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
child(int size,int wr)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
set_watchpoint(pid_t pid,int size,int wp)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
run_test(int wr_size,int wp_size,int wr,int wp)112 static 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
sigalrm(int sig)195 static void sigalrm(int sig)
196 {
197 }
198
main(int argc,char ** argv)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 }
251