Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/arch/alpha/kernel/signal.c | |
3 | * | |
4 | * Copyright (C) 1995 Linus Torvalds | |
5 | * | |
6 | * 1997-11-02 Modified for POSIX.1b signals by Richard Henderson | |
7 | */ | |
8 | ||
9 | #include <linux/sched.h> | |
10 | #include <linux/kernel.h> | |
11 | #include <linux/signal.h> | |
12 | #include <linux/errno.h> | |
13 | #include <linux/wait.h> | |
14 | #include <linux/ptrace.h> | |
15 | #include <linux/unistd.h> | |
16 | #include <linux/mm.h> | |
17 | #include <linux/smp.h> | |
1da177e4 LT |
18 | #include <linux/stddef.h> |
19 | #include <linux/tty.h> | |
20 | #include <linux/binfmts.h> | |
21 | #include <linux/bitops.h> | |
e5d9a90c | 22 | #include <linux/syscalls.h> |
733e5e4b | 23 | #include <linux/tracehook.h> |
1da177e4 LT |
24 | |
25 | #include <asm/uaccess.h> | |
26 | #include <asm/sigcontext.h> | |
27 | #include <asm/ucontext.h> | |
28 | ||
29 | #include "proto.h" | |
30 | ||
31 | ||
32 | #define DEBUG_SIG 0 | |
33 | ||
34 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
35 | ||
36 | asmlinkage void ret_from_sys_call(void); | |
1da177e4 LT |
37 | |
38 | /* | |
39 | * The OSF/1 sigprocmask calling sequence is different from the | |
40 | * C sigprocmask() sequence.. | |
1da177e4 | 41 | */ |
c52c2ddc | 42 | SYSCALL_DEFINE2(osf_sigprocmask, int, how, unsigned long, newmask) |
1da177e4 | 43 | { |
c52c2ddc AV |
44 | sigset_t oldmask; |
45 | sigset_t mask; | |
46 | unsigned long res; | |
1da177e4 | 47 | |
87400e54 | 48 | siginitset(&mask, newmask & _BLOCKABLE); |
0f44fbd2 | 49 | res = sigprocmask(how, &mask, &oldmask); |
c52c2ddc AV |
50 | if (!res) { |
51 | force_successful_syscall_return(); | |
0f44fbd2 | 52 | res = oldmask.sig[0]; |
1da177e4 | 53 | } |
c52c2ddc | 54 | return res; |
1da177e4 LT |
55 | } |
56 | ||
e5d9a90c IK |
57 | SYSCALL_DEFINE3(osf_sigaction, int, sig, |
58 | const struct osf_sigaction __user *, act, | |
59 | struct osf_sigaction __user *, oact) | |
1da177e4 LT |
60 | { |
61 | struct k_sigaction new_ka, old_ka; | |
62 | int ret; | |
63 | ||
64 | if (act) { | |
65 | old_sigset_t mask; | |
66 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
67 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
18e6bfa9 AV |
68 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || |
69 | __get_user(mask, &act->sa_mask)) | |
1da177e4 | 70 | return -EFAULT; |
1da177e4 LT |
71 | siginitset(&new_ka.sa.sa_mask, mask); |
72 | new_ka.ka_restorer = NULL; | |
73 | } | |
74 | ||
75 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
76 | ||
77 | if (!ret && oact) { | |
78 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
79 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
18e6bfa9 AV |
80 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || |
81 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) | |
1da177e4 | 82 | return -EFAULT; |
1da177e4 LT |
83 | } |
84 | ||
85 | return ret; | |
86 | } | |
87 | ||
e5d9a90c IK |
88 | SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act, |
89 | struct sigaction __user *, oact, | |
90 | size_t, sigsetsize, void __user *, restorer) | |
1da177e4 LT |
91 | { |
92 | struct k_sigaction new_ka, old_ka; | |
93 | int ret; | |
94 | ||
95 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
96 | if (sigsetsize != sizeof(sigset_t)) | |
97 | return -EINVAL; | |
98 | ||
99 | if (act) { | |
100 | new_ka.ka_restorer = restorer; | |
101 | if (copy_from_user(&new_ka.sa, act, sizeof(*act))) | |
102 | return -EFAULT; | |
103 | } | |
104 | ||
105 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
106 | ||
107 | if (!ret && oact) { | |
108 | if (copy_to_user(oact, &old_ka.sa, sizeof(*oact))) | |
109 | return -EFAULT; | |
110 | } | |
111 | ||
