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Commit | Line | Data |
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1da177e4 | 1 | /* |
1da177e4 LT |
2 | * Copyright (C) 1991, 1992 Linus Torvalds |
3 | * | |
4 | * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson | |
5 | * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes | |
6 | */ | |
7 | ||
8 | #include <linux/sched.h> | |
9 | #include <linux/mm.h> | |
10 | #include <linux/smp.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/unistd.h> | |
16 | #include <linux/stddef.h> | |
17 | #include <linux/personality.h> | |
18 | #include <linux/suspend.h> | |
19 | #include <linux/ptrace.h> | |
20 | #include <linux/elf.h> | |
9fbbd4dd | 21 | #include <linux/binfmts.h> |
1da177e4 LT |
22 | #include <asm/processor.h> |
23 | #include <asm/ucontext.h> | |
24 | #include <asm/uaccess.h> | |
25 | #include <asm/i387.h> | |
6c3652ef | 26 | #include <asm/vdso.h> |
56cc623c | 27 | #include "sigframe_32.h" |
1da177e4 LT |
28 | |
29 | #define DEBUG_SIG 0 | |
30 | ||
31 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) | |
32 | ||
33 | /* | |
34 | * Atomically swap in the new signal mask, and wait for a signal. | |
35 | */ | |
36 | asmlinkage int | |
37 | sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
38 | { | |
1da177e4 LT |
39 | mask &= _BLOCKABLE; |
40 | spin_lock_irq(¤t->sighand->siglock); | |
283828f3 | 41 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
42 | siginitset(¤t->blocked, mask); |
43 | recalc_sigpending(); | |
44 | spin_unlock_irq(¤t->sighand->siglock); | |
45 | ||
283828f3 DH |
46 | current->state = TASK_INTERRUPTIBLE; |
47 | schedule(); | |
48 | set_thread_flag(TIF_RESTORE_SIGMASK); | |
49 | return -ERESTARTNOHAND; | |
1da177e4 LT |
50 | } |
51 | ||
52 | asmlinkage int | |
53 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
54 | struct old_sigaction __user *oact) | |
55 | { | |
56 | struct k_sigaction new_ka, old_ka; | |
57 | int ret; | |
58 | ||
59 | if (act) { | |
60 | old_sigset_t mask; | |
61 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
62 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
63 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
64 | return -EFAULT; | |
65 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
66 | __get_user(mask, &act->sa_mask); | |
67 | siginitset(&new_ka.sa.sa_mask, mask); | |
68 | } | |
69 | ||
70 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
71 | ||
72 | if (!ret && oact) { | |
73 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
74 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
75 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
76 | return -EFAULT; | |
77 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
78 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
79 | } | |
80 | ||
81 | return ret; | |
82 | } | |
83 | ||
84 | asmlinkage int | |
65ea5b03 | 85 | sys_sigaltstack(unsigned long bx) |
1da177e4 LT |
86 | { |
87 | /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */ | |
65ea5b03 PA |
88 | struct pt_regs *regs = (struct pt_regs *)&bx; |
89 | const stack_t __user *uss = (const stack_t __user *)bx; | |
90 | stack_t __user *uoss = (stack_t __user *)regs->cx; | |
1da177e4 | 91 | |
65ea5b03 | 92 | return do_sigaltstack(uss, uoss, regs->sp); |
1da177e4 LT |
93 | } |
94 | ||
95 | ||
96 | /* | |
97 | * Do a signal return; undo the signal stack. | |
98 | */ | |
99 | ||
100 | static int | |
101 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, int *peax) | |
102 | { | |
103 | unsigned int err = 0; | |
