1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Copyright (C) 2022 ARM Limited.
4 */
5 #include <errno.h>
6 #include <stdbool.h>
7 #include <stddef.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <string.h>
11 #include <unistd.h>
12 #include <sys/auxv.h>
13 #include <sys/prctl.h>
14 #include <sys/ptrace.h>
15 #include <sys/types.h>
16 #include <sys/uio.h>
17 #include <sys/wait.h>
18 #include <asm/sigcontext.h>
19 #include <asm/ptrace.h>
20
21 #include "../../kselftest.h"
22
23 #define EXPECTED_TESTS 11
24
25 #define MAX_TPIDRS 2
26
have_sme(void)27 static bool have_sme(void)
28 {
29 return getauxval(AT_HWCAP2) & HWCAP2_SME;
30 }
31
test_tpidr(pid_t child)32 static void test_tpidr(pid_t child)
33 {
34 uint64_t read_val[MAX_TPIDRS];
35 uint64_t write_val[MAX_TPIDRS];
36 struct iovec read_iov, write_iov;
37 bool test_tpidr2 = false;
38 int ret, i;
39
40 read_iov.iov_base = read_val;
41 write_iov.iov_base = write_val;
42
43 /* Should be able to read a single TPIDR... */
44 read_iov.iov_len = sizeof(uint64_t);
45 ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
46 ksft_test_result(ret == 0, "read_tpidr_one\n");
47
48 /* ...write a new value.. */
49 write_iov.iov_len = sizeof(uint64_t);
50 write_val[0] = read_val[0] + 1;
51 ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
52 ksft_test_result(ret == 0, "write_tpidr_one\n");
53
54 /* ...then read it back */
55 ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
56 ksft_test_result(ret == 0 && write_val[0] == read_val[0],
57 "verify_tpidr_one\n");
58
59 /* If we have TPIDR2 we should be able to read it */
60 read_iov.iov_len = sizeof(read_val);
61 ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
62 if (ret == 0) {
63 /* If we have SME there should be two TPIDRs */
64 if (read_iov.iov_len >= sizeof(read_val))
65 test_tpidr2 = true;
66
67 if (have_sme() && test_tpidr2) {
68 ksft_test_result(test_tpidr2, "count_tpidrs\n");
69 } else {
70 ksft_test_result(read_iov.iov_len % sizeof(uint64_t) == 0,
71 "count_tpidrs\n");
72 }
73 } else {
74 ksft_test_result_fail("count_tpidrs\n");
75 }
76
77 if (test_tpidr2) {
78 /* Try to write new values to all known TPIDRs... */
79 write_iov.iov_len = sizeof(write_val);
80 for (i = 0; i < MAX_TPIDRS; i++)
81 write_val[i] = read_val[i] + 1;
82 ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
83
84 ksft_test_result(ret == 0 &&
85 write_iov.iov_len == sizeof(write_val),
86 "tpidr2_write\n");
87
88 /* ...then read them back */
89 read_iov.iov_len = sizeof(read_val);
90 ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS, &read_iov);
91
92 if (have_sme()) {
93 /* Should read back the written value */
94 ksft_test_result(ret == 0 &&
95 read_iov.iov_len >= sizeof(read_val) &&
96 memcmp(read_val, write_val,
97 sizeof(read_val)) == 0,
98 "tpidr2_read\n");
99 } else {
100 /* TPIDR2 should read as zero */
101 ksft_test_result(ret == 0 &&
102 read_iov.iov_len >= sizeof(read_val) &&
103 read_val[0] == write_val[0] &&
104 read_val[1] == 0,
105 "tpidr2_read\n");
106 }
107
108 /* Writing only TPIDR... */
109 write_iov.iov_len = sizeof(uint64_t);
110 memcpy(write_val, read_val, sizeof(read_val));
111 write_val[0] += 1;
112 ret = ptrace(PTRACE_SETREGSET, child, NT_ARM_TLS, &write_iov);
113
114 if (ret == 0) {
115 /* ...should leave TPIDR2 untouched */
116 read_iov.iov_len = sizeof(read_val);
117 ret = ptrace(PTRACE_GETREGSET, child, NT_ARM_TLS,
118 &read_iov);
119
