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1da177e4 LT |
1 | /* |
2 | * linux/arch/ppc64/kernel/signal.c | |
3 | * | |
4 | * PowerPC version | |
5 | * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org) | |
6 | * | |
7 | * Derived from "arch/i386/kernel/signal.c" | |
8 | * Copyright (C) 1991, 1992 Linus Torvalds | |
9 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
10 | * | |
11 | * This program is free software; you can redistribute it and/or | |
12 | * modify it under the terms of the GNU General Public License | |
13 | * as published by the Free Software Foundation; either version | |
14 | * 2 of the License, or (at your option) any later version. | |
15 | */ | |
16 | ||
17 | #include <linux/config.h> | |
18 | #include <linux/sched.h> | |
19 | #include <linux/mm.h> | |
20 | #include <linux/smp.h> | |
21 | #include <linux/smp_lock.h> | |
22 | #include <linux/kernel.h> | |
23 | #include <linux/signal.h> | |
24 | #include <linux/errno.h> | |
25 | #include <linux/wait.h> | |
26 | #include <linux/unistd.h> | |
27 | #include <linux/stddef.h> | |
28 | #include <linux/elf.h> | |
29 | #include <linux/ptrace.h> | |
30 | #include <linux/module.h> | |
31 | ||
32 | #include <asm/sigcontext.h> | |
33 | #include <asm/ucontext.h> | |
34 | #include <asm/uaccess.h> | |
35 | #include <asm/pgtable.h> | |
1da177e4 LT |
36 | #include <asm/unistd.h> |
37 | #include <asm/cacheflush.h> | |
38 | #include <asm/vdso.h> | |
39 | ||
40 | #define DEBUG_SIG 0 | |
41 | ||
42 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
43 | ||
6741f3a7 | 44 | #define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs)) |
1da177e4 LT |
45 | #define FP_REGS_SIZE sizeof(elf_fpregset_t) |
46 | ||
47 | #define TRAMP_TRACEBACK 3 | |
48 | #define TRAMP_SIZE 6 | |
49 | ||
50 | /* | |
51 | * When we have signals to deliver, we set up on the user stack, | |
52 | * going down from the original stack pointer: | |
53 | * 1) a rt_sigframe struct which contains the ucontext | |
54 | * 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller | |
55 | * frame for the signal handler. | |
56 | */ | |
57 | ||
58 | struct rt_sigframe { | |
59 | /* sys_rt_sigreturn requires the ucontext be the first field */ | |
60 | struct ucontext uc; | |
61 | unsigned long _unused[2]; | |
62 | unsigned int tramp[TRAMP_SIZE]; | |
63 | struct siginfo *pinfo; | |
64 | void *puc; | |
65 | struct siginfo info; | |
66 | /* 64 bit ABI allows for 288 bytes below sp before decrementing it. */ | |
67 | char abigap[288]; | |
68 | } __attribute__ ((aligned (16))); | |
69 | ||
70 | ||
71 | /* | |
72 | * Atomically swap in the new signal mask, and wait for a signal. | |
73 | */ | |
74 | long sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, int p3, int p4, | |
75 | int p6, int p7, struct pt_regs *regs) | |
76 | { | |
77 | sigset_t saveset, newset; | |
78 | ||
79 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
80 | if (sigsetsize != sizeof(sigset_t)) | |
81 | return -EINVAL; | |
82 | ||
83 | if (copy_from_user(&newset, unewset, sizeof(newset))) | |
84 | return -EFAULT; | |
85 | sigdelsetmask(&newset, ~_BLOCKABLE); | |
86 | ||
87 | spin_lock_irq(¤t->sighand->siglock); | |
88 | saveset = current->blocked; | |
89 | current->blocked = newset; | |
90 | recalc_sigpending(); | |
91 | spin_unlock_irq(¤t->sighand->siglock); | |
92 | ||
93 | regs->result = -EINTR; | |
94 | regs->gpr[3] = EINTR; | |
95 | regs->ccr |= 0x10000000; | |
96 | while (1) { | |
97 | current->state = TASK_INTERRUPTIBLE; | |
98 | schedule(); | |
401d1f02 DW |
99 | if (do_signal(&saveset, regs)) { |
100 | set_thread_flag(TIF_RESTOREALL); | |