104 | ||
105 | /* Always make any pending restarted system calls return -EINTR */ | |
106 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
107 | ||
742fa54a | 108 | #define COPY(x) err |= __get_user(regs->x, &sc->x) |
1da177e4 LT |
109 | |
110 | #define COPY_SEG(seg) \ | |
111 | { unsigned short tmp; \ | |
112 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 113 | regs->seg = tmp; } |
1da177e4 LT |
114 | |
115 | #define COPY_SEG_STRICT(seg) \ | |
116 | { unsigned short tmp; \ | |
117 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 118 | regs->seg = tmp|3; } |
1da177e4 LT |
119 | |
120 | #define GET_SEG(seg) \ | |
121 | { unsigned short tmp; \ | |
122 | err |= __get_user(tmp, &sc->seg); \ | |
123 | loadsegment(seg,tmp); } | |
124 | ||
8bed51cd CE |
125 | #define FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_RF | \ |
126 | X86_EFLAGS_OF | X86_EFLAGS_DF | \ | |
1da177e4 LT |
127 | X86_EFLAGS_TF | X86_EFLAGS_SF | X86_EFLAGS_ZF | \ |
128 | X86_EFLAGS_AF | X86_EFLAGS_PF | X86_EFLAGS_CF) | |
129 | ||
464d1a78 JF |
130 | GET_SEG(gs); |
131 | COPY_SEG(fs); | |
1da177e4 LT |
132 | COPY_SEG(es); |
133 | COPY_SEG(ds); | |
ac66f3fd HH |
134 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
135 | COPY(dx); COPY(cx); COPY(ip); | |
1da177e4 LT |
136 | COPY_SEG_STRICT(cs); |
137 | COPY_SEG_STRICT(ss); | |
138 | ||
139 | { | |
140 | unsigned int tmpflags; | |
742fa54a | 141 | err |= __get_user(tmpflags, &sc->flags); |
65ea5b03 PA |
142 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); |
143 | regs->orig_ax = -1; /* disable syscall checks */ | |
1da177e4 LT |
144 | } |
145 | ||
146 | { | |
147 | struct _fpstate __user * buf; | |
148 | err |= __get_user(buf, &sc->fpstate); | |
149 | if (buf) { | |
150 | if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) | |
151 | goto badframe; | |
152 | err |= restore_i387(buf); | |
153 | } else { | |
154 | struct task_struct *me = current; | |
155 | if (used_math()) { | |
156 | clear_fpu(me); | |
157 | clear_used_math(); | |
158 | } | |
159 | } | |
160 | } | |
161 | ||
742fa54a | 162 | err |= __get_user(*peax, &sc->ax); |
1da177e4 LT |
163 | return err; |
164 | ||
165 | badframe: | |
166 | return 1; | |
167 | } | |
168 | ||
169 | asmlinkage int sys_sigreturn(unsigned long __unused) | |
170 | { | |
171 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
65ea5b03 | 172 | struct sigframe __user *frame = (struct sigframe __user *)(regs->sp - 8); |
1da177e4 | 173 | sigset_t set; |
65ea5b03 | 174 | int ax; |
1da177e4 LT |
175 | |
176 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
177 | goto badframe; | |
178 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
179 | || (_NSIG_WORDS > 1 | |
180 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
181 | sizeof(frame->extramask)))) | |
182 | goto badframe; | |
183 | ||
184 | sigdelsetmask(&set, ~_BLOCKABLE); | |
185 | spin_lock_irq(¤t->sighand->siglock); | |
186 | current->blocked = set; | |
187 | recalc_sigpending(); | |
188 | spin_unlock_irq(¤t->sighand->siglock); | |
189 | ||
65ea5b03 | 190 | if (restore_sigcontext(regs, &frame->sc, &ax)) |
1da177e4 | 191 | goto badframe; |
65ea5b03 | 192 | return ax; |
1da177e4 LT |
193 | |
194 | badframe: | |
03252919 | 195 | if (show_unhandled_signals && printk_ratelimit()) { |
65ea5b03 | 196 | printk("%s%s[%d] bad frame in sigreturn frame:%p ip:%lx" |
03252919 | 197 | " sp:%lx oeax:%lx", |
19c5870c | 198 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
65ea5b03 PA |
199 | current->comm, task_pid_nr(current), frame, regs->ip, |
