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1da177e4 LT |
1 | /* |
2 | * linux/arch/alpha/kernel/signal.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * | |
6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson | |
7 | */ | |
8 | ||
9 | #include <linux/sched.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/signal.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/wait.h> | |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/unistd.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/smp.h> | |
18 | #include <linux/smp_lock.h> | |
19 | #include <linux/stddef.h> | |
20 | #include <linux/tty.h> | |
21 | #include <linux/binfmts.h> | |
22 | #include <linux/bitops.h> | |
23 | ||
24 | #include <asm/uaccess.h> | |
25 | #include <asm/sigcontext.h> | |
26 | #include <asm/ucontext.h> | |
27 | ||
28 | #include "proto.h" | |
29 | ||
30 | ||
31 | #define DEBUG_SIG 0 | |
32 | ||
33 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
34 | ||
35 | asmlinkage void ret_from_sys_call(void); | |
36 | static int do_signal(sigset_t *, struct pt_regs *, struct switch_stack *, | |
37 | unsigned long, unsigned long); | |
38 | ||
39 | ||
40 | /* | |
41 | * The OSF/1 sigprocmask calling sequence is different from the | |
42 | * C sigprocmask() sequence.. | |
43 | * | |
44 | * how: | |
45 | * 1 - SIG_BLOCK | |
46 | * 2 - SIG_UNBLOCK | |
47 | * 3 - SIG_SETMASK | |
48 | * | |
49 | * We change the range to -1 .. 1 in order to let gcc easily | |
50 | * use the conditional move instructions. | |
51 | * | |
52 | * Note that we don't need to acquire the kernel lock for SMP | |
53 | * operation, as all of this is local to this thread. | |
54 | */ | |
55 | asmlinkage unsigned long | |
56 | do_osf_sigprocmask(int how, unsigned long newmask, struct pt_regs *regs) | |
57 | { | |
58 | unsigned long oldmask = -EINVAL; | |
59 | ||
60 | if ((unsigned long)how-1 <= 2) { | |
61 | long sign = how-2; /* -1 .. 1 */ | |
62 | unsigned long block, unblock; | |
63 | ||
64 | newmask &= _BLOCKABLE; | |
65 | spin_lock_irq(¤t->sighand->siglock); | |
66 | oldmask = current->blocked.sig[0]; | |
67 | ||
68 | unblock = oldmask & ~newmask; | |
69 | block = oldmask | newmask; | |
70 | if (!sign) | |
71 | block = unblock; | |
72 | if (sign <= 0) | |
73 | newmask = block; | |
74 | if (_NSIG_WORDS > 1 && sign > 0) | |
75 | sigemptyset(¤t->blocked); | |
76 | current->blocked.sig[0] = newmask; | |
77 | recalc_sigpending(); | |
78 | spin_unlock_irq(¤t->sighand->siglock); | |
79 | ||
80 | regs->r0 = 0; /* special no error return */ | |
81 | } | |
82 | return oldmask; | |
83 | } | |
84 | ||
85 | asmlinkage int | |
86 | osf_sigaction(int sig, const struct osf_sigaction __user *act, | |
87 | struct osf_sigaction __user *oact) | |
88 | { | |
89 | struct k_sigaction new_ka, old_ka; | |
90 | int ret; | |
91 | ||
92 | if (act) { | |
93 | old_sigset_t mask; | |
94 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
95 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
96 | __get_user(new_ka.sa.sa_flags, &act->sa_flags)) | |
97 | return -EFAULT; | |
98 | __get_user(mask, &act->sa_mask); | |
99 | siginitset(&new_ka.sa.sa_mask, mask); | |
100 | new_ka.ka_restorer = NULL; | |
101 | } | |
102 | ||
103 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
104 | ||
105 | if (!ret && oact) { | |
106 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
107 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
