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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2021 ARM Limited.4 */5#include <errno.h>6#include <stdbool.h>7#include <stddef.h>8#include <stdio.h>9#include <stdlib.h>10#include <string.h>11#include <unistd.h>12#include <sys/auxv.h>13#include <sys/prctl.h>14#include <sys/ptrace.h>15#include <sys/types.h>16#include <sys/uio.h>17#include <sys/wait.h>18#include <asm/sigcontext.h>19#include <asm/ptrace.h>20 21#include "../../kselftest.h"22 23/* <linux/elf.h> and <sys/auxv.h> don't like each other, so: */24#ifndef NT_ARM_ZA25#define NT_ARM_ZA 0x40c26#endif27#ifndef NT_ARM_ZT28#define NT_ARM_ZT 0x40d29#endif30 31#define EXPECTED_TESTS 332 33static int sme_vl;34 35static void fill_buf(char *buf, size_t size)36{37 int i;38 39 for (i = 0; i < size; i++)40 buf[i] = random();41}42 43static int do_child(void)44{45 if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))46 ksft_exit_fail_msg("PTRACE_TRACEME", strerror(errno));47 48 if (raise(SIGSTOP))49 ksft_exit_fail_msg("raise(SIGSTOP)", strerror(errno));50 51 return EXIT_SUCCESS;52}53 54static struct user_za_header *get_za(pid_t pid, void **buf, size_t *size)55{56 struct user_za_header *za;57 void *p;58 size_t sz = sizeof(*za);59 struct iovec iov;60 61 while (1) {62 if (*size < sz) {63 p = realloc(*buf, sz);64 if (!p) {65 errno = ENOMEM;66 goto error;67 }68 69 *buf = p;70 *size = sz;71 }72 73 iov.iov_base = *buf;74 iov.iov_len = sz;75 if (ptrace(PTRACE_GETREGSET, pid, NT_ARM_ZA, &iov))76 goto error;77 78 za = *buf;79 if (za->size <= sz)80 break;81 82 sz = za->size;83 }84 85 return za;86 87error:88 return NULL;89}90 91static int set_za(pid_t pid, const struct user_za_header *za)92{93 struct iovec iov;94 95 iov.iov_base = (void *)za;96 iov.iov_len = za->size;97 return ptrace(PTRACE_SETREGSET, pid, NT_ARM_ZA, &iov);98}99 100static int get_zt(pid_t pid, char zt[ZT_SIG_REG_BYTES])101{102 struct iovec iov;103 104 iov.iov_base = zt;105 iov.iov_len = ZT_SIG_REG_BYTES;106 return ptrace(PTRACE_GETREGSET, pid, NT_ARM_ZT, &iov);107}108 109 110static int set_zt(pid_t pid, const char zt[ZT_SIG_REG_BYTES])111{112 struct iovec iov;113 114 iov.iov_base = (void *)zt;115 iov.iov_len = ZT_SIG_REG_BYTES;116 return ptrace(PTRACE_SETREGSET, pid, NT_ARM_ZT, &iov);117}118 119/* Reading with ZA disabled returns all zeros */120static void ptrace_za_disabled_read_zt(pid_t child)121{122 struct user_za_header za;123 char zt[ZT_SIG_REG_BYTES];124 int ret, i;125 bool fail = false;126 127 /* Disable PSTATE.ZA using the ZA interface */128 memset(&za, 0, sizeof(za));129 za.vl = sme_vl;130 za.size = sizeof(za);131 132 ret = set_za(child, &za);133 if (ret != 0) {134 ksft_print_msg("Failed to disable ZA\n");135 fail = true;136 }137 138 /* Read back ZT */139 ret = get_zt(child, zt);140 if (ret != 0) {141 ksft_print_msg("Failed to read ZT\n");142 fail = true;143 }144 145 for (i = 0; i < ARRAY_SIZE(zt); i++) {146 if (zt[i]) {147 ksft_print_msg("zt[%d]: 0x%x != 0\n", i, zt[i]);148 fail = true;149 }150 }151 152 ksft_test_result(!fail, "ptrace_za_disabled_read_zt\n");153}154 155/* Writing then reading ZT should return the data written */156static void ptrace_set_get_zt(pid_t child)157{158 char zt_in[ZT_SIG_REG_BYTES];159 char zt_out[ZT_SIG_REG_BYTES];160 int ret, i;161 bool fail = false;162 163 fill_buf(zt_in, sizeof(zt_in));164 165 ret = set_zt(child, zt_in);166 if (ret != 0) {167 ksft_print_msg("Failed to set ZT\n");168 fail = true;169 }170 171 ret = get_zt(child, zt_out);172 if (ret != 0) {173 ksft_print_msg("Failed to read ZT\n");174 fail = true;175 }176 177 for (i = 0; i < ARRAY_SIZE(zt_in); i++) {178 if (zt_in[i] != zt_out[i]) {179 ksft_print_msg("zt[%d]: 0x%x != 0x%x\n", i, 180 zt_in[i], zt_out[i]);181 fail = true;182 }183 }184 185 