200 | regs->sp, regs->orig_ax); | |
03252919 AK |
201 | print_vma_addr(" in ", regs->ip); |
202 | printk("\n"); | |
203 | } | |
abd4f750 | 204 | |
1da177e4 LT |
205 | force_sig(SIGSEGV, current); |
206 | return 0; | |
207 | } | |
208 | ||
209 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
210 | { | |
211 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
65ea5b03 | 212 | struct rt_sigframe __user *frame = (struct rt_sigframe __user *)(regs->sp - 4); |
1da177e4 | 213 | sigset_t set; |
65ea5b03 | 214 | int ax; |
1da177e4 LT |
215 | |
216 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
217 | goto badframe; | |
218 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
219 | goto badframe; | |
220 | ||
221 | sigdelsetmask(&set, ~_BLOCKABLE); | |
222 | spin_lock_irq(¤t->sighand->siglock); | |
223 | current->blocked = set; | |
224 | recalc_sigpending(); | |
225 | spin_unlock_irq(¤t->sighand->siglock); | |
226 | ||
65ea5b03 | 227 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
1da177e4 LT |
228 | goto badframe; |
229 | ||
65ea5b03 | 230 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
1da177e4 LT |
231 | goto badframe; |
232 | ||
65ea5b03 | 233 | return ax; |
1da177e4 LT |
234 | |
235 | badframe: | |
236 | force_sig(SIGSEGV, current); | |
237 | return 0; | |
238 | } | |
239 | ||
240 | /* | |
241 | * Set up a signal frame. | |
242 | */ | |
243 | ||
244 | static int | |
245 | setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, | |
246 | struct pt_regs *regs, unsigned long mask) | |
247 | { | |
248 | int tmp, err = 0; | |
249 | ||
65ea5b03 | 250 | err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
464d1a78 JF |
251 | savesegment(gs, tmp); |
252 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 | 253 | |
65ea5b03 PA |
254 | err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
255 | err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); | |
742fa54a PA |
256 | err |= __put_user(regs->di, &sc->di); |
257 | err |= __put_user(regs->si, &sc->si); | |
258 | err |= __put_user(regs->bp, &sc->bp); | |
259 | err |= __put_user(regs->sp, &sc->sp); | |
260 | err |= __put_user(regs->bx, &sc->bx); | |
261 | err |= __put_user(regs->dx, &sc->dx); | |
262 | err |= __put_user(regs->cx, &sc->cx); | |
263 | err |= __put_user(regs->ax, &sc->ax); | |
1da177e4 LT |
264 | err |= __put_user(current->thread.trap_no, &sc->trapno); |
265 | err |= __put_user(current->thread.error_code, &sc->err); | |
742fa54a | 266 | err |= __put_user(regs->ip, &sc->ip); |
65ea5b03 | 267 | err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
742fa54a PA |
268 | err |= __put_user(regs->flags, &sc->flags); |
269 | err |= __put_user(regs->sp, &sc->sp_at_signal); | |
65ea5b03 | 270 | err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
1da177e4 LT |
271 | |
272 | tmp = save_i387(fpstate); | |
273 | if (tmp < 0) | |
274 | err = 1; | |
275 | else | |
276 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); | |
277 | ||
278 | /* non-iBCS2 extensions.. */ | |
279 | err |= __put_user(mask, &sc->oldmask); | |
280 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
281 | ||
282 | return err; | |
283 | } | |
284 | ||
285 | /* | |
286 | * Determine which stack to use.. | |
287 | */ | |
288 | static inline void __user * | |
289 | get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) | |
290 | { | |
65ea5b03 | 291 | unsigned long sp; |
1da177e4 LT |
292 | |
293 | /* Default to using normal stack */ | |
65ea5b03 | 294 | sp = regs->sp; |
1da177e4 | 295 | |
83bd0102 RM |
296 | /* |
