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Source at commit 0de2b2b3be81048189a32f7a3d3ba0ba9ec817b6 created 11 years 11 months ago. By Maarten ter Huurne, MIPS: JZ4740: Fixed value for round robin constant. | |
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1 | /* |
2 | * linux/arch/sh/kernel/signal.c |
3 | * |
4 | * Copyright (C) 1991, 1992 Linus Torvalds |
5 | * |
6 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson |
7 | * |
8 | * SuperH version: Copyright (C) 1999, 2000 Niibe Yutaka & Kaz Kojima |
9 | * |
10 | */ |
11 | #include <linux/sched.h> |
12 | #include <linux/mm.h> |
13 | #include <linux/smp.h> |
14 | #include <linux/kernel.h> |
15 | #include <linux/signal.h> |
16 | #include <linux/errno.h> |
17 | #include <linux/wait.h> |
18 | #include <linux/ptrace.h> |
19 | #include <linux/unistd.h> |
20 | #include <linux/stddef.h> |
21 | #include <linux/tty.h> |
22 | #include <linux/elf.h> |
23 | #include <linux/personality.h> |
24 | #include <linux/binfmts.h> |
25 | #include <linux/freezer.h> |
26 | #include <linux/io.h> |
27 | #include <linux/tracehook.h> |
28 | #include <asm/system.h> |
29 | #include <asm/ucontext.h> |
30 | #include <asm/uaccess.h> |
31 | #include <asm/pgtable.h> |
32 | #include <asm/cacheflush.h> |
33 | #include <asm/syscalls.h> |
34 | #include <asm/fpu.h> |
35 | |
36 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
37 | |
38 | struct fdpic_func_descriptor { |
39 | unsigned long text; |
40 | unsigned long GOT; |
41 | }; |
42 | |
43 | /* |
44 | * The following define adds a 64 byte gap between the signal |
45 | * stack frame and previous contents of the stack. This allows |
46 | * frame unwinding in a function epilogue but only if a frame |
47 | * pointer is used in the function. This is necessary because |
48 | * current gcc compilers (<4.3) do not generate unwind info on |
49 | * SH for function epilogues. |
50 | */ |
51 | #define UNWINDGUARD 64 |
52 | |
53 | /* |
54 | * Atomically swap in the new signal mask, and wait for a signal. |
55 | */ |
56 | asmlinkage int |
57 | sys_sigsuspend(old_sigset_t mask, |
58 | unsigned long r5, unsigned long r6, unsigned long r7, |
59 | struct pt_regs __regs) |
60 | { |
61 | mask &= _BLOCKABLE; |
62 | spin_lock_irq(¤t->sighand->siglock); |
63 | current->saved_sigmask = current->blocked; |
64 | siginitset(¤t->blocked, mask); |
65 | recalc_sigpending(); |
66 | spin_unlock_irq(¤t->sighand->siglock); |
67 | |
68 | current->state = TASK_INTERRUPTIBLE; |
69 | schedule(); |
70 | set_restore_sigmask(); |
71 | |
72 | return -ERESTARTNOHAND; |
73 | } |
74 | |
75 | asmlinkage int |
76 | sys_sigaction(int sig, const struct old_sigaction __user *act, |
77 | struct old_sigaction __user *oact) |
78 | { |
79 | struct k_sigaction new_ka, old_ka; |
80 | int ret; |
81 | |
82 | if (act) { |
83 | old_sigset_t mask; |
84 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
85 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || |
86 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) |
87 | return -EFAULT; |
88 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
89 | __get_user(mask, &act->sa_mask); |
90 | siginitset(&new_ka.sa.sa_mask, mask); |
91 | } |
92 | |
93 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); |
94 | |
95 | if (!ret && oact) { |
96 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || |
97 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || |
98 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) |
99 | return -EFAULT; |
100 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
101 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); |
102 | } |
103 | |
104 | return ret; |
105 | } |
106 | |
107 | asmlinkage int |