112 | return ret; | |
113 | } | |
114 | ||
115 | /* | |
116 | * Atomically swap in the new signal mask, and wait for a signal. | |
117 | */ | |
392fb6e3 | 118 | SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask) |
1da177e4 | 119 | { |
2561b069 | 120 | sigset_t blocked; |
2561b069 | 121 | siginitset(&blocked, mask); |
68f3f16d | 122 | return sigsuspend(&blocked); |
1da177e4 LT |
123 | } |
124 | ||
125 | asmlinkage int | |
126 | sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss) | |
127 | { | |
128 | return do_sigaltstack(uss, uoss, rdusp()); | |
129 | } | |
130 | ||
131 | /* | |
132 | * Do a signal return; undo the signal stack. | |
133 | */ | |
134 | ||
135 | #if _NSIG_WORDS > 1 | |
136 | # error "Non SA_SIGINFO frame needs rearranging" | |
137 | #endif | |
138 | ||
139 | struct sigframe | |
140 | { | |
141 | struct sigcontext sc; | |
142 | unsigned int retcode[3]; | |
143 | }; | |
144 | ||
145 | struct rt_sigframe | |
146 | { | |
147 | struct siginfo info; | |
148 | struct ucontext uc; | |
149 | unsigned int retcode[3]; | |
150 | }; | |
151 | ||
152 | /* If this changes, userland unwinders that Know Things about our signal | |
153 | frame will break. Do not undertake lightly. It also implies an ABI | |
154 | change wrt the size of siginfo_t, which may cause some pain. */ | |
155 | extern char compile_time_assert | |
156 | [offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1]; | |
157 | ||
158 | #define INSN_MOV_R30_R16 0x47fe0410 | |
159 | #define INSN_LDI_R0 0x201f0000 | |
160 | #define INSN_CALLSYS 0x00000083 | |
161 | ||
162 | static long | |
163 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
164 | struct switch_stack *sw) | |
165 | { | |
166 | unsigned long usp; | |
167 | long i, err = __get_user(regs->pc, &sc->sc_pc); | |
168 | ||
2deba1bd AV |
169 | current_thread_info()->restart_block.fn = do_no_restart_syscall; |
170 | ||
1da177e4 LT |
171 | sw->r26 = (unsigned long) ret_from_sys_call; |
172 | ||
173 | err |= __get_user(regs->r0, sc->sc_regs+0); | |
174 | err |= __get_user(regs->r1, sc->sc_regs+1); | |
175 | err |= __get_user(regs->r2, sc->sc_regs+2); | |
176 | err |= __get_user(regs->r3, sc->sc_regs+3); | |
177 | err |= __get_user(regs->r4, sc->sc_regs+4); | |
178 | err |= __get_user(regs->r5, sc->sc_regs+5); | |
179 | err |= __get_user(regs->r6, sc->sc_regs+6); | |
180 | err |= __get_user(regs->r7, sc->sc_regs+7); | |
181 | err |= __get_user(regs->r8, sc->sc_regs+8); | |
182 | err |= __get_user(sw->r9, sc->sc_regs+9); | |
183 | err |= __get_user(sw->r10, sc->sc_regs+10); | |
184 | err |= __get_user(sw->r11, sc->sc_regs+11); | |
185 | err |= __get_user(sw->r12, sc->sc_regs+12); | |
186 | err |= __get_user(sw->r13, sc->sc_regs+13); | |
187 | err |= __get_user(sw->r14, sc->sc_regs+14); | |
188 | err |= __get_user(sw->r15, sc->sc_regs+15); | |
189 | err |= __get_user(regs->r16, sc->sc_regs+16); | |
190 | err |= __get_user(regs->r17, sc->sc_regs+17); | |
191 | err |= __get_user(regs->r18, sc->sc_regs+18); | |
192 | err |= __get_user(regs->r19, sc->sc_regs+19); | |
193 | err |= __get_user(regs->r20, sc->sc_regs+20); | |
194 | err |= __get_user(regs->r21, sc->sc_regs+21); | |
195 | err |= __get_user(regs->r22, sc->sc_regs+22); | |
196 | err |= __get_user(regs->r23, sc->sc_regs+23); | |
197 | err |= __get_user(regs->r24, sc->sc_regs+24); | |
198 | err |= __get_user(regs->r25, sc->sc_regs+25); | |
199 | err |= __get_user(regs->r26, sc->sc_regs+26); | |
200 | err |= __get_user(regs->r27, sc->sc_regs+27); | |
201 | err |= __get_user(regs->r28, sc->sc_regs+28); | |
202 | err |= __get_user(regs->gp, sc->sc_regs+29); | |
203 | err |= __get_user(usp, sc->sc_regs+30); | |
204 | wrusp(usp); | |
205 | ||
