Messages in this thread |  | | | Date | Tue, 24 Mar 2009 09:27:54 +0100 | | From | Ingo Molnar <> | | Subject | Re: [PATCH 3/5] blktrace: fix off-by-one bug |
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* Li Zefan <lizf@cn.fujitsu.com> wrote:
> '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)))
ah, nice. How did you notice - did we miss "remap" events due to this bug?
Ingo
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