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1da177e4 LT |
1 | /* |
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 | ||
39 | static 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 | |
46 | save_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(¤t->sighand->siglock); | |
58 | saveset = current->blocked; | |
59 | current->blocked = newset; | |
60 | recalc_sigpending(); | |
61 | spin_unlock_irq(¤t->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, ®s)) | |
69 | return -EINTR; | |
70 | } | |
71 | } | |
72 | #endif | |
73 | ||
74 | save_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(¤t->sighand->siglock); | |
92 | saveset = current->blocked; | |
93 | current->blocked = newset; | |
94 | recalc_sigpending(); | |
95 | spin_unlock_irq(¤t->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, ®s)) | |
103 | return -EINTR; | |
104 | } | |
105 | } | |
106 | ||
107 | #ifdef CONFIG_TRAD_SIGNALS | |
108 | asmlinkage 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 | ||
148 | asmlinkage 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 | |
164 | struct 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 | ||
172 | struct 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 | |
180 | save_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(¤t->sighand->siglock); | |
195 | current->blocked = blocked; | |
196 | recalc_sigpending(); | |
197 | spin_unlock_irq(¤t->sighand->siglock); | |
198 | ||
199 | if (restore_sigcontext(®s, &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(®s, 1); | |
207 | __asm__ __volatile__( | |
208 | "move\t$29, %0\n\t" | |
209 | "j\tsyscall_exit" | |
210 | :/* no outputs */ | |
211 | :"r" (®s)); | |
212 | /* Unreached */ | |
213 | ||
214 | badframe: | |
215 | force_sig(SIGSEGV, current); | |
216 | } | |
217 | #endif | |
218 | ||
219 | save_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(¤t->sighand->siglock); | |
235 | current->blocked = set; | |
236 | recalc_sigpending(); | |
237 | spin_unlock_irq(¤t->sighand->siglock); | |
238 | ||
239 | if (restore_sigcontext(®s, &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" (®s)); | |
256 | /* Unreached */ | |
257 | ||
258 | badframe: | |
259 | force_sig(SIGSEGV, current); | |
260 | } | |
261 | ||
262 | #ifdef CONFIG_TRAD_SIGNALS | |
263 | static 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 | ||
314 | give_sigsegv: | |
315 | force_sigsegv(signr, current); | |
316 | } | |
317 | #endif | |
318 | ||
319 | static 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 | ||
383 | give_sigsegv: | |
384 | force_sigsegv(signr, current); | |
385 | } | |
386 | ||
387 | extern void setup_rt_frame_n32(struct k_sigaction * ka, | |
388 | struct pt_regs *regs, int signr, sigset_t *set, siginfo_t *info); | |
389 | ||
390 | static 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(¤t->sighand->siglock); | |
430 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
431 | sigaddset(¤t->blocked,sig); | |
432 | recalc_sigpending(); | |
433 | spin_unlock_irq(¤t->sighand->siglock); | |
434 | } | |
435 | } | |
436 | ||
437 | extern int do_signal32(sigset_t *oldset, struct pt_regs *regs); | |
438 | extern int do_irix_signal(sigset_t *oldset, struct pt_regs *regs); | |
439 | ||
440 | static 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 = ¤t->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 | ||
472 | no_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 | */ | |
498 | asmlinkage 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 | } |