Add a test case that does some basic verification of the SVE ptrace interface, forking off a child with known values in the registers and then using ptrace to inspect and manipulate the SVE registers of the child, including in FPSIMD mode to account for sharing between the SVE and FPSIMD registers.
This program was written by Dave Martin and modified for kselftest by me.
Signed-off-by: Mark Brown broonie@kernel.org --- .../selftests/arm64/fp/sve-ptrace-asm.S | 33 ++ tools/testing/selftests/arm64/fp/sve-ptrace.c | 336 ++++++++++++++++++ 2 files changed, 369 insertions(+) create mode 100644 tools/testing/selftests/arm64/fp/sve-ptrace-asm.S create mode 100644 tools/testing/selftests/arm64/fp/sve-ptrace.c
diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace-asm.S b/tools/testing/selftests/arm64/fp/sve-ptrace-asm.S new file mode 100644 index 000000000000..3e81f9fab574 --- /dev/null +++ b/tools/testing/selftests/arm64/fp/sve-ptrace-asm.S @@ -0,0 +1,33 @@ +// 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 diff --git a/tools/testing/selftests/arm64/fp/sve-ptrace.c b/tools/testing/selftests/arm64/fp/sve-ptrace.c new file mode 100644 index 000000000000..b2282be6f938 --- /dev/null +++ b/tools/testing/selftests/arm64/fp/sve-ptrace.c @@ -0,0 +1,336 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015-2020 ARM Limited. + * Original author: Dave Martin Dave.Martin@arm.com + */ +#include <errno.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <unistd.h> +#include <sys/auxv.h> +#include <sys/ptrace.h> +#include <sys/types.h> +#include <sys/uio.h> +#include <sys/wait.h> +#include <asm/sigcontext.h> +#include <asm/ptrace.h> + +#include "../../kselftest.h" + +/* <linux/elf.h> and <sys/auxv.h> don't like each other, so: */ +#ifndef NT_ARM_SVE +#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; + const unsigned char *p = buf; + + for (i = 0; i < size; ++i) + 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)) + ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno)); + + if (raise(SIGSTOP)) + ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno)); + + return EXIT_SUCCESS; +} + +static struct user_sve_header *get_sve(pid_t pid, void **buf, size_t *size) +{ + struct user_sve_header *sve; + void *p; + size_t sz = sizeof *sve; + struct iovec iov; + + while (1) { + if (*size < sz) { + p = realloc(*buf, sz); + if (!p) { + errno = ENOMEM; + goto error; + } + + *buf = p; + *size = sz; + } + + iov.iov_base = *buf; + iov.iov_len = sz; + if (ptrace(PTRACE_GETREGSET, pid, NT_ARM_SVE, &iov)) + goto error; + + sve = *buf; + if (sve->size <= sz) + break; + + sz = sve->size; + } + + return sve; + +error: + return NULL; +} + +static int set_sve(pid_t pid, const struct user_sve_header *sve) +{ + struct iovec iov; + + iov.iov_base = (void *)sve; + iov.iov_len = sve->size; + return ptrace(PTRACE_SETREGSET, pid, NT_ARM_SVE, &iov); +} + +static void dump_sve_regs(const struct user_sve_header *sve, unsigned int num, + unsigned int vlmax) +{ + unsigned int vq; + unsigned int i; + + if ((sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_SVE) + ksft_exit_fail_msg("Dumping non-SVE register\n"); + + if (vlmax > sve->vl) + vlmax = sve->vl; + + vq = sve_vq_from_vl(sve->vl); + for (i = 0; i < num; ++i) { + printf("# z%u:", i); + dump((const char *)sve + SVE_PT_SVE_ZREG_OFFSET(vq, i), + vlmax); + printf("%s\n", vlmax == sve->vl ? "" : " ..."); + } +} + +static int do_parent(pid_t child) +{ + int ret = EXIT_FAILURE; + pid_t pid; + int status; + siginfo_t si; + void *svebuf = NULL, *newsvebuf; + size_t svebufsz = 0, newsvebufsz; + struct user_sve_header *sve, *new_sve; + struct user_fpsimd_state *fpsimd; + unsigned int i, j; + unsigned char *p; + unsigned int vq; + + /* Attach to the child */ + while (1) { + int sig; + + pid = wait(&status); + if (pid == -1) { + perror("wait"); + goto error; + } + + /* + * This should never happen but it's hard to flag in + * the framework. + */ + if (pid != child) + continue; + + if (WIFEXITED(status) || WIFSIGNALED(status)) + ksft_exit_fail_msg("Child died unexpectedly\n"); + + ksft_test_result(WIFSTOPPED(status), "WIFSTOPPED(%d)\n", + status); + if (!WIFSTOPPED(status)) + goto error; + + sig = WSTOPSIG(status); + + if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) { + if (errno == ESRCH) + goto disappeared; + + if (errno == EINVAL) { + sig = 0; /* bust group-stop */ + goto cont; + } + + ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n", + strerror(errno)); + goto error; + } + + if (sig == SIGSTOP && si.si_code == SI_TKILL && + si.si_pid == pid) + break; + + cont: + if (ptrace(PTRACE_CONT, pid, NULL, sig)) { + if (errno == ESRCH) + goto disappeared; + + ksft_test_result_fail("PTRACE_CONT: %s\n", + strerror(errno)); + goto error; + } + } + + sve = get_sve(pid, &svebuf, &svebufsz); + if (!sve) { + int e = errno; + + ksft_test_result_fail("get_sve: %s\n", strerror(errno)); + if (e == ESRCH) + goto disappeared; + + goto error; + } else { + ksft_test_result_pass("get_sve\n"); + } + + ksft_test_result((sve->flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD, + "FPSIMD registers\n"); + if ((sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_FPSIMD) + goto error; + + 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; + } + + if (set_sve(pid, sve)) { + int e = errno; + + ksft_test_result_fail("set_sve(FPSIMD): %s\n", + strerror(errno)); + if (e == ESRCH) + goto disappeared; + + goto error; + } + + vq = sve_vq_from_vl(sve->vl); + + newsvebufsz = SVE_PT_SVE_ZREG_OFFSET(vq, 1); + new_sve = newsvebuf = malloc(newsvebufsz); + if (!new_sve) { + errno = ENOMEM; + perror(NULL); + goto error; + } + + *new_sve = *sve; + new_sve->flags &= ~SVE_PT_REGS_MASK; + new_sve->flags |= SVE_PT_REGS_SVE; + memset((char *)new_sve + SVE_PT_SVE_ZREG_OFFSET(vq, 0), + 0, SVE_PT_SVE_ZREG_SIZE(vq)); + new_sve->size = SVE_PT_SVE_ZREG_OFFSET(vq, 1); + if (set_sve(pid, new_sve)) { + int e = errno; + + ksft_test_result_fail("set_sve(ZREG): %s\n", strerror(errno)); + if (e == ESRCH) + goto disappeared; + + goto error; + } + + new_sve = get_sve(pid, &newsvebuf, &newsvebufsz); + if (!new_sve) { + int e = errno; + + ksft_test_result_fail("get_sve(ZREG): %s\n", strerror(errno)); + if (e == ESRCH) + goto disappeared; + + goto error; + } + + ksft_test_result((new_sve->flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_SVE, + "SVE registers\n"); + if ((new_sve->flags & SVE_PT_REGS_MASK) != SVE_PT_REGS_SVE) + goto error; + + dump_sve_regs(new_sve, 3, sizeof fpsimd->vregs[0]); + + p = (unsigned char *)new_sve + SVE_PT_SVE_ZREG_OFFSET(vq, 1); + for (i = 0; i < sizeof fpsimd->vregs[0]; ++i) { + unsigned char expected = i; + + if (__BYTE_ORDER == __BIG_ENDIAN) + expected = sizeof fpsimd->vregs[0] - 1 - expected; + + ksft_test_result(p[i] == expected, "p[%d] == expected\n", i); + if (p[i] != expected) + goto error; + } + + ret = EXIT_SUCCESS; + +error: + kill(child, SIGKILL); + +disappeared: + return ret; +} + +int main(void) +{ + int ret = EXIT_SUCCESS; + __uint128_t v[NR_VREGS]; + pid_t child; + + ksft_print_header(); + ksft_set_plan(20); + + 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(); + + if (do_parent(child)) + ret = EXIT_FAILURE; + + ksft_print_cnts(); + + return 0; +}