108 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags)) | |
109 | return -EFAULT; | |
110 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
111 | } | |
112 | ||
113 | return ret; | |
114 | } | |
115 | ||
116 | asmlinkage long | |
117 | sys_rt_sigaction(int sig, const struct sigaction __user *act, | |
118 | struct sigaction __user *oact, | |
119 | size_t sigsetsize, void __user *restorer) | |
120 | { | |
121 | struct k_sigaction new_ka, old_ka; | |
122 | int ret; | |
123 | ||
124 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
125 | if (sigsetsize != sizeof(sigset_t)) | |
126 | return -EINVAL; | |
127 | ||
128 | if (act) { | |
129 | new_ka.ka_restorer = restorer; | |
130 | if (copy_from_user(&new_ka.sa, act, sizeof(*act))) | |
131 | return -EFAULT; | |
132 | } | |
133 | ||
134 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
135 | ||
136 | if (!ret && oact) { | |
137 | if (copy_to_user(oact, &old_ka.sa, sizeof(*oact))) | |
138 | return -EFAULT; | |
139 | } | |
140 | ||
141 | return ret; | |
142 | } | |
143 | ||
144 | /* | |
145 | * Atomically swap in the new signal mask, and wait for a signal. | |
146 | */ | |
147 | asmlinkage int | |
148 | do_sigsuspend(old_sigset_t mask, struct pt_regs *regs, struct switch_stack *sw) | |
149 | { | |
150 | sigset_t oldset; | |
151 | ||
152 | mask &= _BLOCKABLE; | |
153 | spin_lock_irq(¤t->sighand->siglock); | |
154 | oldset = current->blocked; | |
155 | siginitset(¤t->blocked, mask); | |
156 | recalc_sigpending(); | |
157 | spin_unlock_irq(¤t->sighand->siglock); | |
158 | ||
159 | /* Indicate EINTR on return from any possible signal handler, | |
160 | which will not come back through here, but via sigreturn. */ | |
161 | regs->r0 = EINTR; | |
162 | regs->r19 = 1; | |
163 | ||
164 | while (1) { | |
165 | current->state = TASK_INTERRUPTIBLE; | |
166 | schedule(); | |
167 | if (do_signal(&oldset, regs, sw, 0, 0)) | |
168 | return -EINTR; | |
169 | } | |
170 | } | |
171 | ||
172 | asmlinkage int | |
173 | do_rt_sigsuspend(sigset_t __user *uset, size_t sigsetsize, | |
174 | struct pt_regs *regs, struct switch_stack *sw) | |
175 | { | |
176 | sigset_t oldset, set; | |
177 | ||
178 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
179 | if (sigsetsize != sizeof(sigset_t)) | |
180 | return -EINVAL; | |
181 | if (copy_from_user(&set, uset, sizeof(set))) | |
182 | return -EFAULT; | |
183 | ||
184 | sigdelsetmask(&set, ~_BLOCKABLE); | |
185 | spin_lock_irq(¤t->sighand->siglock); | |
186 | oldset = current->blocked; | |
187 | current->blocked = set; | |
188 | recalc_sigpending(); | |
189 | spin_unlock_irq(¤t->sighand->siglock); | |
190 | ||
191 | /* Indicate EINTR on return from any possible signal handler, | |
192 | which will not come back through here, but via sigreturn. */ | |
193 | regs->r0 = EINTR; | |
194 | regs->r19 = 1; | |
195 | ||
196 | while (1) { | |
197 | current->state = TASK_INTERRUPTIBLE; | |
198 | schedule(); | |
199 | if (do_signal(&oldset, regs, sw, 0, 0)) | |
200 | return -EINTR; | |
201 | } | |
202 | } | |
203 | ||
204 | asmlinkage int | |
205 | sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) | |
206 | { | |
207 | return do_sigaltstack(uss, uoss, rdusp()); | |
208 | } | |
209 | ||
210 | /* | |
211 | * Do a signal return; undo the signal stack. | |
212 | */ | |
213 | ||
214 | #if _NSIG_WORDS > 1 | |
215 | # error "Non SA_SIGINFO frame needs rearranging" | |
216 | #endif | |
217 | ||
