The test assumes an insufficient altstack is allowed. Then it raises a signal to test the delivery failure due to an altstack overflow.
The kernel now provides the STRICT_SIGALTSTACK_SIZE option to tweak sigaltstack()'s sanity check to prevent an insufficient altstack. ENOMEM is returned on the check failure.
Adjust the code to skip the test when this option is on.
Signed-off-by: Chang S. Bae chang.seok.bae@intel.com Reviewed-by: Shuah Khan skhan@linuxfoundation.org Cc: Shuah Khan shuah@kernel.org Cc: Thomas Gleixner tglx@linutronix.de Cc: Borislav Petkov bp@alien8.de Cc: Dave Hansen dave.hansen@linux.intel.com Cc: linux-kselftest@vger.kernel.org Cc: linux-kernel@vger.kernel.org --- Changes from v2: * Fix the subsystem name in the subject.
Changes from v1: * Call out the config name (Shuah Khan). * Massage the print message (Shuah Khan). --- tools/testing/selftests/x86/sigaltstack.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/x86/sigaltstack.c b/tools/testing/selftests/x86/sigaltstack.c index f689af75e979..22a88b764a8e 100644 --- a/tools/testing/selftests/x86/sigaltstack.c +++ b/tools/testing/selftests/x86/sigaltstack.c @@ -88,8 +88,18 @@ static void sigalrm(int sig, siginfo_t *info, void *ctx_void)
static void test_sigaltstack(void *altstack, unsigned long size) { - if (setup_altstack(altstack, size)) + if (setup_altstack(altstack, size)) { + /* + * The kernel may return ENOMEM when the altstack size + * is insufficient. Skip the test in this case. + */ + if (errno == ENOMEM && size < at_minstack_size) { + printf("[SKIP]\tThe running kernel disallows an insufficient size.\n"); + return; + } + err(1, "sigaltstack()"); + }
sigalrm_expected = (size > at_minstack_size) ? true : false;