blob: 508026ae584222fe93fb4d24ed747fc2314bfe28 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
4 * for more details.
5 *
6 * Copyright (C) 1991, 1992 Linus Torvalds
7 * Copyright (C) 1994 - 2000 Ralf Baechle
8 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
9 */
10#include <linux/config.h>
11#include <linux/sched.h>
12#include <linux/mm.h>
13#include <linux/personality.h>
14#include <linux/smp.h>
15#include <linux/smp_lock.h>
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/compiler.h>
23
24#include <asm/asm.h>
25#include <linux/bitops.h>
26#include <asm/cacheflush.h>
27#include <asm/fpu.h>
28#include <asm/sim.h>
29#include <asm/uaccess.h>
30#include <asm/ucontext.h>
31#include <asm/cpu-features.h>
32
33#include "signal-common.h"
34
35#define DEBUG_SIG 0
36
37#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
38
39static int do_signal(sigset_t *oldset, struct pt_regs *regs);
40
41/*
42 * Atomically swap in the new signal mask, and wait for a signal.
43 */
44
45#ifdef CONFIG_TRAD_SIGNALS
46save_static_function(sys_sigsuspend);
47__attribute_used__ noinline static int
48_sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
49{
50 sigset_t *uset, saveset, newset;
51
52 uset = (sigset_t *) regs.regs[4];
53 if (copy_from_user(&newset, uset, sizeof(sigset_t)))
54 return -EFAULT;
55 sigdelsetmask(&newset, ~_BLOCKABLE);
56
57 spin_lock_irq(&current->sighand->siglock);
58 saveset = current->blocked;
59 current->blocked = newset;
60 recalc_sigpending();
61 spin_unlock_irq(&current->sighand->siglock);
62
63 regs.regs[2] = EINTR;
64 regs.regs[7] = 1;
65 while (1) {
66 current->state = TASK_INTERRUPTIBLE;
67 schedule();
68 if (do_signal(&saveset, &regs))
69 return -EINTR;
70 }
71}
72#endif
73
74save_static_function(sys_rt_sigsuspend);
75__attribute_used__ noinline static int
76_sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
77{
78 sigset_t *unewset, saveset, newset;
79 size_t sigsetsize;
80
81 /* XXX Don't preclude handling different sized sigset_t's. */
82 sigsetsize = regs.regs[5];
83 if (sigsetsize != sizeof(sigset_t))
84 return -EINVAL;
85
86 unewset = (sigset_t *) regs.regs[4];
87 if (copy_from_user(&newset, unewset, sizeof(newset)))
88 return -EFAULT;
89 sigdelsetmask(&newset, ~_BLOCKABLE);
90
91 spin_lock_irq(&current->sighand->siglock);
92 saveset = current->blocked;
93 current->blocked = newset;
94 recalc_sigpending();
95 spin_unlock_irq(&current->sighand->siglock);
96
97 regs.regs[2] = EINTR;
98 regs.regs[7] = 1;
99 while (1) {
100 current->state = TASK_INTERRUPTIBLE;
101 schedule();
102 if (do_signal(&saveset, &regs))
103 return -EINTR;
104 }
105}
106
107#ifdef CONFIG_TRAD_SIGNALS
108asmlinkage int sys_sigaction(int sig, const struct sigaction *act,
109 struct sigaction *oact)
110{
111 struct k_sigaction new_ka, old_ka;
112 int ret;
113 int err = 0;
114
115 if (act) {
116 old_sigset_t mask;
117
118 if (!access_ok(VERIFY_READ, act, sizeof(*act)))
119 return -EFAULT;
120 err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
121 err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
122 err |= __get_user(mask, &act->sa_mask.sig[0]);
123 if (err)
124 return -EFAULT;
125
126 siginitset(&new_ka.sa.sa_mask, mask);
127 }
128
129 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
130
131 if (!ret && oact) {
132 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
133 return -EFAULT;
134 err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
135 err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
136 err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
137 err |= __put_user(0, &oact->sa_mask.sig[1]);
