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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 | ||
3f07c014 | 9 | #include <linux/sched/signal.h> |
68db0cf1 | 10 | #include <linux/sched/task_stack.h> |
1da177e4 LT |
11 | #include <linux/kernel.h> |
12 | #include <linux/signal.h> | |
13 | #include <linux/errno.h> | |
14 | #include <linux/wait.h> | |
15 | #include <linux/ptrace.h> | |
16 | #include <linux/unistd.h> | |
17 | #include <linux/mm.h> | |
18 | #include <linux/smp.h> | |
1da177e4 LT |
19 | #include <linux/stddef.h> |
20 | #include <linux/tty.h> | |
21 | #include <linux/binfmts.h> | |
22 | #include <linux/bitops.h> | |
e5d9a90c | 23 | #include <linux/syscalls.h> |
733e5e4b | 24 | #include <linux/tracehook.h> |
1da177e4 | 25 | |
7c0f6ba6 | 26 | #include <linux/uaccess.h> |
1da177e4 LT |
27 | #include <asm/sigcontext.h> |
28 | #include <asm/ucontext.h> | |
29 | ||
30 | #include "proto.h" | |
31 | ||
32 | ||
33 | #define DEBUG_SIG 0 | |
34 | ||
35 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
36 | ||
37 | asmlinkage void ret_from_sys_call(void); | |
1da177e4 LT |
38 | |
39 | /* | |
40 | * The OSF/1 sigprocmask calling sequence is different from the | |
41 | * C sigprocmask() sequence.. | |
1da177e4 | 42 | */ |
c52c2ddc | 43 | SYSCALL_DEFINE2(osf_sigprocmask, int, how, unsigned long, newmask) |
1da177e4 | 44 | { |
c52c2ddc AV |
45 | sigset_t oldmask; |
46 | sigset_t mask; | |
47 | unsigned long res; | |
1da177e4 | 48 | |
87400e54 | 49 | siginitset(&mask, newmask & _BLOCKABLE); |
0f44fbd2 | 50 | res = sigprocmask(how, &mask, &oldmask); |
c52c2ddc AV |
51 | if (!res) { |
52 | force_successful_syscall_return(); | |
0f44fbd2 | 53 | res = oldmask.sig[0]; |
1da177e4 | 54 | } |
c52c2ddc | 55 | return res; |
1da177e4 LT |
56 | } |
57 | ||
e5d9a90c IK |
58 | SYSCALL_DEFINE3(osf_sigaction, int, sig, |
59 | const struct osf_sigaction __user *, act, | |
60 | struct osf_sigaction __user *, oact) | |
1da177e4 LT |
61 | { |
62 | struct k_sigaction new_ka, old_ka; | |
63 | int ret; | |
64 | ||
65 | if (act) { | |
66 | old_sigset_t mask; | |
67 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
68 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
18e6bfa9 AV |
69 | __get_user(new_ka.sa.sa_flags, &act->sa_flags) || |
70 | __get_user(mask, &act->sa_mask)) | |
1da177e4 | 71 | return -EFAULT; |
1da177e4 LT |
72 | siginitset(&new_ka.sa.sa_mask, mask); |
73 | new_ka.ka_restorer = NULL; | |
74 | } | |
75 | ||
76 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
77 | ||
78 | if (!ret && oact) { | |
79 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
80 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
18e6bfa9 AV |
81 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags) || |
82 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask)) | |
1da177e4 | 83 | return -EFAULT; |
1da177e4 LT |
84 | } |
85 | ||
86 | return ret; | |
87 | } | |
88 | ||
e5d9a90c IK |
89 | SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act, |
90 | struct sigaction __user *, oact, | |
91 | size_t, sigsetsize, void __user *, restorer) | |
1da177e4 LT |
92 | { |
93 | struct k_sigaction new_ka, old_ka; | |
94 | int ret; | |
95 | ||
96 | /* XXX: Don't preclude handling different sized sigset_t's. */ | |
97 | if (sigsetsize != sizeof(sigset_t)) | |
98 | return -EINVAL; | |
99 | ||
100 | if (act) { | |
101 | new_ka.ka_restorer = restorer; | |
102 | if (copy_from_user(&new_ka.sa, act, sizeof(*act))) | |
103 | return -EFAULT; | |
104 | } | |
105 | ||
