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Commit c13d2f7c authored by Carsten Emde's avatar Carsten Emde Committed by Steven Rostedt
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tracing: Fix trace_marker output 



When a string was written to <debugfs>/tracing/trace_marker, some
strange characters appeared in the trace output instead of the
string, since a vprint function erroneously called a vararg print
function with a va_list argument. This patch fixes the problem and
simplifies the related code.

Signed-off-by: default avatarCarsten Emde <C.Emde@osadl.org>
LKML-Reference: <4B01AE5D.1010801@osadl.org>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 811cb50b

kernel/trace/trace.c

+14 −25
Original line number Original line Diff line number Diff line
@@ -1361,11 +1361,12 @@ int trace_array_vprintk(struct trace_array *tr, 
	pause_graph_tracing();

	pause_graph_tracing();

	raw_local_irq_save(irq_flags);

	raw_local_irq_save(irq_flags);

	__raw_spin_lock(&trace_buf_lock);

	__raw_spin_lock(&trace_buf_lock);

	if (args == NULL) {

		strncpy(trace_buf, fmt, TRACE_BUF_SIZE);

		len = strlen(trace_buf);

	} else

		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);

		len = vsnprintf(trace_buf, TRACE_BUF_SIZE, fmt, args);





	len = min(len, TRACE_BUF_SIZE-1);

	trace_buf[len] = 0;



	size = sizeof(*entry) + len + 1;

	size = sizeof(*entry) + len + 1;

	buffer = tr->buffer;

	buffer = tr->buffer;

	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,

	event = trace_buffer_lock_reserve(buffer, TRACE_PRINT, size,
@@ -1376,7 +1377,7 @@ int trace_array_vprintk(struct trace_array *tr, 
	entry->ip = ip;

	entry->ip = ip;





	memcpy(&entry->buf, trace_buf, len);

	memcpy(&entry->buf, trace_buf, len);

	entry->buf[len] = 0;

	entry->buf[len] = '\0';

	if (!filter_check_discard(call, entry, buffer, event))

	if (!filter_check_discard(call, entry, buffer, event))

		ring_buffer_unlock_commit(buffer, event);

		ring_buffer_unlock_commit(buffer, event);
@@ -3319,22 +3320,11 @@ tracing_entries_write(struct file *filp, const char __user *ubuf, 
	return cnt;

	return cnt;

}

}





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

static ssize_t

tracing_mark_write(struct file *filp, const char __user *ubuf,

tracing_mark_write(struct file *filp, const char __user *ubuf,

					size_t cnt, loff_t *fpos)

					size_t cnt, loff_t *fpos)

{

{

	char *buf;

	char *buf;

	char *end;





	if (tracing_disabled)

	if (tracing_disabled)

		return -EINVAL;

		return -EINVAL;
@@ -3342,7 +3332,7 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, 
	if (cnt > TRACE_BUF_SIZE)

	if (cnt > TRACE_BUF_SIZE)

		cnt = TRACE_BUF_SIZE;

		cnt = TRACE_BUF_SIZE;





	buf = kmalloc(cnt + 1, GFP_KERNEL);

	buf = kmalloc(cnt + 2, GFP_KERNEL);

	if (buf == NULL)

	if (buf == NULL)

		return -ENOMEM;

		return -ENOMEM;
@@ -3350,14 +3340,13 @@ tracing_mark_write(struct file *filp, const char __user *ubuf, 
		kfree(buf);

		kfree(buf);

		return -EFAULT;

		return -EFAULT;

	}

	}



	if (buf[cnt-1] != '\n') {

	/* Cut from the first nil or newline. */

		buf[cnt] = '\n';

		buf[cnt+1] = '\0';

	} else

		buf[cnt] = '\0';

		buf[cnt] = '\0';

	end = strchr(buf, '\n');

	if (end)

		*end = '\0';





	cnt = mark_printk("%s\n", buf);

	cnt = trace_vprintk(0, buf, NULL);

	kfree(buf);

	kfree(buf);

	*fpos += cnt;

	*fpos += cnt;