Commit eb9df6d6 authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

kselftst/arm64: Test NT_ARM_SVE FPSIMD format writes on non-SVE systems 



In order to allow exiting streaming mode on systems with SME but not SVE
we allow writes of FPSIMD format data via NT_ARM_SVE even when SVE is not
supported, add a test case that covers this to sve-ptrace.

We do not support reads.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 472800cd

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

+61 −0
Original line number Diff line number Diff line
@@ -394,6 +394,58 @@ static void ptrace_sve_fpsimd(pid_t child, const struct vec_type *type) 
	free(svebuf);

}



/* Write the FPSIMD registers via the SVE regset when SVE is not supported */

static void ptrace_sve_fpsimd_no_sve(pid_t child)

{

	void *svebuf;

	struct user_sve_header *sve;

	struct user_fpsimd_state *fpsimd, new_fpsimd;

	unsigned int i, j;

	unsigned char *p;

	int ret;



	svebuf = malloc(SVE_PT_SIZE(0, SVE_PT_REGS_FPSIMD));

	if (!svebuf) {

		ksft_test_result_fail("Failed to allocate FPSIMD buffer\n");

		return;

	}



	/* On a system without SVE the VL should be set to 0 */

	memset(svebuf, 0, SVE_PT_SIZE(0, SVE_PT_REGS_FPSIMD));

	sve = svebuf;

	sve->flags = SVE_PT_REGS_FPSIMD;

	sve->size = SVE_PT_SIZE(0, SVE_PT_REGS_FPSIMD);

	sve->vl = 0;



	/* Try to set a known FPSIMD state via PT_REGS_SVE */

	fpsimd = (struct user_fpsimd_state *)((char *)sve +

					      SVE_PT_FPSIMD_OFFSET);

	for (i = 0; i < 32; ++i) {

		p = (unsigned char *)&fpsimd->vregs[i];



		for (j = 0; j < sizeof(fpsimd->vregs[i]); ++j)

			p[j] = j;

	}



	ret = set_sve(child, &vec_types[0], sve);

	ksft_test_result(ret == 0, "FPSIMD write via SVE\n");

	if (ret) {

		ksft_test_result_skip("Verify FPSIMD write via SVE\n");

		goto out;

	}



	/* Verify via the FPSIMD regset */

	if (get_fpsimd(child, &new_fpsimd)) {

		ksft_test_result_skip("Verify FPSIMD write via SVE\n");

		goto out;

	}

	ksft_test_result(memcmp(fpsimd, &new_fpsimd, sizeof(*fpsimd)) == 0,

			 "Verify FPSIMD write via SVE\n");



out:

	free(svebuf);

}



/* Validate attempting to set SVE data and read SVE data */

static void ptrace_set_sve_get_sve_data(pid_t child,

					const struct vec_type *type,
@@ -826,6 +878,15 @@ static int do_parent(pid_t child) 
		}

	}



	/* We support SVE writes of FPSMID format on SME only systems */

	if (!(getauxval(AT_HWCAP) & HWCAP_SVE) &&

	    (getauxval(AT_HWCAP2) & HWCAP2_SME)) {

		ptrace_sve_fpsimd_no_sve(child);

	} else {

		ksft_test_result_skip("FPSIMD write via SVE\n");

		ksft_test_result_skip("Verify FPSIMD write via SVE\n");

	}



	ret = EXIT_SUCCESS;



error: