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1da177e4 LT |
1 | /* signal.c: FRV specific bits of signal handling |
2 | * | |
3 | * Copyright (C) 2003-5 Red Hat, Inc. All Rights Reserved. | |
4 | * Written by David Howells (dhowells@redhat.com) | |
5 | * - Derived from arch/m68k/kernel/signal.c | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License | |
9 | * as published by the Free Software Foundation; either version | |
10 | * 2 of the License, or (at your option) any later version. | |
11 | */ | |
12 | ||
13 | #include <linux/sched.h> | |
14 | #include <linux/mm.h> | |
15 | #include <linux/smp.h> | |
1da177e4 LT |
16 | #include <linux/kernel.h> |
17 | #include <linux/signal.h> | |
18 | #include <linux/errno.h> | |
19 | #include <linux/wait.h> | |
20 | #include <linux/ptrace.h> | |
21 | #include <linux/unistd.h> | |
22 | #include <linux/personality.h> | |
4a3b9893 | 23 | #include <linux/tracehook.h> |
1da177e4 LT |
24 | #include <asm/ucontext.h> |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/cacheflush.h> | |
27 | ||
28 | #define DEBUG_SIG 0 | |
29 | ||
1da177e4 LT |
30 | struct fdpic_func_descriptor { |
31 | unsigned long text; | |
32 | unsigned long GOT; | |
33 | }; | |
34 | ||
1da177e4 LT |
35 | /* |
36 | * Do a signal return; undo the signal stack. | |
37 | */ | |
38 | ||
39 | struct sigframe | |
40 | { | |
9e4d11f8 | 41 | __sigrestore_t pretcode; |
1da177e4 LT |
42 | int sig; |
43 | struct sigcontext sc; | |
44 | unsigned long extramask[_NSIG_WORDS-1]; | |
45 | uint32_t retcode[2]; | |
46 | }; | |
47 | ||
48 | struct rt_sigframe | |
49 | { | |
9e4d11f8 | 50 | __sigrestore_t pretcode; |
1da177e4 | 51 | int sig; |
9e4d11f8 AV |
52 | struct siginfo __user *pinfo; |
53 | void __user *puc; | |
1da177e4 LT |
54 | struct siginfo info; |
55 | struct ucontext uc; | |
56 | uint32_t retcode[2]; | |
57 | }; | |
58 | ||
59 | static int restore_sigcontext(struct sigcontext __user *sc, int *_gr8) | |
60 | { | |
61 | struct user_context *user = current->thread.user; | |
62 | unsigned long tbr, psr; | |
63 | ||
20cd514d | 64 | /* Always make any pending restarted system calls return -EINTR */ |
f56141e3 | 65 | current->restart_block.fn = do_no_restart_syscall; |
20cd514d | 66 | |
1da177e4 LT |
67 | tbr = user->i.tbr; |
68 | psr = user->i.psr; | |
69 | if (copy_from_user(user, &sc->sc_context, sizeof(sc->sc_context))) | |
70 | goto badframe; | |
71 | user->i.tbr = tbr; | |
72 | user->i.psr = psr; | |
73 | ||
74 | restore_user_regs(user); | |
75 | ||
76 | user->i.syscallno = -1; /* disable syscall checks */ | |
77 | ||
78 | *_gr8 = user->i.gr[8]; | |
79 | return 0; | |
80 | ||
81 | badframe: | |
82 | return 1; | |
83 | } | |
84 | ||
85 | asmlinkage int sys_sigreturn(void) | |
86 | { | |
87 | struct sigframe __user *frame = (struct sigframe __user *) __frame->sp; | |
88 | sigset_t set; | |
89 | int gr8; | |
90 | ||
91 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
92 | goto badframe; | |
93 | if (__get_user(set.sig[0], &frame->sc.sc_oldmask)) | |
94 | goto badframe; | |
95 | ||
96 | if (_NSIG_WORDS > 1 && | |
97 | __copy_from_user(&set.sig[1], &frame->extramask, sizeof(frame->extramask))) | |