297 | * If we are on the alternate signal stack and would overflow it, don't. | |
298 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
299 | */ | |
65ea5b03 | 300 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
83bd0102 RM |
301 | return (void __user *) -1L; |
302 | ||
1da177e4 LT |
303 | /* This is the X/Open sanctioned signal stack switching. */ |
304 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
65ea5b03 PA |
305 | if (sas_ss_flags(sp) == 0) |
306 | sp = current->sas_ss_sp + current->sas_ss_size; | |
1da177e4 LT |
307 | } |
308 | ||
309 | /* This is the legacy signal stack switching. */ | |
65ea5b03 | 310 | else if ((regs->ss & 0xffff) != __USER_DS && |
1da177e4 LT |
311 | !(ka->sa.sa_flags & SA_RESTORER) && |
312 | ka->sa.sa_restorer) { | |
65ea5b03 | 313 | sp = (unsigned long) ka->sa.sa_restorer; |
1da177e4 LT |
314 | } |
315 | ||
65ea5b03 | 316 | sp -= frame_size; |
d347f372 MO |
317 | /* Align the stack pointer according to the i386 ABI, |
318 | * i.e. so that on function entry ((sp + 4) & 15) == 0. */ | |
65ea5b03 PA |
319 | sp = ((sp + 4) & -16ul) - 4; |
320 | return (void __user *) sp; | |
1da177e4 LT |
321 | } |
322 | ||
323 | /* These symbols are defined with the addresses in the vsyscall page. | |
324 | See vsyscall-sigreturn.S. */ | |
325 | extern void __user __kernel_sigreturn; | |
326 | extern void __user __kernel_rt_sigreturn; | |
327 | ||
7c1def16 RM |
328 | static int setup_frame(int sig, struct k_sigaction *ka, |
329 | sigset_t *set, struct pt_regs * regs) | |
1da177e4 LT |
330 | { |
331 | void __user *restorer; | |
332 | struct sigframe __user *frame; | |
333 | int err = 0; | |
334 | int usig; | |
335 | ||
336 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
337 | ||
338 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
339 | goto give_sigsegv; | |
340 | ||
341 | usig = current_thread_info()->exec_domain | |
342 | && current_thread_info()->exec_domain->signal_invmap | |
343 | && sig < 32 | |
344 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
345 | : sig; | |
346 | ||
347 | err = __put_user(usig, &frame->sig); | |
348 | if (err) | |
349 | goto give_sigsegv; | |
350 | ||
351 | err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); | |
352 | if (err) | |
353 | goto give_sigsegv; | |
354 | ||
355 | if (_NSIG_WORDS > 1) { | |
356 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
357 | sizeof(frame->extramask)); | |
358 | if (err) | |
359 | goto give_sigsegv; | |
360 | } | |
361 | ||
1a3e4ca4 | 362 | if (current->mm->context.vdso) |
6c3652ef | 363 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
9fbbd4dd | 364 | else |
ade1af77 | 365 | restorer = &frame->retcode; |
1da177e4 LT |
366 | if (ka->sa.sa_flags & SA_RESTORER) |
367 | restorer = ka->sa.sa_restorer; | |
368 | ||
369 | /* Set up to return from userspace. */ | |
370 | err |= __put_user(restorer, &frame->pretcode); | |
371 | ||
372 | /* | |
373 | * This is popl %eax ; movl $,%eax ; int $0x80 | |
374 | * | |
375 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
376 | * reasons and because gdb uses it as a signature to notice | |
377 | * signal handler stack frames. | |
378 | */ | |
379 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
380 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
381 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
382 | ||
383 | if (err) | |
384 | goto give_sigsegv; | |
385 | ||
386 | /* Set up registers for signal handler */ | |
65ea5b03 PA |
387 | regs->sp = (unsigned long) frame; |
388 | regs->ip = (unsigned long) ka->sa.sa_handler; | |