108 | sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, |
109 | unsigned long r6, unsigned long r7, |
110 | struct pt_regs __regs) |
111 | { |
112 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
113 | |
114 | return do_sigaltstack(uss, uoss, regs->regs[15]); |
115 | } |
116 | |
117 | |
118 | /* |
119 | * Do a signal return; undo the signal stack. |
120 | */ |
121 | |
122 | #define MOVW(n) (0x9300|((n)-2)) /* Move mem word at PC+n to R3 */ |
123 | #if defined(CONFIG_CPU_SH2) |
124 | #define TRAP_NOARG 0xc320 /* Syscall w/no args (NR in R3) */ |
125 | #else |
126 | #define TRAP_NOARG 0xc310 /* Syscall w/no args (NR in R3) */ |
127 | #endif |
128 | #define OR_R0_R0 0x200b /* or r0,r0 (insert to avoid hardware bug) */ |
129 | |
130 | struct sigframe |
131 | { |
132 | struct sigcontext sc; |
133 | unsigned long extramask[_NSIG_WORDS-1]; |
134 | u16 retcode[8]; |
135 | }; |
136 | |
137 | struct rt_sigframe |
138 | { |
139 | struct siginfo info; |
140 | struct ucontext uc; |
141 | u16 retcode[8]; |
142 | }; |
143 | |
144 | #ifdef CONFIG_SH_FPU |
145 | static inline int restore_sigcontext_fpu(struct sigcontext __user *sc) |
146 | { |
147 | struct task_struct *tsk = current; |
148 | |
149 | if (!(boot_cpu_data.flags & CPU_HAS_FPU)) |
150 | return 0; |
151 | |
152 | set_used_math(); |
153 | return __copy_from_user(&tsk->thread.xstate->hardfpu, &sc->sc_fpregs[0], |
154 | sizeof(long)*(16*2+2)); |
155 | } |
156 | |
157 | static inline int save_sigcontext_fpu(struct sigcontext __user *sc, |
158 | struct pt_regs *regs) |
159 | { |
160 | struct task_struct *tsk = current; |
161 | |
162 | if (!(boot_cpu_data.flags & CPU_HAS_FPU)) |
163 | return 0; |
164 | |
165 | if (!used_math()) { |
166 | __put_user(0, &sc->sc_ownedfp); |
167 | return 0; |
168 | } |
169 | |
170 | __put_user(1, &sc->sc_ownedfp); |
171 | |
172 | /* This will cause a "finit" to be triggered by the next |
173 | attempted FPU operation by the 'current' process. |
174 | */ |
175 | clear_used_math(); |
176 | |
177 | unlazy_fpu(tsk, regs); |
178 | return __copy_to_user(&sc->sc_fpregs[0], &tsk->thread.xstate->hardfpu, |
179 | sizeof(long)*(16*2+2)); |
180 | } |
181 | #endif /* CONFIG_SH_FPU */ |
182 | |
183 | static int |
184 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *r0_p) |
185 | { |
186 | unsigned int err = 0; |
187 | |
188 | #define COPY(x) err |= __get_user(regs->x, &sc->sc_##x) |
189 | COPY(regs[1]); |
190 | COPY(regs[2]); COPY(regs[3]); |
191 | COPY(regs[4]); COPY(regs[5]); |
192 | COPY(regs[6]); COPY(regs[7]); |
193 | COPY(regs[8]); COPY(regs[9]); |
194 | COPY(regs[10]); COPY(regs[11]); |
195 | COPY(regs[12]); COPY(regs[13]); |
196 | COPY(regs[14]); COPY(regs[15]); |
197 | COPY(gbr); COPY(mach); |
198 | COPY(macl); COPY(pr); |
199 | COPY(sr); COPY(pc); |
200 | #undef COPY |
201 | |
202 | #ifdef CONFIG_SH_FPU |
203 | if (boot_cpu_data.flags & CPU_HAS_FPU) { |
204 | int owned_fp; |
205 | struct task_struct *tsk = current; |
206 | |
207 | regs->sr |= SR_FD; /* Release FPU */ |
208 | clear_fpu(tsk, regs); |
209 | clear_used_math(); |
210 | __get_user (owned_fp, &sc->sc_ownedfp); |
211 | if (owned_fp) |
212 | err |= restore_sigcontext_fpu(sc); |
213 | } |
214 | #endif |
215 | |
216 | regs->tra = -1; /* disable syscall checks */ |
217 | err |= __get_user(*r0_p, &sc->sc_regs[0]); |
218 | return err; |
219 | } |
220 | |
221 | asmlinkage int sys_sigreturn(unsigned long r4, unsigned long r5, |
222 | unsigned long r6, unsigned long r7, |
223 | struct pt_regs __regs) |
224 | { |
225 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
226 | struct sigframe __user *frame = (struct sigframe __user *)regs->regs[15]; |
227 | sigset_t set; |
