ia64/linux-2.6.18-xen.hg

view arch/v850/kernel/signal.c @ 0:831230e53067

Import 2.6.18 from kernel.org tarball.
author Ian Campbell <ian.campbell@xensource.com>
date Wed Apr 11 14:15:44 2007 +0100 (2007-04-11)
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1 /*
2 * arch/v850/kernel/signal.c -- Signal handling
3 *
4 * Copyright (C) 2001,02,03 NEC Electronics Corporation
5 * Copyright (C) 2001,02,03 Miles Bader <miles@gnu.org>
6 * Copyright (C) 1999,2000,2002 Niibe Yutaka & Kaz Kojima
7 * Copyright (C) 1991,1992 Linus Torvalds
8 *
9 * This file is subject to the terms and conditions of the GNU General
10 * Public License. See the file COPYING in the main directory of this
11 * archive for more details.
12 *
13 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
14 *
15 * This file was derived from the sh version, arch/sh/kernel/signal.c
16 */
18 #include <linux/mm.h>
19 #include <linux/smp.h>
20 #include <linux/smp_lock.h>
21 #include <linux/kernel.h>
22 #include <linux/signal.h>
23 #include <linux/errno.h>
24 #include <linux/wait.h>
25 #include <linux/ptrace.h>
26 #include <linux/unistd.h>
27 #include <linux/stddef.h>
28 #include <linux/personality.h>
29 #include <linux/tty.h>
31 #include <asm/ucontext.h>
32 #include <asm/uaccess.h>
33 #include <asm/pgtable.h>
34 #include <asm/pgalloc.h>
35 #include <asm/thread_info.h>
36 #include <asm/cacheflush.h>
38 #define DEBUG_SIG 0
40 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
42 asmlinkage int do_signal(struct pt_regs *regs, sigset_t *oldset);
44 /*
45 * Atomically swap in the new signal mask, and wait for a signal.
46 */
47 asmlinkage int
48 sys_sigsuspend(old_sigset_t mask, struct pt_regs *regs)
49 {
50 sigset_t saveset;
52 mask &= _BLOCKABLE;
53 spin_lock_irq(&current->sighand->siglock);
54 saveset = current->blocked;
55 siginitset(&current->blocked, mask);
56 recalc_sigpending();
57 spin_unlock_irq(&current->sighand->siglock);
59 regs->gpr[GPR_RVAL] = -EINTR;
60 while (1) {
61 current->state = TASK_INTERRUPTIBLE;
62 schedule();
63 if (do_signal(regs, &saveset))
64 return -EINTR;
65 }
66 }
68 asmlinkage int
69 sys_rt_sigsuspend(sigset_t *unewset, size_t sigsetsize,
70 struct pt_regs *regs)
71 {
72 sigset_t saveset, newset;
74 /* XXX: Don't preclude handling different sized sigset_t's. */
75 if (sigsetsize != sizeof(sigset_t))
76 return -EINVAL;
78 if (copy_from_user(&newset, unewset, sizeof(newset)))
79 return -EFAULT;
80 sigdelsetmask(&newset, ~_BLOCKABLE);
81 spin_lock_irq(&current->sighand->siglock);
82 saveset = current->blocked;
83 current->blocked = newset;
84 recalc_sigpending();
85 spin_unlock_irq(&current->sighand->siglock);
87 regs->gpr[GPR_RVAL] = -EINTR;
88 while (1) {
89 current->state = TASK_INTERRUPTIBLE;
90 schedule();
91 if (do_signal(regs, &saveset))
92 return -EINTR;
93 }
94 }
96 asmlinkage int
97 sys_sigaction(int sig, const struct old_sigaction *act,
98 struct old_sigaction *oact)
99 {
100 struct k_sigaction new_ka, old_ka;
101 int ret;
103 if (act) {
104 old_sigset_t mask;
105 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
106 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
107 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
108 return -EFAULT;
109 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
110 __get_user(mask, &act->sa_mask);
111 siginitset(&new_ka.sa.sa_mask, mask);
112 }
114 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
116 if (!ret && oact) {
117 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
118 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
119 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
120 return -EFAULT;
121 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
122 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
123 }
125 return ret;
126 }
128 asmlinkage int
129 sys_sigaltstack(const stack_t *uss, stack_t *uoss,
130 struct pt_regs *regs)
131 {
132 return do_sigaltstack(uss, uoss, regs->gpr[GPR_SP]);
133 }
136 /*
137 * Do a signal return; undo the signal stack.
