1 // SPDX-License-Identifier: GPL-2.0
2 /* Copyright (C) 2019 ARM Limited */
3
4 #include <stdio.h>
5 #include <stdlib.h>
6 #include <signal.h>
7 #include <string.h>
8 #include <unistd.h>
9 #include <assert.h>
10 #include <sys/auxv.h>
11 #include <linux/auxvec.h>
12 #include <ucontext.h>
13
14 #include <asm/unistd.h>
15
16 #include <kselftest.h>
17
18 #include "test_signals.h"
19 #include "test_signals_utils.h"
20 #include "testcases/testcases.h"
21
22
23 extern struct tdescr *current;
24
25 static int sig_copyctx = SIGTRAP;
26
27 static char const *const feats_names[FMAX_END] = {
28 " SSBS ",
29 };
30
31 #define MAX_FEATS_SZ 128
32 static char feats_string[MAX_FEATS_SZ];
33
feats_to_string(unsigned long feats)34 static inline char *feats_to_string(unsigned long feats)
35 {
36 size_t flen = MAX_FEATS_SZ - 1;
37
38 for (int i = 0; i < FMAX_END; i++) {
39 if (feats & (1UL << i)) {
40 size_t tlen = strlen(feats_names[i]);
41
42 assert(flen > tlen);
43 flen -= tlen;
44 strncat(feats_string, feats_names[i], flen);
45 }
46 }
47
48 return feats_string;
49 }
50
unblock_signal(int signum)51 static void unblock_signal(int signum)
52 {
53 sigset_t sset;
54
55 sigemptyset(&sset);
56 sigaddset(&sset, signum);
57 sigprocmask(SIG_UNBLOCK, &sset, NULL);
58 }
59
default_result(struct tdescr * td,bool force_exit)60 static void default_result(struct tdescr *td, bool force_exit)
61 {
62 if (td->result == KSFT_SKIP) {
63 fprintf(stderr, "==>> completed. SKIP.\n");
64 } else if (td->pass) {
65 fprintf(stderr, "==>> completed. PASS(1)\n");
66 td->result = KSFT_PASS;
67 } else {
68 fprintf(stdout, "==>> completed. FAIL(0)\n");
69 td->result = KSFT_FAIL;
70 }
71
72 if (force_exit)
73 exit(td->result);
74 }
75
76 /*
77 * The following handle_signal_* helpers are used by main default_handler
78 * and are meant to return true when signal is handled successfully:
79 * when false is returned instead, it means that the signal was somehow
80 * unexpected in that context and it was NOT handled; default_handler will
81 * take care of such unexpected situations.
82 */
83
handle_signal_unsupported(struct tdescr * td,siginfo_t * si,void * uc)84 static bool handle_signal_unsupported(struct tdescr *td,
85 siginfo_t *si, void *uc)
86 {
87 if (feats_ok(td))
88 return false;
89
90 /* Mangling PC to avoid loops on original SIGILL */
91 ((ucontext_t *)uc)->uc_mcontext.pc += 4;
92
93 if (!td->initialized) {
94 fprintf(stderr,
95 "Got SIG_UNSUPP @test_init. Ignore.\n");
96 } else {
97 fprintf(stderr,
98 "-- RX SIG_UNSUPP on unsupported feat...OK\n");
99 td->pass = 1;
100 default_result(current, 1);
101 }
102
103 return true;
104 }
105
handle_signal_trigger(struct tdescr * td,siginfo_t * si,void * uc)106 static bool handle_signal_trigger(struct tdescr *td,
107 siginfo_t *si, void *uc)
108 {
109 td->triggered = 1;
110 /* ->run was asserted NON-NULL in test_setup() already */
111 td->run(td, si, uc);
112
113 return true;
114 }
115
handle_signal_ok(struct tdescr * td,siginfo_t * si,void * uc)116 static bool handle_signal_ok(struct tdescr *td,
117 siginfo_t *si, void *uc)
118 {
119 /*
120 * it's a bug in the test code when this assert fail:
121 * if sig_trig was defined, it must have been used before getting here.