206 | for (i = 0; i < 31; i++) | |
207 | err |= __get_user(sw->fp[i], sc->sc_fpregs+i); | |
208 | err |= __get_user(sw->fp[31], &sc->sc_fpcr); | |
209 | ||
210 | return err; | |
211 | } | |
212 | ||
213 | /* Note that this syscall is also used by setcontext(3) to install | |
214 | a given sigcontext. This because it's impossible to set *all* | |
215 | registers and transfer control from userland. */ | |
216 | ||
217 | asmlinkage void | |
218 | do_sigreturn(struct sigcontext __user *sc, struct pt_regs *regs, | |
219 | struct switch_stack *sw) | |
220 | { | |
221 | sigset_t set; | |
222 | ||
223 | /* Verify that it's a good sigcontext before using it */ | |
224 | if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) | |
225 | goto give_sigsegv; | |
226 | if (__get_user(set.sig[0], &sc->sc_mask)) | |
227 | goto give_sigsegv; | |
228 | ||
229 | sigdelsetmask(&set, ~_BLOCKABLE); | |
2561b069 | 230 | set_current_blocked(&set); |
1da177e4 LT |
231 | |
232 | if (restore_sigcontext(sc, regs, sw)) | |
233 | goto give_sigsegv; | |
234 | ||
235 | /* Send SIGTRAP if we're single-stepping: */ | |
236 | if (ptrace_cancel_bpt (current)) { | |
237 | siginfo_t info; | |
238 | ||
239 | info.si_signo = SIGTRAP; | |
240 | info.si_errno = 0; | |
241 | info.si_code = TRAP_BRKPT; | |
242 | info.si_addr = (void __user *) regs->pc; | |
243 | info.si_trapno = 0; | |
244 | send_sig_info(SIGTRAP, &info, current); | |
245 | } | |
246 | return; | |
247 | ||
248 | give_sigsegv: | |
249 | force_sig(SIGSEGV, current); | |
250 | } | |
251 | ||
252 | asmlinkage void | |
253 | do_rt_sigreturn(struct rt_sigframe __user *frame, struct pt_regs *regs, | |
254 | struct switch_stack *sw) | |
255 | { | |
256 | sigset_t set; | |
257 | ||
258 | /* Verify that it's a good ucontext_t before using it */ | |
259 | if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc))) | |
260 | goto give_sigsegv; | |
261 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
262 | goto give_sigsegv; | |
263 | ||
264 | sigdelsetmask(&set, ~_BLOCKABLE); | |
2561b069 | 265 | set_current_blocked(&set); |
1da177e4 LT |
266 | |
267 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs, sw)) | |
268 | goto give_sigsegv; | |
269 | ||
270 | /* Send SIGTRAP if we're single-stepping: */ | |
271 | if (ptrace_cancel_bpt (current)) { | |
272 | siginfo_t info; | |
273 | ||
274 | info.si_signo = SIGTRAP; | |
275 | info.si_errno = 0; | |
276 | info.si_code = TRAP_BRKPT; | |
277 | info.si_addr = (void __user *) regs->pc; | |
278 | info.si_trapno = 0; | |
279 | send_sig_info(SIGTRAP, &info, current); | |
280 | } | |
281 | return; | |
282 | ||
283 | give_sigsegv: | |
284 | force_sig(SIGSEGV, current); | |
285 | } | |
286 | ||
287 | ||
288 | /* | |
289 | * Set up a signal frame. | |
290 | */ | |
291 | ||
292 | static inline void __user * | |
293 | get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size) | |
294 | { | |
d09042da | 295 | if ((ka->sa.sa_flags & SA_ONSTACK) != 0 && ! sas_ss_flags(sp)) |
1da177e4 LT |
296 | sp = current->sas_ss_sp + current->sas_ss_size; |
297 | ||
298 | return (void __user *)((sp - frame_size) & -32ul); | |
299 | } | |
300 | ||
301 | static long | |
302 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
303 | struct switch_stack *sw, unsigned long mask, unsigned long sp) | |
304 | { | |
305 | long i, err = 0; | |
306 | ||
307 | err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack); | |
308 | err |= __put_user(mask, &sc->sc_mask); | |
309 | err |= __put_user(regs->pc, &sc->sc_pc); | |
310 | err |= __put_user(8, &sc->sc_ps); | |
311 | ||
312 | err |= __put_user(regs->r0 , sc->sc_regs+0); | |
313 | err |= __put_user(regs->r1 , sc->sc_regs+1); | |
314 | err |= __put_user(regs->r2 , sc->sc_regs+2); | |