1da177e4 | 101 | return 0; |
401d1f02 | 102 | } |
1da177e4 LT |
103 | } |
104 | } | |
105 | ||
106 | long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, unsigned long r5, | |
107 | unsigned long r6, unsigned long r7, unsigned long r8, | |
108 | struct pt_regs *regs) | |
109 | { | |
110 | return do_sigaltstack(uss, uoss, regs->gpr[1]); | |
111 | } | |
112 | ||
113 | ||
114 | /* | |
115 | * Set up the sigcontext for the signal frame. | |
116 | */ | |
117 | ||
118 | static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
119 | int signr, sigset_t *set, unsigned long handler) | |
120 | { | |
121 | /* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the | |
122 | * process never used altivec yet (MSR_VEC is zero in pt_regs of | |
123 | * the context). This is very important because we must ensure we | |
124 | * don't lose the VRSAVE content that may have been set prior to | |
125 | * the process doing its first vector operation | |
126 | * Userland shall check AT_HWCAP to know wether it can rely on the | |
127 | * v_regs pointer or not | |
128 | */ | |
129 | #ifdef CONFIG_ALTIVEC | |
130 | elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful); | |
131 | #endif | |
132 | long err = 0; | |
133 | ||
134 | flush_fp_to_thread(current); | |
135 | ||
1da177e4 LT |
136 | #ifdef CONFIG_ALTIVEC |
137 | err |= __put_user(v_regs, &sc->v_regs); | |
138 | ||
139 | /* save altivec registers */ | |
140 | if (current->thread.used_vr) { | |
141 | flush_altivec_to_thread(current); | |
142 | /* Copy 33 vec registers (vr0..31 and vscr) to the stack */ | |
143 | err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128)); | |
144 | /* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg) | |
145 | * contains valid data. | |
146 | */ | |
147 | regs->msr |= MSR_VEC; | |
148 | } | |
149 | /* We always copy to/from vrsave, it's 0 if we don't have or don't | |
150 | * use altivec. | |
151 | */ | |
152 | err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); | |
153 | #else /* CONFIG_ALTIVEC */ | |
154 | err |= __put_user(0, &sc->v_regs); | |
155 | #endif /* CONFIG_ALTIVEC */ | |
156 | err |= __put_user(&sc->gp_regs, &sc->regs); | |
401d1f02 DW |
157 | if (!FULL_REGS(regs)) { |
158 | /* Zero out the unsaved GPRs to avoid information | |
159 | leak, and set TIF_SAVE_NVGPRS to ensure that the | |
160 | registers do actually get saved later. */ | |
161 | memset(®s->gpr[14], 0, 18 * sizeof(unsigned long)); | |
162 | set_thread_flag(TIF_SAVE_NVGPRS); | |
163 | current_thread_info()->nvgprs_frame = &sc->gp_regs; | |
164 | } | |
1da177e4 LT |
165 | err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE); |
166 | err |= __copy_to_user(&sc->fp_regs, ¤t->thread.fpr, FP_REGS_SIZE); | |
167 | err |= __put_user(signr, &sc->signal); | |
168 | err |= __put_user(handler, &sc->handler); | |
169 | if (set != NULL) | |
170 | err |= __put_user(set->sig[0], &sc->oldmask); | |
171 | ||
172 | return err; | |
173 | } | |
174 | ||
175 | /* | |
176 | * Restore the sigcontext from the signal frame. | |
177 | */ | |
178 | ||
179 | static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig, | |
180 | struct sigcontext __user *sc) | |
181 | { | |
182 | #ifdef CONFIG_ALTIVEC | |
183 | elf_vrreg_t __user *v_regs; | |
184 | #endif | |
185 | unsigned long err = 0; | |
186 | unsigned long save_r13 = 0; | |
187 | elf_greg_t *gregs = (elf_greg_t *)regs; | |
188 | #ifdef CONFIG_ALTIVEC | |
189 | unsigned long msr; | |
190 | #endif | |
191 | int i; | |
192 | ||
193 | /* If this is not a signal return, we preserve the TLS in r13 */ | |
194 | if (!sig) | |
195 | save_r13 = regs->gpr[13]; | |
