From 5bf9a1ee350a10feb94107de32a203d81fbbe706 Mon Sep 17 00:00:00 2001 From: Pekka Paalanen Date: Tue, 16 Sep 2008 22:06:42 +0300 Subject: ftrace: inject markers via trace_marker file MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Allow a user to inject a marker (TRACE_PRINT entry) into the trace ring buffer. The related file operations are derived from code by Frédéric Weisbecker . Signed-off-by: Pekka Paalanen Acked-by: Steven Rostedt Signed-off-by: Ingo Molnar --- kernel/trace/trace.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++---- kernel/trace/trace.h | 4 +++ 2 files changed, 75 insertions(+), 5 deletions(-) (limited to 'kernel') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7e7154f..eee1fd9 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2879,6 +2879,66 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, return cnt; } +static int tracing_open_mark(struct inode *inode, struct file *filp) +{ + int ret; + + ret = tracing_open_generic(inode, filp); + if (ret) + return ret; + + if (current_trace == &no_tracer) + return -ENODEV; + + return 0; +} + +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 (current_trace == &no_tracer || !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, @@ -2910,6 +2970,11 @@ static struct file_operations tracing_entries_fops = { .write = tracing_entries_write, }; +static struct file_operations tracing_mark_fops = { + .open = tracing_open_mark, + .write = tracing_mark_write, +}; + #ifdef CONFIG_DYNAMIC_FTRACE static ssize_t @@ -3027,6 +3092,12 @@ static __init void tracer_init_debugfs(void) pr_warning("Could not create debugfs " "'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, &ftrace_update_tot_cnt, @@ -3040,11 +3111,6 @@ static __init void tracer_init_debugfs(void) #endif } -#define TRACE_BUF_SIZE 1024 -#define TRACE_PRINT_BUF_SIZE \ - (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) -#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) - int trace_vprintk(unsigned long ip, const char *fmt, va_list args) { static DEFINE_SPINLOCK(trace_buf_lock); diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 648433d..42f65d0 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -124,6 +124,10 @@ struct trace_entry { }; #define TRACE_ENTRY_SIZE sizeof(struct trace_entry) +#define TRACE_BUF_SIZE 1024 +#define TRACE_PRINT_BUF_SIZE \ + (sizeof(struct trace_field) - offsetof(struct trace_field, print.buf)) +#define TRACE_CONT_BUF_SIZE sizeof(struct trace_field) /* * The CPU trace array - it consists of thousands of trace entries -- cgit v1.1