[PATCH 7/8] tracing/filters: Fix MATCH_FULL filter matching for PTR_STRING

From: Steven Rostedt
Date: Thu Jan 14 2010 - 23:00:56 EST


From: Li Zefan <lizf@xxxxxxxxxxxxxx>

MATCH_FULL matching for PTR_STRING is not working correctly:

# echo 'func == vt' > events/bkl/lock_kernel/filter
# echo 1 > events/bkl/lock_kernel/enable
...
# cat trace
Xorg-1484 [000] 1973.392586: lock_kernel: ... func=vt_ioctl()
gpm-1402 [001] 1974.027740: lock_kernel: ... func=vt_ioctl()

We should pass to regex.match(..., len) the length (including '\0')
of the source string instead of the length of the pattern string.

Signed-off-by: Li Zefan <lizf@xxxxxxxxxxxxxx>
LKML-Reference: <4B4E8763.5070707@xxxxxxxxxxxxxx>
Acked-by: Frederic Weisbecker <fweisbec@xxxxxxxxx>
Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
---
kernel/trace/trace_events_filter.c | 7 +++----
1 files changed, 3 insertions(+), 4 deletions(-)

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index f364b08..60c2a4e 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -211,8 +211,9 @@ static int filter_pred_pchar(struct filter_pred *pred, void *event,
{
char **addr = (char **)(event + pred->offset);
int cmp, match;
+ int len = strlen(*addr) + 1; /* including tailing '\0' */

- cmp = pred->regex.match(*addr, &pred->regex, pred->regex.field_len);
+ cmp = pred->regex.match(*addr, &pred->regex, len);

match = cmp ^ pred->not;

@@ -782,10 +783,8 @@ static int filter_add_pred(struct filter_parse_state *ps,
pred->regex.field_len = field->size;
} else if (field->filter_type == FILTER_DYN_STRING)
fn = filter_pred_strloc;
- else {
+ else
fn = filter_pred_pchar;
- pred->regex.field_len = strlen(pred->regex.pattern);
- }
} else {
if (field->is_signed)
ret = strict_strtoll(pred->regex.pattern, 0, &val);
--
1.6.5


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