106 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
107 | ||
108 | if (!ret && oact) { | |
109 | if (copy_to_user(oact, &old_ka.sa, sizeof(*oact))) | |
110 | return -EFAULT; | |
111 | } | |
112 | ||
113 | return ret; | |
114 | } | |
115 | ||
1da177e4 LT |
116 | /* |
117 | * Do a signal return; undo the signal stack. | |
118 | */ | |
119 | ||
120 | #if _NSIG_WORDS > 1 | |
121 | # error "Non SA_SIGINFO frame needs rearranging" | |
122 | #endif | |
123 | ||
124 | struct sigframe | |
125 | { | |
126 | struct sigcontext sc; | |
127 | unsigned int retcode[3]; | |
128 | }; | |
129 | ||
130 | struct rt_sigframe | |
131 | { | |
132 | struct siginfo info; | |
133 | struct ucontext uc; | |
134 | unsigned int retcode[3]; | |
135 | }; | |
136 | ||
137 | /* If this changes, userland unwinders that Know Things about our signal | |
138 | frame will break. Do not undertake lightly. It also implies an ABI | |
139 | change wrt the size of siginfo_t, which may cause some pain. */ | |
140 | extern char compile_time_assert | |
141 | [offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1]; | |
142 | ||
143 | #define INSN_MOV_R30_R16 0x47fe0410 | |
144 | #define INSN_LDI_R0 0x201f0000 | |
145 | #define INSN_CALLSYS 0x00000083 | |
146 | ||
147 | static long | |
b960f303 | 148 | restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs) |
1da177e4 LT |
149 | { |
150 | unsigned long usp; | |
b960f303 | 151 | struct switch_stack *sw = (struct switch_stack *)regs - 1; |
1da177e4 LT |
152 | long i, err = __get_user(regs->pc, &sc->sc_pc); |
153 | ||
f56141e3 | 154 | current->restart_block.fn = do_no_restart_syscall; |
2deba1bd | 155 | |
1da177e4 LT |
156 | sw->r26 = (unsigned long) ret_from_sys_call; |
157 | ||
158 | err |= __get_user(regs->r0, sc->sc_regs+0); | |
159 | err |= __get_user(regs->r1, sc->sc_regs+1); | |
160 | err |= __get_user(regs->r2, sc->sc_regs+2); | |
161 | err |= __get_user(regs->r3, sc->sc_regs+3); | |
162 | err |= __get_user(regs->r4, sc->sc_regs+4); | |
163 | err |= __get_user(regs->r5, sc->sc_regs+5); | |
164 | err |= __get_user(regs->r6, sc->sc_regs+6); | |
165 | err |= __get_user(regs->r7, sc->sc_regs+7); | |
166 | err |= __get_user(regs->r8, sc->sc_regs+8); | |
167 | err |= __get_user(sw->r9, sc->sc_regs+9); | |
168 | err |= __get_user(sw->r10, sc->sc_regs+10); | |
169 | err |= __get_user(sw->r11, sc->sc_regs+11); | |
170 | err |= __get_user(sw->r12, sc->sc_regs+12); | |
171 | err |= __get_user(sw->r13, sc->sc_regs+13); | |
172 | err |= __get_user(sw->r14, sc->sc_regs+14); | |
173 | err |= __get_user(sw->r15, sc->sc_regs+15); | |
174 | err |= __get_user(regs->r16, sc->sc_regs+16); | |
175 | err |= __get_user(regs->r17, sc->sc_regs+17); | |
176 | err |= __get_user(regs->r18, sc->sc_regs+18); | |
177 | err |= __get_user(regs->r19, sc->sc_regs+19); | |
178 | err |= __get_user(regs->r20, sc->sc_regs+20); | |
179 | err |= __get_user(regs->r21, sc->sc_regs+21); | |
180 | err |= __get_user(regs->r22, sc->sc_regs+22); | |
181 | err |= __get_user(regs->r23, sc->sc_regs+23); | |
182 | err |= __get_user(regs->r24, sc->sc_regs+24); | |
183 | err |= __get_user(regs->r25, sc->sc_regs+25); | |
184 | err |= __get_user(regs->r26, sc->sc_regs+26); | |
185 | err |= __get_user(regs->r27, sc->sc_regs+27); | |
186 | err |= __get_user(regs->r28, sc->sc_regs+28); | |
187 | err |= __get_user(regs->gp, sc->sc_regs+29); | |
188 | err |= __get_user(usp, sc->sc_regs+30); | |
189 | wrusp(usp); | |
190 | ||
191 | for (i = 0; i < 31; i++) | |
192 | err |= __get_user(sw->fp[i], sc->sc_fpregs+i); | |