218 | struct sigframe | |
219 | { | |
220 | struct sigcontext sc; | |
221 | unsigned int retcode[3]; | |
222 | }; | |
223 | ||
224 | struct rt_sigframe | |
225 | { | |
226 | struct siginfo info; | |
227 | struct ucontext uc; | |
228 | unsigned int retcode[3]; | |
229 | }; | |
230 | ||
231 | /* If this changes, userland unwinders that Know Things about our signal | |
232 | frame will break. Do not undertake lightly. It also implies an ABI | |
233 | change wrt the size of siginfo_t, which may cause some pain. */ | |
234 | extern char compile_time_assert | |
235 | [offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1]; | |
236 | ||
237 | #define INSN_MOV_R30_R16 0x47fe0410 | |
238 | #define INSN_LDI_R0 0x201f0000 | |
239 | #define INSN_CALLSYS 0x00000083 | |
240 | ||
241 | static long | |
242 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
243 | struct switch_stack *sw) | |
244 | { | |
245 | unsigned long usp; | |
246 | long i, err = __get_user(regs->pc, &sc->sc_pc); | |
247 | ||
248 | sw->r26 = (unsigned long) ret_from_sys_call; | |
249 | ||
250 | err |= __get_user(regs->r0, sc->sc_regs+0); | |
251 | err |= __get_user(regs->r1, sc->sc_regs+1); | |
252 | err |= __get_user(regs->r2, sc->sc_regs+2); | |
253 | err |= __get_user(regs->r3, sc->sc_regs+3); | |
254 | err |= __get_user(regs->r4, sc->sc_regs+4); | |
255 | err |= __get_user(regs->r5, sc->sc_regs+5); | |
256 | err |= __get_user(regs->r6, sc->sc_regs+6); | |
257 | err |= __get_user(regs->r7, sc->sc_regs+7); | |
258 | err |= __get_user(regs->r8, sc->sc_regs+8); | |
259 | err |= __get_user(sw->r9, sc->sc_regs+9); | |
260 | err |= __get_user(sw->r10, sc->sc_regs+10); | |
261 | err |= __get_user(sw->r11, sc->sc_regs+11); | |
262 | err |= __get_user(sw->r12, sc->sc_regs+12); | |
263 | err |= __get_user(sw->r13, sc->sc_regs+13); | |
264 | err |= __get_user(sw->r14, sc->sc_regs+14); | |
265 | err |= __get_user(sw->r15, sc->sc_regs+15); | |
266 | err |= __get_user(regs->r16, sc->sc_regs+16); | |
267 | err |= __get_user(regs->r17, sc->sc_regs+17); | |
268 | err |= __get_user(regs->r18, sc->sc_regs+18); | |
269 | err |= __get_user(regs->r19, sc->sc_regs+19); | |
270 | err |= __get_user(regs->r20, sc->sc_regs+20); | |
271 | err |= __get_user(regs->r21, sc->sc_regs+21); | |
272 | err |= __get_user(regs->r22, sc->sc_regs+22); | |
273 | err |= __get_user(regs->r23, sc->sc_regs+23); | |
274 | err |= __get_user(regs->r24, sc->sc_regs+24); | |
275 | err |= __get_user(regs->r25, sc->sc_regs+25); | |
276 | err |= __get_user(regs->r26, sc->sc_regs+26); | |
277 | err |= __get_user(regs->r27, sc->sc_regs+27); | |
278 | err |= __get_user(regs->r28, sc->sc_regs+28); | |
279 | err |= __get_user(regs->gp, sc->sc_regs+29); | |
280 | err |= __get_user(usp, sc->sc_regs+30); | |
281 | wrusp(usp); | |
282 | ||
283 | for (i = 0; i < 31; i++) | |
284 | err |= __get_user(sw->fp[i], sc->sc_fpregs+i); | |
285 | err |= __get_user(sw->fp[31], &sc->sc_fpcr); | |
286 | ||
287 | return err; | |
288 | } | |
289 | ||
290 | /* Note that this syscall is also used by setcontext(3) to install | |
291 | a given sigcontext. This because it's impossible to set *all* | |
292 | registers and transfer control from userland. */ | |
293 | ||
294 | asmlinkage void | |
295 | do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs, | |
296 | struct switch_stack *sw) | |
297 | { | |
298 | sigset_t set; | |
299 | ||
300 | /* Verify that it's a good sigcontext before using it */ | |