138 err |= __put_user(0, &oact->sa_mask.sig[2]);
139 err |= __put_user(0, &oact->sa_mask.sig[3]);
140 if (err)
141 return -EFAULT;
142 }
143
144 return ret;
145}
146#endif
147
148asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
149{
150 const stack_t *uss = (const stack_t *) regs.regs[4];
151 stack_t *uoss = (stack_t *) regs.regs[5];
152 unsigned long usp = regs.regs[29];
153
154 return do_sigaltstack(uss, uoss, usp);
155}
156
157#if PLAT_TRAMPOLINE_STUFF_LINE
158#define __tramp __attribute__((aligned(PLAT_TRAMPOLINE_STUFF_LINE)))
159#else
160#define __tramp
161#endif
162
163#ifdef CONFIG_TRAD_SIGNALS
164struct sigframe {
165 u32 sf_ass[4]; /* argument save space for o32 */
166 u32 sf_code[2] __tramp; /* signal trampoline */
167 struct sigcontext sf_sc __tramp;
168 sigset_t sf_mask;
169};
170#endif
171
172struct rt_sigframe {
173 u32 rs_ass[4]; /* argument save space for o32 */
174 u32 rs_code[2] __tramp; /* signal trampoline */
175 struct siginfo rs_info __tramp;
176 struct ucontext rs_uc;
177};
178
179#ifdef CONFIG_TRAD_SIGNALS
180save_static_function(sys_sigreturn);
181__attribute_used__ noinline static void
182_sys_sigreturn(nabi_no_regargs struct pt_regs regs)
183{
184 struct sigframe *frame;
185 sigset_t blocked;
186
187 frame = (struct sigframe *) regs.regs[29];
188 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
189 goto badframe;
190 if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
191 goto badframe;
192
193 sigdelsetmask(&blocked, ~_BLOCKABLE);
194 spin_lock_irq(&current->sighand->siglock);
195 current->blocked = blocked;
196 recalc_sigpending();
197 spin_unlock_irq(&current->sighand->siglock);
198
199 if (restore_sigcontext(&regs, &frame->sf_sc))
200 goto badframe;
201
202 /*
203 * Don't let your children do this ...
204 */
205 if (current_thread_info()->flags & TIF_SYSCALL_TRACE)
206 do_syscall_trace(&regs, 1);
207 __asm__ __volatile__(
208 "move\t$29, %0\n\t"
209 "j\tsyscall_exit"
210 :/* no outputs */
211 :"r" (&regs));
212 /* Unreached */
213
214badframe:
215 force_sig(SIGSEGV, current);
216}
217#endif
218
219save_static_function(sys_rt_sigreturn);
220__attribute_used__ noinline static void
221_sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
222{
223 struct rt_sigframe *frame;
224 sigset_t set;
225 stack_t st;
226
227 frame = (struct rt_sigframe *) regs.regs[29];
228 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
229 goto badframe;
230 if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
231 goto badframe;
232
233 sigdelsetmask(&set, ~_BLOCKABLE);
234 spin_lock_irq(&current->sighand->siglock);
235 current->blocked = set;
236 recalc_sigpending();
237 spin_unlock_irq(&current->sighand->siglock);
238
239 if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
240 goto badframe;
241
242 if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
243 goto badframe;
244 /* It is more difficult to avoid calling this function than to
245 call it and ignore errors. */
246 do_sigaltstack(&st, NULL, regs.regs[29]);
247
248 /*
249 * Don't let your children do this ...
250 */
251 __asm__ __volatile__(
252 "move\t$29, %0\n\t"
253 "j\tsyscall_exit"
254 :/* no outputs */
255 :"r" (&regs));
256 /* Unreached */
257
258badframe:
259 force_sig(SIGSEGV, current);
260}
261
262#ifdef CONFIG_TRAD_SIGNALS
263static void inline setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
264 int signr, sigset_t *set)
265{
266 struct sigframe *frame;
267 int err = 0;
268
269 frame = get_sigframe(ka, regs, sizeof(*frame));
270 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
271 goto give_sigsegv;
272
273 /*
274 * Set up the return code ...
