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20#define _GNU_SOURCE
21
22#include <asm/ptrace.h>
23#include <sys/types.h>
24#include <sys/wait.h>
25#include <sys/ptrace.h>
26#include <sys/param.h>
27#include <sys/uio.h>
28#include <stdint.h>
29#include <stdbool.h>
30#include <stddef.h>
31#include <string.h>
32#include <stdio.h>
33#include <unistd.h>
34#include <elf.h>
35#include <errno.h>
36#include <signal.h>
37
38#include "../kselftest.h"
39
40static volatile uint8_t var[96] __attribute__((__aligned__(32)));
41
42static void child(int size, int wr)
43{
44 volatile uint8_t *addr = &var[32 + wr];
45
46 if (ptrace(PTRACE_TRACEME, 0, NULL, NULL) != 0) {
47 ksft_print_msg(
48 "ptrace(PTRACE_TRACEME) failed: %s\n",
49 strerror(errno));
50 _exit(1);
51 }
52
53 if (raise(SIGSTOP) != 0) {
54 ksft_print_msg(
55 "raise(SIGSTOP) failed: %s\n", strerror(errno));
56 _exit(1);
57 }
58
59 if ((uintptr_t) addr % size) {
60 ksft_print_msg(
61 "Wrong address write for the given size: %s\n",
62 strerror(errno));
63 _exit(1);
64 }
65
66 switch (size) {
67 case 1:
68 *addr = 47;
69 break;
70 case 2:
71 *(uint16_t *)addr = 47;
72 break;
73 case 4:
74 *(uint32_t *)addr = 47;
75 break;
76 case 8:
77 *(uint64_t *)addr = 47;
78 break;
79 case 16:
80 __asm__ volatile ("stp x29, x30, %0" : "=m" (addr[0]));
81 break;
82 case 32:
83 __asm__ volatile ("stp q29, q30, %0" : "=m" (addr[0]));
84 break;
85 }
86
87 _exit(0);
88}
89
90static bool set_watchpoint(pid_t pid, int size, int wp)
91{
92 const volatile uint8_t *addr = &var[32 + wp];
93 const int offset = (uintptr_t)addr % 8;
94 const unsigned int byte_mask = ((1 << size) - 1) << offset;
95 const unsigned int type = 2;
96 const unsigned int enable = 1;
97 const unsigned int control = byte_mask << 5 | type << 3 | enable;
98 struct user_hwdebug_state dreg_state;
99 struct iovec iov;
100
101 memset(&dreg_state, 0, sizeof(dreg_state));
102 dreg_state.dbg_regs[0].addr = (uintptr_t)(addr - offset);
103 dreg_state.dbg_regs[0].ctrl = control;
104 iov.iov_base = &dreg_state;
105 iov.iov_len = offsetof(struct user_hwdebug_state, dbg_regs) +
106 sizeof(dreg_state.dbg_regs[0]);
107 if (ptrace(PTRACE_SETREGSET, pid, NT_ARM_HW_WATCH, &iov) == 0)
108 return true;
109
110 if (errno == EIO)
111 ksft_print_msg(
112 "ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) not supported on this hardware: %s\n",
113 strerror(errno));
114
115 ksft_print_msg(
116 "ptrace(PTRACE_SETREGSET, NT_ARM_HW_WATCH) failed: %s\n",
117 strerror(errno));
118 return false;
119}
120
121static bool run_test(int wr_size, int wp_size, int wr, int wp)
122{
123 int status;
124 siginfo_t siginfo;
125 pid_t pid = fork();
126 pid_t wpid;
127
128 if (pid < 0) {
129 ksft_test_result_fail(
130 "fork() failed: %s\n", strerror(errno));
131 return false;
132 }
133 if (pid == 0)
134 child(wr_size, wr);
135
136 wpid = waitpid(pid, &status, __WALL);
137 if (wpid != pid) {
138 ksft_print_msg(
139 "waitpid() failed: %s\n", strerror(errno));
140 return false;
141 }
142 if (!WIFSTOPPED(status)) {
143 ksft_print_msg(
144 "child did not stop: %s\n", strerror(errno));
145 return false;
146 }
147 if (WSTOPSIG(status) != SIGSTOP) {
148 ksft_print_msg("child did not stop with SIGSTOP\n");
149 return false;
150 }
151
152 if (!set_watchpoint(pid, wp_size, wp))
153 return false;
154
155 if (ptrace(PTRACE_CONT, pid, NULL, NULL) < 0) {
156 ksft_print_msg(
157 "ptrace(PTRACE_SINGLESTEP) failed: %s\n",
158 strerror(errno));
159 return false;
160 }
161
162 alarm(3);
163 wpid = waitpid(pid, &status, __WALL);
164 if (wpid != pid) {
165 ksft_print_msg(
166 "waitpid() failed: %s\n", strerror(errno));
167 return false;
168 }
169 alarm(0);
170 if (WIFEXITED(status)) {
171 ksft_print_msg("child did not single-step\n");
172 return false;
173 }
174 if (!WIFSTOPPED(status)) {
175 ksft_print_msg("child did not stop\n");
176 return false;
177 }
178 if (WSTOPSIG(status) != SIGTRAP) {
179 ksft_print_msg("child did not stop with SIGTRAP\n");
180 return false;
181 }
182 if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &siginfo) != 0) {
183 ksft_print_msg(
184 "ptrace(PTRACE_GETSIGINFO): %s\n",
185 strerror(errno));
186 return false;
187 }
188 if (siginfo.si_code != TRAP_HWBKPT) {
189 ksft_print_msg(
190 "Unexpected si_code %d\n", siginfo.si_code);
191 return false;
192 }
193
194 kill(pid, SIGKILL);
195 wpid = waitpid(pid, &status, 0);
196 if (wpid != pid) {
197 ksft_print_msg(
198 "waitpid() failed: %s\n", strerror(errno));
199 return false;
200 }
201 return true;
202}
203
204static void sigalrm(int sig)
205{
206}
207
208int main(int argc, char **argv)
209{
210 int opt;
211 bool succeeded = true;
212 struct sigaction act;
213 int wr, wp, size;
214 bool result;
215
216 ksft_print_header();
217
218 act.sa_handler = sigalrm;
219 sigemptyset(&act.sa_mask);
220 act.sa_flags = 0;
221 sigaction(SIGALRM, &act, NULL);
222 for (size = 1; size <= 32; size = size*2) {
223 for (wr = 0; wr <= 32; wr = wr + size) {
224 for (wp = wr - size; wp <= wr + size; wp = wp + size) {
225 result = run_test(size, MIN(size, 8), wr, wp);
226 if ((result && wr == wp) ||
227 (!result && wr != wp))
228 ksft_test_result_pass(
229 "Test size = %d write offset = %d watchpoint offset = %d\n",
230 size, wr, wp);
231 else {
232 ksft_test_result_fail(
233 "Test size = %d write offset = %d watchpoint offset = %d\n",
234 size, wr, wp);
235 succeeded = false;
236 }
237 }
238 }
239 }
240
241 for (size = 1; size <= 32; size = size*2) {
242 if (run_test(size, 8, -size, -8))
243 ksft_test_result_pass(
244 "Test size = %d write offset = %d watchpoint offset = -8\n",
245 size, -size);
246 else {
247 ksft_test_result_fail(
248 "Test size = %d write offset = %d watchpoint offset = -8\n",
249 size, -size);
250 succeeded = false;
251 }
252 }
253
254 if (succeeded)
255 ksft_exit_pass();
256 else
257 ksft_exit_fail();
258}
259