122 */
123 assert(!td->sig_trig || td->triggered);
124 fprintf(stderr,
125 "SIG_OK -- SP:0x%llX si_addr@:%p si_code:%d token@:%p offset:%ld\n",
126 ((ucontext_t *)uc)->uc_mcontext.sp,
127 si->si_addr, si->si_code, td->token, td->token - si->si_addr);
128 /*
129 * fake_sigreturn tests, which have sanity_enabled=1, set, at the very
130 * last time, the token field to the SP address used to place the fake
131 * sigframe: so token==0 means we never made it to the end,
132 * segfaulting well-before, and the test is possibly broken.
133 */
134 if (!td->sanity_disabled && !td->token) {
135 fprintf(stdout,
136 "current->token ZEROED...test is probably broken!\n");
137 abort();
138 }
139 /*
140 * Trying to narrow down the SEGV to the ones generated by Kernel itself
141 * via arm64_notify_segfault(). This is a best-effort check anyway, and
142 * the si_code check may need to change if this aspect of the kernel
143 * ABI changes.
144 */
145 if (td->sig_ok == SIGSEGV && si->si_code != SEGV_ACCERR) {
146 fprintf(stdout,
147 "si_code != SEGV_ACCERR...test is probably broken!\n");
148 abort();
149 }
150 td->pass = 1;
151 /*
152 * Some tests can lead to SEGV loops: in such a case we want to
153 * terminate immediately exiting straight away; some others are not
154 * supposed to outlive the signal handler code, due to the content of
155 * the fake sigframe which caused the signal itself.
156 */
157 default_result(current, 1);
158
159 return true;
160 }
161
handle_signal_copyctx(struct tdescr * td,siginfo_t * si,void * uc)162 static bool handle_signal_copyctx(struct tdescr *td,
163 siginfo_t *si, void *uc)
164 {
165 /* Mangling PC to avoid loops on original BRK instr */
166 ((ucontext_t *)uc)->uc_mcontext.pc += 4;
167 memcpy(td->live_uc, uc, td->live_sz);
168 ASSERT_GOOD_CONTEXT(td->live_uc);
169 td->live_uc_valid = 1;
170 fprintf(stderr,
171 "GOOD CONTEXT grabbed from sig_copyctx handler\n");
172
173 return true;
174 }
175
default_handler(int signum,siginfo_t * si,void * uc)176 static void default_handler(int signum, siginfo_t *si, void *uc)
177 {
178 if (current->sig_unsupp && signum == current->sig_unsupp &&
179 handle_signal_unsupported(current, si, uc)) {
180 fprintf(stderr, "Handled SIG_UNSUPP\n");
181 } else if (current->sig_trig && signum == current->sig_trig &&
182 handle_signal_trigger(current, si, uc)) {
183 fprintf(stderr, "Handled SIG_TRIG\n");
184 } else if (current->sig_ok && signum == current->sig_ok &&
185 handle_signal_ok(current, si, uc)) {
186 fprintf(stderr, "Handled SIG_OK\n");
187 } else if (signum == sig_copyctx && current->live_uc &&
188 handle_signal_copyctx(current, si, uc)) {
189 fprintf(stderr, "Handled SIG_COPYCTX\n");
190 } else {
191 if (signum == SIGALRM && current->timeout) {
192 fprintf(stderr, "-- Timeout !\n");
193 } else {
194 fprintf(stderr,
195 "-- RX UNEXPECTED SIGNAL: %d\n", signum);
196 }
197 default_result(current, 1);
198 }
199 }
200
default_setup(struct tdescr * td)201 static int default_setup(struct tdescr *td)
202 {
203 struct sigaction sa;
204
205 sa.sa_sigaction = default_handler;
206 sa.sa_flags = SA_SIGINFO | SA_RESTART;
207 sa.sa_flags |= td->sa_flags;
208 sigemptyset(&sa.sa_mask);
209 /* uncatchable signals naturally skipped ... */
210 for (int sig = 1; sig < 32; sig++)
211 sigaction(sig, &sa, NULL);
212 /*
213 * RT Signals default disposition is Term but they cannot be
214 * generated by the Kernel in response to our tests; so just catch
215 * them all and report them as UNEXPECTED signals.
