| From | "Paul E. McKenney" <> | Subject | [PATCH v2 nolibc 01/15] tools/nolibc: tests: use volatile to force stack smashing | Date | Thu, 18 May 2023 07:55:07 -0700 |
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From: Thomas Weißschuh <linux@weissschuh.net>
Use a volatile pointer to write outside the buffer so the compiler can't optimize it away.
Reported-by: Alexey Dobriyan <adobriyan@gmail.com> Link: https://lore.kernel.org/lkml/c0584807-511c-4496-b062-1263ea38f349@p183/ Signed-off-by: Thomas Weißschuh <linux@weissschuh.net> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Paul E. McKenney <paulmck@kernel.org> --- tools/testing/selftests/nolibc/nolibc-test.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c index 21bacc928bf7..47013b78972e 100644 --- a/tools/testing/selftests/nolibc/nolibc-test.c +++ b/tools/testing/selftests/nolibc/nolibc-test.c @@ -667,17 +667,13 @@ int run_stdlib(int min, int max) return ret; } -#if defined(__clang__) -__attribute__((optnone)) -#elif defined(__GNUC__) -__attribute__((optimize("O0"))) -#endif static int smash_stack(void) { char buf[100]; + volatile char *ptr = buf; for (size_t i = 0; i < 200; i++) - buf[i] = 'P'; + ptr[i] = 'P'; return 1; } -- 2.40.1
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