120 ksft_test_result(ret == 0 &&
121 read_iov.iov_len >= sizeof(read_val) &&
122 memcmp(read_val, write_val,
123 sizeof(read_val)) == 0,
124 "write_tpidr_only\n");
125 } else {
126 ksft_test_result_fail("write_tpidr_only\n");
127 }
128 } else {
129 ksft_test_result_skip("tpidr2_write\n");
130 ksft_test_result_skip("tpidr2_read\n");
131 ksft_test_result_skip("write_tpidr_only\n");
132 }
133 }
134
test_hw_debug(pid_t child,int type,const char * type_name)135 static void test_hw_debug(pid_t child, int type, const char *type_name)
136 {
137 struct user_hwdebug_state state;
138 struct iovec iov;
139 int slots, arch, ret;
140
141 iov.iov_len = sizeof(state);
142 iov.iov_base = &state;
143
144 /* Should be able to read the values */
145 ret = ptrace(PTRACE_GETREGSET, child, type, &iov);
146 ksft_test_result(ret == 0, "read_%s\n", type_name);
147
148 if (ret == 0) {
149 /* Low 8 bits is the number of slots, next 4 bits the arch */
150 slots = state.dbg_info & 0xff;
151 arch = (state.dbg_info >> 8) & 0xf;
152
153 ksft_print_msg("%s version %d with %d slots\n", type_name,
154 arch, slots);
155
156 /* Zero is not currently architecturally valid */
157 ksft_test_result(arch, "%s_arch_set\n", type_name);
158 } else {
159 ksft_test_result_skip("%s_arch_set\n", type_name);
160 }
161 }
162
do_child(void)163 static int do_child(void)
164 {
165 if (ptrace(PTRACE_TRACEME, -1, NULL, NULL))
166 ksft_exit_fail_perror("PTRACE_TRACEME");
167
168 if (raise(SIGSTOP))
169 ksft_exit_fail_perror("raise(SIGSTOP)");
170
171 return EXIT_SUCCESS;
172 }
173
do_parent(pid_t child)174 static int do_parent(pid_t child)
175 {
176 int ret = EXIT_FAILURE;
177 pid_t pid;
178 int status;
179 siginfo_t si;
180
181 /* Attach to the child */
182 while (1) {
183 int sig;
184
185 pid = wait(&status);
186 if (pid == -1) {
187 perror("wait");
188 goto error;
189 }
190
191 /*
192 * This should never happen but it's hard to flag in
193 * the framework.
194 */
195 if (pid != child)
196 continue;
197
198 if (WIFEXITED(status) || WIFSIGNALED(status))
199 ksft_exit_fail_msg("Child died unexpectedly\n");
200
201 if (!WIFSTOPPED(status))
202 goto error;
203
204 sig = WSTOPSIG(status);
205
206 if (ptrace(PTRACE_GETSIGINFO, pid, NULL, &si)) {
207 if (errno == ESRCH)
208 goto disappeared;
209
210 if (errno == EINVAL) {
211 sig = 0; /* bust group-stop */
212 goto cont;
213 }
214
215 ksft_test_result_fail("PTRACE_GETSIGINFO: %s\n",
216 strerror(errno));
217 goto error;
218 }
219
220 if (sig == SIGSTOP && si.si_code == SI_TKILL &&
221 si.si_pid == pid)
222 break;
223
224 cont:
225 if (ptrace(PTRACE_CONT, pid, NULL, sig)) {
226 if (errno == ESRCH)
227 goto disappeared;
228
229 ksft_test_result_fail("PTRACE_CONT: %s\n",
230 strerror(errno));
231 goto error;
232 }
233 }
234
235 ksft_print_msg("Parent is %d, child is %d\n", getpid(), child);
236
237 test_tpidr(child);
238 test_hw_debug(child, NT_ARM_HW_WATCH, "NT_ARM_HW_WATCH");
239 test_hw_debug(child, NT_ARM_HW_BREAK, "NT_ARM_HW_BREAK");
240
241 ret = EXIT_SUCCESS;
242
243 error:
244 kill(child, SIGKILL);
245
246 disappeared:
247 return ret;
248 }
249
main(void)250 int main(void)
251 {
252 int ret = EXIT_SUCCESS;
253 pid_t child;
254
255 srandom(getpid());
256
257 ksft_print_header();
258
259 ksft_set_plan(EXPECTED_TESTS);
260
261 child = fork();
262 if (!child)
263 return do_child();
264
265 if (do_parent(child))
266 ret = EXIT_FAILURE;
267
268 ksft_print_cnts();
269
270 return ret;
271 }
272