98 | goto badframe; | |
99 | ||
7ebe0c5d | 100 | set_current_blocked(&set); |
1da177e4 LT |
101 | |
102 | if (restore_sigcontext(&frame->sc, &gr8)) | |
103 | goto badframe; | |
104 | return gr8; | |
105 | ||
106 | badframe: | |
107 | force_sig(SIGSEGV, current); | |
108 | return 0; | |
109 | } | |
110 | ||
111 | asmlinkage int sys_rt_sigreturn(void) | |
112 | { | |
113 | struct rt_sigframe __user *frame = (struct rt_sigframe __user *) __frame->sp; | |
114 | sigset_t set; | |
115 | int gr8; | |
116 | ||
117 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
118 | goto badframe; | |
119 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
120 | goto badframe; | |
121 | ||
7ebe0c5d | 122 | set_current_blocked(&set); |
1da177e4 LT |
123 | |
124 | if (restore_sigcontext(&frame->uc.uc_mcontext, &gr8)) | |
125 | goto badframe; | |
126 | ||
fe761416 | 127 | if (restore_altstack(&frame->uc.uc_stack)) |
1da177e4 LT |
128 | goto badframe; |
129 | ||
130 | return gr8; | |
131 | ||
132 | badframe: | |
133 | force_sig(SIGSEGV, current); | |
134 | return 0; | |
135 | } | |
136 | ||
137 | /* | |
138 | * Set up a signal frame | |
139 | */ | |
140 | static int setup_sigcontext(struct sigcontext __user *sc, unsigned long mask) | |
141 | { | |
142 | save_user_regs(current->thread.user); | |
143 | ||
144 | if (copy_to_user(&sc->sc_context, current->thread.user, sizeof(sc->sc_context)) != 0) | |
145 | goto badframe; | |
146 | ||
147 | /* non-iBCS2 extensions.. */ | |
148 | if (__put_user(mask, &sc->sc_oldmask) < 0) | |
149 | goto badframe; | |
150 | ||
151 | return 0; | |
152 | ||
153 | badframe: | |
154 | return 1; | |
155 | } | |
156 | ||
157 | /*****************************************************************************/ | |
158 | /* | |
159 | * Determine which stack to use.. | |
160 | */ | |
4a03ac36 | 161 | static inline void __user *get_sigframe(struct ksignal *ksig, |
1da177e4 LT |
162 | size_t frame_size) |
163 | { | |
4a03ac36 | 164 | unsigned long sp = sigsp(__frame->sp, ksig); |
1da177e4 LT |
165 | |
166 | return (void __user *) ((sp - frame_size) & ~7UL); | |
fef2b580 | 167 | |
1da177e4 LT |
168 | } /* end get_sigframe() */ |
169 | ||
170 | /*****************************************************************************/ | |
171 | /* | |
172 | * | |
173 | */ | |
720f36b9 | 174 | static int setup_frame(struct ksignal *ksig, sigset_t *set) |
1da177e4 LT |
175 | { |
176 | struct sigframe __user *frame; | |
7bd83010 | 177 | int sig = ksig->sig; |
1da177e4 | 178 | |
4a03ac36 | 179 | frame = get_sigframe(ksig, sizeof(*frame)); |
1da177e4 LT |
180 | |
181 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
720f36b9 | 182 | return -EFAULT; |
1da177e4 | 183 | |
7bd83010 | 184 | if (__put_user(sig, &frame->sig) < 0) |
720f36b9 | 185 | return -EFAULT; |
1da177e4 LT |
186 | |
187 | if (setup_sigcontext(&frame->sc, set->sig[0])) | |
720f36b9 | 188 | return -EFAULT; |
1da177e4 LT |
189 | |
190 | if (_NSIG_WORDS > 1) { | |
191 | if (__copy_to_user(frame->extramask, &set->sig[1], | |
192 | sizeof(frame->extramask))) | |
720f36b9 | 193 | return -EFAULT; |
1da177e4 LT |
194 | } |
195 | ||
