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[v3,1/3] selftests/x86/sigaltstack: Adjust the test to the kernel's altstack check

Message ID 20230330233520.21937-2-chang.seok.bae@intel.com
State New
Headers show
Series [v3,1/3] selftests/x86/sigaltstack: Adjust the test to the kernel's altstack check | expand

Commit Message

Chang S. Bae March 30, 2023, 11:35 p.m. UTC 
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 mbox series

Patch

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;