138 */
140 struct sigframe
141 {
142 struct sigcontext sc;
143 unsigned long extramask[_NSIG_WORDS-1];
144 unsigned long tramp[2]; /* signal trampoline */
145 };
147 struct rt_sigframe
148 {
149 struct siginfo info;
150 struct ucontext uc;
151 unsigned long tramp[2]; /* signal trampoline */
152 };
154 static int
155 restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc, int *rval_p)
156 {
157 unsigned int err = 0;
159 #define COPY(x) err |= __get_user(regs->x, &sc->regs.x)
160 COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]);
161 COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]);
162 COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]);
163 COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]);
164 COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]);
165 COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]);
166 COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]);
167 COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]);
168 COPY(pc); COPY(psw);
169 COPY(ctpc); COPY(ctpsw); COPY(ctbp);
170 #undef COPY
172 return err;
173 }
175 asmlinkage int sys_sigreturn(struct pt_regs *regs)
176 {
177 struct sigframe *frame = (struct sigframe *)regs->gpr[GPR_SP];
178 sigset_t set;
179 int rval;
181 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
182 goto badframe;
184 if (__get_user(set.sig[0], &frame->sc.oldmask)
185 || (_NSIG_WORDS > 1
186 && __copy_from_user(&set.sig[1], &frame->extramask,
187 sizeof(frame->extramask))))
188 goto badframe;
190 sigdelsetmask(&set, ~_BLOCKABLE);
191 spin_lock_irq(&current->sighand->siglock);
192 current->blocked = set;
193 recalc_sigpending();
194 spin_unlock_irq(&current->sighand->siglock);
196 if (restore_sigcontext(regs, &frame->sc, &rval))
197 goto badframe;
198 return rval;
200 badframe:
201 force_sig(SIGSEGV, current);
202 return 0;
203 }
205 asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
206 {
207 struct rt_sigframe *frame = (struct rt_sigframe *)regs->gpr[GPR_SP];
208 sigset_t set;
209 stack_t st;
210 int rval;
212 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
213 goto badframe;
215 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
216 goto badframe;
218 sigdelsetmask(&set, ~_BLOCKABLE);
219 spin_lock_irq(&current->sighand->siglock);
220 current->blocked = set;
221 recalc_sigpending();
222 spin_unlock_irq(&current->sighand->siglock);
224 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &rval))
225 goto badframe;
227 if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
228 goto badframe;
229 /* It is more difficult to avoid calling this function than to
230 call it and ignore errors. */
231 do_sigaltstack(&st, NULL, regs->gpr[GPR_SP]);
233 return rval;
235 badframe:
236 force_sig(SIGSEGV, current);
237 return 0;
238 }
240 /*
241 * Set up a signal frame.
242 */
244 static int
245 setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
246 unsigned long mask)
247 {
248 int err = 0;
250 #define COPY(x) err |= __put_user(regs->x, &sc->regs.x)
251 COPY(gpr[0]); COPY(gpr[1]); COPY(gpr[2]); COPY(gpr[3]);
252 COPY(gpr[4]); COPY(gpr[5]); COPY(gpr[6]); COPY(gpr[7]);
253 COPY(gpr[8]); COPY(gpr[9]); COPY(gpr[10]); COPY(gpr[11]);
254 COPY(gpr[12]); COPY(gpr[13]); COPY(gpr[14]); COPY(gpr[15]);
255 COPY(gpr[16]); COPY(gpr[17]); COPY(gpr[18]); COPY(gpr[19]);
256 COPY(gpr[20]); COPY(gpr[21]); COPY(gpr[22]); COPY(gpr[23]);
257 COPY(gpr[24]); COPY(gpr[25]); COPY(gpr[26]); COPY(gpr[27]);
258 COPY(gpr[28]); COPY(gpr[29]); COPY(gpr[30]); COPY(gpr[31]);
259 COPY(pc); COPY(psw);
260 COPY(ctpc); COPY(ctpsw); COPY(ctbp);
261 #undef COPY
263 err |= __put_user(mask, &sc->oldmask);
265 return err;
266 }
268 /*
269 * Determine which stack to use..