228 | int r0; |
229 | |
230 | /* Always make any pending restarted system calls return -EINTR */ |
231 | current_thread_info()->restart_block.fn = do_no_restart_syscall; |
232 | |
233 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
234 | goto badframe; |
235 | |
236 | if (__get_user(set.sig[0], &frame->sc.oldmask) |
237 | || (_NSIG_WORDS > 1 |
238 | && __copy_from_user(&set.sig[1], &frame->extramask, |
239 | sizeof(frame->extramask)))) |
240 | goto badframe; |
241 | |
242 | sigdelsetmask(&set, ~_BLOCKABLE); |
243 | |
244 | spin_lock_irq(¤t->sighand->siglock); |
245 | current->blocked = set; |
246 | recalc_sigpending(); |
247 | spin_unlock_irq(¤t->sighand->siglock); |
248 | |
249 | if (restore_sigcontext(regs, &frame->sc, &r0)) |
250 | goto badframe; |
251 | return r0; |
252 | |
253 | badframe: |
254 | force_sig(SIGSEGV, current); |
255 | return 0; |
256 | } |
257 | |
258 | asmlinkage int sys_rt_sigreturn(unsigned long r4, unsigned long r5, |
259 | unsigned long r6, unsigned long r7, |
260 | struct pt_regs __regs) |
261 | { |
262 | struct pt_regs *regs = RELOC_HIDE(&__regs, 0); |
263 | struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->regs[15]; |
264 | sigset_t set; |
265 | int r0; |
266 | |
267 | /* Always make any pending restarted system calls return -EINTR */ |
268 | current_thread_info()->restart_block.fn = do_no_restart_syscall; |
269 | |
270 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
271 | goto badframe; |
272 | |
273 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) |
274 | goto badframe; |
275 | |
276 | sigdelsetmask(&set, ~_BLOCKABLE); |
277 | spin_lock_irq(¤t->sighand->siglock); |
278 | current->blocked = set; |
279 | recalc_sigpending(); |
280 | spin_unlock_irq(¤t->sighand->siglock); |
281 | |
282 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &r0)) |
283 | goto badframe; |
284 | |
285 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, |
286 | regs->regs[15]) == -EFAULT) |
287 | goto badframe; |
288 | |
289 | return r0; |
290 | |
291 | badframe: |
292 | force_sig(SIGSEGV, current); |
293 | return 0; |
294 | } |
295 | |
296 | /* |
297 | * Set up a signal frame. |
298 | */ |
299 | |
300 | static int |
301 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, |
302 | unsigned long mask) |
303 | { |
304 | int err = 0; |
305 | |
306 | #define COPY(x) err |= __put_user(regs->x, &sc->sc_##x) |
307 | COPY(regs[0]); COPY(regs[1]); |
308 | COPY(regs[2]); COPY(regs[3]); |
309 | COPY(regs[4]); COPY(regs[5]); |
310 | COPY(regs[6]); COPY(regs[7]); |
311 | COPY(regs[8]); COPY(regs[9]); |
312 | COPY(regs[10]); COPY(regs[11]); |
313 | COPY(regs[12]); COPY(regs[13]); |
314 | COPY(regs[14]); COPY(regs[15]); |
315 | COPY(gbr); COPY(mach); |
316 | COPY(macl); COPY(pr); |
317 | COPY(sr); COPY(pc); |
318 | #undef COPY |
319 | |
320 | #ifdef CONFIG_SH_FPU |
321 | err |= save_sigcontext_fpu(sc, regs); |
322 | #endif |
323 | |
324 | /* non-iBCS2 extensions.. */ |
325 | err |= __put_user(mask, &sc->oldmask); |
326 | |
327 | return err; |
328 | } |
329 | |
330 | /* |
331 | * Determine which stack to use.. |
332 | */ |
333 | static inline void __user * |
334 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) |
335 | { |
336 | if (ka->sa.sa_flags & SA_ONSTACK) { |
337 | if (sas_ss_flags(sp) == 0) |
338 | sp = current->sas_ss_sp + current->sas_ss_size; |
339 | } |
340 | |
341 | return (void __user *)((sp - (frame_size+UNWINDGUARD)) & -8ul); |
342 | } |
343 | |
344 | /* These symbols are defined with the addresses in the vsyscall page. |
345 | See vsyscall-trapa.S. */ |
346 | extern void __kernel_sigreturn(void); |
347 | extern void __kernel_rt_sigreturn(void); |
348 | |