275 *
276 * li v0, __NR_sigreturn
277 * syscall
278 */
279 if (PLAT_TRAMPOLINE_STUFF_LINE)
280 __clear_user(frame->sf_code, PLAT_TRAMPOLINE_STUFF_LINE);
281 err |= __put_user(0x24020000 + __NR_sigreturn, frame->sf_code + 0);
282 err |= __put_user(0x0000000c , frame->sf_code + 1);
283 flush_cache_sigtramp((unsigned long) frame->sf_code);
284
285 err |= setup_sigcontext(regs, &frame->sf_sc);
286 err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
287 if (err)
288 goto give_sigsegv;
289
290 /*
291 * Arguments to signal handler:
292 *
293 * a0 = signal number
294 * a1 = 0 (should be cause)
295 * a2 = pointer to struct sigcontext
296 *
297 * $25 and c0_epc point to the signal handler, $29 points to the
298 * struct sigframe.
299 */
300 regs->regs[ 4] = signr;
301 regs->regs[ 5] = 0;
302 regs->regs[ 6] = (unsigned long) &frame->sf_sc;
303 regs->regs[29] = (unsigned long) frame;
304 regs->regs[31] = (unsigned long) frame->sf_code;
305 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
306
307#if DEBUG_SIG
308 printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
309 current->comm, current->pid,
310 frame, regs->cp0_epc, frame->regs[31]);
311#endif
312 return;
313
314give_sigsegv:
315 force_sigsegv(signr, current);
316}
317#endif
318
319static void inline setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
320 int signr, sigset_t *set, siginfo_t *info)
321{
322 struct rt_sigframe *frame;
323 int err = 0;
324
325 frame = get_sigframe(ka, regs, sizeof(*frame));
326 if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
327 goto give_sigsegv;
328
329 /*
330 * Set up the return code ...
331 *
332 * li v0, __NR_rt_sigreturn
333 * syscall
334 */
335 if (PLAT_TRAMPOLINE_STUFF_LINE)
336 __clear_user(frame->rs_code, PLAT_TRAMPOLINE_STUFF_LINE);
337 err |= __put_user(0x24020000 + __NR_rt_sigreturn, frame->rs_code + 0);
338 err |= __put_user(0x0000000c , frame->rs_code + 1);
339 flush_cache_sigtramp((unsigned long) frame->rs_code);
340
341 /* Create siginfo. */
342 err |= copy_siginfo_to_user(&frame->rs_info, info);
343
344 /* Create the ucontext. */
345 err |= __put_user(0, &frame->rs_uc.uc_flags);
346 err |= __put_user(0, &frame->rs_uc.uc_link);
347 err |= __put_user((void *)current->sas_ss_sp,
348 &frame->rs_uc.uc_stack.ss_sp);
349 err |= __put_user(sas_ss_flags(regs->regs[29]),
350 &frame->rs_uc.uc_stack.ss_flags);
351 err |= __put_user(current->sas_ss_size,
352 &frame->rs_uc.uc_stack.ss_size);
353 err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
354 err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
355
356 if (err)
357 goto give_sigsegv;
358
359 /*
360 * Arguments to signal handler:
361 *
362 * a0 = signal number
363 * a1 = 0 (should be cause)
364 * a2 = pointer to ucontext
365 *
366 * $25 and c0_epc point to the signal handler, $29 points to
367 * the struct rt_sigframe.