270 */
271 static inline void *
272 get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size)
273 {
274 /* Default to using normal stack */
275 unsigned long sp = regs->gpr[GPR_SP];
277 if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp))
278 sp = current->sas_ss_sp + current->sas_ss_size;
280 return (void *)((sp - frame_size) & -8UL);
281 }
283 static void setup_frame(int sig, struct k_sigaction *ka,
284 sigset_t *set, struct pt_regs *regs)
285 {
286 struct sigframe *frame;
287 int err = 0;
288 int signal;
290 frame = get_sigframe(ka, regs, sizeof(*frame));
292 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
293 goto give_sigsegv;
295 signal = current_thread_info()->exec_domain
296 && current_thread_info()->exec_domain->signal_invmap
297 && sig < 32
298 ? current_thread_info()->exec_domain->signal_invmap[sig]
299 : sig;
301 err |= setup_sigcontext(&frame->sc, regs, set->sig[0]);
303 if (_NSIG_WORDS > 1) {
304 err |= __copy_to_user(frame->extramask, &set->sig[1],
305 sizeof(frame->extramask));
306 }
308 /* Set up to return from userspace. If provided, use a stub
309 already in userspace. */
310 if (ka->sa.sa_flags & SA_RESTORER) {
311 regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer;
312 } else {
313 /* Note, these encodings are _little endian_! */
315 /* addi __NR_sigreturn, r0, r12 */
316 err |= __put_user(0x6600 | (__NR_sigreturn << 16),
317 frame->tramp + 0);
318 /* trap 0 */
319 err |= __put_user(0x010007e0,
320 frame->tramp + 1);
322 regs->gpr[GPR_LP] = (unsigned long)frame->tramp;
324 flush_cache_sigtramp (regs->gpr[GPR_LP]);
325 }
327 if (err)
328 goto give_sigsegv;
330 /* Set up registers for signal handler. */
331 regs->pc = (v850_reg_t) ka->sa.sa_handler;
332 regs->gpr[GPR_SP] = (v850_reg_t)frame;
333 /* Signal handler args: */
334 regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */
335 regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->sc;/* arg 1: sigcontext */
337 set_fs(USER_DS);
339 #if DEBUG_SIG
340 printk("SIG deliver (%s:%d): sp=%p pc=%08lx ra=%08lx\n",
341 current->comm, current->pid, frame, regs->pc, );
342 #endif
344 return;
346 give_sigsegv:
347 force_sigsegv(sig, current);
348 }
350 static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
351 sigset_t *set, struct pt_regs *regs)
352 {
353 struct rt_sigframe *frame;
354 int err = 0;
355 int signal;
357 frame = get_sigframe(ka, regs, sizeof(*frame));
359 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
360 goto give_sigsegv;
362 signal = current_thread_info()->exec_domain
363 && current_thread_info()->exec_domain->signal_invmap
364 && sig < 32
365 ? current_thread_info()->exec_domain->signal_invmap[sig]
366 : sig;
368 err |= copy_siginfo_to_user(&frame->info, info);
370 /* Create the ucontext. */
371 err |= __put_user(0, &frame->uc.uc_flags);
372 err |= __put_user(0, &frame->uc.uc_link);
373 err |= __put_user((void *)current->sas_ss_sp,
374 &frame->uc.uc_stack.ss_sp);
375 err |= __put_user(sas_ss_flags(regs->gpr[GPR_SP]),
376 &frame->uc.uc_stack.ss_flags);
377 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
378 err |= setup_sigcontext(&frame->uc.uc_mcontext,
379 regs, set->sig[0]);
380 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
382 /* Set up to return from userspace. If provided, use a stub
383 already in userspace. */
384 if (ka->sa.sa_flags & SA_RESTORER) {
385 regs->gpr[GPR_LP] = (unsigned long) ka->sa.sa_restorer;
386 } else {
387 /* Note, these encodings are _little endian_! */
389 /* addi __NR_sigreturn, r0, r12 */
390 err |= __put_user(0x6600 | (__NR_sigreturn << 16),
391 frame->tramp + 0);
392 /* trap 0 */