389 | regs->ax = (unsigned long) sig; | |
92bc2056 HH |
390 | regs->dx = 0; |
391 | regs->cx = 0; | |
1da177e4 | 392 | |
65ea5b03 PA |
393 | regs->ds = __USER_DS; |
394 | regs->es = __USER_DS; | |
395 | regs->ss = __USER_DS; | |
396 | regs->cs = __USER_CS; | |
1da177e4 LT |
397 | |
398 | /* | |
399 | * Clear TF when entering the signal handler, but | |
400 | * notify any tracer that was single-stepping it. | |
401 | * The tracer may want to single-step inside the | |
402 | * handler too. | |
403 | */ | |
e40cd10c | 404 | regs->flags &= ~(TF_MASK | X86_EFLAGS_DF); |
1da177e4 LT |
405 | if (test_thread_flag(TIF_SINGLESTEP)) |
406 | ptrace_notify(SIGTRAP); | |
407 | ||
408 | #if DEBUG_SIG | |
ac66f3fd | 409 | printk("SIG deliver (%s:%d): sp=%p pc=%lx ra=%p\n", |
65ea5b03 | 410 | current->comm, current->pid, frame, regs->ip, frame->pretcode); |
1da177e4 LT |
411 | #endif |
412 | ||
283828f3 | 413 | return 0; |
1da177e4 LT |
414 | |
415 | give_sigsegv: | |
416 | force_sigsegv(sig, current); | |
283828f3 | 417 | return -EFAULT; |
1da177e4 LT |
418 | } |
419 | ||
7c1def16 | 420 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
1da177e4 LT |
421 | sigset_t *set, struct pt_regs * regs) |
422 | { | |
423 | void __user *restorer; | |
424 | struct rt_sigframe __user *frame; | |
425 | int err = 0; | |
426 | int usig; | |
427 | ||
428 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
429 | ||
430 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
431 | goto give_sigsegv; | |
432 | ||
433 | usig = current_thread_info()->exec_domain | |
434 | && current_thread_info()->exec_domain->signal_invmap | |
435 | && sig < 32 | |
436 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
437 | : sig; | |
438 | ||
439 | err |= __put_user(usig, &frame->sig); | |
440 | err |= __put_user(&frame->info, &frame->pinfo); | |
441 | err |= __put_user(&frame->uc, &frame->puc); | |
442 | err |= copy_siginfo_to_user(&frame->info, info); | |
443 | if (err) | |
444 | goto give_sigsegv; | |
445 | ||
446 | /* Create the ucontext. */ | |
447 | err |= __put_user(0, &frame->uc.uc_flags); | |
448 | err |= __put_user(0, &frame->uc.uc_link); | |
449 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
65ea5b03 | 450 | err |= __put_user(sas_ss_flags(regs->sp), |
1da177e4 LT |
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, &frame->fpstate, | |
454 | regs, set->sig[0]); | |
455 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); | |
456 | if (err) | |
457 | goto give_sigsegv; | |
458 | ||
459 | /* Set up to return from userspace. */ | |
6c3652ef | 460 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); |
1da177e4 LT |
461 | if (ka->sa.sa_flags & SA_RESTORER) |
462 | restorer = ka->sa.sa_restorer; | |
463 | err |= __put_user(restorer, &frame->pretcode); | |
464 | ||
465 | /* | |
65ea5b03 | 466 | * This is movl $,%ax ; int $0x80 |
1da177e4 LT |
467 | * |
468 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
469 | * reasons and because gdb uses it as a signature to notice | |
470 | * signal handler stack frames. | |
471 | */ | |
472 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); | |
473 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); | |
474 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); | |
475 | ||
476 | if (err) | |
477 | goto give_sigsegv; | |
478 | ||
479 | /* Set up registers for signal handler */ | |
65ea5b03 PA |
480 | regs->sp = (unsigned long) frame; |
481 | regs->ip = (unsigned long) ka->sa.sa_handler; | |
482 | regs->ax = (unsigned long) usig; | |
