Commit | Line | Data |
---|---|---|
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> |
123a6347 | 27 | #include "sigframe.h" |
1da177e4 | 28 | |
1da177e4 LT |
29 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
30 | ||
1a176803 HH |
31 | #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \ |
32 | X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \ | |
33 | X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \ | |
34 | X86_EFLAGS_CF) | |
35 | ||
36 | #ifdef CONFIG_X86_32 | |
37 | # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF) | |
38 | #else | |
39 | # define FIX_EFLAGS __FIX_EFLAGS | |
40 | #endif | |
41 | ||
1da177e4 LT |
42 | /* |
43 | * Atomically swap in the new signal mask, and wait for a signal. | |
44 | */ | |
45 | asmlinkage int | |
46 | sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
47 | { | |
1da177e4 LT |
48 | mask &= _BLOCKABLE; |
49 | spin_lock_irq(¤t->sighand->siglock); | |
283828f3 | 50 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
51 | siginitset(¤t->blocked, mask); |
52 | recalc_sigpending(); | |
53 | spin_unlock_irq(¤t->sighand->siglock); | |
54 | ||
283828f3 DH |
55 | current->state = TASK_INTERRUPTIBLE; |
56 | schedule(); | |
57 | set_thread_flag(TIF_RESTORE_SIGMASK); | |
58 | return -ERESTARTNOHAND; | |
1da177e4 LT |
59 | } |
60 | ||
61 | asmlinkage int | |
62 | sys_sigaction(int sig, const struct old_sigaction __user *act, | |
63 | struct old_sigaction __user *oact) | |
64 | { | |
65 | struct k_sigaction new_ka, old_ka; | |
66 | int ret; | |
67 | ||
68 | if (act) { | |
69 | old_sigset_t mask; | |
70 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || | |
71 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
72 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
73 | return -EFAULT; | |
74 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); | |
75 | __get_user(mask, &act->sa_mask); | |
76 | siginitset(&new_ka.sa.sa_mask, mask); | |
77 | } | |
78 | ||
79 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
80 | ||
81 | if (!ret && oact) { | |
82 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
83 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
84 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
85 | return -EFAULT; | |
86 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); | |
87 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
88 | } | |
89 | ||
90 | return ret; | |
91 | } | |
92 | ||
93 | asmlinkage int | |
65ea5b03 | 94 | sys_sigaltstack(unsigned long bx) |
1da177e4 LT |
95 | { |
96 | /* This is needed to make gcc realize it doesn't own the "struct pt_regs" */ | |
65ea5b03 PA |
97 | struct pt_regs *regs = (struct pt_regs *)&bx; |
98 | const stack_t __user *uss = (const stack_t __user *)bx; | |
99 | stack_t __user *uoss = (stack_t __user *)regs->cx; | |
1da177e4 | 100 | |
65ea5b03 | 101 | return do_sigaltstack(uss, uoss, regs->sp); |
1da177e4 LT |
102 | } |
103 | ||
104 | ||
105 | /* | |
106 | * Do a signal return; undo the signal stack. | |
107 | */ | |
1da177e4 | 108 | static int |
866bc13f HH |
109 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
110 | unsigned long *pax) | |
1da177e4 LT |
111 | { |
112 | unsigned int err = 0; | |
113 | ||
114 | /* Always make any pending restarted system calls return -EINTR */ | |
115 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
116 | ||
742fa54a | 117 | #define COPY(x) err |= __get_user(regs->x, &sc->x) |
1da177e4 LT |
118 | |
119 | #define COPY_SEG(seg) \ | |
120 | { unsigned short tmp; \ | |
121 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 122 | regs->seg = tmp; } |
1da177e4 LT |
123 | |
124 | #define COPY_SEG_STRICT(seg) \ | |
125 | { unsigned short tmp; \ | |
126 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 127 | regs->seg = tmp|3; } |
1da177e4 LT |
128 | |
129 | #define GET_SEG(seg) \ | |
130 | { unsigned short tmp; \ | |
131 | err |= __get_user(tmp, &sc->seg); \ | |
132 | loadsegment(seg,tmp); } | |
133 | ||
464d1a78 JF |
134 | GET_SEG(gs); |
135 | COPY_SEG(fs); | |
1da177e4 LT |
136 | COPY_SEG(es); |
137 | COPY_SEG(ds); | |
ac66f3fd HH |
138 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
139 | COPY(dx); COPY(cx); COPY(ip); | |
1da177e4 LT |
140 | COPY_SEG_STRICT(cs); |
141 | COPY_SEG_STRICT(ss); | |
142 | ||
143 | { | |
144 | unsigned int tmpflags; | |
742fa54a | 145 | err |= __get_user(tmpflags, &sc->flags); |
65ea5b03 PA |
146 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); |
147 | regs->orig_ax = -1; /* disable syscall checks */ | |