ksft_test_result(!fail, "ptrace_set_get_zt\n");186}187 188/* Writing ZT should set PSTATE.ZA */189static void ptrace_enable_za_via_zt(pid_t child)190{191 struct user_za_header za_in;192 struct user_za_header *za_out;193 char zt[ZT_SIG_REG_BYTES];194 char *za_data;195 size_t za_out_size;196 int ret, i, vq;197 bool fail = false;198 199 /* Disable PSTATE.ZA using the ZA interface */200 memset(&za_in, 0, sizeof(za_in));201 za_in.vl = sme_vl;202 za_in.size = sizeof(za_in);203 204 ret = set_za(child, &za_in);205 if (ret != 0) {206 ksft_print_msg("Failed to disable ZA\n");207 fail = true;208 }209 210 /* Write ZT */211 fill_buf(zt, sizeof(zt));212 ret = set_zt(child, zt);213 if (ret != 0) {214 ksft_print_msg("Failed to set ZT\n");215 fail = true;216 }217 218 /* Read back ZA and check for register data */219 za_out = NULL;220 za_out_size = 0;221 if (get_za(child, (void **)&za_out, &za_out_size)) {222 /* Should have an unchanged VL */223 if (za_out->vl != sme_vl) {224 ksft_print_msg("VL changed from %d to %d\n",225 sme_vl, za_out->vl);226 fail = true;227 }228 vq = __sve_vq_from_vl(za_out->vl);229 za_data = (char *)za_out + ZA_PT_ZA_OFFSET;230 231 /* Should have register data */232 if (za_out->size < ZA_PT_SIZE(vq)) {233 ksft_print_msg("ZA data less than expected: %u < %u\n",234 za_out->size, ZA_PT_SIZE(vq));235 fail = true;236 vq = 0;237 }238 239 /* That register data should be non-zero */240 for (i = 0; i < ZA_PT_ZA_SIZE(vq); i++) {241 if (za_data[i]) {242 ksft_print_msg("ZA byte %d is %x\n",243 i, za_data[i]);244 fail = true;245 }246 }247 } else {248 ksft_print_msg("Failed to read ZA\n");249 fail = true;250 }251 252 ksft_test_result(!fail, "ptrace_enable_za_via_zt\n");253}254 255static int do_parent(pid_t child)256{257 int ret = EXIT_FAILURE;258 pid_t pid;259 int status;260 siginfo_t si;261 262 /* Attach to the child */263 while (1) {264 int sig;265 266 pid = wait(&status);267 if (pid == -1) {268 perror("wait");269 goto error;270 }271 272 /*273 * This should never happen but it's hard to flag in274 * the framework.275 */276 if (pid != child)277 continue;278 279 if (WIFEXITED(status) || WIFSIGNALED(status))280 ksft_exit_fail_msg("Child died unexpectedly\n");281 282 if (!WIFSTOPPED(status))283 goto error;284 285 sig = WSTOPSIG(status);286 287 if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {288 if (errno == ESRCH)289 goto disappeared;290 291 if (errno == EINVAL) {292 sig = 0; /* bust group-stop */293 goto cont;294 }295 296 ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",297 strerror(errno));298 goto error;299 }300 301 if (sig == SIGSTOP && si.si_code == SI_TKILL &&302 si.si_pid == pid)303 break;304 305 cont:306 if (ptrace(PTRACE_CONT, pid, NULL, sig)) {307 if (errno == ESRCH)308 goto disappeared;309 310 ksft_test_result_fail("PTRACE_CONT: %s\n",311 strerror(errno));312 goto error;313 }314 }315 316 ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);317 318 ptrace_za_disabled_read_zt(child);319 ptrace_set_get_zt(child);320 ptrace_enable_za_via_zt(child);321 322 ret = EXIT_SUCCESS;323 324error:325 kill(child, SIGKILL);326 327disappeared:328 return ret;329}330 331int main(void)332{333 int ret = EXIT_SUCCESS;334 pid_t child;335 336 srandom(getpid());337 338 ksft_print_header();339 340 if (!(getauxval(AT_HWCAP2) & HWCAP2_SME2)) {341 ksft_set_plan(1);342 ksft_exit_skip("SME2 not available\n");343 }344 345 /* We need a valid SME VL to enable/disable ZA */346 sme_vl = prctl(PR_SME_GET_VL);347 if (sme_vl == -1) {348 ksft_set_plan(1);349 ksft_exit_skip("Failed to read SME VL: %d (%s)\n",350 errno, strerror(errno));351 }352 353 ksft_set_plan(EXPECTED_TESTS);354 355 child = fork();356 if (!child)357 return do_child();358 359 if (do_parent(child))360 ret = EXIT_FAILURE;361 362 ksft_print_cnts();363 364 return ret;365}366