368 */
369 regs->regs[ 4] = signr;
370 regs->regs[ 5] = (unsigned long) &frame->rs_info;
371 regs->regs[ 6] = (unsigned long) &frame->rs_uc;
372 regs->regs[29] = (unsigned long) frame;
373 regs->regs[31] = (unsigned long) frame->rs_code;
374 regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
375
376#if DEBUG_SIG
377 printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
378 current->comm, current->pid,
379 frame, regs->cp0_epc, regs->regs[31]);
380#endif
381 return;
382
383give_sigsegv:
384 force_sigsegv(signr, current);
385}
386
387extern void setup_rt_frame_n32(struct k_sigaction * ka,
388 struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info);
389
390static inline void handle_signal(unsigned long sig, siginfo_t *info,
391 struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
392{
393 switch(regs->regs[0]) {
394 case ERESTART_RESTARTBLOCK:
395 case ERESTARTNOHAND:
396 regs->regs[2] = EINTR;
397 break;
398 case ERESTARTSYS:
399 if(!(ka->sa.sa_flags & SA_RESTART)) {
400 regs->regs[2] = EINTR;
401 break;
402 }
403 /* fallthrough */
404 case ERESTARTNOINTR: /* Userland will reload $v0. */
405 regs->regs[7] = regs->regs[26];
406 regs->cp0_epc -= 8;
407 }
408
409 regs->regs[0] = 0; /* Don't deal with this again. */
410
411#ifdef CONFIG_TRAD_SIGNALS
412 if (ka->sa.sa_flags & SA_SIGINFO) {
413#else
414 if (1) {
415#endif
416#ifdef CONFIG_MIPS32_N32
417 if ((current->thread.mflags & MF_ABI_MASK) == MF_N32)
418 setup_rt_frame_n32 (ka, regs, sig, oldset, info);
419 else
420#endif
421 setup_rt_frame(ka, regs, sig, oldset, info);
422 }
423#ifdef CONFIG_TRAD_SIGNALS
424 else
425 setup_frame(ka, regs, sig, oldset);
426#endif
427
428 if (!(ka->sa.sa_flags & SA_NODEFER)) {
429 spin_lock_irq(&current->sighand->siglock);
430 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
431 sigaddset(&current->blocked,sig);
432 recalc_sigpending();
433 spin_unlock_irq(&current->sighand->siglock);
434 }
435}
436
437extern int do_signal32(sigset_t *oldset, struct pt_regs *regs);
438extern int do_irix_signal(sigset_t *oldset, struct pt_regs *regs);
439
440static int do_signal(sigset_t *oldset, struct pt_regs *regs)
441{
442 struct k_sigaction ka;
443 siginfo_t info;
444 int signr;
445
446#ifdef CONFIG_BINFMT_ELF32
447 if ((current->thread.mflags & MF_ABI_MASK) == MF_O32) {
448 return do_signal32(oldset, regs);
449 }
450#endif
451
452 /*
453 * We want the common case to go fast, which is why we may in certain
454 * cases get here from kernel mode. Just return without doing anything
455 * if so.
456 */
457 if (!user_mode(regs))
458 return 1;
459
460 if (try_to_freeze(0))
461 goto no_signal;
462
463 if (!oldset)
464 oldset = &current->blocked;
465
466 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
467 if (signr > 0) {
468 handle_signal(signr, &info, &ka, oldset, regs);
469 return 1;
470 }
471
472no_signal:
473 /*
474 * Who's code doesn't conform to the restartable syscall convention
475 * dies here!!! The li instruction, a single machine instruction,
476 * must directly be followed by the syscall instruction.
477 */
478 if (regs->regs[0]) {
479 if (regs->regs[2] == ERESTARTNOHAND ||
480 regs->regs[2] == ERESTARTSYS ||
481 regs->regs[2] == ERESTARTNOINTR) {
482 regs->regs[7] = regs->regs[26];
483 regs->cp0_epc -= 8;
484 }
485 if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
486 regs->regs[2] = __NR_restart_syscall;
487 regs->regs[7] = regs->regs[26];
488 regs->cp0_epc -= 4;
489 }
490 }
491 return 0;
492}
493
494/*
495 * notification of userspace execution resumption
496 * - triggered by current->work.notify_resume
497 */
498asmlinkage void do_notify_resume(struct pt_regs *regs, sigset_t *oldset,
499 __u32 thread_info_flags)
500{
501 /* deal with pending signal delivery */
502 if (thread_info_flags & _TIF_SIGPENDING) {
503#ifdef CONFIG_BINFMT_ELF32
504 if (likely((current->thread.mflags & MF_ABI_MASK) == MF_O32)) {
505 do_signal32(oldset, regs);
506 return;
507 }
508#endif
509#ifdef CONFIG_BINFMT_IRIX
510 if (unlikely(current->personality != PER_LINUX)) {
511 do_irix_signal(oldset, regs);
512 return;
513 }
514#endif
515 do_signal(oldset, regs);
516 }
517}