301 | if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) | |
302 | goto give_sigsegv; | |
303 | if (__get_user(set.sig[0], &sc->sc_mask)) | |
304 | goto give_sigsegv; | |
305 | ||
306 | sigdelsetmask(&set, ~_BLOCKABLE); | |
307 | spin_lock_irq(¤t->sighand->siglock); | |
308 | current->blocked = set; | |
309 | recalc_sigpending(); | |
310 | spin_unlock_irq(¤t->sighand->siglock); | |
311 | ||
312 | if (restore_sigcontext(sc, regs, sw)) | |
313 | goto give_sigsegv; | |
314 | ||
315 | /* Send SIGTRAP if we're single-stepping: */ | |
316 | if (ptrace_cancel_bpt (current)) { | |
317 | siginfo_t info; | |
318 | ||
319 | info.si_signo = SIGTRAP; | |
320 | info.si_errno = 0; | |
321 | info.si_code = TRAP_BRKPT; | |
322 | info.si_addr = (void __user *) regs->pc; | |
323 | info.si_trapno = 0; | |
324 | send_sig_info(SIGTRAP, &info, current); | |
325 | } | |
326 | return; | |
327 | ||
328 | give_sigsegv: | |
329 | force_sig(SIGSEGV, current); | |
330 | } | |
331 | ||
332 | asmlinkage void | |
333 | do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs, | |
334 | struct switch_stack *sw) | |
335 | { | |
336 | sigset_t set; | |
337 | ||
338 | /* Verify that it's a good ucontext_t before using it */ | |
339 | if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc))) | |
340 | goto give_sigsegv; | |
341 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
342 | goto give_sigsegv; | |
343 | ||
344 | sigdelsetmask(&set, ~_BLOCKABLE); | |
345 | spin_lock_irq(¤t->sighand->siglock); | |
346 | current->blocked = set; | |
347 | recalc_sigpending(); | |
348 | spin_unlock_irq(¤t->sighand->siglock); | |
349 | ||
350 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs, sw)) | |
351 | goto give_sigsegv; | |
352 | ||
353 | /* Send SIGTRAP if we're single-stepping: */ | |
354 | if (ptrace_cancel_bpt (current)) { | |
355 | siginfo_t info; | |
356 | ||
357 | info.si_signo = SIGTRAP; | |
358 | info.si_errno = 0; | |
359 | info.si_code = TRAP_BRKPT; | |
360 | info.si_addr = (void __user *) regs->pc; | |
361 | info.si_trapno = 0; | |
362 | send_sig_info(SIGTRAP, &info, current); | |
363 | } | |
364 | return; | |
365 | ||
366 | give_sigsegv: | |
367 | force_sig(SIGSEGV, current); | |
368 | } | |
369 | ||
370 | ||
371 | /* | |
372 | * Set up a signal frame. | |
373 | */ | |
374 | ||
375 | static inline void __user * | |
376 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
377 | { | |
378 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! on_sig_stack(sp)) | |
379 | sp = current->sas_ss_sp + current->sas_ss_size; | |
380 | ||
381 | return (void __user *)((sp - frame_size) & -32ul); | |
382 | } | |
383 | ||
384 | static long | |
385 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
386 | struct switch_stack *sw, unsigned long mask, unsigned long sp) | |
387 | { | |
388 | long i, err = 0; | |
389 | ||
390 | err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack); | |
391 | err |= __put_user(mask, &sc->sc_mask); | |
392 | err |= __put_user(regs->pc, &sc->sc_pc); | |
393 | err |= __put_user(8, &sc->sc_ps); | |
394 | ||
395 | err |= __put_user(regs->r0 , sc->sc_regs+0); | |
396 | err |= __put_user(regs->r1 , sc->sc_regs+1); | |
397 | err |= __put_user(regs->r2 , sc->sc_regs+2); | |
398 | err |= __put_user(regs->r3 , sc->sc_regs+3); | |
399 | err |= __put_user(regs->r4 , sc->sc_regs+4); | |
400 | err |= __put_user(regs->r5 , sc->sc_regs+5); | |