196 | ||
197 | /* copy everything before MSR */ | |
198 | err |= __copy_from_user(regs, &sc->gp_regs, | |
199 | PT_MSR*sizeof(unsigned long)); | |
200 | ||
201 | /* skip MSR and SOFTE */ | |
202 | for (i = PT_MSR+1; i <= PT_RESULT; i++) { | |
203 | if (i == PT_SOFTE) | |
204 | continue; | |
205 | err |= __get_user(gregs[i], &sc->gp_regs[i]); | |
206 | } | |
207 | ||
208 | if (!sig) | |
209 | regs->gpr[13] = save_r13; | |
210 | err |= __copy_from_user(¤t->thread.fpr, &sc->fp_regs, FP_REGS_SIZE); | |
211 | if (set != NULL) | |
212 | err |= __get_user(set->sig[0], &sc->oldmask); | |
213 | ||
214 | #ifdef CONFIG_ALTIVEC | |
215 | err |= __get_user(v_regs, &sc->v_regs); | |
216 | err |= __get_user(msr, &sc->gp_regs[PT_MSR]); | |
217 | if (err) | |
218 | return err; | |
219 | /* Copy 33 vec registers (vr0..31 and vscr) from the stack */ | |
220 | if (v_regs != 0 && (msr & MSR_VEC) != 0) | |
221 | err |= __copy_from_user(current->thread.vr, v_regs, | |
222 | 33 * sizeof(vector128)); | |
223 | else if (current->thread.used_vr) | |
224 | memset(current->thread.vr, 0, 33 * sizeof(vector128)); | |
225 | /* Always get VRSAVE back */ | |
226 | if (v_regs != 0) | |
227 | err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]); | |
228 | else | |
229 | current->thread.vrsave = 0; | |
230 | #endif /* CONFIG_ALTIVEC */ | |
231 | ||
232 | #ifndef CONFIG_SMP | |
233 | preempt_disable(); | |
234 | if (last_task_used_math == current) | |
235 | last_task_used_math = NULL; | |
236 | if (last_task_used_altivec == current) | |
237 | last_task_used_altivec = NULL; | |
238 | preempt_enable(); | |
239 | #endif | |
240 | /* Force reload of FP/VEC */ | |
241 | regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC); | |
242 | ||
243 | return err; | |
244 | } | |
245 | ||
246 | /* | |
247 | * Allocate space for the signal frame | |
248 | */ | |
249 | static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, | |
250 | size_t frame_size) | |
251 | { | |
252 | unsigned long newsp; | |
253 | ||
254 | /* Default to using normal stack */ | |
255 | newsp = regs->gpr[1]; | |
256 | ||
257 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
258 | if (! on_sig_stack(regs->gpr[1])) | |
259 | newsp = (current->sas_ss_sp + current->sas_ss_size); | |
260 | } | |
261 | ||
262 | return (void __user *)((newsp - frame_size) & -16ul); | |
263 | } | |
264 | ||
265 | /* | |
266 | * Setup the trampoline code on the stack | |
267 | */ | |
268 | static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp) | |
269 | { | |
270 | int i; | |
271 | long err = 0; | |
272 | ||
273 | /* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */ | |
274 | err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]); | |
275 | /* li r0, __NR_[rt_]sigreturn| */ | |
276 | err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]); | |
277 | /* sc */ | |
278 | err |= __put_user(0x44000002UL, &tramp[2]); | |
279 | ||
280 | /* Minimal traceback info */ | |
281 | for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++) | |
282 | err |= __put_user(0, &tramp[i]); | |
283 | ||
284 | if (!err) | |
285 | flush_icache_range((unsigned long) &tramp[0], | |
286 | (unsigned long) &tramp[TRAMP_SIZE]); | |
287 | ||
288 | return err; | |
289 | } | |
290 | ||
291 | /* | |
292 | * Restore the user process's signal mask (also used by signal32.c) | |
293 | */ | |
294 | void restore_sigmask(sigset_t *set) | |
295 | { | |
296 | sigdelsetmask(set, ~_BLOCKABLE); | |
297 | spin_lock_irq(¤t->sighand->siglock); | |
298 | current->blocked = *set; | |
299 | recalc_sigpending(); | |
300 | spin_unlock_irq(¤t->sighand->siglock); | |
