[PATCH v2 3/3] kselftest/arm64: Cover disabling streaming mode without SVE in fp-ptrace

Mark Brown
2025-10-15T18:34:10Z

On a system which support SME but not SVE we can now disable streaming mode
via ptrace by writing FPSIMD formatted data through NT_ARM_SVE with a VL of
0. Extend fp-ptrace to cover rather than skip these cases, relax the check
for SVE writes of FPSIMD format data to not skip if SME is supported and
accept 0 as the VL when performing the ptrace write.

Signed-off-by: Mark Brown <broonie@kernel.org>
---
tools/testing/selftests/arm64/fp/fp-ptrace.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/tools/testing/selftests/arm64/fp/fp-ptrace.c b/tools/testing/selftests/arm64/fp/fp-ptrace.c
index a85c19e9524e..0114108ab25f 100644
--- a/tools/testing/selftests/arm64/fp/fp-ptrace.c
+++ b/tools/testing/selftests/arm64/fp/fp-ptrace.c
@@ -1071,7 +1071,7 @@ static bool sve_write_supported(struct test_config *config)

static bool sve_write_fpsimd_supported(struct test_config *config)
{
- if (!sve_supported())
+ if (!sve_supported() && !sme_supported())
return false;

if ((config->svcr_in & SVCR_ZA) != (config->svcr_expected & SVCR_ZA))
@@ -1231,9 +1231,6 @@ static void sve_write_fpsimd(pid_t child, struct test_config *config)
vl = vl_expected(config);
vq = __sve_vq_from_vl(vl);

- if (!vl)
- return;
-
iov.iov_len = SVE_PT_SIZE(vq, SVE_PT_REGS_FPSIMD);
iov.iov_base = malloc(iov.iov_len);
if (!iov.iov_base) {

--
2.47.2