401 | err |= __put_user(regs->r6 , sc->sc_regs+6); | |
402 | err |= __put_user(regs->r7 , sc->sc_regs+7); | |
403 | err |= __put_user(regs->r8 , sc->sc_regs+8); | |
404 | err |= __put_user(sw->r9 , sc->sc_regs+9); | |
405 | err |= __put_user(sw->r10 , sc->sc_regs+10); | |
406 | err |= __put_user(sw->r11 , sc->sc_regs+11); | |
407 | err |= __put_user(sw->r12 , sc->sc_regs+12); | |
408 | err |= __put_user(sw->r13 , sc->sc_regs+13); | |
409 | err |= __put_user(sw->r14 , sc->sc_regs+14); | |
410 | err |= __put_user(sw->r15 , sc->sc_regs+15); | |
411 | err |= __put_user(regs->r16, sc->sc_regs+16); | |
412 | err |= __put_user(regs->r17, sc->sc_regs+17); | |
413 | err |= __put_user(regs->r18, sc->sc_regs+18); | |
414 | err |= __put_user(regs->r19, sc->sc_regs+19); | |
415 | err |= __put_user(regs->r20, sc->sc_regs+20); | |
416 | err |= __put_user(regs->r21, sc->sc_regs+21); | |
417 | err |= __put_user(regs->r22, sc->sc_regs+22); | |
418 | err |= __put_user(regs->r23, sc->sc_regs+23); | |
419 | err |= __put_user(regs->r24, sc->sc_regs+24); | |
420 | err |= __put_user(regs->r25, sc->sc_regs+25); | |
421 | err |= __put_user(regs->r26, sc->sc_regs+26); | |
422 | err |= __put_user(regs->r27, sc->sc_regs+27); | |
423 | err |= __put_user(regs->r28, sc->sc_regs+28); | |
424 | err |= __put_user(regs->gp , sc->sc_regs+29); | |
425 | err |= __put_user(sp, sc->sc_regs+30); | |
426 | err |= __put_user(0, sc->sc_regs+31); | |
427 | ||
428 | for (i = 0; i < 31; i++) | |
429 | err |= __put_user(sw->fp[i], sc->sc_fpregs+i); | |
430 | err |= __put_user(0, sc->sc_fpregs+31); | |
431 | err |= __put_user(sw->fp[31], &sc->sc_fpcr); | |
432 | ||
433 | err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0); | |
434 | err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1); | |
435 | err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2); | |
436 | ||
437 | return err; | |
438 | } | |
439 | ||
440 | static void | |
441 | setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, | |
442 | struct pt_regs *regs, struct switch_stack * sw) | |
443 | { | |
444 | unsigned long oldsp, r26, err = 0; | |
445 | struct sigframe __user *frame; | |
446 | ||
447 | oldsp = rdusp(); | |
448 | frame = get_sigframe(ka, oldsp, sizeof(*frame)); | |
449 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
450 | goto give_sigsegv; | |
451 | ||
452 | err |= setup_sigcontext(&frame->sc, regs, sw, set->sig[0], oldsp); | |
453 | if (err) | |
454 | goto give_sigsegv; | |
455 | ||
456 | /* Set up to return from userspace. If provided, use a stub | |
457 | already in userspace. */ | |
458 | if (ka->ka_restorer) { | |
459 | r26 = (unsigned long) ka->ka_restorer; | |
460 | } else { | |
461 | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); | |
462 | err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1); | |
463 | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | |
464 | imb(); | |
465 | r26 = (unsigned long) frame->retcode; | |
466 | } | |
467 | ||
468 | /* Check that everything was written properly. */ | |
469 | if (err) | |
470 | goto give_sigsegv; | |
471 | ||
472 | /* "Return" to the handler */ | |
473 | regs->r26 = r26; | |
474 | regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler; | |
475 | regs->r16 = sig; /* a0: signal number */ | |
476 | regs->r17 = 0; /* a1: exception code */ | |
477 | regs->r18 = (unsigned long) &frame->sc; /* a2: sigcontext pointer */ | |
478 | wrusp((unsigned long) frame); | |
