diff options
Diffstat (limited to 'fs/pstore/ftrace.c')
| -rw-r--r-- | fs/pstore/ftrace.c | 108 |
1 files changed, 91 insertions, 17 deletions
diff --git a/fs/pstore/ftrace.c b/fs/pstore/ftrace.c index bfbfc2698070..776cae20af4e 100644 --- a/fs/pstore/ftrace.c +++ b/fs/pstore/ftrace.c @@ -16,6 +16,7 @@ #include <linux/debugfs.h> #include <linux/err.h> #include <linux/cache.h> +#include <linux/slab.h> #include <asm/barrier.h> #include "internal.h" @@ -25,8 +26,9 @@ static u64 pstore_ftrace_stamp; static void notrace pstore_ftrace_call(unsigned long ip, unsigned long parent_ip, struct ftrace_ops *op, - struct pt_regs *regs) + struct ftrace_regs *fregs) { + int bit; unsigned long flags; struct pstore_ftrace_record rec = {}; struct pstore_record record = { @@ -39,6 +41,10 @@ static void notrace pstore_ftrace_call(unsigned long ip, if (unlikely(oops_in_progress)) return; + bit = ftrace_test_recursion_trylock(ip, parent_ip); + if (bit < 0) + return; + local_irq_save(flags); rec.ip = ip; @@ -48,6 +54,7 @@ static void notrace pstore_ftrace_call(unsigned long ip, psinfo->write(&record); local_irq_restore(flags); + ftrace_test_recursion_unlock(bit); } static struct ftrace_ops pstore_ftrace_ops __read_mostly = { @@ -57,20 +64,12 @@ static struct ftrace_ops pstore_ftrace_ops __read_mostly = { 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) +static int pstore_set_ftrace_enabled(bool on) { - 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 == pstore_ftrace_enabled) + return 0; if (on) { ftrace_ops_set_global_filter(&pstore_ftrace_ops); @@ -82,15 +81,30 @@ static ssize_t pstore_ftrace_knob_write(struct file *f, const char __user *buf, if (ret) { pr_err("%s: unable to %sregister ftrace ops: %zd\n", __func__, on ? "" : "un", ret); - goto err; + } else { + pstore_ftrace_enabled = on; } - pstore_ftrace_enabled = on; -out: - ret = count; -err: + return ret; +} + +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); + ret = pstore_set_ftrace_enabled(on); mutex_unlock(&pstore_ftrace_lock); + if (ret == 0) + ret = count; + return ret; } @@ -110,6 +124,11 @@ static const struct file_operations pstore_knob_fops = { static struct dentry *pstore_ftrace_dir; +static bool record_ftrace; +module_param(record_ftrace, bool, 0400); +MODULE_PARM_DESC(record_ftrace, + "enable ftrace recording immediately (default: off)"); + void pstore_register_ftrace(void) { if (!psinfo->write) @@ -117,6 +136,8 @@ void pstore_register_ftrace(void) pstore_ftrace_dir = debugfs_create_dir("pstore", NULL); + pstore_set_ftrace_enabled(record_ftrace); + debugfs_create_file("record_ftrace", 0600, pstore_ftrace_dir, NULL, &pstore_knob_fops); } @@ -132,3 +153,56 @@ void pstore_unregister_ftrace(void) debugfs_remove_recursive(pstore_ftrace_dir); } + +ssize_t pstore_ftrace_combine_log(char **dest_log, size_t *dest_log_size, + const char *src_log, size_t src_log_size) +{ + size_t dest_size, src_size, total, dest_off, src_off; + size_t dest_idx = 0, src_idx = 0, merged_idx = 0; + void *merged_buf; + struct pstore_ftrace_record *drec, *srec, *mrec; + size_t record_size = sizeof(struct pstore_ftrace_record); + + dest_off = *dest_log_size % record_size; + dest_size = *dest_log_size - dest_off; + + src_off = src_log_size % record_size; + src_size = src_log_size - src_off; + + total = dest_size + src_size; + merged_buf = kmalloc(total, GFP_KERNEL); + if (!merged_buf) + return -ENOMEM; + + drec = (struct pstore_ftrace_record *)(*dest_log + dest_off); + srec = (struct pstore_ftrace_record *)(src_log + src_off); + mrec = (struct pstore_ftrace_record *)(merged_buf); + + while (dest_size > 0 && src_size > 0) { + if (pstore_ftrace_read_timestamp(&drec[dest_idx]) < + pstore_ftrace_read_timestamp(&srec[src_idx])) { + mrec[merged_idx++] = drec[dest_idx++]; + dest_size -= record_size; + } else { + mrec[merged_idx++] = srec[src_idx++]; + src_size -= record_size; + } + } + + while (dest_size > 0) { + mrec[merged_idx++] = drec[dest_idx++]; + dest_size -= record_size; + } + + while (src_size > 0) { + mrec[merged_idx++] = srec[src_idx++]; + src_size -= record_size; + } + + kfree(*dest_log); + *dest_log = merged_buf; + *dest_log_size = total; + + return 0; +} +EXPORT_SYMBOL_GPL(pstore_ftrace_combine_log); |