193 | err |= __get_user(sw->fp[31], &sc->sc_fpcr); | |
194 | ||
195 | return err; | |
196 | } | |
197 | ||
198 | /* Note that this syscall is also used by setcontext(3) to install | |
199 | a given sigcontext. This because it's impossible to set *all* | |
200 | registers and transfer control from userland. */ | |
201 | ||
202 | asmlinkage void | |
b960f303 | 203 | do_sigreturn(struct sigcontext __user *sc) |
1da177e4 | 204 | { |
b960f303 | 205 | struct pt_regs *regs = current_pt_regs(); |
1da177e4 LT |
206 | sigset_t set; |
207 | ||
208 | /* Verify that it's a good sigcontext before using it */ | |
209 | if (!access_ok(VERIFY_READ, sc, sizeof(*sc))) | |
210 | goto give_sigsegv; | |
211 | if (__get_user(set.sig[0], &sc->sc_mask)) | |
212 | goto give_sigsegv; | |
213 | ||
2561b069 | 214 | set_current_blocked(&set); |
1da177e4 | 215 | |
b960f303 | 216 | if (restore_sigcontext(sc, regs)) |
1da177e4 LT |
217 | goto give_sigsegv; |
218 | ||
219 | /* Send SIGTRAP if we're single-stepping: */ | |
220 | if (ptrace_cancel_bpt (current)) { | |
221 | siginfo_t info; | |
222 | ||
223 | info.si_signo = SIGTRAP; | |
224 | info.si_errno = 0; | |
225 | info.si_code = TRAP_BRKPT; | |
226 | info.si_addr = (void __user *) regs->pc; | |
227 | info.si_trapno = 0; | |
228 | send_sig_info(SIGTRAP, &info, current); | |
229 | } | |
230 | return; | |
231 | ||
232 | give_sigsegv: | |
233 | force_sig(SIGSEGV, current); | |
234 | } | |
235 | ||
236 | asmlinkage void | |
b960f303 | 237 | do_rt_sigreturn(struct rt_sigframe __user *frame) |
1da177e4 | 238 | { |
b960f303 | 239 | struct pt_regs *regs = current_pt_regs(); |
1da177e4 LT |
240 | sigset_t set; |
241 | ||
242 | /* Verify that it's a good ucontext_t before using it */ | |
243 | if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc))) | |
244 | goto give_sigsegv; | |
245 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
246 | goto give_sigsegv; | |
247 | ||
2561b069 | 248 | set_current_blocked(&set); |
1da177e4 | 249 | |
b960f303 | 250 | if (restore_sigcontext(&frame->uc.uc_mcontext, regs)) |
1da177e4 LT |
251 | goto give_sigsegv; |
252 | ||
253 | /* Send SIGTRAP if we're single-stepping: */ | |
254 | if (ptrace_cancel_bpt (current)) { | |
255 | siginfo_t info; | |
256 | ||
257 | info.si_signo = SIGTRAP; | |
258 | info.si_errno = 0; | |
259 | info.si_code = TRAP_BRKPT; | |
260 | info.si_addr = (void __user *) regs->pc; | |
261 | info.si_trapno = 0; | |
262 | send_sig_info(SIGTRAP, &info, current); | |
263 | } | |
264 | return; | |
265 | ||
266 | give_sigsegv: | |
267 | force_sig(SIGSEGV, current); | |
268 | } | |
269 | ||
270 | ||
271 | /* | |
272 | * Set up a signal frame. | |
273 | */ | |
274 | ||
275 | static inline void __user * | |
cfd60c07 | 276 | get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size) |
1da177e4 | 277 | { |
cfd60c07 | 278 | return (void __user *)((sigsp(sp, ksig) - frame_size) & -32ul); |
1da177e4 LT |
279 | } |
280 | ||
281 | static long | |
282 | setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, | |
d9d0738a | 283 | unsigned long mask, unsigned long sp) |
1da177e4 | 284 | { |
d9d0738a | 285 | struct switch_stack *sw = (struct switch_stack *)regs - 1; |
1da177e4 LT |
286 | long i, err = 0; |
287 | ||
288 | err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack); | |
289 | err |= __put_user(mask, &sc->sc_mask); | |
290 | err |= __put_user(regs->pc, &sc->sc_pc); | |
291 | err |= __put_user(8, &sc->sc_ps); | |
292 | ||
293 | err |= __put_user(regs->r0 , sc->sc_regs+0); | |
