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[1/2] selftests/x86/signal: Adjust the test to the kernel's altstack check

Message ID 20220401221014.13556-2-chang.seok.bae@intel.com
State Superseded
Headers show
Series selftests/x86: AMX-related test improvements | expand

Commit Message

Chang S. Bae April 1, 2022, 10:10 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 an 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>
Cc: linux-kselftest@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
---
 tools/testing/selftests/x86/sigaltstack.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

Comments

Shuah Khan June 16, 2022, 10:47 p.m. UTC | #1
On 4/1/22 4:10 PM, Chang S. Bae wrote:
> 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 an 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.

Mention the option name here and in the Skip message.

> 
> Signed-off-by: Chang S. Bae <chang.seok.bae@intel.com>
> Cc: linux-kselftest@vger.kernel.org
> Cc: linux-kernel@vger.kernel.org
> ---
>   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");

Please improve this message to clearly why it is okay to skip the test.
Mention that the option to disallowing insufficient is enabled and that
the test can't be run.


> +			return;
> +		}
> +
>   		err(1, "sigaltstack()");
> +	}
>   
>   	sigalrm_expected = (size > at_minstack_size) ? true : false;
>   
> 

With these changes:

Reviewed-by: Shuah Khan <skhan@linuxfoundation.org>

thanks,
-- Shuah
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;