196 | /* Set up to return from userspace. If provided, use a stub | |
197 | * already in userspace. */ | |
720f36b9 RW |
198 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
199 | if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode) < 0) | |
200 | return -EFAULT; | |
1da177e4 LT |
201 | } |
202 | else { | |
203 | /* Set up the following code on the stack: | |
204 | * setlos #__NR_sigreturn,gr7 | |
205 | * tira gr0,0 | |
206 | */ | |
9e4d11f8 | 207 | if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) || |
1da177e4 LT |
208 | __put_user(0x8efc0000|__NR_sigreturn, &frame->retcode[0]) || |
209 | __put_user(0xc0700000, &frame->retcode[1])) | |
720f36b9 | 210 | return -EFAULT; |
1da177e4 LT |
211 | |
212 | flush_icache_range((unsigned long) frame->retcode, | |
213 | (unsigned long) (frame->retcode + 2)); | |
214 | } | |
215 | ||
5f4ad04a | 216 | /* Set up registers for the signal handler */ |
ecd0fa98 | 217 | if (current->personality & FDPIC_FUNCPTRS) { |
1da177e4 | 218 | struct fdpic_func_descriptor __user *funcptr = |
720f36b9 | 219 | (struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler; |
5f4ad04a AV |
220 | struct fdpic_func_descriptor desc; |
221 | if (copy_from_user(&desc, funcptr, sizeof(desc))) | |
720f36b9 | 222 | return -EFAULT; |
5f4ad04a AV |
223 | __frame->pc = desc.text; |
224 | __frame->gr15 = desc.GOT; | |
1da177e4 | 225 | } else { |
720f36b9 | 226 | __frame->pc = (unsigned long) ksig->ka.sa.sa_handler; |
fef2b580 | 227 | __frame->gr15 = 0; |
1da177e4 LT |
228 | } |
229 | ||
5f4ad04a AV |
230 | __frame->sp = (unsigned long) frame; |
231 | __frame->lr = (unsigned long) &frame->retcode; | |
232 | __frame->gr8 = sig; | |
1da177e4 LT |
233 | |
234 | #if DEBUG_SIG | |
235 | printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", | |
fef2b580 | 236 | sig, current->comm, current->pid, frame, __frame->pc, |
8efc0ab5 | 237 | frame->pretcode); |
1da177e4 LT |
238 | #endif |
239 | ||
a411aee9 | 240 | return 0; |
1da177e4 LT |
241 | } /* end setup_frame() */ |
242 | ||
243 | /*****************************************************************************/ | |
244 | /* | |
245 | * | |
246 | */ | |
720f36b9 | 247 | static int setup_rt_frame(struct ksignal *ksig, sigset_t *set) |
1da177e4 LT |
248 | { |
249 | struct rt_sigframe __user *frame; | |
7bd83010 | 250 | int sig = ksig->sig; |
1da177e4 | 251 | |
4a03ac36 | 252 | frame = get_sigframe(ksig, sizeof(*frame)); |
1da177e4 LT |
253 | |
254 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
720f36b9 | 255 | return -EFAULT; |
1da177e4 | 256 | |
7bd83010 | 257 | if (__put_user(sig, &frame->sig) || |
1da177e4 LT |
258 | __put_user(&frame->info, &frame->pinfo) || |
259 | __put_user(&frame->uc, &frame->puc)) | |
720f36b9 | 260 | return -EFAULT; |
1da177e4 | 261 | |
720f36b9 RW |
262 | if (copy_siginfo_to_user(&frame->info, &ksig->info)) |
263 | return -EFAULT; | |
1da177e4 LT |
264 | |
265 | /* Create the ucontext. */ | |
266 | if (__put_user(0, &frame->uc.uc_flags) || | |
9e4d11f8 | 267 | __put_user(NULL, &frame->uc.uc_link) || |
fe761416 | 268 | __save_altstack(&frame->uc.uc_stack, __frame->sp)) |
720f36b9 | 269 | return -EFAULT; |
1da177e4 LT |