315 | err |= __put_user(regs->r3 , sc->sc_regs+3); | |
316 | err |= __put_user(regs->r4 , sc->sc_regs+4); | |
317 | err |= __put_user(regs->r5 , sc->sc_regs+5); | |
318 | err |= __put_user(regs->r6 , sc->sc_regs+6); | |
319 | err |= __put_user(regs->r7 , sc->sc_regs+7); | |
320 | err |= __put_user(regs->r8 , sc->sc_regs+8); | |
321 | err |= __put_user(sw->r9 , sc->sc_regs+9); | |
322 | err |= __put_user(sw->r10 , sc->sc_regs+10); | |
323 | err |= __put_user(sw->r11 , sc->sc_regs+11); | |
324 | err |= __put_user(sw->r12 , sc->sc_regs+12); | |
325 | err |= __put_user(sw->r13 , sc->sc_regs+13); | |
326 | err |= __put_user(sw->r14 , sc->sc_regs+14); | |
327 | err |= __put_user(sw->r15 , sc->sc_regs+15); | |
328 | err |= __put_user(regs->r16, sc->sc_regs+16); | |
329 | err |= __put_user(regs->r17, sc->sc_regs+17); | |
330 | err |= __put_user(regs->r18, sc->sc_regs+18); | |
331 | err |= __put_user(regs->r19, sc->sc_regs+19); | |
332 | err |= __put_user(regs->r20, sc->sc_regs+20); | |
333 | err |= __put_user(regs->r21, sc->sc_regs+21); | |
334 | err |= __put_user(regs->r22, sc->sc_regs+22); | |
335 | err |= __put_user(regs->r23, sc->sc_regs+23); | |
336 | err |= __put_user(regs->r24, sc->sc_regs+24); | |
337 | err |= __put_user(regs->r25, sc->sc_regs+25); | |
338 | err |= __put_user(regs->r26, sc->sc_regs+26); | |
339 | err |= __put_user(regs->r27, sc->sc_regs+27); | |
340 | err |= __put_user(regs->r28, sc->sc_regs+28); | |
341 | err |= __put_user(regs->gp , sc->sc_regs+29); | |
342 | err |= __put_user(sp, sc->sc_regs+30); | |
343 | err |= __put_user(0, sc->sc_regs+31); | |
344 | ||
345 | for (i = 0; i < 31; i++) | |
346 | err |= __put_user(sw->fp[i], sc->sc_fpregs+i); | |
347 | err |= __put_user(0, sc->sc_fpregs+31); | |
348 | err |= __put_user(sw->fp[31], &sc->sc_fpcr); | |
349 | ||
350 | err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0); | |
351 | err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1); | |
352 | err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2); | |
353 | ||
354 | return err; | |
355 | } | |
356 | ||
b927b3e2 | 357 | static int |
1da177e4 LT |
358 | setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, |
359 | struct pt_regs *regs, struct switch_stack * sw) | |
360 | { | |
361 | unsigned long oldsp, r26, err = 0; | |
362 | struct sigframe __user *frame; | |
363 | ||
364 | oldsp = rdusp(); | |
365 | frame = get_sigframe(ka, oldsp, sizeof(*frame)); | |
366 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
cbdfb9ff | 367 | return -EFAULT; |
1da177e4 LT |
368 | |
369 | err |= setup_sigcontext(&frame->sc, regs, sw, set->sig[0], oldsp); | |
370 | if (err) | |
cbdfb9ff | 371 | return -EFAULT; |
1da177e4 LT |
372 | |
373 | /* Set up to return from userspace. If provided, use a stub | |
374 | already in userspace. */ | |
375 | if (ka->ka_restorer) { | |
376 | r26 = (unsigned long) ka->ka_restorer; | |
377 | } else { | |
378 | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); | |
379 | err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1); | |
380 | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | |
381 | imb(); | |
382 | r26 = (unsigned long) frame->retcode; | |
383 | } | |
384 | ||
385 | /* Check that everything was written properly. */ | |
386 | if (err) | |
cbdfb9ff | 387 | return err; |
1da177e4 LT |
388 | |
389 | /* "Return" to the handler */ | |
390 | regs->r26 = r26; | |
391 | regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler; | |
392 | regs->r16 = sig; /* a0: signal number */ | |
393 | regs->r17 = 0; /* a1: exception code */ | |
394 | regs->r18 = (unsigned long) &frame->sc; /* a2: sigcontext pointer */ | |
395 | wrusp((unsigned long) frame); | |
396 | ||
397 | #if DEBUG_SIG | |
