Commit 0ba1ce1e authored by Mark Brown's avatar Mark Brown Committed by Will Deacon
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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: default avatarMark Brown <broonie@kernel.org>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20211005123537.976795-1-broonie@kernel.org


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 8694e5e6

tools/testing/selftests/arm64/fp/sve-ptrace.c

+54 −1
Original line number Diff line number Diff line
@@ -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);