[PATCH] kselftest/arm64: Check that SVCR is 0 in signal handlers

[PATCH] kselftest/arm64: Check that SVCR is 0 in signal handlers

[Mark Brown]

We don't currently validate that we exit streaming mode and clear ZA when
we enter a signal handler. Add simple checks for this in the SSVE and ZA
tests.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
 tools/testing/selftests/arm64/signal/sve_helpers.h         | 13 +++++++++++++
 tools/testing/selftests/arm64/signal/testcases/ssve_regs.c |  5 +++++
 tools/testing/selftests/arm64/signal/testcases/za_regs.c   |  5 +++++
 3 files changed, 23 insertions(+)

diff --git a/tools/testing/selftests/arm64/signal/sve_helpers.h b/tools/testing/selftests/arm64/signal/sve_helpers.h
index 50948ce471cc620118a0c7c8df70d66dbdfbb160..ca133b93375fa587b5e02cd76b2f2fcd92591723 100644
--- a/tools/testing/selftests/arm64/signal/sve_helpers.h
+++ b/tools/testing/selftests/arm64/signal/sve_helpers.h
@@ -18,4 +18,17 @@ extern unsigned int nvls;
 
 int sve_fill_vls(bool use_sme, int min_vls);
 
+static inline uint64_t get_svcr(void)
+{
+	uint64_t val;
+
+	asm volatile (
+		"mrs	%0, S3_3_C4_C2_2\n"
+		: "=r"(val)
+		:
+		: "cc");
+
+	return val;
+}
+
 #endif
diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
index 6dbe48cf8b09ed8b7a5ab47690bd87e39e18e1e6..3dee68fa36d1cf2716f54d5f328b3f4077493c3b 100644
--- a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
@@ -85,6 +85,11 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 	fprintf(stderr, "Got expected size %u and VL %d\n",
 		head->size, ssve->vl);
 
+	if (get_svcr() != 0) {
+		fprintf(stderr, "Unexpected SVCR %llx\n", get_svcr());
+		return 1;
+	}
+
 	return 0;
 }
 
diff --git a/tools/testing/selftests/arm64/signal/testcases/za_regs.c b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
index b9e13f27f1f9aaf55db2a5e391f360993561d0b7..9fff4c50030414d06157e0da0c29fd794f707309 100644
--- a/tools/testing/selftests/arm64/signal/testcases/za_regs.c
+++ b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
@@ -91,6 +91,11 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
 		return 1;
 	}
 
+	if (get_svcr() != 0) {
+		fprintf(stderr, "Unexpected SVCR %llx\n", get_svcr());
+		return 1;
+	}
+
 	return 0;
 }
 

---
base-commit: 8e929cb546ee42c9a61d24fae60605e9e3192354
change-id: 20241106-arm64-fpmr-signal-test-c0a0c5bf0174

Best regards,
-- 
Mark Brown <broonie@kernel.org>

Re: [PATCH] kselftest/arm64: Check that SVCR is 0 in signal handlers

[Catalin Marinas]

On Wed, Nov 06, 2024 at 05:07:51PM +0000, Mark Brown wrote:
> diff --git a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
> index 6dbe48cf8b09ed8b7a5ab47690bd87e39e18e1e6..3dee68fa36d1cf2716f54d5f328b3f4077493c3b 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
> +++ b/tools/testing/selftests/arm64/signal/testcases/ssve_regs.c
> @@ -85,6 +85,11 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
>  	fprintf(stderr, "Got expected size %u and VL %d\n",
>  		head->size, ssve->vl);
>  
> +	if (get_svcr() != 0) {
> +		fprintf(stderr, "Unexpected SVCR %llx\n", get_svcr());
> +		return 1;
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/tools/testing/selftests/arm64/signal/testcases/za_regs.c b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
> index b9e13f27f1f9aaf55db2a5e391f360993561d0b7..9fff4c50030414d06157e0da0c29fd794f707309 100644
> --- a/tools/testing/selftests/arm64/signal/testcases/za_regs.c
> +++ b/tools/testing/selftests/arm64/signal/testcases/za_regs.c
> @@ -91,6 +91,11 @@ static int do_one_sme_vl(struct tdescr *td, siginfo_t *si, ucontext_t *uc,
>  		return 1;
>  	}
>  
> +	if (get_svcr() != 0) {
> +		fprintf(stderr, "Unexpected SVCR %llx\n", get_svcr());
> +		return 1;
> +	}

I think I'll change both printf specifiers to %lx here since in the libc
I have installed, uin64_t is an unsigned long (the kernel defines it as
unsigned long long). Both gcc and clang complain but the compiler
shouldn't matter since the headers come with glibc.

-- 
Catalin

Re: [PATCH] kselftest/arm64: Check that SVCR is 0 in signal handlers

[Mark Brown]

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On Tue, Nov 12, 2024 at 11:30:14AM +0000, Catalin Marinas wrote:
> On Wed, Nov 06, 2024 at 05:07:51PM +0000, Mark Brown wrote:

> > +		fprintf(stderr, "Unexpected SVCR %llx\n", get_svcr());
> > +		return 1;
> > +	}

> I think I'll change both printf specifiers to %lx here since in the libc
> I have installed, uin64_t is an unsigned long (the kernel defines it as
> unsigned long long). Both gcc and clang complain but the compiler
> shouldn't matter since the headers come with glibc.

Makes sense.  I do wish the compilers were more consistent with
including these warnings :(

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Re: [PATCH] kselftest/arm64: Check that SVCR is 0 in signal handlers

[Catalin Marinas]

On Wed, 06 Nov 2024 17:07:51 +0000, Mark Brown wrote:
> We don't currently validate that we exit streaming mode and clear ZA when
> we enter a signal handler. Add simple checks for this in the SSVE and ZA
> tests.
> 
> 

Applied to arm64 (for-next/kselftest), thanks!

[1/1] kselftest/arm64: Check that SVCR is 0 in signal handlers
      https://git.kernel.org/arm64/c/116e50d6474e

-- 
Catalin