398 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
399 | current->comm, current->pid, frame, regs->pc, regs->r26); | |
400 | #endif | |
b927b3e2 | 401 | return 0; |
1da177e4 LT |
402 | } |
403 | ||
b927b3e2 | 404 | static int |
1da177e4 LT |
405 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
406 | sigset_t *set, struct pt_regs *regs, struct switch_stack * sw) | |
407 | { | |
408 | unsigned long oldsp, r26, err = 0; | |
409 | struct rt_sigframe __user *frame; | |
410 | ||
411 | oldsp = rdusp(); | |
412 | frame = get_sigframe(ka, oldsp, sizeof(*frame)); | |
413 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
cbdfb9ff | 414 | return -EFAULT; |
1da177e4 LT |
415 | |
416 | err |= copy_siginfo_to_user(&frame->info, info); | |
417 | ||
418 | /* Create the ucontext. */ | |
419 | err |= __put_user(0, &frame->uc.uc_flags); | |
420 | err |= __put_user(0, &frame->uc.uc_link); | |
421 | err |= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask); | |
422 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
423 | err |= __put_user(sas_ss_flags(oldsp), &frame->uc.uc_stack.ss_flags); | |
424 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
425 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, sw, | |
426 | set->sig[0], oldsp); | |
427 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
428 | if (err) | |
cbdfb9ff | 429 | return -EFAULT; |
1da177e4 LT |
430 | |
431 | /* Set up to return from userspace. If provided, use a stub | |
432 | already in userspace. */ | |
433 | if (ka->ka_restorer) { | |
434 | r26 = (unsigned long) ka->ka_restorer; | |
435 | } else { | |
436 | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); | |
437 | err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn, | |
438 | frame->retcode+1); | |
439 | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | |
440 | imb(); | |
441 | r26 = (unsigned long) frame->retcode; | |
442 | } | |
443 | ||
444 | if (err) | |
cbdfb9ff | 445 | return -EFAULT; |
1da177e4 LT |
446 | |
447 | /* "Return" to the handler */ | |
448 | regs->r26 = r26; | |
449 | regs->r27 = regs->pc = (unsigned long) ka->sa.sa_handler; | |
450 | regs->r16 = sig; /* a0: signal number */ | |
451 | regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */ | |
452 | regs->r18 = (unsigned long) &frame->uc; /* a2: ucontext pointer */ | |
453 | wrusp((unsigned long) frame); | |
454 | ||
455 | #if DEBUG_SIG | |
456 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
457 | current->comm, current->pid, frame, regs->pc, regs->r26); | |
458 | #endif | |
459 | ||
b927b3e2 | 460 | return 0; |
1da177e4 LT |
461 | } |
462 | ||
463 | ||
464 | /* | |
465 | * OK, we're invoking a handler. | |
466 | */ | |
cbdfb9ff | 467 | static inline void |
1da177e4 | 468 | handle_signal(int sig, struct k_sigaction *ka, siginfo_t *info, |
cbdfb9ff | 469 | struct pt_regs * regs, struct switch_stack *sw) |
1da177e4 | 470 | { |
cbdfb9ff | 471 | sigset_t *oldset = ¤t->blocked; |
b927b3e2 RH |
472 | int ret; |
473 | ||
cbdfb9ff AV |
474 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
475 | oldset = ¤t->saved_sigmask; | |
476 | ||
1da177e4 | 477 | if (ka->sa.sa_flags & SA_SIGINFO) |
b927b3e2 | 478 | ret = setup_rt_frame(sig, ka, info, oldset, regs, sw); |
1da177e4 | 479 | else |
b927b3e2 | 480 | ret = setup_frame(sig, ka, oldset, regs, sw); |
1da177e4 | 481 | |
cbdfb9ff AV |
482 | if (ret) { |
483 | force_sigsegv(sig, current); | |
484 | return; | |
485 | } | |
486 | block_sigmask(ka, sig); | |
487 | /* A signal was successfully delivered, and the | |
488 | saved sigmask was stored on the signal frame, | |
489 | and will be restored by sigreturn. So we can | |
490 | simply clear the restore sigmask flag. */ | |