483 | regs->dx = (unsigned long) &frame->info; | |
484 | regs->cx = (unsigned long) &frame->uc; | |
1da177e4 | 485 | |
65ea5b03 PA |
486 | regs->ds = __USER_DS; |
487 | regs->es = __USER_DS; | |
488 | regs->ss = __USER_DS; | |
489 | regs->cs = __USER_CS; | |
1da177e4 LT |
490 | |
491 | /* | |
492 | * Clear TF when entering the signal handler, but | |
493 | * notify any tracer that was single-stepping it. | |
494 | * The tracer may want to single-step inside the | |
495 | * handler too. | |
496 | */ | |
e40cd10c | 497 | regs->flags &= ~(TF_MASK | X86_EFLAGS_DF); |
1da177e4 LT |
498 | if (test_thread_flag(TIF_SINGLESTEP)) |
499 | ptrace_notify(SIGTRAP); | |
500 | ||
501 | #if DEBUG_SIG | |
502 | printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n", | |
65ea5b03 | 503 | current->comm, current->pid, frame, regs->ip, frame->pretcode); |
1da177e4 LT |
504 | #endif |
505 | ||
283828f3 | 506 | return 0; |
1da177e4 LT |
507 | |
508 | give_sigsegv: | |
509 | force_sigsegv(sig, current); | |
283828f3 | 510 | return -EFAULT; |
1da177e4 LT |
511 | } |
512 | ||
513 | /* | |
514 | * OK, we're invoking a handler | |
515 | */ | |
516 | ||
7c1def16 | 517 | static int |
1da177e4 | 518 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
ac66f3fd | 519 | sigset_t *oldset, struct pt_regs *regs) |
1da177e4 | 520 | { |
7c1def16 RM |
521 | int ret; |
522 | ||
1da177e4 | 523 | /* Are we from a system call? */ |
9902a702 | 524 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 525 | /* If so, check system call restarting.. */ |
65ea5b03 | 526 | switch (regs->ax) { |
ac66f3fd HH |
527 | case -ERESTART_RESTARTBLOCK: |
528 | case -ERESTARTNOHAND: | |
529 | regs->ax = -EINTR; | |
530 | break; | |
531 | ||
532 | case -ERESTARTSYS: | |
533 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
65ea5b03 | 534 | regs->ax = -EINTR; |
1da177e4 | 535 | break; |
ac66f3fd HH |
536 | } |
537 | /* fallthrough */ | |
538 | case -ERESTARTNOINTR: | |
539 | regs->ax = regs->orig_ax; | |
540 | regs->ip -= 2; | |
541 | break; | |
1da177e4 LT |
542 | } |
543 | } | |
544 | ||
545 | /* | |
e1f28773 RM |
546 | * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
547 | * flag so that register information in the sigcontext is correct. | |
1da177e4 | 548 | */ |
65ea5b03 | 549 | if (unlikely(regs->flags & X86_EFLAGS_TF) && |
e1f28773 | 550 | likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
65ea5b03 | 551 | regs->flags &= ~X86_EFLAGS_TF; |
1da177e4 LT |
552 | |
553 | /* Set up the stack frame */ | |
554 | if (ka->sa.sa_flags & SA_SIGINFO) | |
7c1def16 | 555 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 556 | else |
7c1def16 | 557 | ret = setup_frame(sig, ka, oldset, regs); |
1da177e4 | 558 | |
283828f3 | 559 | if (ret == 0) { |
1da177e4 LT |
560 | spin_lock_irq(¤t->sighand->siglock); |
561 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
69be8f18 SR |
562 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
563 | sigaddset(¤t->blocked,sig); | |
1da177e4 LT |
564 | recalc_sigpending(); |
565 | spin_unlock_irq(¤t->sighand->siglock); | |
566 | } | |
7c1def16 RM |
567 | |
568 | return ret; | |
1da177e4 LT |
569 | } |
570 | ||
571 | /* | |
572 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
573 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
574 | * mistake. | |
575 | */ | |
75604d7f | 576 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 577 | { |
ac66f3fd | 578 | struct k_sigaction ka; |
1da177e4 LT |
579 | siginfo_t info; |
580 | int signr; | |
283828f3 | 581 | sigset_t *oldset; |