479 | ||
480 | #if DEBUG_SIG | |
481 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
482 | current->comm, current->pid, frame, regs->pc, regs->r26); | |
483 | #endif | |
484 | ||
485 | return; | |
486 | ||
487 | give_sigsegv: | |
488 | force_sigsegv(sig, current); | |
489 | } | |
490 | ||
491 | static void | |
492 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
493 | sigset_t *set, struct pt_regs *regs, struct switch_stack * sw) | |
494 | { | |
495 | unsigned long oldsp, r26, err = 0; | |
496 | struct rt_sigframe __user *frame; | |
497 | ||
498 | oldsp = rdusp(); | |
499 | frame = get_sigframe(ka, oldsp, sizeof(*frame)); | |
500 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
501 | goto give_sigsegv; | |
502 | ||
503 | err |= copy_siginfo_to_user(&frame->info, info); | |
504 | ||
505 | /* Create the ucontext. */ | |
506 | err |= __put_user(0, &frame->uc.uc_flags); | |
507 | err |= __put_user(0, &frame->uc.uc_link); | |
508 | err |= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask); | |
509 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
510 | err |= __put_user(sas_ss_flags(oldsp), &frame->uc.uc_stack.ss_flags); | |
511 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
512 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, sw, | |
513 | set->sig[0], oldsp); | |
514 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
515 | if (err) | |
516 | goto give_sigsegv; | |
517 | ||
518 | /* Set up to return from userspace. If provided, use a stub | |
519 | already in userspace. */ | |
520 | if (ka->ka_restorer) { | |
521 | r26 = (unsigned long) ka->ka_restorer; | |
522 | } else { | |
523 | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); | |
524 | err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn, | |
525 | frame->retcode+1); | |
526 | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | |
527 | imb(); | |
528 | r26 = (unsigned long) frame->retcode; | |
529 | } | |
530 | ||
531 | if (err) | |
532 | goto give_sigsegv; | |
533 | ||
534 | /* "Return" to the handler */ | |
535 | regs->r26 = r26; | |
536 | regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler; | |
537 | regs->r16 = sig; /* a0: signal number */ | |
538 | regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */ | |
539 | regs->r18 = (unsigned long) &frame->uc; /* a2: ucontext pointer */ | |
540 | wrusp((unsigned long) frame); | |
541 | ||
542 | #if DEBUG_SIG | |
543 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
544 | current->comm, current->pid, frame, regs->pc, regs->r26); | |
545 | #endif | |
546 | ||
547 | return; | |
548 | ||
549 | give_sigsegv: | |
550 | force_sigsegv(sig, current); | |
551 | } | |
552 | ||
553 | ||
554 | /* | |
555 | * OK, we're invoking a handler. | |
556 | */ | |
557 | static inline void | |
558 | handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, | |
559 | sigset_t *oldset, struct pt_regs * regs, struct switch_stack *sw) | |
560 | { | |
561 | if (ka->sa.sa_flags & SA_SIGINFO) | |
562 | setup_rt_frame(sig, ka, info, oldset, regs, sw); | |
563 | else | |
564 | setup_frame(sig, ka, oldset, regs, sw); | |
565 | ||
566 | if (ka->sa.sa_flags & SA_RESETHAND) | |
567 | ka->sa.sa_handler = SIG_DFL; | |
568 | ||
69be8f18 SR |
569 | spin_lock_irq(¤t->sighand->siglock); |
570 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
571 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