491 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
1da177e4 LT |
492 | } |
493 | ||
494 | static inline void | |
495 | syscall_restart(unsigned long r0, unsigned long r19, | |
496 | struct pt_regs *regs, struct k_sigaction *ka) | |
497 | { | |
498 | switch (regs->r0) { | |
499 | case ERESTARTSYS: | |
500 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
501 | case ERESTARTNOHAND: | |
502 | regs->r0 = EINTR; | |
503 | break; | |
504 | } | |
505 | /* fallthrough */ | |
506 | case ERESTARTNOINTR: | |
507 | regs->r0 = r0; /* reset v0 and a3 and replay syscall */ | |
508 | regs->r19 = r19; | |
509 | regs->pc -= 4; | |
510 | break; | |
511 | case ERESTART_RESTARTBLOCK: | |
1da177e4 LT |
512 | regs->r0 = EINTR; |
513 | break; | |
514 | } | |
515 | } | |
516 | ||
517 | ||
518 | /* | |
519 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
520 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
521 | * mistake. | |
522 | * | |
523 | * Note that we go through the signals twice: once to check the signals that | |
524 | * the kernel can handle, and then we build all the user-level signal handling | |
525 | * stack-frames in one go after that. | |
526 | * | |
527 | * "r0" and "r19" are the registers we need to restore for system call | |
528 | * restart. "r0" is also used as an indicator whether we can restart at | |
529 | * all (if we get here from anything but a syscall return, it will be 0) | |
530 | */ | |
b927b3e2 RH |
531 | static void |
532 | do_signal(struct pt_regs * regs, struct switch_stack * sw, | |
1da177e4 LT |
533 | unsigned long r0, unsigned long r19) |
534 | { | |
535 | siginfo_t info; | |
536 | int signr; | |
537 | unsigned long single_stepping = ptrace_cancel_bpt(current); | |
538 | struct k_sigaction ka; | |
1da177e4 LT |
539 | |
540 | /* This lets the debugger run, ... */ | |
541 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
b927b3e2 | 542 | |
1da177e4 LT |
543 | /* ... so re-check the single stepping. */ |
544 | single_stepping |= ptrace_cancel_bpt(current); | |
545 | ||
546 | if (signr > 0) { | |
547 | /* Whee! Actually deliver the signal. */ | |
b927b3e2 RH |
548 | if (r0) |
549 | syscall_restart(r0, r19, regs, &ka); | |
cbdfb9ff | 550 | handle_signal(signr, &ka, &info, regs, sw); |
1da177e4 LT |
551 | if (single_stepping) |
552 | ptrace_set_bpt(current); /* re-set bpt */ | |
b927b3e2 | 553 | return; |
1da177e4 LT |
554 | } |
555 | ||
556 | if (r0) { | |
557 | switch (regs->r0) { | |
558 | case ERESTARTNOHAND: | |
559 | case ERESTARTSYS: | |
560 | case ERESTARTNOINTR: | |
561 | /* Reset v0 and a3 and replay syscall. */ | |
562 | regs->r0 = r0; | |
563 | regs->r19 = r19; | |
564 | regs->pc -= 4; | |
565 | break; | |
566 | case ERESTART_RESTARTBLOCK: | |
567 | /* Force v0 to the restart syscall and reply. */ | |
568 | regs->r0 = __NR_restart_syscall; | |
569 | regs->pc -= 4; | |
570 | break; | |
571 | } | |
572 | } | |
b927b3e2 RH |
573 | |
574 | /* If there's no signal to deliver, we just restore the saved mask. */ | |
51a7b448 | 575 | restore_saved_sigmask(); |
1da177e4 LT |
576 | if (single_stepping) |
577 | ptrace_set_bpt(current); /* re-set breakpoint */ | |
1da177e4 LT |
578 | } |
579 | ||
580 | void | |
b927b3e2 RH |
581 | do_notify_resume(struct pt_regs *regs, struct switch_stack *sw, |
582 | unsigned long thread_info_flags, | |
583 | unsigned long r0, unsigned long r19) | |
1da177e4 | 584 | { |
cbdfb9ff | 585 | if (thread_info_flags & _TIF_SIGPENDING) |
b927b3e2 | 586 | do_signal(regs, sw, r0, r19); |
d0420c83 DH |
587 | |
588 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { | |
589 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
590 | tracehook_notify_resume(regs); | |
591 | } | |
1da177e4 | 592 | } |