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20#define _GNU_SOURCE
21
22#include <sys/types.h>
23#include <sys/wait.h>
24#include <sys/ptrace.h>
25#include <sys/param.h>
26#include <sys/uio.h>
27#include <stdint.h>
28#include <stdbool.h>
29#include <stddef.h>
30#include <string.h>
31#include <stdio.h>
32#include <unistd.h>
33#include <elf.h>
34#include <errno.h>
35#include <signal.h>
36
37#include "../kselftest.h"
38
39static volatile uint8_t var[96] __attribute__((__aligned__(32)));
40
41static void child(int size, int wr)
42{
43 volatile uint8_t *addr = &var[32 + wr];
44
45 if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
46 ksft_print_msg(
47 "ptrace(PTRACE_TRACEME) failed: %s\n",
48 strerror(errno));
49 _exit(1);
50 }
51
52 if (raise(SIGSTOP) != 0) {
53 ksft_print_msg(
54 "raise(SIGSTOP) failed: %s\n", strerror(errno));
55 _exit(1);
56 }
57
58 if ((uintptr_t) addr % size) {
59 ksft_print_msg(
60 "Wrong address write for the given size: %s\n",
61 strerror(errno));
62 _exit(1);
63 }
64
65 switch (size) {
66 case 1:
67 *addr = 47;
68 break;
69 case 2:
70 *(uint16_t *)addr = 47;
71 break;
72 case 4:
73 *(uint32_t *)addr = 47;
74 break;
75 case 8:
76 *(uint64_t *)addr = 47;
77 break;
78 case 16:
79 __asm__ volatile ("stp x29, x30, %0" : "=m" (addr[0]));
80 break;
81 case 32:
82 __asm__ volatile ("stp q29, q30, %0" : "=m" (addr[0]));
83 break;
84 }
85
86 _exit(0);
87}
88
89static bool set_watchpoint(pid_t pid, int size, int wp)
90{
91 const volatile uint8_t *addr = &var[32 + wp];
92 const int offset = (uintptr_t)addr % 8;
93 const unsigned int byte_mask = ((1 << size) - 1) << offset;
94 const unsigned int type = 2;
95 const unsigned int enable = 1;
96 const unsigned int control = byte_mask << 5 | type << 3 | enable;
97 struct user_hwdebug_state dreg_state;
98 struct iovec iov;
99
100 memset(&dreg_state, 0, sizeof(dreg_state));
101 dreg_state.dbg_regs[0].addr = (uintptr_t)(addr - offset);
102 dreg_state.dbg_regs[0].ctrl = control;
103 iov.iov_base = &dreg_state;
104 iov.iov_len = offsetof(struct user_hwdebug_state, dbg_regs) +
105 sizeof(dreg_state.dbg_regs[0]);
106 if (ptrace(PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov) == 0)
107 return true;
108
109 if (errno == EIO)
110 ksft_print_msg(
111 "ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) not supported on this hardware: %s\n",
112 strerror(errno));
113
114 ksft_print_msg(
115 "ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) failed: %s\n",
116 strerror(errno));
117 return false;
118}
119
120static bool run_test(int wr_size, int wp_size, int wr, int wp)
121{
122 int status;
123 siginfo_t siginfo;
124 pid_t pid = fork();
125 pid_t wpid;
126
127 if (pid < 0) {
128 ksft_test_result_fail(
129 "fork() failed: %s\n", strerror(errno));
130 return false;
131 }
132 if (pid == 0)
133 child(wr_size, wr);
134
135 wpid = waitpid(pid, &status, __WALL);
136 if (wpid != pid) {
137 ksft_print_msg(
138 "waitpid() failed: %s\n", strerror(errno));
139 return false;
140 }
141 if (!WIFSTOPPED(status)) {
142 ksft_print_msg(
143 "child did not stop: %s\n", strerror(errno));
144 return false;
145 }
146 if (WSTOPSIG(status) != SIGSTOP) {
147 ksft_print_msg("child did not stop with SIGSTOP\n");
148 return false;
149 }
150
151 if (!set_watchpoint(pid, wp_size, wp))
152 return false;
153
154 if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
155 ksft_print_msg(
156 "ptrace(PTRACE_SINGLESTEP) failed: %s\n",
157 strerror(errno));
158 return false;
159 }
160
161 alarm(3);
162 wpid = waitpid(pid, &status, __WALL);
163 if (wpid != pid) {
164 ksft_print_msg(
165 "waitpid() failed: %s\n", strerror(errno));
166 return false;
167 }
168 alarm(0);
169 if (WIFEXITED(status)) {
170 ksft_print_msg("child did not single-step\n");
171 return false;
172 }
173 if (!WIFSTOPPED(status)) {
174 ksft_print_msg("child did not stop\n");
175 return false;
176 }
177 if (WSTOPSIG(status) != SIGTRAP) {
178 ksft_print_msg("child did not stop with SIGTRAP\n");
179 return false;
180 }
181 if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0) {
182 ksft_print_msg(
183 "ptrace(PTRACE_GETSIGINFO): %s\n",
184 strerror(errno));
185 return false;
186 }
187 if (siginfo.si_code != TRAP_HWBKPT) {
188 ksft_print_msg(
189 "Unexpected si_code %d\n", siginfo.si_code);
190 return false;
191 }
192
193 kill(pid, SIGKILL);
194 wpid = waitpid(pid, &status, 0);
195 if (wpid != pid) {
196 ksft_print_msg(
197 "waitpid() failed: %s\n", strerror(errno));
198 return false;
199 }
200 return true;
201}
202
203static void sigalrm(int sig)
204{
205}
206
207int main(int argc, char **argv)
208{
209 int opt;
210 bool succeeded = true;
211 struct sigaction act;
212 int wr, wp, size;
213 bool result;
214
215 ksft_print_header();
216
217 act.sa_handler = sigalrm;
218 sigemptyset(&act.sa_mask);
219 act.sa_flags = 0;
220 sigaction(SIGALRM, &act, NULL);
221 for (size = 1; size <= 32; size = size*2) {
222 for (wr = 0; wr <= 32; wr = wr + size) {
223 for (wp = wr - size; wp <= wr + size; wp = wp + size) {
224 result = run_test(size, MIN(size, 8), wr, wp);
225 if ((result && wr == wp) ||
226 (!result && wr != wp))
227 ksft_test_result_pass(
228 "Test size = %d write offset = %d watchpoint offset = %d\n",
229 size, wr, wp);
230 else {
231 ksft_test_result_fail(
232 "Test size = %d write offset = %d watchpoint offset = %d\n",
233 size, wr, wp);
234 succeeded = false;
235 }
236 }
237 }
238 }
239
240 for (size = 1; size <= 32; size = size*2) {
241 if (run_test(size, 8, -size, -8))
242 ksft_test_result_pass(
243 "Test size = %d write offset = %d watchpoint offset = -8\n",
244 size, -size);
245 else {
246 ksft_test_result_fail(
247 "Test size = %d write offset = %d watchpoint offset = -8\n",
248 size, -size);
249 succeeded = false;
250 }
251 }
252
253 if (succeeded)
254 ksft_exit_pass();
255 else
256 ksft_exit_fail();
257}
258