1da177e4 | 572 | sigaddset(¤t->blocked,sig); |
69be8f18 SR |
573 | recalc_sigpending(); |
574 | spin_unlock_irq(¤t->sighand->siglock); | |
1da177e4 LT |
575 | } |
576 | ||
577 | static inline void | |
578 | syscall_restart(unsigned long r0, unsigned long r19, | |
579 | struct pt_regs *regs, struct k_sigaction *ka) | |
580 | { | |
581 | switch (regs->r0) { | |
582 | case ERESTARTSYS: | |
583 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
584 | case ERESTARTNOHAND: | |
585 | regs->r0 = EINTR; | |
586 | break; | |
587 | } | |
588 | /* fallthrough */ | |
589 | case ERESTARTNOINTR: | |
590 | regs->r0 = r0; /* reset v0 and a3 and replay syscall */ | |
591 | regs->r19 = r19; | |
592 | regs->pc -= 4; | |
593 | break; | |
594 | case ERESTART_RESTARTBLOCK: | |
595 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
596 | regs->r0 = EINTR; | |
597 | break; | |
598 | } | |
599 | } | |
600 | ||
601 | ||
602 | /* | |
603 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
604 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
605 | * mistake. | |
606 | * | |
607 | * Note that we go through the signals twice: once to check the signals that | |
608 | * the kernel can handle, and then we build all the user-level signal handling | |
609 | * stack-frames in one go after that. | |
610 | * | |
611 | * "r0" and "r19" are the registers we need to restore for system call | |
612 | * restart. "r0" is also used as an indicator whether we can restart at | |
613 | * all (if we get here from anything but a syscall return, it will be 0) | |
614 | */ | |
615 | static int | |
616 | do_signal(sigset_t *oldset, struct pt_regs * regs, struct switch_stack * sw, | |
617 | unsigned long r0, unsigned long r19) | |
618 | { | |
619 | siginfo_t info; | |
620 | int signr; | |
621 | unsigned long single_stepping = ptrace_cancel_bpt(current); | |
622 | struct k_sigaction ka; | |
623 | ||
624 | if (!oldset) | |
625 | oldset = ¤t->blocked; | |
626 | ||
627 | /* This lets the debugger run, ... */ | |
628 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
629 | /* ... so re-check the single stepping. */ | |
630 | single_stepping |= ptrace_cancel_bpt(current); | |
631 | ||
632 | if (signr > 0) { | |
633 | /* Whee! Actually deliver the signal. */ | |
634 | if (r0) syscall_restart(r0, r19, regs, &ka); | |
635 | handle_signal(signr, &ka, &info, oldset, regs, sw); | |
636 | if (single_stepping) | |
637 | ptrace_set_bpt(current); /* re-set bpt */ | |
638 | return 1; | |
639 | } | |
640 | ||
641 | if (r0) { | |
642 | switch (regs->r0) { | |
643 | case ERESTARTNOHAND: | |
644 | case ERESTARTSYS: | |
645 | case ERESTARTNOINTR: | |
646 | /* Reset v0 and a3 and replay syscall. */ | |
647 | regs->r0 = r0; | |
648 | regs->r19 = r19; | |
649 | regs->pc -= 4; | |
650 | break; | |
651 | case ERESTART_RESTARTBLOCK: | |
652 | /* Force v0 to the restart syscall and reply. */ | |
653 | regs->r0 = __NR_restart_syscall; | |
654 | regs->pc -= 4; | |
655 | break; | |
656 | } | |
657 | } | |
658 | if (single_stepping) | |
659 | ptrace_set_bpt(current); /* re-set breakpoint */ | |
660 | ||
661 | return 0; | |
662 | } | |
663 | ||
664 | void | |
665 | do_notify_resume(sigset_t *oldset, struct pt_regs *regs, | |
666 | struct switch_stack *sw, unsigned long r0, | |
667 | unsigned long r19, unsigned long thread_info_flags) | |
668 | { | |
669 | if (thread_info_flags & _TIF_SIGPENDING) | |
670 | do_signal(oldset, regs, sw, r0, r19); | |
671 | } |