270 | |
271 | if (setup_sigcontext(&frame->uc.uc_mcontext, set->sig[0])) | |
720f36b9 | 272 | return -EFAULT; |
1da177e4 LT |
273 | |
274 | if (__copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set))) | |
720f36b9 | 275 | return -EFAULT; |
1da177e4 LT |
276 | |
277 | /* Set up to return from userspace. If provided, use a stub | |
278 | * already in userspace. */ | |
720f36b9 RW |
279 | if (ksig->ka.sa.sa_flags & SA_RESTORER) { |
280 | if (__put_user(ksig->ka.sa.sa_restorer, &frame->pretcode)) | |
281 | return -EFAULT; | |
1da177e4 LT |
282 | } |
283 | else { | |
284 | /* Set up the following code on the stack: | |
285 | * setlos #__NR_sigreturn,gr7 | |
286 | * tira gr0,0 | |
287 | */ | |
9e4d11f8 | 288 | if (__put_user((__sigrestore_t)frame->retcode, &frame->pretcode) || |
1da177e4 LT |
289 | __put_user(0x8efc0000|__NR_rt_sigreturn, &frame->retcode[0]) || |
290 | __put_user(0xc0700000, &frame->retcode[1])) | |
720f36b9 | 291 | return -EFAULT; |
1da177e4 LT |
292 | |
293 | flush_icache_range((unsigned long) frame->retcode, | |
294 | (unsigned long) (frame->retcode + 2)); | |
295 | } | |
296 | ||
297 | /* Set up registers for signal handler */ | |
ecd0fa98 | 298 | if (current->personality & FDPIC_FUNCPTRS) { |
9e4d11f8 | 299 | struct fdpic_func_descriptor __user *funcptr = |
720f36b9 | 300 | (struct fdpic_func_descriptor __user *) ksig->ka.sa.sa_handler; |
5f4ad04a AV |
301 | struct fdpic_func_descriptor desc; |
302 | if (copy_from_user(&desc, funcptr, sizeof(desc))) | |
720f36b9 | 303 | return -EFAULT; |
5f4ad04a AV |
304 | __frame->pc = desc.text; |
305 | __frame->gr15 = desc.GOT; | |
1da177e4 | 306 | } else { |
720f36b9 | 307 | __frame->pc = (unsigned long) ksig->ka.sa.sa_handler; |
fef2b580 | 308 | __frame->gr15 = 0; |
1da177e4 LT |
309 | } |
310 | ||
5f4ad04a AV |
311 | __frame->sp = (unsigned long) frame; |
312 | __frame->lr = (unsigned long) &frame->retcode; | |
313 | __frame->gr8 = sig; | |
314 | __frame->gr9 = (unsigned long) &frame->info; | |
1da177e4 LT |
315 | |
316 | #if DEBUG_SIG | |
317 | printk("SIG deliver %d (%s:%d): sp=%p pc=%lx ra=%p\n", | |
fef2b580 | 318 | sig, current->comm, current->pid, frame, __frame->pc, |
8efc0ab5 | 319 | frame->pretcode); |
1da177e4 | 320 | #endif |
a411aee9 | 321 | return 0; |
1da177e4 | 322 | |
1da177e4 LT |
323 | } /* end setup_rt_frame() */ |
324 | ||
325 | /*****************************************************************************/ | |
326 | /* | |
327 | * OK, we're invoking a handler | |
328 | */ | |
720f36b9 | 329 | static void handle_signal(struct ksignal *ksig) |
1da177e4 | 330 | { |
b7f9a11a | 331 | sigset_t *oldset = sigmask_to_save(); |
8efc0ab5 DH |
332 | int ret; |
333 | ||
1da177e4 | 334 | /* Are we from a system call? */ |
ed1cde68 | 335 | if (__frame->syscallno != -1) { |
1da177e4 | 336 | /* If so, check system call restarting.. */ |
fef2b580 | 337 | switch (__frame->gr8) { |
1da177e4 LT |
338 | case -ERESTART_RESTARTBLOCK: |
339 | case -ERESTARTNOHAND: | |
fef2b580 | 340 | __frame->gr8 = -EINTR; |
1da177e4 LT |
341 | break; |
342 | ||
343 | case -ERESTARTSYS: | |
720f36b9 | 344 | if (!(ksig->ka.sa.sa_flags & SA_RESTART)) { |
