Commit 66790bc8 authored Mar 14, 2018 by Colin Ian King Committed by Arnaldo Carvalho de Melo Mar 16, 2018

perf tests: Fix out of bounds access on array fd when cnt is 100



Currently when cnt is 100 an array bounds overflow occurs on the
assignment of fd[cnt]. Fix this by performing the bounds check on cnt
before writing to fd.

Detected by cppcheck:

tools/perf/tests/bp_account.c:115: (warning) Either the condition
'cnt==100' is redundant or the array 'fd[100]' is accessed at index 100,
which is out of bounds.

Signed-off-by: Colin King <colin.king@canonical.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: kernel-janitors@vger.kernel.org
Fixes: 032db28e ("perf tests: Add breakpoint accounting/modify test")
Link: http://lkml.kernel.org/r/20180314173354.11250-1-colin.king@canonical.com


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

parent 6810158d

tools/perf/tests/bp_account.c

+3 −5

Original line number	Diff line number	Diff line
		@@ -107,16 +107,14 @@ static int detect_cnt(bool is_x)
		int fd[100], cnt = 0, i;

		while (1) {
		fd[cnt] = __event(is_x, addr, &attr);

		if (fd[cnt] < 0)
		break;

		if (cnt == 100) {
		pr_debug("way too many debug registers, fix the test\n");
		return 0;
		}
		fd[cnt] = __event(is_x, addr, &attr);

		if (fd[cnt] < 0)
		break;
		cnt++;
		}

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