1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
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 perror("ptrace(PTRACE_TRACEME) failed");
47 _exit(1);
48 }
49
50 if (raise(SIGSTOP) != 0) {
51 perror("raise(SIGSTOP) failed");
52 _exit(1);
53 }
54
55 if ((uintptr_t) addr % size) {
56 perror("Wrong address write for the given size\n");
57 _exit(1);
58 }
59 switch (size) {
60 case 1:
61 *addr = 47;
62 break;
63 case 2:
64 *(uint16_t *)addr = 47;
65 break;
66 case 4:
67 *(uint32_t *)addr = 47;
68 break;
69 case 8:
70 *(uint64_t *)addr = 47;
71 break;
72 case 16:
73 __asm__ volatile ("stp x29, x30, %0" : "=m" (addr[0]));
74 break;
75 case 32:
76 __asm__ volatile ("stp q29, q30, %0" : "=m" (addr[0]));
77 break;
78 }
79
80 _exit(0);
81}
82
83static bool set_watchpoint(pid_t pid, int size, int wp)
84{
85 const volatile uint8_t *addr = &var[32 + wp];
86 const int offset = (uintptr_t)addr % 8;
87 const unsigned int byte_mask = ((1 << size) - 1) << offset;
88 const unsigned int type = 2;
89 const unsigned int enable = 1;
90 const unsigned int control = byte_mask << 5 | type << 3 | enable;
91 struct user_hwdebug_state dreg_state;
92 struct iovec iov;
93
94 memset(&dreg_state, 0, sizeof(dreg_state));
95 dreg_state.dbg_regs[0].addr = (uintptr_t)(addr - offset);
96 dreg_state.dbg_regs[0].ctrl = control;
97 iov.iov_base = &dreg_state;
98 iov.iov_len = offsetof(struct user_hwdebug_state, dbg_regs) +
99 sizeof(dreg_state.dbg_regs[0]);
100 if (ptrace(PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov) == 0)
101 return true;
102
103 if (errno == EIO) {
104 printf("ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) "
105 "not supported on this hardware\n");
106 ksft_exit_skip();
107 }
108 perror("ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) failed");
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 perror("fork() failed");
121 return false;
122 }
123 if (pid == 0)
124 child(wr_size, wr);
125
126 wpid = waitpid(pid, &status, __WALL);
127 if (wpid != pid) {
128 perror("waitpid() failed");
129 return false;
130 }
131 if (!WIFSTOPPED(status)) {
132 printf("child did not stop\n");
133 return false;
134 }
135 if (WSTOPSIG(status) != SIGSTOP) {
136 printf("child did not stop with SIGSTOP\n");
137 return false;
138 }
139
140 if (!set_watchpoint(pid, wp_size, wp))
141 return false;
142
143 if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
144 perror("ptrace(PTRACE_SINGLESTEP) failed");
145 return false;
146 }
147
148 alarm(3);
149 wpid = waitpid(pid, &status, __WALL);
150 if (wpid != pid) {
151 perror("waitpid() failed");
152 return false;
153 }
154 alarm(0);
155 if (WIFEXITED(status)) {
156 printf("child did not single-step\t");
157 return false;
158 }
159 if (!WIFSTOPPED(status)) {
160 printf("child did not stop\n");
161 return false;
162 }
163 if (WSTOPSIG(status) != SIGTRAP) {
164 printf("child did not stop with SIGTRAP\n");
165 return false;
166 }
167 if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0) {
168 perror("ptrace(PTRACE_GETSIGINFO)");
169 return false;
170 }
171 if (siginfo.si_code != TRAP_HWBKPT) {
172 printf("Unexpected si_code %d\n", siginfo.si_code);
173 return false;
174 }
175
176 kill(pid, SIGKILL);
177 wpid = waitpid(pid, &status, 0);
178 if (wpid != pid) {
179 perror("waitpid() failed");
180 return false;
181 }
182 return true;
183}
184
185static void sigalrm(int sig)
186{
187}
188
189int main(int argc, char **argv)
190{
191 int opt;
192 bool succeeded = true;
193 struct sigaction act;
194 int wr, wp, size;
195 bool result;
196
197 act.sa_handler = sigalrm;
198 sigemptyset(&act.sa_mask);
199 act.sa_flags = 0;
200 sigaction(SIGALRM, &act, NULL);
201 for (size = 1; size <= 32; size = size*2) {
202 for (wr = 0; wr <= 32; wr = wr + size) {
203 for (wp = wr - size; wp <= wr + size; wp = wp + size) {
204 printf("Test size = %d write offset = %d watchpoint offset = %d\t", size, wr, wp);
205 result = run_test(size, MIN(size, 8), wr, wp);
206 if ((result && wr == wp) || (!result && wr != wp)) {
207 printf("[OK]\n");
208 ksft_inc_pass_cnt();
209 } else {
210 printf("[FAILED]\n");
211 ksft_inc_fail_cnt();
212 succeeded = false;
213 }
214 }
215 }
216 }
217
218 for (size = 1; size <= 32; size = size*2) {
219 printf("Test size = %d write offset = %d watchpoint offset = -8\t", size, -size);
220
221 if (run_test(size, 8, -size, -8)) {
222 printf("[OK]\n");
223 ksft_inc_pass_cnt();
224 } else {
225 printf("[FAILED]\n");
226 ksft_inc_fail_cnt();
227 succeeded = false;
228 }
229 }
230
231 ksft_print_cnts();
232 if (succeeded)
233 ksft_exit_pass();
234 else
235 ksft_exit_fail();
236}
237