fef2b580 | 345 | __frame->gr8 = -EINTR; |
1da177e4 LT |
346 | break; |
347 | } | |
8efc0ab5 | 348 | |
1da177e4 LT |
349 | /* fallthrough */ |
350 | case -ERESTARTNOINTR: | |
fef2b580 DH |
351 | __frame->gr8 = __frame->orig_gr8; |
352 | __frame->pc -= 4; | |
1da177e4 | 353 | } |
ed1cde68 | 354 | __frame->syscallno = -1; |
1da177e4 LT |
355 | } |
356 | ||
357 | /* Set up the stack frame */ | |
720f36b9 RW |
358 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
359 | ret = setup_rt_frame(ksig, oldset); | |
1da177e4 | 360 | else |
720f36b9 | 361 | ret = setup_frame(ksig, oldset); |
1da177e4 | 362 | |
720f36b9 | 363 | signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP)); |
1da177e4 LT |
364 | } /* end handle_signal() */ |
365 | ||
366 | /*****************************************************************************/ | |
367 | /* | |
368 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
369 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
370 | * mistake. | |
371 | */ | |
a411aee9 | 372 | static void do_signal(void) |
1da177e4 | 373 | { |
720f36b9 | 374 | struct ksignal ksig; |
1da177e4 | 375 | |
720f36b9 RW |
376 | if (get_signal(&ksig)) { |
377 | handle_signal(&ksig); | |
a411aee9 DH |
378 | return; |
379 | } | |
1da177e4 | 380 | |
1da177e4 | 381 | /* Did we come from a system call? */ |
c896a2e0 | 382 | if (__frame->syscallno != -1) { |
1da177e4 | 383 | /* Restart the system call - no handlers present */ |
a411aee9 DH |
384 | switch (__frame->gr8) { |
385 | case -ERESTARTNOHAND: | |
386 | case -ERESTARTSYS: | |
387 | case -ERESTARTNOINTR: | |
fef2b580 DH |
388 | __frame->gr8 = __frame->orig_gr8; |
389 | __frame->pc -= 4; | |
a411aee9 | 390 | break; |
1da177e4 | 391 | |
a411aee9 | 392 | case -ERESTART_RESTARTBLOCK: |
44c7afff | 393 | __frame->gr7 = __NR_restart_syscall; |
fef2b580 | 394 | __frame->pc -= 4; |
a411aee9 | 395 | break; |
1da177e4 | 396 | } |
ed1cde68 | 397 | __frame->syscallno = -1; |
1da177e4 LT |
398 | } |
399 | ||
a411aee9 DH |
400 | /* if there's no signal to deliver, we just put the saved sigmask |
401 | * back */ | |
51a7b448 | 402 | restore_saved_sigmask(); |
1da177e4 LT |
403 | } /* end do_signal() */ |
404 | ||
405 | /*****************************************************************************/ | |
406 | /* | |
407 | * notification of userspace execution resumption | |
a411aee9 | 408 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 LT |
409 | */ |
410 | asmlinkage void do_notify_resume(__u32 thread_info_flags) | |
411 | { | |
412 | /* pending single-step? */ | |
413 | if (thread_info_flags & _TIF_SINGLESTEP) | |
414 | clear_thread_flag(TIF_SINGLESTEP); | |
415 | ||
416 | /* deal with pending signal delivery */ | |
a3936249 | 417 | if (thread_info_flags & _TIF_SIGPENDING) |
a411aee9 | 418 | do_signal(); |
1da177e4 | 419 | |
b7bab880 DH |
420 | /* deal with notification on about to resume userspace execution */ |
421 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { | |
422 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
4a3b9893 | 423 | tracehook_notify_resume(__frame); |
b7bab880 DH |
424 | } |
425 | ||
1da177e4 | 426 | } /* end do_notify_resume() */ |