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authorSteven Rostedt (Red Hat) <srostedt@redhat.com>2013-03-05 16:18:16 -0500
committerSteven Rostedt <rostedt@goodmis.org>2013-03-15 00:35:47 -0400
commit6de58e6269cd0568ca5fbae14423914eff0f7811 (patch)
tree3ce4d96d1549925a2724ed713d76cf2f9683ff72 /kernel/trace/trace.c
parent0b85ffc293044393623059eda9904a7d5b644e36 (diff)
tracing: Add snapshot_raw to extract the raw data from snapshot
Add a 'snapshot_raw' per_cpu file that allows tools to read the raw binary data of the snapshot buffer. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c113
1 files changed, 95 insertions, 18 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 30393268896..9bb0b52cbd3 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4206,6 +4206,12 @@ static int tracing_clock_open(struct inode *inode, struct file *file)
return single_open(file, tracing_clock_show, inode->i_private);
}
+struct ftrace_buffer_info {
+ struct trace_iterator iter;
+ void *spare;
+ unsigned int read;
+};
+
#ifdef CONFIG_TRACER_SNAPSHOT
static int tracing_snapshot_open(struct inode *inode, struct file *file)
{
@@ -4336,6 +4342,35 @@ static int tracing_snapshot_release(struct inode *inode, struct file *file)
return 0;
}
+static int tracing_buffers_open(struct inode *inode, struct file *filp);
+static ssize_t tracing_buffers_read(struct file *filp, char __user *ubuf,
+ size_t count, loff_t *ppos);
+static int tracing_buffers_release(struct inode *inode, struct file *file);
+static ssize_t tracing_buffers_splice_read(struct file *file, loff_t *ppos,
+ struct pipe_inode_info *pipe, size_t len, unsigned int flags);
+
+static int snapshot_raw_open(struct inode *inode, struct file *filp)
+{
+ struct ftrace_buffer_info *info;
+ int ret;
+
+ ret = tracing_buffers_open(inode, filp);
+ if (ret < 0)
+ return ret;
+
+ info = filp->private_data;
+
+ if (info->iter.trace->use_max_tr) {
+ tracing_buffers_release(inode, filp);
+ return -EBUSY;
+ }
+
+ info->iter.snapshot = true;
+ info->iter.trace_buffer = &info->iter.tr->max_buffer;
+
+ return ret;
+}
+
#endif /* CONFIG_TRACER_SNAPSHOT */
@@ -4402,14 +4437,17 @@ static const struct file_operations snapshot_fops = {
.llseek = tracing_seek,
.release = tracing_snapshot_release,
};
-#endif /* CONFIG_TRACER_SNAPSHOT */
-struct ftrace_buffer_info {
- struct trace_iterator iter;
- void *spare;
- unsigned int read;
+static const struct file_operations snapshot_raw_fops = {
+ .open = snapshot_raw_open,
+ .read = tracing_buffers_read,
+ .release = tracing_buffers_release,
+ .splice_read = tracing_buffers_splice_read,
+ .llseek = no_llseek,
};
+#endif /* CONFIG_TRACER_SNAPSHOT */
+
static int tracing_buffers_open(struct inode *inode, struct file *filp)
{
struct trace_cpu *tc = inode->i_private;
@@ -4452,16 +4490,26 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
struct ftrace_buffer_info *info = filp->private_data;
struct trace_iterator *iter = &info->iter;
ssize_t ret;
- size_t size;
+ ssize_t size;
if (!count)
return 0;
+ mutex_lock(&trace_types_lock);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
+ size = -EBUSY;
+ goto out_unlock;
+ }
+#endif
+
if (!info->spare)
info->spare = ring_buffer_alloc_read_page(iter->trace_buffer->buffer,
iter->cpu_file);
+ size = -ENOMEM;
if (!info->spare)
- return -ENOMEM;
+ goto out_unlock;
/* Do we have previous read data to read? */
if (info->read < PAGE_SIZE)
@@ -4477,31 +4525,42 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
if (ret < 0) {
if (trace_empty(iter)) {
- if ((filp->f_flags & O_NONBLOCK))
- return -EAGAIN;
+ if ((filp->f_flags & O_NONBLOCK)) {
+ size = -EAGAIN;
+ goto out_unlock;
+ }
+ mutex_unlock(&trace_types_lock);
iter->trace->wait_pipe(iter);
- if (signal_pending(current))
- return -EINTR;
+ mutex_lock(&trace_types_lock);
+ if (signal_pending(current)) {
+ size = -EINTR;
+ goto out_unlock;
+ }
goto again;
}
- return 0;
+ size = 0;
+ goto out_unlock;
}
info->read = 0;
-
read:
size = PAGE_SIZE - info->read;
if (size > count)
size = count;
ret = copy_to_user(ubuf, info->spare + info->read, size);
- if (ret == size)
- return -EFAULT;
+ if (ret == size) {
+ size = -EFAULT;
+ goto out_unlock;
+ }
size -= ret;
*ppos += size;
info->read += size;
+ out_unlock:
+ mutex_unlock(&trace_types_lock);
+
return size;
}
@@ -4591,10 +4650,21 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
};
struct buffer_ref *ref;
int entries, size, i;
- size_t ret;
+ ssize_t ret;
- if (splice_grow_spd(pipe, &spd))
- return -ENOMEM;
+ mutex_lock(&trace_types_lock);
+
+#ifdef CONFIG_TRACER_MAX_TRACE
+ if (iter->snapshot && iter->tr->current_trace->use_max_tr) {
+ ret = -EBUSY;
+ goto out;
+ }
+#endif
+
+ if (splice_grow_spd(pipe, &spd)) {
+ ret = -ENOMEM;
+ goto out;
+ }
if (*ppos & (PAGE_SIZE - 1)) {
ret = -EINVAL;
@@ -4666,7 +4736,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
ret = -EAGAIN;
goto out;
}
+ mutex_unlock(&trace_types_lock);
iter->trace->wait_pipe(iter);
+ mutex_lock(&trace_types_lock);
if (signal_pending(current)) {
ret = -EINTR;
goto out;
@@ -4677,6 +4749,8 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
ret = splice_to_pipe(pipe, &spd);
splice_shrink_spd(&spd);
out:
+ mutex_unlock(&trace_types_lock);
+
return ret;
}
@@ -4880,6 +4954,9 @@ tracing_init_debugfs_percpu(struct trace_array *tr, long cpu)
#ifdef CONFIG_TRACER_SNAPSHOT
trace_create_file("snapshot", 0644, d_cpu,
(void *)&data->trace_cpu, &snapshot_fops);
+
+ trace_create_file("snapshot_raw", 0444, d_cpu,
+ (void *)&data->trace_cpu, &snapshot_raw_fops);
#endif
}