294 | err |= __put_user(regs->r1 , sc->sc_regs+1); | |
295 | err |= __put_user(regs->r2 , sc->sc_regs+2); | |
296 | err |= __put_user(regs->r3 , sc->sc_regs+3); | |
297 | err |= __put_user(regs->r4 , sc->sc_regs+4); | |
298 | err |= __put_user(regs->r5 , sc->sc_regs+5); | |
299 | err |= __put_user(regs->r6 , sc->sc_regs+6); | |
300 | err |= __put_user(regs->r7 , sc->sc_regs+7); | |
301 | err |= __put_user(regs->r8 , sc->sc_regs+8); | |
302 | err |= __put_user(sw->r9 , sc->sc_regs+9); | |
303 | err |= __put_user(sw->r10 , sc->sc_regs+10); | |
304 | err |= __put_user(sw->r11 , sc->sc_regs+11); | |
305 | err |= __put_user(sw->r12 , sc->sc_regs+12); | |
306 | err |= __put_user(sw->r13 , sc->sc_regs+13); | |
307 | err |= __put_user(sw->r14 , sc->sc_regs+14); | |
308 | err |= __put_user(sw->r15 , sc->sc_regs+15); | |
309 | err |= __put_user(regs->r16, sc->sc_regs+16); | |
310 | err |= __put_user(regs->r17, sc->sc_regs+17); | |
311 | err |= __put_user(regs->r18, sc->sc_regs+18); | |
312 | err |= __put_user(regs->r19, sc->sc_regs+19); | |
313 | err |= __put_user(regs->r20, sc->sc_regs+20); | |
314 | err |= __put_user(regs->r21, sc->sc_regs+21); | |
315 | err |= __put_user(regs->r22, sc->sc_regs+22); | |
316 | err |= __put_user(regs->r23, sc->sc_regs+23); | |
317 | err |= __put_user(regs->r24, sc->sc_regs+24); | |
318 | err |= __put_user(regs->r25, sc->sc_regs+25); | |
319 | err |= __put_user(regs->r26, sc->sc_regs+26); | |
320 | err |= __put_user(regs->r27, sc->sc_regs+27); | |
321 | err |= __put_user(regs->r28, sc->sc_regs+28); | |
322 | err |= __put_user(regs->gp , sc->sc_regs+29); | |
323 | err |= __put_user(sp, sc->sc_regs+30); | |
324 | err |= __put_user(0, sc->sc_regs+31); | |
325 | ||
326 | for (i = 0; i < 31; i++) | |
327 | err |= __put_user(sw->fp[i], sc->sc_fpregs+i); | |
328 | err |= __put_user(0, sc->sc_fpregs+31); | |
329 | err |= __put_user(sw->fp[31], &sc->sc_fpcr); | |
330 | ||
331 | err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0); | |
332 | err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1); | |
333 | err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2); | |
334 | ||
335 | return err; | |
336 | } | |
337 | ||
b927b3e2 | 338 | static int |
cfd60c07 | 339 | setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1da177e4 LT |
340 | { |
341 | unsigned long oldsp, r26, err = 0; | |
342 | struct sigframe __user *frame; | |
343 | ||
344 | oldsp = rdusp(); | |
cfd60c07 | 345 | frame = get_sigframe(ksig, oldsp, sizeof(*frame)); |
1da177e4 | 346 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
cbdfb9ff | 347 | return -EFAULT; |
1da177e4 | 348 | |
d9d0738a | 349 | err |= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp); |
1da177e4 | 350 | if (err) |
cbdfb9ff | 351 | return -EFAULT; |
1da177e4 LT |
352 | |
353 | /* Set up to return from userspace. If provided, use a stub | |
354 | already in userspace. */ | |
cfd60c07 AV |
355 | r26 = (unsigned long) ksig->ka.ka_restorer; |
356 | if (!r26) { | |
1da177e4 LT |
357 | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); |
358 | err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1); | |
359 | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | |
360 | imb(); | |
361 | r26 = (unsigned long) frame->retcode; | |
362 | } | |
363 | ||
364 | /* Check that everything was written properly. */ | |
365 | if (err) | |
cbdfb9ff | 366 | return err; |
1da177e4 LT |
367 | |
368 | /* "Return" to the handler */ | |
369 | regs->r26 = r26; | |
