[PATCH 3/5] blktrace: fix off-by-one bug

Li Zefan
2009-03-24T08:05:52Z

'what' is used as the index of array what2act, so it can't >= the array size.

Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
---
kernel/trace/blktrace.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9af4143..0e91caa 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1149,7 +1149,7 @@ static enum print_line_t blk_trace_event_print(struct trace_iterator *iter,
if (!trace_print_context(iter))
return TRACE_TYPE_PARTIAL_LINE;

- if (unlikely(what == 0 || what > ARRAY_SIZE(what2act)))
+ if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
ret = trace_seq_printf(s, "Bad pc action %x\n", what);
else {
const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
@@ -1196,7 +1196,7 @@ static enum print_line_t blk_tracer_print_line(struct trace_iterator *iter)
t = (const struct blk_io_trace *)iter->ent;
what = t->action & ((1 << BLK_TC_SHIFT) - 1);

- if (unlikely(what == 0 || what > ARRAY_SIZE(what2act)))
+ if (unlikely(what == 0 || what >= ARRAY_SIZE(what2act)))
ret = trace_seq_printf(&iter->seq, "Bad pc action %x\n", what);
else {
const bool long_act = !!(trace_flags & TRACE_ITER_VERBOSE);
--
1.5.4.rc3