349 | static int setup_frame(int sig, struct k_sigaction *ka, |
350 | sigset_t *set, struct pt_regs *regs) |
351 | { |
352 | struct sigframe __user *frame; |
353 | int err = 0; |
354 | int signal; |
355 | |
356 | frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); |
357 | |
358 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
359 | goto give_sigsegv; |
360 | |
361 | signal = current_thread_info()->exec_domain |
362 | && current_thread_info()->exec_domain->signal_invmap |
363 | && sig < 32 |
364 | ? current_thread_info()->exec_domain->signal_invmap[sig] |
365 | : sig; |
366 | |
367 | err |= setup_sigcontext(&frame->sc, regs, set->sig[0]); |
368 | |
369 | if (_NSIG_WORDS > 1) |
370 | err |= __copy_to_user(frame->extramask, &set->sig[1], |
371 | sizeof(frame->extramask)); |
372 | |
373 | /* Set up to return from userspace. If provided, use a stub |
374 | already in userspace. */ |
375 | if (ka->sa.sa_flags & SA_RESTORER) { |
376 | regs->pr = (unsigned long) ka->sa.sa_restorer; |
377 | #ifdef CONFIG_VSYSCALL |
378 | } else if (likely(current->mm->context.vdso)) { |
379 | regs->pr = VDSO_SYM(&__kernel_sigreturn); |
380 | #endif |
381 | } else { |
382 | /* Generate return code (system call to sigreturn) */ |
383 | err |= __put_user(MOVW(7), &frame->retcode[0]); |
384 | err |= __put_user(TRAP_NOARG, &frame->retcode[1]); |
385 | err |= __put_user(OR_R0_R0, &frame->retcode[2]); |
386 | err |= __put_user(OR_R0_R0, &frame->retcode[3]); |
387 | err |= __put_user(OR_R0_R0, &frame->retcode[4]); |
388 | err |= __put_user(OR_R0_R0, &frame->retcode[5]); |
389 | err |= __put_user(OR_R0_R0, &frame->retcode[6]); |
390 | err |= __put_user((__NR_sigreturn), &frame->retcode[7]); |
391 | regs->pr = (unsigned long) frame->retcode; |
392 | flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode)); |
393 | } |
394 | |
395 | if (err) |
396 | goto give_sigsegv; |
397 | |
398 | /* Set up registers for signal handler */ |
399 | regs->regs[15] = (unsigned long) frame; |
400 | regs->regs[4] = signal; /* Arg for signal handler */ |
401 | regs->regs[5] = 0; |
402 | regs->regs[6] = (unsigned long) &frame->sc; |
403 | |
404 | if (current->personality & FDPIC_FUNCPTRS) { |
405 | struct fdpic_func_descriptor __user *funcptr = |
406 | (struct fdpic_func_descriptor __user *)ka->sa.sa_handler; |
407 | |
408 | __get_user(regs->pc, &funcptr->text); |
409 | __get_user(regs->regs[12], &funcptr->GOT); |
410 | } else |
411 | regs->pc = (unsigned long)ka->sa.sa_handler; |
412 | |
413 | set_fs(USER_DS); |
414 | |
415 | pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", |
416 | current->comm, task_pid_nr(current), frame, regs->pc, regs->pr); |
417 | |
418 | return 0; |
419 | |
420 | give_sigsegv: |
421 | force_sigsegv(sig, current); |
422 | return -EFAULT; |
423 | } |
424 | |
425 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
426 | sigset_t *set, struct pt_regs *regs) |
427 | { |
428 | struct rt_sigframe __user *frame; |
429 | int err = 0; |
430 | int signal; |
431 | |
432 | frame = get_sigframe(ka, regs->regs[15], sizeof(*frame)); |
433 | |
434 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
435 | goto give_sigsegv; |
436 | |
437 | signal = current_thread_info()->exec_domain |
438 | && current_thread_info()->exec_domain->signal_invmap |
439 | && sig < 32 |
440 | ? current_thread_info()->exec_domain->signal_invmap[sig] |
441 | : sig; |
442 | |
443 | err |= copy_siginfo_to_user(&frame->info, info); |
444 | |
445 | /* Create the ucontext. */ |
446 | err |= __put_user(0, &frame->uc.uc_flags); |
447 | err |= __put_user(NULL, &frame->uc.uc_link); |
448 | err |= __put_user((void *)current->sas_ss_sp, |
449 | &frame->uc.uc_stack.ss_sp); |