cfd60c07 AV |
370 | regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
371 | regs->r16 = ksig->sig; /* a0: signal number */ | |
1da177e4 LT |
372 | regs->r17 = 0; /* a1: exception code */ |
373 | regs->r18 = (unsigned long) &frame->sc; /* a2: sigcontext pointer */ | |
374 | wrusp((unsigned long) frame); | |
375 | ||
376 | #if DEBUG_SIG | |
377 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
378 | current->comm, current->pid, frame, regs->pc, regs->r26); | |
379 | #endif | |
b927b3e2 | 380 | return 0; |
1da177e4 LT |
381 | } |
382 | ||
b927b3e2 | 383 | static int |
cfd60c07 | 384 | setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs) |
1da177e4 LT |
385 | { |
386 | unsigned long oldsp, r26, err = 0; | |
387 | struct rt_sigframe __user *frame; | |
388 | ||
389 | oldsp = rdusp(); | |
cfd60c07 | 390 | frame = get_sigframe(ksig, oldsp, sizeof(*frame)); |
1da177e4 | 391 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) |
cbdfb9ff | 392 | return -EFAULT; |
1da177e4 | 393 | |
cfd60c07 | 394 | err |= copy_siginfo_to_user(&frame->info, &ksig->info); |
1da177e4 LT |
395 | |
396 | /* Create the ucontext. */ | |
397 | err |= __put_user(0, &frame->uc.uc_flags); | |
398 | err |= __put_user(0, &frame->uc.uc_link); | |
399 | err |= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask); | |
50ececcf | 400 | err |= __save_altstack(&frame->uc.uc_stack, oldsp); |
d9d0738a | 401 | err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, |
1da177e4 LT |
402 | set->sig[0], oldsp); |
403 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
404 | if (err) | |
cbdfb9ff | 405 | return -EFAULT; |
1da177e4 LT |
406 | |
407 | /* Set up to return from userspace. If provided, use a stub | |
408 | already in userspace. */ | |
cfd60c07 AV |
409 | r26 = (unsigned long) ksig->ka.ka_restorer; |
410 | if (!r26) { | |
1da177e4 LT |
411 | err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0); |
412 | err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn, | |
413 | frame->retcode+1); | |
414 | err |= __put_user(INSN_CALLSYS, frame->retcode+2); | |
415 | imb(); | |
416 | r26 = (unsigned long) frame->retcode; | |
417 | } | |
418 | ||
419 | if (err) | |
cbdfb9ff | 420 | return -EFAULT; |
1da177e4 LT |
421 | |
422 | /* "Return" to the handler */ | |
423 | regs->r26 = r26; | |
cfd60c07 AV |
424 | regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler; |
425 | regs->r16 = ksig->sig; /* a0: signal number */ | |
1da177e4 LT |
426 | regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */ |
427 | regs->r18 = (unsigned long) &frame->uc; /* a2: ucontext pointer */ | |
428 | wrusp((unsigned long) frame); | |
429 | ||
430 | #if DEBUG_SIG | |
431 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
432 | current->comm, current->pid, frame, regs->pc, regs->r26); | |
433 | #endif | |
434 | ||
b927b3e2 | 435 | return 0; |
1da177e4 LT |
436 | } |
437 | ||
438 | ||
439 | /* | |
440 | * OK, we're invoking a handler. | |
441 | */ | |
cbdfb9ff | 442 | static inline void |
cfd60c07 | 443 | handle_signal(struct ksignal *ksig, struct pt_regs *regs) |
1da177e4 | 444 | { |
b7f9a11a | 445 | sigset_t *oldset = sigmask_to_save(); |
b927b3e2 RH |
446 | int ret; |
447 | ||
cfd60c07 AV |
448 | if (ksig->ka.sa.sa_flags & SA_SIGINFO) |
449 | ret = setup_rt_frame(ksig, oldset, regs); | |
1da177e4 | 450 | else |
cfd60c07 | 451 | ret = setup_frame(ksig, oldset, regs); |
1da177e4 | 452 | |
cfd60c07 | 453 | signal_setup_done(ret, ksig, 0); |
1da177e4 LT |
454 | } |
455 | ||
