selftests: arm64: Remove extraneous register setting code

For some reason the SVE ptrace test code starts off by setting values in
some of the SVE vector registers in the parent process which it then never
interacts with when verifying the ptrace interfaces. This is not especially
relevant to what's being tested and somewhat confusing when reading the
code so let's remove it.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20210913125505.52619-4-broonie@kernel.orgSigned-off-by: Will Deacon <will@kernel.org>

tools/testing/selftests/arm64/fp/Makefile

@@ -12,7 +12,7 @@ all: $(TEST_GEN_PROGS) $(TEST_PROGS_EXTENDED)
 fpsimd-test: fpsimd-test.o
 	$(CC) -nostdlib $^ -o $@
 rdvl-sve: rdvl-sve.o rdvl.o
-sve-ptrace: sve-ptrace.o sve-ptrace-asm.o
+sve-ptrace: sve-ptrace.o
 sve-probe-vls: sve-probe-vls.o rdvl.o
 sve-test: sve-test.o
 	$(CC) -nostdlib $^ -o $@

tools/testing/selftests/arm64/fp/sve-ptrace-asm.S

-// SPDX-License-Identifier: GPL-2.0-only
-// Copyright (C) 2015-2019 ARM Limited.
-// Original author: Dave Martin <Dave.Martin@arm.com>
-#include <asm/unistd.h>
-
-.arch_extension sve
-
-.globl sve_store_patterns
-
-sve_store_patterns:
-	mov	x1, x0
-
-	index	z0.b, #0, #1
-	str	q0, [x1]
-
-	mov	w8, #__NR_getpid
-	svc	#0
-	str	q0, [x1, #0x10]
-
-	mov	z1.d, z0.d
-	str	q0, [x1, #0x20]
-
-	mov	w8, #__NR_getpid
-	svc	#0
-	str	q0, [x1, #0x30]
-
-	mov	z1.d, z0.d
-	str	q0, [x1, #0x40]
-
-	ret
-
-.size	sve_store_patterns, . - sve_store_patterns
-.type	sve_store_patterns, @function

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

@@ -26,11 +26,6 @@
 #define NT_ARM_SVE 0x405
 #endif
 
-/* Number of registers filled in by sve_store_patterns */
-#define NR_VREGS 5
-
-void sve_store_patterns(__uint128_t v[NR_VREGS]);
-
 static void dump(const void *buf, size_t size)
 {
 	size_t i;
@@ -40,23 +35,6 @@ static void dump(const void *buf, size_t size)
 		printf(" %.2x", *p++);
 }
 
-static int check_vregs(const __uint128_t vregs[NR_VREGS])
-{
-	int i;
-	int ok = 1;
-
-	for (i = 0; i < NR_VREGS; ++i) {
-		printf("# v[%d]:", i);
-		dump(&vregs[i], sizeof vregs[i]);
-		putchar('\n');
-
-		if (vregs[i] != vregs[0])
-			ok = 0;
-	}
-
-	return ok;
-}
-
 static int do_child(void)
 {
 	if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
@@ -309,7 +287,6 @@ static int do_parent(pid_t child)
 int main(void)
 {
 	int ret = EXIT_SUCCESS;
-	__uint128_t v[NR_VREGS];
 	pid_t child;
 
 	ksft_print_header();
@@ -318,11 +295,6 @@ int main(void)
 	if (!(getauxval(AT_HWCAP) & HWCAP_SVE))
 		ksft_exit_skip("SVE not available\n");
 
-	sve_store_patterns(v);
-
-	if (!check_vregs(v))
-		ksft_exit_fail_msg("Initial check_vregs() failed\n");
-
 	child = fork();
 	if (!child)
 		return do_child();