selftests: arm64: Add coverage of ptrace flags for SVE VL inheritance
Add a test that covers enabling and disabling of SVE vector length
inheritance via the ptrace interface.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20211005123537.976795-1-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c
index ac0629f..c4417bc 100644
--- a/tools/testing/selftests/arm64/fp/sve-ptrace.c
+++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c
@@ -22,7 +22,7 @@
#include "../../kselftest.h"
#define VL_TESTS (((SVE_VQ_MAX - SVE_VQ_MIN) + 1) * 3)
-#define FPSIMD_TESTS 3
+#define FPSIMD_TESTS 5
#define EXPECTED_TESTS (VL_TESTS + FPSIMD_TESTS)
@@ -105,6 +105,56 @@ static int set_sve(pid_t pid, const struct user_sve_header *sve)
return ptrace(PTRACE_SETREGSET, pid, NT_ARM_SVE, &iov);
}
+/* Validate setting and getting the inherit flag */
+static void ptrace_set_get_inherit(pid_t child)
+{
+ struct user_sve_header sve;
+ struct user_sve_header *new_sve = NULL;
+ size_t new_sve_size = 0;
+ int ret;
+
+ /* First set the flag */
+ memset(&sve, 0, sizeof(sve));
+ sve.size = sizeof(sve);
+ sve.vl = sve_vl_from_vq(SVE_VQ_MIN);
+ sve.flags = SVE_PT_VL_INHERIT;
+ ret = set_sve(child, &sve);
+ if (ret != 0) {
+ ksft_test_result_fail("Failed to set SVE_PT_VL_INHERIT\n");
+ return;
+ }
+
+ /*
+ * Read back the new register state and verify that we have
+ * set the flags we expected.
+ */
+ if (!get_sve(child, (void **)&new_sve, &new_sve_size)) {
+ ksft_test_result_fail("Failed to read SVE flags\n");
+ return;
+ }
+
+ ksft_test_result(new_sve->flags & SVE_PT_VL_INHERIT,
+ "SVE_PT_VL_INHERIT set\n");
+
+ /* Now clear */
+ sve.flags &= ~SVE_PT_VL_INHERIT;
+ ret = set_sve(child, &sve);
+ if (ret != 0) {
+ ksft_test_result_fail("Failed to clear SVE_PT_VL_INHERIT\n");
+ return;
+ }
+
+ if (!get_sve(child, (void **)&new_sve, &new_sve_size)) {
+ ksft_test_result_fail("Failed to read SVE flags\n");
+ return;
+ }
+
+ ksft_test_result(!(new_sve->flags & SVE_PT_VL_INHERIT),
+ "SVE_PT_VL_INHERIT cleared\n");
+
+ free(new_sve);
+}
+
/* Validate attempting to set the specfied VL via ptrace */
static void ptrace_set_get_vl(pid_t child, unsigned int vl, bool *supported)
{
@@ -452,6 +502,9 @@ static int do_parent(pid_t child)
/* FPSIMD via SVE regset */
ptrace_sve_fpsimd(child);
+ /* prctl() flags */
+ ptrace_set_get_inherit(child);
+
/* Step through every possible VQ */
for (vq = SVE_VQ_MIN; vq <= SVE_VQ_MAX; vq++) {
vl = sve_vl_from_vq(vq);