450 | err |= __put_user(sas_ss_flags(regs->regs[15]), |
451 | &frame->uc.uc_stack.ss_flags); |
452 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); |
453 | err |= setup_sigcontext(&frame->uc.uc_mcontext, |
454 | regs, set->sig[0]); |
455 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
456 | |
457 | /* Set up to return from userspace. If provided, use a stub |
458 | already in userspace. */ |
459 | if (ka->sa.sa_flags & SA_RESTORER) { |
460 | regs->pr = (unsigned long) ka->sa.sa_restorer; |
461 | #ifdef CONFIG_VSYSCALL |
462 | } else if (likely(current->mm->context.vdso)) { |
463 | regs->pr = VDSO_SYM(&__kernel_rt_sigreturn); |
464 | #endif |
465 | } else { |
466 | /* Generate return code (system call to rt_sigreturn) */ |
467 | err |= __put_user(MOVW(7), &frame->retcode[0]); |
468 | err |= __put_user(TRAP_NOARG, &frame->retcode[1]); |
469 | err |= __put_user(OR_R0_R0, &frame->retcode[2]); |
470 | err |= __put_user(OR_R0_R0, &frame->retcode[3]); |
471 | err |= __put_user(OR_R0_R0, &frame->retcode[4]); |
472 | err |= __put_user(OR_R0_R0, &frame->retcode[5]); |
473 | err |= __put_user(OR_R0_R0, &frame->retcode[6]); |
474 | err |= __put_user((__NR_rt_sigreturn), &frame->retcode[7]); |
475 | regs->pr = (unsigned long) frame->retcode; |
476 | flush_icache_range(regs->pr, regs->pr + sizeof(frame->retcode)); |
477 | } |
478 | |
479 | if (err) |
480 | goto give_sigsegv; |
481 | |
482 | /* Set up registers for signal handler */ |
483 | regs->regs[15] = (unsigned long) frame; |
484 | regs->regs[4] = signal; /* Arg for signal handler */ |
485 | regs->regs[5] = (unsigned long) &frame->info; |
486 | regs->regs[6] = (unsigned long) &frame->uc; |
487 | |
488 | if (current->personality & FDPIC_FUNCPTRS) { |
489 | struct fdpic_func_descriptor __user *funcptr = |
490 | (struct fdpic_func_descriptor __user *)ka->sa.sa_handler; |
491 | |
492 | __get_user(regs->pc, &funcptr->text); |
493 | __get_user(regs->regs[12], &funcptr->GOT); |
494 | } else |
495 | regs->pc = (unsigned long)ka->sa.sa_handler; |
496 | |
497 | set_fs(USER_DS); |
498 | |
499 | pr_debug("SIG deliver (%s:%d): sp=%p pc=%08lx pr=%08lx\n", |
500 | current->comm, task_pid_nr(current), frame, regs->pc, regs->pr); |
501 | |
502 | return 0; |
503 | |
504 | give_sigsegv: |
505 | force_sigsegv(sig, current); |
506 | return -EFAULT; |
507 | } |
508 | |
509 | static inline void |
510 | handle_syscall_restart(unsigned long save_r0, struct pt_regs *regs, |
511 | struct sigaction *sa) |
512 | { |
513 | /* If we're not from a syscall, bail out */ |
514 | if (regs->tra < 0) |
515 | return; |
516 | |
517 | /* check for system call restart.. */ |
518 | switch (regs->regs[0]) { |
519 | case -ERESTART_RESTARTBLOCK: |
520 | case -ERESTARTNOHAND: |
521 | no_system_call_restart: |
522 | regs->regs[0] = -EINTR; |
523 | break; |
524 | |
525 | case -ERESTARTSYS: |
526 | if (!(sa->sa_flags & SA_RESTART)) |
527 | goto no_system_call_restart; |
528 | /* fallthrough */ |
529 | case -ERESTARTNOINTR: |
530 | regs->regs[0] = save_r0; |
531 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
532 | break; |
533 | } |
534 | } |
535 | |
536 | /* |
537 | * OK, we're invoking a handler |
538 | */ |
539 | static int |
540 | handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info, |
541 | sigset_t *oldset, struct pt_regs *regs, unsigned int save_r0) |
542 | { |
543 | int ret; |
544 | |
545 | /* Set up the stack frame */ |
546 | if (ka->sa.sa_flags & SA_SIGINFO) |
547 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
548 | else |
549 | ret = setup_frame(sig, ka, oldset, regs); |
550 | |
551 | if (ka->sa.sa_flags & SA_ONESHOT) |
552 | ka->sa.sa_handler = SIG_DFL; |
553 | |
554 | if (ret == 0) { |
