tools/testing/selftests/breakpoints/breakpoint_test_arm64.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   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_SOURCE
  12
  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
  31 static volatile uint8_t var[96] __attribute__((__aligned__(32)));
  32
  33 static 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
  81 static 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
 112 static bool arun_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_SINGLESTEP) 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 did not single-step\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
 195 static void sigalrm(int sig)
 196 {
 197 }
 198
 199 int 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         else
 249                 ksft_exit_fail();
 250 }