[PATCH 1/5] kselftest/arm64: Verify that we reject out of bounds VLs in sve-ptrace
From: Mark Brown <broonie@kernel.org>
Date: 2025-08-20 18:29:30
Also in:
linux-arm-kernel, linux-kselftest, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel selftest framework, the rest · Maintainers:
Catalin Marinas, Will Deacon, Shuah Khan, Linus Torvalds
We do not currently have a test that asserts that we reject attempts to set a vector length smaller than SVE_VL_MIN or larger than SVE_VL_MAX, add one since that is our current behaviour. Signed-off-by: Mark Brown <broonie@kernel.org> --- tools/testing/selftests/arm64/fp/sve-ptrace.c | 32 ++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-)
diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c
index b22303778fb0..a9b2377c46b8 100644
--- a/tools/testing/selftests/arm64/fp/sve-ptrace.c
+++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c@@ -66,7 +66,7 @@ static const struct vec_type vec_types[] = { }; #define VL_TESTS (((TEST_VQ_MAX - SVE_VQ_MIN) + 1) * 4) -#define FLAG_TESTS 2 +#define FLAG_TESTS 4 #define FPSIMD_TESTS 2 #define EXPECTED_TESTS ((VL_TESTS + FLAG_TESTS + FPSIMD_TESTS) * ARRAY_SIZE(vec_types))
@@ -270,6 +270,25 @@ static void check_u32(unsigned int vl, const char *reg, } } +/* Set out of range VLs */ +static void ptrace_set_vl_ranges(pid_t child, const struct vec_type *type) +{ + struct user_sve_header sve; + int ret; + + memset(&sve, 0, sizeof(sve)); + sve.flags = SVE_PT_REGS_SVE; + sve.size = sizeof(sve); + + ret = set_sve(child, type, &sve); + ksft_test_result(ret != 0, "%s Set invalid VL 0\n", type->name); + + sve.vl = SVE_VL_MAX + SVE_VQ_BYTES; + ret = set_sve(child, type, &sve); + ksft_test_result(ret != 0, "%s Set invalid VL %d\n", type->name, + SVE_VL_MAX + SVE_VQ_BYTES); +} + /* Access the FPSIMD registers via the SVE regset */ static void ptrace_sve_fpsimd(pid_t child, const struct vec_type *type) {
@@ -703,6 +722,17 @@ static int do_parent(pid_t child) vec_types[i].name); } + /* Setting out of bounds VLs should fail */ + if (getauxval(vec_types[i].hwcap_type) & vec_types[i].hwcap) { + ptrace_set_vl_ranges(child, &vec_types[i]); + } else { + ksft_test_result_skip("%s Set invalid VL 0\n", + vec_types[i].name); + ksft_test_result_skip("%s Set invalid VL %d\n", + vec_types[i].name, + SVE_VL_MAX + SVE_VQ_BYTES); + } + /* Step through every possible VQ */ for (vq = SVE_VQ_MIN; vq <= TEST_VQ_MAX; vq++) { vl = sve_vl_from_vq(vq);
--
2.39.5