read(struct file *f, char __user *buf, + size_t count, loff_t *ppos) +{ + char val[] = { '0' + pstore_ftrace_enabled, '\n' }; + + return simple_read_from_buffer(buf, count, ppos, val, sizeof(val)); +} + +static const struct file_operations pstore_knob_fops = { + .open = simple_open, + .read = pstore_ftrace_knob_read, + .write = pstore_ftrace_knob_write, +}; + +void pstore_register_ftrace(void) +{ + struct dentry *dir; + struct dentry *file; + + if (!psinfo->write_buf) + return; + + dir = debugfs_create_dir("pstore", NULL); + if (!dir) { + pr_err("%s: unable to create pstore directory\n", __func__); + return; + } + + file = debugfs_create_file("record_ftrace", 0600, dir, NULL, + &pstore_knob_fops); + if (!file) { + pr_err("%s: unable to create record_ftrace file\n", __func__); + goto err_file; + } + + return; +err_file: + debugfs_remove(dir); } diff --git a/fs/pstore/internal.h b/fs/pstore/internal.h index 0d0d3b7d5f12..4847f588b7d5 100644 --- a/fs/pstore/internal.h +++ b/fs/pstore/internal.h @@ -39,6 +39,12 @@ pstore_ftrace_decode_cpu(struct pstore_ftrace_record *rec) #endif } +#ifdef CONFIG_PSTORE_FTRACE +extern void pstore_register_ftrace(void); +#else +static inline void pstore_register_ftrace(void) {} +#endif + extern struct pstore_info *psinfo; extern void pstore_set_kmsg_bytes(int); diff --git a/fs/pstore/platform.c b/fs/pstore/platform.c index 29996e8793a7..a40da07e93d6 100644 --- a/fs/pstore/platform.c +++ b/fs/pstore/platform.c @@ -164,7 +164,13 @@ static void pstore_console_write(struct console *con, const char *s, unsigned c) if (c > psinfo->bufsize) c = psinfo->bufsize; - spin_lock_irqsave(&psinfo->buf_lock, flags); + + if (oops_in_progress) { + if (!spin_trylock_irqsave(&psinfo->buf_lock, flags)) + break; + } else { + spin_lock_irqsave(&psinfo->buf_lock, flags); + } memcpy(psinfo->buf, s, c); psinfo->write(PSTORE_TYPE_CONSOLE, 0, NULL, 0, c, psinfo); spin_unlock_irqrestore(&psinfo->buf_lock, flags); @@ -236,6 +242,7 @@ int pstore_register(struct pstore_info *psi) kmsg_dump_register(&pstore_dumper); pstore_register_console(); + pstore_register_ftrace(); if (pstore_update_ms >= 0) { pstore_timer.expires = jiffies + diff --git a/fs/pstore/ram.c b/fs/pstore/ram.c index 0b311bc18916..1a4f6da58eab 100644 --- a/fs/pstore/ram.c +++ b/fs/pstore/ram.c @@ -32,6 +32,7 @@ #include <linux/ioport.h> #include <linux/platform_device.h> #include <linux/slab.h> +#include <linux/compiler.h> #include <linux/pstore_ram.h> #define RAMOOPS_KERNMSG_HDR "====" @@ -181,12 +182,11 @@ static size_t ramoops_write_kmsg_hdr(struct persistent_ram_zone *prz) return len; } - -static int ramoops_pstore_write_buf(enum pstore_type_id type, - enum kmsg_dump_reason reason, - u64 *id, unsigned int part, - const char *buf, size_t size, - struct pstore_info *psi) +static int notrace ramoops_pstore_write_buf(enum pstore_type_id type, + enum kmsg_dump_reason reason, + u64 *id, unsigned int part, + const char *buf, size_t size, + struct pstore_info *psi) { struct ramoops_context *cxt = psi->data; struct persistent_ram_zone *prz = cxt->przs[cxt->dump_write_cnt]; @@ -406,7 +406,7 @@ static int __devinit ramoops_probe(struct platform_device *pdev) goto fail_init_fprz; if (!cxt->przs && !cxt->cprz && !cxt->fprz) { - pr_err("memory size too small, minimum is %lu\n", + pr_err("memory size too small, minimum is %zu\n", cxt->console_size + cxt->record_size + cxt->ftrace_size); goto fail_cnt; @@ -414,13 +414,14 @@ static int __devinit ramoops_probe(struct platform_device *pdev) cxt->pstore.data = cxt; /* - * Console can handle any buffer size, so prefer dumps buffer - * size since usually it is smaller. + * Console can handle any buffer size, so prefer LOG_LINE_MAX. If we + * have to handle dumps, we must have at least record_size buffer. And + * for ftrace, bufsize is irrelevant (if bufsize is 0, buf will be + * ZERO_SIZE_PTR). */ - if (cxt->przs) - cxt->pstore.bufsize = cxt->przs[0]->buffer_size; - else - cxt->pstore.bufsize = cxt->cprz->buffer_size; + if (cxt->console_size) + cxt->pstore.bufsize = 1024; /* LOG_LINE_MAX */ + cxt->pstore.bufsize = max(cxt->record_size, cxt->pstore.bufsize); cxt->pstore.buf = kmalloc(cxt->pstore.bufsize, GFP_KERNEL); spin_lock_init(&cxt->pstore.buf_lock); if (!cxt->pstore.buf) { @@ -537,6 +538,7 @@ postcore_initcall(ramoops_init); static void __exit ramoops_exit(void) { platform_driver_unregister(&ramoops_driver); + platform_device_unregister(dummy); kfree(dummy_data); } module_exit(ramoops_exit); |