Commit e7654c3f authored by Thomas Weißschuh's avatar Thomas Weißschuh Committed by Paul E. McKenney
Browse files

tools/nolibc: tests: use volatile to force stack smashing 



Use a volatile pointer to write outside the buffer so the compiler can't
optimize it away.

Reported-by: default avatarAlexey Dobriyan <adobriyan@gmail.com>
Link: https://lore.kernel.org/lkml/c0584807-511c-4496-b062-1263ea38f349@p183/


Signed-off-by: default avatarThomas Weißschuh <linux@weissschuh.net>
Signed-off-by: default avatarWilly Tarreau <w@1wt.eu>
Signed-off-by: default avatarPaul E. McKenney <paulmck@kernel.org>
parent ac9a7868

tools/testing/selftests/nolibc/nolibc-test.c

+2 −6
Original line number Diff line number Diff line
@@ -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;

}