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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * Copyright (C) 2016 Google, Inc.4 *5 * Original Code by Pavel Labath <labath@google.com>6 *7 * Code modified by Pratyush Anand <panand@redhat.com>8 * for testing different byte select for each access size.9 */10 11#define _GNU_SOURCE12 13#include <asm/ptrace.h>14#include <sys/types.h>15#include <sys/wait.h>16#include <sys/ptrace.h>17#include <sys/param.h>18#include <sys/uio.h>19#include <stdint.h>20#include <stdbool.h>21#include <stddef.h>22#include <string.h>23#include <stdio.h>24#include <unistd.h>25#include <elf.h>26#include <errno.h>27#include <signal.h>28 29#include "../kselftest.h"30 31static volatile uint8_t var[96] __attribute__((__aligned__(32)));32 33static void child(int size, int wr)34{35 volatile uint8_t *addr = &var[32 + wr];36 37 if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {38 ksft_print_msg(39 "ptrace(PTRACE_TRACEME) failed: %s\n",40 strerror(errno));41 _exit(1);42 }43 44 if (raise(SIGSTOP) != 0) {45 ksft_print_msg(46 "raise(SIGSTOP) failed: %s\n", strerror(errno));47 _exit(1);48 }49 50 if ((uintptr_t) addr % size) {51 ksft_print_msg(52 "Wrong address write for the given size: %s\n",53 strerror(errno));54 _exit(1);55 }56 57 switch (size) {58 case 1:59 *addr = 47;60 break;61 case 2:62 *(uint16_t *)addr = 47;63 break;64 case 4:65 *(uint32_t *)addr = 47;66 break;67 case 8:68 *(uint64_t *)addr = 47;69 break;70 case 16:71 __asm__ volatile ("stp x29, x30, %0" : "=m" (addr[0]));72 break;73 case 32:74 __asm__ volatile ("stp q29, q30, %0" : "=m" (addr[0]));75 break;76 }77 78 _exit(0);79}80 81static bool set_watchpoint(pid_t pid, int size, int wp)82{83 const volatile uint8_t *addr = &var[32 + wp];84 const int offset = (uintptr_t)addr % 8;85 const unsigned int byte_mask = ((1 << size) - 1) << offset;86 const unsigned int type = 2; /* Write */87 const unsigned int enable = 1;88 const unsigned int control = byte_mask << 5 | type << 3 | enable;89 struct user_hwdebug_state dreg_state;90 struct iovec iov;91 92 memset(&dreg_state, 0, sizeof(dreg_state));93 dreg_state.dbg_regs[0].addr = (uintptr_t)(addr - offset);94 dreg_state.dbg_regs[0].ctrl = control;95 iov.iov_base = &dreg_state;96 iov.iov_len = offsetof(struct user_hwdebug_state, dbg_regs) +97 sizeof(dreg_state.dbg_regs[0]);98 if (ptrace(PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov) == 0)99 return true;100 101 if (errno == EIO)102 ksft_print_msg(103 "ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) not supported on this hardware: %s\n",104 strerror(errno));105 106 ksft_print_msg(107 "ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) failed: %s\n",108 strerror(errno));109 return false;110}111 112static bool run_test(int wr_size, int wp_size, int wr, int wp)113{114 int status;115 siginfo_t siginfo;116 pid_t pid = fork();117 pid_t wpid;118 119 if (pid < 0) {120 ksft_test_result_fail(121 "fork() failed: %s\n", strerror(errno));122 return false;123 }124 if (pid == 0)125 child(wr_size, wr);126 127 wpid = waitpid(pid, &status, __WALL);128 if (wpid != pid) {129 ksft_print_msg(130 "waitpid() failed: %s\n", strerror(errno));131 return false;132 }133 if (!WIFSTOPPED(status)) {134 ksft_print_msg(135 "child did not stop: %s\n", strerror(errno));136 return false;137 }138 if (WSTOPSIG(status) != SIGSTOP) {139 ksft_print_msg("child did not stop with SIGSTOP\n");140 return false;141 }142 143 if (!set_watchpoint(pid, wp_size, wp))144 return false;145 146 if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {147 ksft_print_msg(148 "ptrace(PTRACE_CONT) failed: %s\n",149 strerror(errno));150 return false;151 }152 153 alarm(3);154 wpid = waitpid(pid, &status, __WALL);155 if (wpid != pid) {156 ksft_print_msg(157 "waitpid() failed: %s\n", strerror(errno));158 return false;159 }160 alarm(0);161 if (WIFEXITED(status)) {162 ksft_print_msg("child exited prematurely\n");163 return false;164 }165 if (!WIFSTOPPED(status)) {166 ksft_print_msg("child did not stop\n");167 return false;168 }169 if (WSTOPSIG(status) != SIGTRAP) {170 ksft_print_msg("child did not stop with SIGTRAP\n");171 return false;172 }173 if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0) {174 ksft_print_msg(175 "ptrace(PTRACE_GETSIGINFO): %s\n",176 strerror(errno));177 return false;178 }179 if (siginfo.si_code != TRAP_HWBKPT) {180 ksft_print_msg(181 "Unexpected si_code %d\n", siginfo.si_code);182 return false;183 }184 185 kill(pid, SIGKILL);186 wpid = waitpid(pid, &status, 0);187 if (wpid != pid) {188 ksft_print_msg(189 "waitpid() failed: %s\n", strerror(errno));190 return false;191 }192 return true;193}194 195static void sigalrm(int sig)196{197}198 199int main(int argc, char **argv)200{201 int opt;202 bool succeeded = true;203 struct sigaction act;204 int wr, wp, size;205 bool result;206 207 ksft_print_header();208 ksft_set_plan(213);209 210 act.sa_handler = sigalrm;211 sigemptyset(&act.sa_mask);212 act.sa_flags = 0;213 sigaction(SIGALRM, &act, NULL);214 for (size = 1; size <= 32; size = size*2) {215 for (wr = 0; wr <= 32; wr = wr + size) {216 for (wp = wr - size; wp <= wr + size; wp = wp + size) {217 result = run_test(size, MIN(size, 8), wr, wp);218 if ((result && wr == wp) ||219 (!result && wr != wp))220 ksft_test_result_pass(221 "Test size = %d write offset = %d watchpoint offset = %d\n",222 size, wr, wp);223 else {224 ksft_test_result_fail(225 "Test size = %d write offset = %d watchpoint offset = %d\n",226 size, wr, wp);227 succeeded = false;228 }229 }230 }231 }232 233 for (size = 1; size <= 32; size = size*2) {234 if (run_test(size, 8, -size, -8))235 ksft_test_result_pass(236 "Test size = %d write offset = %d watchpoint offset = -8\n",237 size, -size);238 else {239 ksft_test_result_fail(240 "Test size = %d write offset = %d watchpoint offset = -8\n",241 size, -size);242 succeeded = false;243 }244 }245 246 if (succeeded)247 ksft_exit_pass();248 else249 ksft_exit_fail();250}251