Messages in this thread Patch in this message | | | Date | Wed, 24 Jul 2019 11:45:11 -0700 | Subject | [PATCH 2/3] Fix ordered-events.c array-bounds error | From | Numfor Mbiziwo-Tiapo <> |
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Perf does not build with the ubsan (undefined behavior sanitizer) and there is an error that says:
tools/perf/util/debug.h:38:2: error: array subscript is above array bounds [-Werror=array-bounds] eprintf_time(n, var, t, fmt, ##__VA_ARGS__) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
tools/perf/util/debug.h:40:34: note: in expansion of macro ‘pr_time_N’ #define pr_oe_time(t, fmt, ...) pr_time_N(1, debug_ordered_events, t, pr_fmt(fmt), ##__VA_ARGS__)
util/ordered-events.c:329:2: note: in expansion of macro ‘pr_oe_time’ pr_oe_time(oe->next_flush, "next_flush - ordered_events__flush POST %s, nr_events %u\n",
This can be reproduced by running (from the tip directory): make -C tools/perf USE_CLANG=1 EXTRA_CFLAGS="-fsanitize=undefined"
The error stems from the 'str' array in the __ordered_events__flush function in tools/perf/util/ordered-events.c. On line 319 of this file, they use values of the variable 'how' (which has the type enum oeflush - defined in ordered-events.h) as indices for the 'str' array. Since 'how' has 5 values and the 'str' array only has 3, when the 4th and 5th values of 'how' (OE_FLUSH__TOP and OE_FLUSH__TIME) are used as indices, this will go out of the bounds of the 'str' array. Adding the matching strings from the enum values into the 'str' array fixes this.
Signed-off-by: Numfor Mbiziwo-Tiapo <nums@google.com> --- tools/perf/util/ordered-events.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/tools/perf/util/ordered-events.c b/tools/perf/util/ordered-events.c index 897589507d97..c092b0c39d2b 100644 --- a/tools/perf/util/ordered-events.c +++ b/tools/perf/util/ordered-events.c @@ -270,6 +270,8 @@ static int __ordered_events__flush(struct ordered_events *oe, enum oe_flush how, "FINAL", "ROUND", "HALF ", + "TOP", + "TIME", }; int err; bool show_progress = false; -- 2.22.0.657.g960e92d24f-goog
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