216 */
217 for (int sig = SIGRTMIN; sig <= SIGRTMAX; sig++)
218 sigaction(sig, &sa, NULL);
219
220 /* just in case...unblock explicitly all we need */
221 if (td->sig_trig)
222 unblock_signal(td->sig_trig);
223 if (td->sig_ok)
224 unblock_signal(td->sig_ok);
225 if (td->sig_unsupp)
226 unblock_signal(td->sig_unsupp);
227
228 if (td->timeout) {
229 unblock_signal(SIGALRM);
230 alarm(td->timeout);
231 }
232 fprintf(stderr, "Registered handlers for all signals.\n");
233
234 return 1;
235 }
236
default_trigger(struct tdescr * td)237 static inline int default_trigger(struct tdescr *td)
238 {
239 return !raise(td->sig_trig);
240 }
241
test_init(struct tdescr * td)242 int test_init(struct tdescr *td)
243 {
244 if (td->sig_trig == sig_copyctx) {
245 fprintf(stdout,
246 "Signal %d is RESERVED, cannot be used as a trigger. Aborting\n",
247 sig_copyctx);
248 return 0;
249 }
250 /* just in case */
251 unblock_signal(sig_copyctx);
252
253 td->minsigstksz = getauxval(AT_MINSIGSTKSZ);
254 if (!td->minsigstksz)
255 td->minsigstksz = MINSIGSTKSZ;
256 fprintf(stderr, "Detected MINSTKSIGSZ:%d\n", td->minsigstksz);
257
258 if (td->feats_required) {
259 td->feats_supported = 0;
260 /*
261 * Checking for CPU required features using both the
262 * auxval and the arm64 MRS Emulation to read sysregs.
263 */
264 if (getauxval(AT_HWCAP) & HWCAP_SSBS)
265 td->feats_supported |= FEAT_SSBS;
266 if (feats_ok(td))
267 fprintf(stderr,
268 "Required Features: [%s] supported\n",
269 feats_to_string(td->feats_required &
270 td->feats_supported));
271 else
272 fprintf(stderr,
273 "Required Features: [%s] NOT supported\n",
274 feats_to_string(td->feats_required &
275 ~td->feats_supported));
276 }
277
278 /* Perform test specific additional initialization */
279 if (td->init && !td->init(td)) {
280 fprintf(stderr, "FAILED Testcase initialization.\n");
281 return 0;
282 }
283 td->initialized = 1;
284 fprintf(stderr, "Testcase initialized.\n");
285
286 return 1;
287 }
288
test_setup(struct tdescr * td)289 int test_setup(struct tdescr *td)
290 {
291 /* assert core invariants symptom of a rotten testcase */
292 assert(current);
293 assert(td);
294 assert(td->name);
295 assert(td->run);
296
297 /* Default result is FAIL if test setup fails */
298 td->result = KSFT_FAIL;
299 if (td->setup)
300 return td->setup(td);
301 else
302 return default_setup(td);
303 }
304
test_run(struct tdescr * td)305 int test_run(struct tdescr *td)
306 {
307 if (td->sig_trig) {
308 if (td->trigger)
309 return td->trigger(td);
310 else
311 return default_trigger(td);
312 } else {
313 return td->run(td, NULL, NULL);
314 }
315 }
316
test_result(struct tdescr * td)317 void test_result(struct tdescr *td)
318 {
319 if (td->initialized && td->result != KSFT_SKIP && td->check_result)
320 td->check_result(td);
321 default_result(td, 0);
322 }
323
test_cleanup(struct tdescr * td)324 void test_cleanup(struct tdescr *td)
325 {
326 if (td->cleanup)
327 td->cleanup(td);
328 }
329