301 | } | |
302 | ||
303 | ||
304 | /* | |
305 | * Handle {get,set,swap}_context operations | |
306 | */ | |
307 | int sys_swapcontext(struct ucontext __user *old_ctx, | |
308 | struct ucontext __user *new_ctx, | |
309 | long ctx_size, long r6, long r7, long r8, struct pt_regs *regs) | |
310 | { | |
311 | unsigned char tmp; | |
312 | sigset_t set; | |
313 | ||
314 | /* Context size is for future use. Right now, we only make sure | |
315 | * we are passed something we understand | |
316 | */ | |
317 | if (ctx_size < sizeof(struct ucontext)) | |
318 | return -EINVAL; | |
319 | ||
320 | if (old_ctx != NULL) { | |
321 | if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx)) | |
322 | || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0) | |
323 | || __copy_to_user(&old_ctx->uc_sigmask, | |
324 | ¤t->blocked, sizeof(sigset_t))) | |
325 | return -EFAULT; | |
326 | } | |
327 | if (new_ctx == NULL) | |
328 | return 0; | |
329 | if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx)) | |
330 | || __get_user(tmp, (u8 __user *) new_ctx) | |
331 | || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1)) | |
332 | return -EFAULT; | |
333 | ||
334 | /* | |
335 | * If we get a fault copying the context into the kernel's | |
336 | * image of the user's registers, we can't just return -EFAULT | |
337 | * because the user's registers will be corrupted. For instance | |
338 | * the NIP value may have been updated but not some of the | |
339 | * other registers. Given that we have done the access_ok | |
340 | * and successfully read the first and last bytes of the region | |
341 | * above, this should only happen in an out-of-memory situation | |
342 | * or if another thread unmaps the region containing the context. | |
343 | * We kill the task with a SIGSEGV in this situation. | |
344 | */ | |
345 | ||
346 | if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set))) | |
347 | do_exit(SIGSEGV); | |
348 | restore_sigmask(&set); | |
349 | if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext)) | |
350 | do_exit(SIGSEGV); | |
351 | ||
352 | /* This returns like rt_sigreturn */ | |
401d1f02 | 353 | set_thread_flag(TIF_RESTOREALL); |
1da177e4 LT |
354 | return 0; |
355 | } | |
356 | ||
357 | ||
358 | /* | |
359 | * Do a signal return; undo the signal stack. | |
360 | */ | |
361 | ||
362 | int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5, | |
363 | unsigned long r6, unsigned long r7, unsigned long r8, | |
364 | struct pt_regs *regs) | |
365 | { | |
366 | struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1]; | |
367 | sigset_t set; | |
368 | ||
369 | /* Always make any pending restarted system calls return -EINTR */ | |
370 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
371 | ||
372 | if (!access_ok(VERIFY_READ, uc, sizeof(*uc))) | |
373 | goto badframe; | |
374 | ||
375 | if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set))) | |
376 | goto badframe; | |
377 | restore_sigmask(&set); | |
378 | if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext)) | |
379 | goto badframe; | |
380 | ||
381 | /* do_sigaltstack expects a __user pointer and won't modify | |
382 | * what's in there anyway | |
383 | */ | |
384 | do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]); | |
385 | ||
401d1f02 DW |
386 | set_thread_flag(TIF_RESTOREALL); |
387 | return 0; | |
1da177e4 LT |
388 | |
389 | badframe: | |
390 | #if DEBUG_SIG | |
391 | printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n", | |
392 | regs, uc, &uc->uc_mcontext); | |
393 | #endif | |
394 | force_sig(SIGSEGV, current); | |
395 | return 0; | |
396 | } | |
