1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/compiler.h>
3 #include <sys/types.h>
4 #include <sys/wait.h>
5 #include <sys/user.h>
6 #include <syscall.h>
7 #include <unistd.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <sys/ptrace.h>
11 #include <asm/ptrace.h>
12 #include <errno.h>
13 #include "debug.h"
14 #include "tests/tests.h"
15 #include "arch-tests.h"
17 static noinline int bp_1(void)
18 {
19 pr_debug("in %s\n", __func__);
20 return 0;
21 }
23 static noinline int bp_2(void)
24 {
25 pr_debug("in %s\n", __func__);
26 return 0;
27 }
29 static int spawn_child(void)
30 {
31 int child = fork();
33 if (child == 0) {
34 /*
35 * The child sets itself for as tracee and
36 * waits in signal for parent to trace it,
37 * then it calls bp_1 and quits.
38 */
39 int err = ptrace(PTRACE_TRACEME, 0, NULL, NULL);
41 if (err) {
42 pr_debug("failed to PTRACE_TRACEME\n");
43 exit(1);
44 }
46 raise(SIGCONT);
47 bp_1();
48 exit(0);
49 }
51 return child;
52 }
54 /*
55 * This tests creates HW breakpoint, tries to
56 * change it and checks it was properly changed.
57 */
58 static int bp_modify1(void)
59 {
60 pid_t child;
61 int status;
62 unsigned long rip = 0, dr7 = 1;
64 child = spawn_child();
66 waitpid(child, &status, 0);
67 if (WIFEXITED(status)) {
68 pr_debug("tracee exited prematurely 1\n");
69 return TEST_FAIL;
70 }
72 /*
73 * The parent does following steps:
74 * - creates a new breakpoint (id 0) for bp_2 function
75 * - changes that breakponit to bp_1 function
76 * - waits for the breakpoint to hit and checks
77 * it has proper rip of bp_1 function
78 * - detaches the child
79 */
80 if (ptrace(PTRACE_POKEUSER, child,
81 offsetof(struct user, u_debugreg[0]), bp_2)) {
82 pr_debug("failed to set breakpoint, 1st time: %s\n",
83 strerror(errno));
84 goto out;
85 }
87 if (ptrace(PTRACE_POKEUSER, child,
88 offsetof(struct user, u_debugreg[0]), bp_1)) {
89 pr_debug("failed to set breakpoint, 2nd time: %s\n",
90 strerror(errno));
91 goto out;
92 }
94 if (ptrace(PTRACE_POKEUSER, child,
95 offsetof(struct user, u_debugreg[7]), dr7)) {
96 pr_debug("failed to set dr7: %s\n", strerror(errno));
97 goto out;
98 }
100 if (ptrace(PTRACE_CONT, child, NULL, NULL)) {
101 pr_debug("failed to PTRACE_CONT: %s\n", strerror(errno));
102 goto out;
103 }
105 waitpid(child, &status, 0);
106 if (WIFEXITED(status)) {
107 pr_debug("tracee exited prematurely 2\n");
108 return TEST_FAIL;
109 }
111 rip = ptrace(PTRACE_PEEKUSER, child,
112 offsetof(struct user_regs_struct, rip), NULL);
113 if (rip == (unsigned long) -1) {
114 pr_debug("failed to PTRACE_PEEKUSER: %s\n",
115 strerror(errno));
116 goto out;
117 }
119 pr_debug("rip %lx, bp_1 %p\n", rip, bp_1);
121 out:
122 if (ptrace(PTRACE_DETACH, child, NULL, NULL)) {
123 pr_debug("failed to PTRACE_DETACH: %s", strerror(errno));
124 return TEST_FAIL;
125 }
127 return rip == (unsigned long) bp_1 ? TEST_OK : TEST_FAIL;
128 }
130 /*
131 * This tests creates HW breakpoint, tries to
132 * change it to bogus value and checks the original
133 * breakpoint is hit.
134 */
135 static int bp_modify2(void)
136 {
137 pid_t child;
138 int status;
139 unsigned long rip = 0, dr7 = 1;
141 child = spawn_child();
143 waitpid(child, &status, 0);
144 if (WIFEXITED(status)) {
145 pr_debug("tracee exited prematurely 1\n");
146 return TEST_FAIL;
147 }
149 /*
150 * The parent does following steps:
151 * - creates a new breakpoint (id 0) for bp_1 function
152 * - tries to change that breakpoint to (-1) address
153 * - waits for the breakpoint to hit and checks
154 * it has proper rip of bp_1 function
155 * - detaches the child
156 */
157 if (ptrace(PTRACE_POKEUSER, child,
158 offsetof(struct user, u_debugreg[0]), bp_1)) {
159 pr_debug("failed to set breakpoint: %s\n",
160 strerror(errno));
161 goto out;
162 }
164 if (ptrace(PTRACE_POKEUSER, child,
165 offsetof(struct user, u_debugreg[7]), dr7)) {
166 pr_debug("failed to set dr7: %s\n", strerror(errno));
167 goto out;
168 }
170 if (!ptrace(PTRACE_POKEUSER, child,
171 offsetof(struct user, u_debugreg[0]), (unsigned long) (-1))) {
172 pr_debug("failed, breakpoint set to bogus address\n");
173 goto out;
174 }
176 if (ptrace(PTRACE_CONT, child, NULL, NULL)) {
177 pr_debug("failed to PTRACE_CONT: %s\n", strerror(errno));
178 goto out;
179 }
181 waitpid(child, &status, 0);
182 if (WIFEXITED(status)) {
183 pr_debug("tracee exited prematurely 2\n");
184 return TEST_FAIL;
185 }
187 rip = ptrace(PTRACE_PEEKUSER, child,
188 offsetof(struct user_regs_struct, rip), NULL);
189 if (rip == (unsigned long) -1) {
190 pr_debug("failed to PTRACE_PEEKUSER: %s\n",
191 strerror(errno));
192 goto out;
193 }
195 pr_debug("rip %lx, bp_1 %p\n", rip, bp_1);
197 out:
198 if (ptrace(PTRACE_DETACH, child, NULL, NULL)) {
199 pr_debug("failed to PTRACE_DETACH: %s", strerror(errno));
200 return TEST_FAIL;
201 }
203 return rip == (unsigned long) bp_1 ? TEST_OK : TEST_FAIL;
204 }
206 int test__bp_modify(struct test *test __maybe_unused,
207 int subtest __maybe_unused)
208 {
209 TEST_ASSERT_VAL("modify test 1 failed\n", !bp_modify1());
210 TEST_ASSERT_VAL("modify test 2 failed\n", !bp_modify2());
212 return 0;
213 }