dect
/
linux-2.6
Archived
13
0
Fork 0
Code Releases Activity

tracing: limit the number of loops the ring buffer self test can make 

Impact: prevent deadlock if ring buffer gets corrupted

This patch adds a paranoid check to make sure the ring buffer consumer
does not go into an infinite loop. Since the ring buffer has been set
to read only, the consumer should not loop for more than the ring buffer
size. A check is added to make sure the consumer does not loop more than
the ring buffer size.

Signed-off-by: Steven Rostedt <srostedt@redhat.com>
This commit is contained in:
Steven Rostedt 2009-02-18 22:50:01 -05:00
parent 4d7a077c0c
commit 4b3e3d2284
1 changed files with 10 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

10
kernel/trace/trace_selftest.c
View File

@ -23,10 +23,20 @@ static int trace_test_buffer_cpu(struct trace_array *tr, int cpu)
{
struct ring_buffer_event *event;
struct trace_entry *entry;
unsigned int loops = 0;
while ((event = ring_buffer_consume(tr->buffer, cpu, NULL))) {
entry = ring_buffer_event_data(event);
/*
* The ring buffer is a size of trace_buf_size, if
* we loop more than the size, there's something wrong
* with the ring buffer.
*/
if (loops++ > trace_buf_size) {
printk(KERN_CONT ".. bad ring buffer ");
goto failed;
}
if (!trace_valid_entry(entry)) {
printk(KERN_CONT ".. invalid entry %d ",
entry->type);