Commit 212b0426 authored by Mark Brown's avatar Mark Brown Committed by Catalin Marinas
Browse files

selftests/arm64: Add a testcase for handling of ZA on clone() 



Add a small testcase that attempts to do a clone() with ZA enabled and
verifies that it remains enabled with the same contents. We only check
one word in one horizontal vector of ZA since there's already other tests
that check for data corruption more broadly, we're just looking to make
sure that ZA is still enabled and it looks like the data got copied.

Signed-off-by: default avatarMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220419112247.711548-40-broonie@kernel.org


Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent 43e3f855

tools/testing/selftests/arm64/fp/.gitignore

+1 −0
Original line number Diff line number Diff line
@@ -8,5 +8,6 @@ sve-test 
ssve-test

vec-syscfg

vlset

za-fork

za-ptrace

za-test

tools/testing/selftests/arm64/fp/Makefile

+8 −1
Original line number Diff line number Diff line 
# SPDX-License-Identifier: GPL-2.0



CFLAGS += -I../../../../../usr/include/

TEST_GEN_PROGS := sve-ptrace sve-probe-vls vec-syscfg za-ptrace

TEST_GEN_PROGS := sve-ptrace sve-probe-vls vec-syscfg za-fork za-ptrace

TEST_PROGS_EXTENDED := fp-pidbench fpsimd-test fpsimd-stress \

	rdvl-sme rdvl-sve \

	sve-test sve-stress \
@@ -11,6 +11,7 @@ TEST_PROGS_EXTENDED := fp-pidbench fpsimd-test fpsimd-stress \ 


all: $(TEST_GEN_PROGS) $(TEST_PROGS_EXTENDED)



# Build with nolibc to avoid effects due to libc's clone() support

fp-pidbench: fp-pidbench.S asm-utils.o

	$(CC) -nostdlib $^ -o $@

fpsimd-test: fpsimd-test.o asm-utils.o
@@ -25,6 +26,12 @@ ssve-test: sve-test.S asm-utils.o 
	$(CC) -DSSVE -nostdlib $^ -o $@

vec-syscfg: vec-syscfg.o rdvl.o

vlset: vlset.o

za-fork: za-fork.o za-fork-asm.o

	$(CC) -nostdlib -static $^ -o $@ -lgcc

za-fork.o: za-fork.c

	$(CC) -c -fno-asynchronous-unwind-tables -fno-ident -s -Os -nostdlib \

		-include ../../../../include/nolibc/nolibc.h \

		-ffreestanding -Wall $^ -o $@

za-test: za-test.o asm-utils.o

	$(CC) -nostdlib $^ -o $@

za-ptrace: za-ptrace.o

tools/testing/selftests/arm64/fp/za-fork-asm.S

0 → 100644
+61 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

// Copyright (C) 2021 ARM Limited.



#include "sme-inst.h"



.arch_extension sve



#define MAGIC     42



#define MAXVL     2048

#define MAXVL_B   (MAXVL / 8)



.pushsection .text

.data

.align 4

scratch:

	.space	MAXVL_B

.popsection



.globl fork_test

fork_test:

	smstart_za



	// For simplicity just set one word in one vector, other tests

	// cover general data corruption issues.

	ldr	x0, =scratch

	mov	x1, #MAGIC

	str	x1, [x0]

	mov	w12, wzr

	_ldr_za 12, 0			// ZA.H[W12] loaded from [X0]



	// Tail call into the C portion that does the fork & verify

	b	fork_test_c



.globl verify_fork

verify_fork:

	// SVCR should have ZA=1, SM=0

	mrs	x0, S3_3_C4_C2_2

	and	x1, x0, #3

	cmp	x1, #2

	beq	1f

	mov	x0, xzr

	b	100f

1:



	// ZA should still have the value we loaded

	ldr	x0, =scratch

	mov	w12, wzr

	_str_za 12, 0			// ZA.H[W12] stored to [X0]

	ldr	x1, [x0]

	cmp	x1, #MAGIC

	beq	2f

	mov	x0, xzr

	b	100f



2:

	// All tests passed

	mov	x0, #1

100:

	ret

tools/testing/selftests/arm64/fp/za-fork.c

0 → 100644
+156 −0
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0-only

/*

 * Copyright (C) 2022 ARM Limited.

 * Original author: Mark Brown <broonie@kernel.org>

 */



// SPDX-License-Identifier: GPL-2.0-only



#include <linux/sched.h>

#include <linux/wait.h>



#define EXPECTED_TESTS 1



static void putstr(const char *str)

{

	write(1, str, strlen(str));

}



static void putnum(unsigned int num)

{

	char c;



	if (num / 10)

		putnum(num / 10);



	c = '0' + (num % 10);

	write(1, &c, 1);

}



static int tests_run;

static int tests_passed;

static int tests_failed;

static int tests_skipped;



static void print_summary(void)

{

	if (tests_passed + tests_failed + tests_skipped != EXPECTED_TESTS)

		putstr("# UNEXPECTED TEST COUNT: ");



	putstr("# Totals: pass:");

	putnum(tests_passed);

	putstr(" fail:");

	putnum(tests_failed);

	putstr(" xfail:0 xpass:0 skip:");

	putnum(tests_skipped);

	putstr(" error:0\n");

}



int fork_test(void);

int verify_fork(void);



/*

 * If we fork the value in the parent should be unchanged and the

 * child should start with the same value.  This is called from the

 * fork_test() asm function.

 */

int fork_test_c(void)

{

	pid_t newpid, waiting;

	int child_status, parent_result;



	newpid = fork();

	if (newpid == 0) {

		/* In child */

		if (!verify_fork()) {

			putstr("# ZA state invalid in child\n");

			exit(0);

		} else {

			exit(1);

		}

	}

	if (newpid < 0) {

		putstr("# fork() failed: -");

		putnum(-newpid);

		putstr("\n");

		return 0;

	}



	parent_result = verify_fork();

	if (!parent_result)

		putstr("# ZA state invalid in parent\n");



	for (;;) {

		waiting = waitpid(newpid, &child_status, 0);



		if (waiting < 0) {

			if (errno == EINTR)

				continue;

			putstr("# waitpid() failed: ");

			putnum(errno);

			putstr("\n");

			return 0;

		}

		if (waiting != newpid) {

			putstr("# waitpid() returned wrong PID\n");

			return 0;

		}



		if (!WIFEXITED(child_status)) {

			putstr("# child did not exit\n");

			return 0;

		}



		return WEXITSTATUS(child_status) && parent_result;

	}

}



#define run_test(name)			     \

	if (name()) {			     \

		tests_passed++;		     \

	} else {			     \

		tests_failed++;		     \

		putstr("not ");		     \

	}				     \

	putstr("ok ");			     \

	putnum(++tests_run);		     \

	putstr(" " #name "\n");



int main(int argc, char **argv)

{

	int ret, i;



	putstr("TAP version 13\n");

	putstr("1..");

	putnum(EXPECTED_TESTS);

	putstr("\n");



	putstr("# PID: ");

	putnum(getpid());

	putstr("\n");



	/*

	 * This test is run with nolibc which doesn't support hwcap and

	 * it's probably disproportionate to implement so instead check

	 * for the default vector length configuration in /proc.

	 */

	ret = open("/proc/sys/abi/sme_default_vector_length", O_RDONLY, 0);

	if (ret >= 0) {

		run_test(fork_test);



	} else {

		putstr("# SME support not present\n");



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

			putstr("ok ");

			putnum(i);

			putstr(" skipped\n");

		}



		tests_skipped += EXPECTED_TESTS;

	}



	print_summary();



	return 0;

}