555 | spin_lock_irq(¤t->sighand->siglock); |
556 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); |
557 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
558 | sigaddset(¤t->blocked,sig); |
559 | recalc_sigpending(); |
560 | spin_unlock_irq(¤t->sighand->siglock); |
561 | } |
562 | |
563 | return ret; |
564 | } |
565 | |
566 | /* |
567 | * Note that 'init' is a special process: it doesn't get signals it doesn't |
568 | * want to handle. Thus you cannot kill init even with a SIGKILL even by |
569 | * mistake. |
570 | * |
571 | * Note that we go through the signals twice: once to check the signals that |
572 | * the kernel can handle, and then we build all the user-level signal handling |
573 | * stack-frames in one go after that. |
574 | */ |
575 | static void do_signal(struct pt_regs *regs, unsigned int save_r0) |
576 | { |
577 | siginfo_t info; |
578 | int signr; |
579 | struct k_sigaction ka; |
580 | sigset_t *oldset; |
581 | |
582 | /* |
583 | * We want the common case to go fast, which |
584 | * is why we may in certain cases get here from |
585 | * kernel mode. Just return without doing anything |
586 | * if so. |
587 | */ |
588 | if (!user_mode(regs)) |
589 | return; |
590 | |
591 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) |
592 | oldset = ¤t->saved_sigmask; |
593 | else |
594 | oldset = ¤t->blocked; |
595 | |
596 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); |
597 | if (signr > 0) { |
598 | handle_syscall_restart(save_r0, regs, &ka.sa); |
599 | |
600 | /* Whee! Actually deliver the signal. */ |
601 | if (handle_signal(signr, &ka, &info, oldset, |
602 | regs, save_r0) == 0) { |
603 | /* |
604 | * A signal was successfully delivered; the saved |
605 | * sigmask will have been stored in the signal frame, |
606 | * and will be restored by sigreturn, so we can simply |
607 | * clear the TS_RESTORE_SIGMASK flag |
608 | */ |
609 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
610 | |
611 | tracehook_signal_handler(signr, &info, &ka, regs, |
612 | test_thread_flag(TIF_SINGLESTEP)); |
613 | } |
614 | |
615 | return; |
616 | } |
617 | |
618 | /* Did we come from a system call? */ |
619 | if (regs->tra >= 0) { |
620 | /* Restart the system call - no handlers present */ |
621 | if (regs->regs[0] == -ERESTARTNOHAND || |
622 | regs->regs[0] == -ERESTARTSYS || |
623 | regs->regs[0] == -ERESTARTNOINTR) { |
624 | regs->regs[0] = save_r0; |
625 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
626 | } else if (regs->regs[0] == -ERESTART_RESTARTBLOCK) { |
627 | regs->pc -= instruction_size(__raw_readw(regs->pc - 4)); |
628 | regs->regs[3] = __NR_restart_syscall; |
629 | } |
630 | } |
631 | |
632 | /* |
633 | * If there's no signal to deliver, we just put the saved sigmask |
634 | * back. |
635 | */ |
636 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) { |
637 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
638 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
639 | } |
640 | } |
641 | |
642 | asmlinkage void do_notify_resume(struct pt_regs *regs, unsigned int save_r0, |
643 | unsigned long thread_info_flags) |
644 | { |
645 | /* deal with pending signal delivery */ |
646 | if (thread_info_flags & _TIF_SIGPENDING) |
647 | do_signal(regs, save_r0); |
648 | |
649 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
650 | clear_thread_flag(TIF_NOTIFY_RESUME); |
651 | tracehook_notify_resume(regs); |
652 | if (current->replacement_session_keyring) |
653 | key_replace_session_keyring(); |
654 | } |
655 | } |
656 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
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master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9