393 err |= __put_user(0x010007e0,
394 frame->tramp + 1);
396 regs->gpr[GPR_LP] = (unsigned long)frame->tramp;
398 flush_cache_sigtramp (regs->gpr[GPR_LP]);
399 }
401 if (err)
402 goto give_sigsegv;
404 /* Set up registers for signal handler. */
405 regs->pc = (v850_reg_t) ka->sa.sa_handler;
406 regs->gpr[GPR_SP] = (v850_reg_t)frame;
407 /* Signal handler args: */
408 regs->gpr[GPR_ARG0] = signal; /* arg 0: signum */
409 regs->gpr[GPR_ARG1] = (v850_reg_t)&frame->info; /* arg 1: siginfo */
410 regs->gpr[GPR_ARG2] = (v850_reg_t)&frame->uc; /* arg 2: ucontext */
412 set_fs(USER_DS);
414 #if DEBUG_SIG
415 printk("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n",
416 current->comm, current->pid, frame, regs->pc, regs->pr);
417 #endif
419 return;
421 give_sigsegv:
422 force_sigsegv(sig, current);
423 }
425 /*
426 * OK, we're invoking a handler
427 */
429 static void
430 handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
431 sigset_t *oldset, struct pt_regs * regs)
432 {
433 /* Are we from a system call? */
434 if (PT_REGS_SYSCALL (regs)) {
435 /* If so, check system call restarting.. */
436 switch (regs->gpr[GPR_RVAL]) {
437 case -ERESTART_RESTARTBLOCK:
438 current_thread_info()->restart_block.fn =
439 do_no_restart_syscall;
440 /* fall through */
441 case -ERESTARTNOHAND:
442 regs->gpr[GPR_RVAL] = -EINTR;
443 break;
445 case -ERESTARTSYS:
446 if (!(ka->sa.sa_flags & SA_RESTART)) {
447 regs->gpr[GPR_RVAL] = -EINTR;
448 break;
449 }
450 /* fallthrough */
451 case -ERESTARTNOINTR:
452 regs->gpr[12] = PT_REGS_SYSCALL (regs);
453 regs->pc -= 4; /* Size of `trap 0' insn. */
454 }
456 PT_REGS_SET_SYSCALL (regs, 0);
457 }
459 /* Set up the stack frame */
460 if (ka->sa.sa_flags & SA_SIGINFO)
461 setup_rt_frame(sig, ka, info, oldset, regs);
462 else
463 setup_frame(sig, ka, oldset, regs);
465 spin_lock_irq(&current->sighand->siglock);
466 sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
467 if (!(ka->sa.sa_flags & SA_NODEFER))
468 sigaddset(&current->blocked,sig);
469 recalc_sigpending();
470 spin_unlock_irq(&current->sighand->siglock);
471 }
473 /*
474 * Note that 'init' is a special process: it doesn't get signals it doesn't
475 * want to handle. Thus you cannot kill init even with a SIGKILL even by
476 * mistake.
477 *
478 * Note that we go through the signals twice: once to check the signals that
479 * the kernel can handle, and then we build all the user-level signal handling
480 * stack-frames in one go after that.
481 */
482 int do_signal(struct pt_regs *regs, sigset_t *oldset)
483 {
484 siginfo_t info;
485 int signr;
486 struct k_sigaction ka;
488 /*
489 * We want the common case to go fast, which
490 * is why we may in certain cases get here from
491 * kernel mode. Just return without doing anything
492 * if so.
493 */
494 if (!user_mode(regs))
495 return 1;
497 if (!oldset)
498 oldset = &current->blocked;
500 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
501 if (signr > 0) {
502 /* Whee! Actually deliver the signal. */
503 handle_signal(signr, &info, &ka, oldset, regs);
504 return 1;
505 }
507 /* Did we come from a system call? */
508 if (PT_REGS_SYSCALL (regs)) {
509 int rval = (int)regs->gpr[GPR_RVAL];
510 /* Restart the system call - no handlers present */
511 if (rval == -ERESTARTNOHAND
512 || rval == -ERESTARTSYS
513 || rval == -ERESTARTNOINTR)
514 {
515 regs->gpr[12] = PT_REGS_SYSCALL (regs);
516 regs->pc -= 4; /* Size of `trap 0' insn. */
517 }
518 else if (rval == -ERESTART_RESTARTBLOCK) {
519 regs->gpr[12] = __NR_restart_syscall;
520 regs->pc -= 4; /* Size of `trap 0' insn. */
521 }
522 }
523 return 0;
524 }