397 | ||
398 | static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info, | |
399 | sigset_t *set, struct pt_regs *regs) | |
400 | { | |
401 | /* Handler is *really* a pointer to the function descriptor for | |
402 | * the signal routine. The first entry in the function | |
403 | * descriptor is the entry address of signal and the second | |
404 | * entry is the TOC value we need to use. | |
405 | */ | |
406 | func_descr_t __user *funct_desc_ptr; | |
407 | struct rt_sigframe __user *frame; | |
408 | unsigned long newsp = 0; | |
409 | long err = 0; | |
410 | ||
411 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
412 | ||
413 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
414 | goto badframe; | |
415 | ||
416 | err |= __put_user(&frame->info, &frame->pinfo); | |
417 | err |= __put_user(&frame->uc, &frame->puc); | |
418 | err |= copy_siginfo_to_user(&frame->info, info); | |
419 | if (err) | |
420 | goto badframe; | |
421 | ||
422 | /* Create the ucontext. */ | |
423 | err |= __put_user(0, &frame->uc.uc_flags); | |
424 | err |= __put_user(0, &frame->uc.uc_link); | |
425 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
426 | err |= __put_user(sas_ss_flags(regs->gpr[1]), | |
427 | &frame->uc.uc_stack.ss_flags); | |
428 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
429 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL, | |
430 | (unsigned long)ka->sa.sa_handler); | |
431 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
432 | if (err) | |
433 | goto badframe; | |
434 | ||
cc657f53 PM |
435 | /* Make sure signal handler doesn't get spurious FP exceptions */ |
436 | current->thread.fpscr.val = 0; | |
437 | ||
1da177e4 LT |
438 | /* Set up to return from userspace. */ |
439 | if (vdso64_rt_sigtramp && current->thread.vdso_base) { | |
440 | regs->link = current->thread.vdso_base + vdso64_rt_sigtramp; | |
441 | } else { | |
442 | err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]); | |
443 | if (err) | |
444 | goto badframe; | |
445 | regs->link = (unsigned long) &frame->tramp[0]; | |
446 | } | |
447 | funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler; | |
448 | ||
449 | /* Allocate a dummy caller frame for the signal handler. */ | |
450 | newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE; | |
451 | err |= put_user(regs->gpr[1], (unsigned long __user *)newsp); | |
452 | ||
453 | /* Set up "regs" so we "return" to the signal handler. */ | |
454 | err |= get_user(regs->nip, &funct_desc_ptr->entry); | |
455 | regs->gpr[1] = newsp; | |
456 | err |= get_user(regs->gpr[2], &funct_desc_ptr->toc); | |
457 | regs->gpr[3] = signr; | |
458 | regs->result = 0; | |
459 | if (ka->sa.sa_flags & SA_SIGINFO) { | |
460 | err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo); | |
461 | err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc); | |
462 | regs->gpr[6] = (unsigned long) frame; | |
463 | } else { | |
464 | regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext; | |
465 | } | |
466 | if (err) | |
467 | goto badframe; | |
468 | ||
1da177e4 LT |
469 | return 1; |
470 | ||
471 | badframe: | |
472 | #if DEBUG_SIG | |
473 | printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n", | |
474 | regs, frame, newsp); | |
475 | #endif | |
476 | force_sigsegv(signr, current); | |
477 | return 0; | |
478 | } | |
479 | ||
480 | ||
481 | /* | |
482 | * OK, we're invoking a handler | |
483 | */ | |
484 | static int handle_signal(unsigned long sig, struct k_sigaction *ka, | |
485 | siginfo_t *info, sigset_t *oldset, struct pt_regs *regs) | |
486 | { | |
487 | int ret; | |
488 | ||
489 | /* Set up Signal Frame */ | |