1da177e4 LT |
582 | |
583 | /* | |
ac66f3fd HH |
584 | * We want the common case to go fast, which is why we may in certain |
585 | * cases get here from kernel mode. Just return without doing anything | |
586 | * if so. | |
587 | * X86_32: vm86 regs switched out by assembly code before reaching | |
588 | * here, so testing against kernel CS suffices. | |
1da177e4 | 589 | */ |
717b594a | 590 | if (!user_mode(regs)) |
283828f3 | 591 | return; |
1da177e4 | 592 | |
283828f3 DH |
593 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
594 | oldset = ¤t->saved_sigmask; | |
595 | else | |
1da177e4 LT |
596 | oldset = ¤t->blocked; |
597 | ||
598 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
599 | if (signr > 0) { | |
27b46d76 | 600 | /* Re-enable any watchpoints before delivering the |
1da177e4 LT |
601 | * signal to user space. The processor register will |
602 | * have been cleared if the watchpoint triggered | |
603 | * inside the kernel. | |
604 | */ | |
ac66f3fd | 605 | if (current->thread.debugreg7) |
0f534093 | 606 | set_debugreg(current->thread.debugreg7, 7); |
1da177e4 LT |
607 | |
608 | /* Whee! Actually deliver the signal. */ | |
283828f3 DH |
609 | if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
610 | /* a signal was successfully delivered; the saved | |
611 | * sigmask will have been stored in the signal frame, | |
612 | * and will be restored by sigreturn, so we can simply | |
613 | * clear the TIF_RESTORE_SIGMASK flag */ | |
614 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) | |
615 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
616 | } | |
617 | ||
618 | return; | |
1da177e4 LT |
619 | } |
620 | ||
1da177e4 | 621 | /* Did we come from a system call? */ |
9902a702 | 622 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 623 | /* Restart the system call - no handlers present */ |
65ea5b03 | 624 | switch (regs->ax) { |
283828f3 DH |
625 | case -ERESTARTNOHAND: |
626 | case -ERESTARTSYS: | |
627 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
628 | regs->ax = regs->orig_ax; |
629 | regs->ip -= 2; | |
283828f3 DH |
630 | break; |
631 | ||
632 | case -ERESTART_RESTARTBLOCK: | |
65ea5b03 PA |
633 | regs->ax = __NR_restart_syscall; |
634 | regs->ip -= 2; | |
283828f3 | 635 | break; |
1da177e4 LT |
636 | } |
637 | } | |
283828f3 | 638 | |
ac66f3fd HH |
639 | /* |
640 | * If there's no signal to deliver, we just put the saved sigmask | |
641 | * back. | |
642 | */ | |
283828f3 DH |
643 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
644 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
645 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
646 | } | |
1da177e4 LT |
647 | } |
648 | ||
649 | /* | |
650 | * notification of userspace execution resumption | |
283828f3 | 651 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 652 | */ |
ac66f3fd | 653 | void do_notify_resume(struct pt_regs *regs, void *unused, |
1da177e4 LT |
654 | __u32 thread_info_flags) |
655 | { | |
656 | /* Pending single-step? */ | |
657 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
ac66f3fd | 658 | regs->flags |= X86_EFLAGS_TF; |
1da177e4 LT |
659 | clear_thread_flag(TIF_SINGLESTEP); |
660 | } | |
283828f3 | 661 | |
1da177e4 | 662 | /* deal with pending signal delivery */ |
283828f3 DH |
663 | if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) |
664 | do_signal(regs); | |
8f4d37ec PZ |
665 | |
666 | if (thread_info_flags & _TIF_HRTICK_RESCHED) | |
667 | hrtick_resched(); | |
1da177e4 LT |
668 | |
669 | clear_thread_flag(TIF_IRET); | |
670 | } |