456 | static inline void | |
457 | syscall_restart(unsigned long r0, unsigned long r19, | |
458 | struct pt_regs *regs, struct k_sigaction *ka) | |
459 | { | |
460 | switch (regs->r0) { | |
461 | case ERESTARTSYS: | |
462 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
463 | case ERESTARTNOHAND: | |
464 | regs->r0 = EINTR; | |
465 | break; | |
466 | } | |
467 | /* fallthrough */ | |
468 | case ERESTARTNOINTR: | |
469 | regs->r0 = r0; /* reset v0 and a3 and replay syscall */ | |
470 | regs->r19 = r19; | |
471 | regs->pc -= 4; | |
472 | break; | |
473 | case ERESTART_RESTARTBLOCK: | |
1da177e4 LT |
474 | regs->r0 = EINTR; |
475 | break; | |
476 | } | |
477 | } | |
478 | ||
479 | ||
480 | /* | |
481 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
482 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
483 | * mistake. | |
484 | * | |
485 | * Note that we go through the signals twice: once to check the signals that | |
486 | * the kernel can handle, and then we build all the user-level signal handling | |
487 | * stack-frames in one go after that. | |
488 | * | |
489 | * "r0" and "r19" are the registers we need to restore for system call | |
490 | * restart. "r0" is also used as an indicator whether we can restart at | |
491 | * all (if we get here from anything but a syscall return, it will be 0) | |
492 | */ | |
b927b3e2 | 493 | static void |
d9d0738a | 494 | do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19) |
1da177e4 | 495 | { |
1da177e4 | 496 | unsigned long single_stepping = ptrace_cancel_bpt(current); |
cfd60c07 | 497 | struct ksignal ksig; |
1da177e4 LT |
498 | |
499 | /* This lets the debugger run, ... */ | |
cfd60c07 AV |
500 | if (get_signal(&ksig)) { |
501 | /* ... so re-check the single stepping. */ | |
502 | single_stepping |= ptrace_cancel_bpt(current); | |
1da177e4 | 503 | /* Whee! Actually deliver the signal. */ |
b927b3e2 | 504 | if (r0) |
cfd60c07 AV |
505 | syscall_restart(r0, r19, regs, &ksig.ka); |
506 | handle_signal(&ksig, regs); | |
507 | } else { | |
508 | single_stepping |= ptrace_cancel_bpt(current); | |
509 | if (r0) { | |
510 | switch (regs->r0) { | |
511 | case ERESTARTNOHAND: | |
512 | case ERESTARTSYS: | |
513 | case ERESTARTNOINTR: | |
514 | /* Reset v0 and a3 and replay syscall. */ | |
515 | regs->r0 = r0; | |
516 | regs->r19 = r19; | |
517 | regs->pc -= 4; | |
518 | break; | |
519 | case ERESTART_RESTARTBLOCK: | |
520 | /* Set v0 to the restart_syscall and replay */ | |
521 | regs->r0 = __NR_restart_syscall; | |
522 | regs->pc -= 4; | |
523 | break; | |
524 | } | |
1da177e4 | 525 | } |
cfd60c07 | 526 | restore_saved_sigmask(); |
1da177e4 LT |
527 | } |
528 | if (single_stepping) | |
529 | ptrace_set_bpt(current); /* re-set breakpoint */ | |
1da177e4 LT |
530 | } |
531 | ||
532 | void | |
cb450766 | 533 | do_work_pending(struct pt_regs *regs, unsigned long thread_flags, |
b927b3e2 | 534 | unsigned long r0, unsigned long r19) |
1da177e4 | 535 | { |
6972d6f2 AV |
536 | do { |
537 | if (thread_flags & _TIF_NEED_RESCHED) { | |
538 | schedule(); | |
539 | } else { | |
540 | local_irq_enable(); | |
541 | if (thread_flags & _TIF_SIGPENDING) { | |
d9d0738a | 542 | do_signal(regs, r0, r19); |
6972d6f2 AV |
543 | r0 = 0; |
544 | } else { | |
545 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
546 | tracehook_notify_resume(regs); | |
547 | } | |
548 | } | |
549 | local_irq_disable(); | |
550 | thread_flags = current_thread_info()->flags; | |
551 | } while (thread_flags & _TIF_WORK_MASK); | |
1da177e4 | 552 | } |