490 | ret = setup_rt_frame(sig, ka, info, oldset, regs); | |
491 | ||
69be8f18 | 492 | if (ret) { |
1da177e4 LT |
493 | spin_lock_irq(¤t->sighand->siglock); |
494 | sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); | |
69be8f18 SR |
495 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
496 | sigaddset(¤t->blocked,sig); | |
1da177e4 LT |
497 | recalc_sigpending(); |
498 | spin_unlock_irq(¤t->sighand->siglock); | |
499 | } | |
500 | ||
501 | return ret; | |
502 | } | |
503 | ||
504 | static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka) | |
505 | { | |
506 | switch ((int)regs->result) { | |
507 | case -ERESTART_RESTARTBLOCK: | |
508 | case -ERESTARTNOHAND: | |
509 | /* ERESTARTNOHAND means that the syscall should only be | |
510 | * restarted if there was no handler for the signal, and since | |
511 | * we only get here if there is a handler, we dont restart. | |
512 | */ | |
513 | regs->result = -EINTR; | |
401d1f02 DW |
514 | regs->gpr[3] = EINTR; |
515 | regs->ccr |= 0x10000000; | |
1da177e4 LT |
516 | break; |
517 | case -ERESTARTSYS: | |
518 | /* ERESTARTSYS means to restart the syscall if there is no | |
519 | * handler or the handler was registered with SA_RESTART | |
520 | */ | |
521 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
522 | regs->result = -EINTR; | |
401d1f02 DW |
523 | regs->gpr[3] = EINTR; |
524 | regs->ccr |= 0x10000000; | |
1da177e4 LT |
525 | break; |
526 | } | |
527 | /* fallthrough */ | |
528 | case -ERESTARTNOINTR: | |
529 | /* ERESTARTNOINTR means that the syscall should be | |
530 | * called again after the signal handler returns. | |
531 | */ | |
532 | regs->gpr[3] = regs->orig_gpr3; | |
533 | regs->nip -= 4; | |
534 | regs->result = 0; | |
535 | break; | |
536 | } | |
537 | } | |
538 | ||
539 | /* | |
540 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
541 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
542 | * mistake. | |
543 | */ | |
544 | int do_signal(sigset_t *oldset, struct pt_regs *regs) | |
545 | { | |
546 | siginfo_t info; | |
547 | int signr; | |
548 | struct k_sigaction ka; | |
549 | ||
550 | /* | |
551 | * If the current thread is 32 bit - invoke the | |
552 | * 32 bit signal handling code | |
553 | */ | |
554 | if (test_thread_flag(TIF_32BIT)) | |
555 | return do_signal32(oldset, regs); | |
556 | ||
557 | if (!oldset) | |
558 | oldset = ¤t->blocked; | |
559 | ||
560 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
561 | if (signr > 0) { | |
562 | /* Whee! Actually deliver the signal. */ | |
563 | if (TRAP(regs) == 0x0C00) | |
564 | syscall_restart(regs, &ka); | |
fd9648df AB |
565 | |
566 | /* | |
567 | * Reenable the DABR before delivering the signal to | |
568 | * user space. The DABR will have been cleared if it | |
569 | * triggered inside the kernel. | |
570 | */ | |
571 | if (current->thread.dabr) | |
572 | set_dabr(current->thread.dabr); | |
573 | ||
1da177e4 LT |
574 | return handle_signal(signr, &ka, &info, oldset, regs); |
575 | } | |
576 | ||
577 | if (TRAP(regs) == 0x0C00) { /* System Call! */ | |
578 | if ((int)regs->result == -ERESTARTNOHAND || | |
579 | (int)regs->result == -ERESTARTSYS || | |
580 | (int)regs->result == -ERESTARTNOINTR) { | |
581 | regs->gpr[3] = regs->orig_gpr3; | |
582 | regs->nip -= 4; /* Back up & retry system call */ | |
583 | regs->result = 0; | |
584 | } else if ((int)regs->result == -ERESTART_RESTARTBLOCK) { | |
585 | regs->gpr[0] = __NR_restart_syscall; | |
586 | regs->nip -= 4; | |
587 | regs->result = 0; | |
588 | } | |
589 | } | |
590 | ||
591 | return 0; | |
592 | } | |
593 | EXPORT_SYMBOL(do_signal); |