[PATCH] perf record: Fix tool crash with xyarray

From: Ravi Bangoria
Date: Wed Oct 18 2017 - 07:51:03 EST


I see 'perf record -p <pid>' crashes with following log:

*** Error in `./perf': free(): invalid next size (normal): 0x000000000298b340 ***
======= Backtrace: =========
/lib/x86_64-linux-gnu/libc.so.6(+0x777e5)[0x7f7fd85c87e5]
/lib/x86_64-linux-gnu/libc.so.6(+0x8037a)[0x7f7fd85d137a]
/lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7f7fd85d553c]
./perf(perf_evsel__close+0xb4)[0x4b7614]
./perf(perf_evlist__delete+0x100)[0x4ab180]
./perf(cmd_record+0x1d9)[0x43a5a9]
./perf[0x49aa2f]
./perf(main+0x631)[0x427841]
/lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f7fd8571830]
./perf(_start+0x29)[0x427a59]

This is because functions xyarray__max_x() and xyarray__max_y()
are returning incorrect values, causing crash while accessing
xyarray.

Fixes: d74be4767367 ("perf xyarray: Save max_x, max_y")
Signed-off-by: Ravi Bangoria <ravi.bangoria@xxxxxxxxxxxxxxxxxx>
---
tools/perf/util/xyarray.h | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/tools/perf/util/xyarray.h b/tools/perf/util/xyarray.h
index 4ba726c..d6858ed 100644
--- a/tools/perf/util/xyarray.h
+++ b/tools/perf/util/xyarray.h
@@ -21,12 +21,12 @@ static inline void *xyarray__entry(struct xyarray *xy, int x, int y)
return &xy->contents[x * xy->row_size + y * xy->entry_size];
}

-static inline int xyarray__max_y(struct xyarray *xy)
+static inline int xyarray__max_x(struct xyarray *xy)
{
return xy->max_x;
}

-static inline int xyarray__max_x(struct xyarray *xy)
+static inline int xyarray__max_y(struct xyarray *xy)
{
return xy->max_y;
}
--
2.7.4