1da177e4 LT |
148 | } |
149 | ||
150 | { | |
151 | struct _fpstate __user * buf; | |
152 | err |= __get_user(buf, &sc->fpstate); | |
153 | if (buf) { | |
154 | if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) | |
155 | goto badframe; | |
156 | err |= restore_i387(buf); | |
157 | } else { | |
158 | struct task_struct *me = current; | |
159 | if (used_math()) { | |
160 | clear_fpu(me); | |
161 | clear_used_math(); | |
162 | } | |
163 | } | |
164 | } | |
165 | ||
866bc13f | 166 | err |= __get_user(*pax, &sc->ax); |
1da177e4 LT |
167 | return err; |
168 | ||
169 | badframe: | |
170 | return 1; | |
171 | } | |
172 | ||
866bc13f | 173 | asmlinkage unsigned long sys_sigreturn(unsigned long __unused) |
1da177e4 LT |
174 | { |
175 | struct pt_regs *regs = (struct pt_regs *) &__unused; | |
65ea5b03 | 176 | struct sigframe __user *frame = (struct sigframe __user *)(regs->sp - 8); |
1da177e4 | 177 | sigset_t set; |
866bc13f | 178 | unsigned long ax; |
1da177e4 LT |
179 | |
180 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
181 | goto badframe; | |
182 | if (__get_user(set.sig[0], &frame->sc.oldmask) | |
183 | || (_NSIG_WORDS > 1 | |
184 | && __copy_from_user(&set.sig[1], &frame->extramask, | |
185 | sizeof(frame->extramask)))) | |
186 | goto badframe; | |
187 | ||
188 | sigdelsetmask(&set, ~_BLOCKABLE); | |
189 | spin_lock_irq(¤t->sighand->siglock); | |
190 | current->blocked = set; | |
191 | recalc_sigpending(); | |
192 | spin_unlock_irq(¤t->sighand->siglock); | |
193 | ||
65ea5b03 | 194 | if (restore_sigcontext(regs, &frame->sc, &ax)) |
1da177e4 | 195 | goto badframe; |
65ea5b03 | 196 | return ax; |
1da177e4 LT |
197 | |
198 | badframe: | |
03252919 | 199 | if (show_unhandled_signals && printk_ratelimit()) { |
65ea5b03 | 200 | printk("%s%s[%d] bad frame in sigreturn frame:%p ip:%lx" |
03252919 | 201 | " sp:%lx oeax:%lx", |
19c5870c | 202 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
65ea5b03 PA |
203 | current->comm, task_pid_nr(current), frame, regs->ip, |
204 | regs->sp, regs->orig_ax); | |
03252919 AK |
205 | print_vma_addr(" in ", regs->ip); |
206 | printk("\n"); | |
207 | } | |
abd4f750 | 208 | |
1da177e4 LT |
209 | force_sig(SIGSEGV, current); |
210 | return 0; | |
211 | } | |
212 | ||
213 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
214 | { | |
2d19c458 HH |
215 | struct pt_regs *regs = (struct pt_regs *)&__unused; |
216 | struct rt_sigframe __user *frame; | |
866bc13f | 217 | unsigned long ax; |
1da177e4 | 218 | sigset_t set; |
1da177e4 | 219 | |
2d19c458 | 220 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); |
1da177e4 LT |
221 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
222 | goto badframe; | |
223 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
224 | goto badframe; | |
225 | ||
226 | sigdelsetmask(&set, ~_BLOCKABLE); | |
227 | spin_lock_irq(¤t->sighand->siglock); | |
228 | current->blocked = set; | |
229 | recalc_sigpending(); | |
230 | spin_unlock_irq(¤t->sighand->siglock); | |
231 | ||
65ea5b03 | 232 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
1da177e4 LT |
233 | goto badframe; |
234 | ||
65ea5b03 | 235 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
1da177e4 LT |
236 | goto badframe; |
237 | ||
65ea5b03 | 238 | return ax; |
1da177e4 LT |
239 | |
240 | badframe: | |
241 | force_sig(SIGSEGV, current); | |
242 | return 0; | |
243 | } | |
244 | ||
245 | /* | |
246 | * Set up a signal frame. | |
247 | */ | |
248 | ||
249 | static int | |
250 | setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, | |
251 | struct pt_regs *regs, unsigned long mask) | |
252 | { | |
253 | int tmp, err = 0; | |
254 | ||
65ea5b03 | 255 | err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
464d1a78 JF |
256 | savesegment(gs, tmp); |
257 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 | 258 | |
65ea5b03 PA |
259 | err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
260 | err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); | |
742fa54a PA |
261 | err |= __put_user(regs->di, &sc->di); |
262 | err |= __put_user(regs->si, &sc->si); | |
263 | err |= __put_user(regs->bp, &sc->bp); | |
264 | err |= __put_user(regs->sp, &sc->sp); | |
265 | err |= __put_user(regs->bx, &sc->bx); | |
266 | err |= __put_user(regs->dx, &sc->dx); | |
267 | err |= __put_user(regs->cx, &sc->cx); | |
268 | err |= __put_user(regs->ax, &sc->ax); | |
1da177e4 LT |
269 | err |= __put_user(current->thread.trap_no, &sc->trapno); |
270 | err |= __put_user(current->thread.error_code, &sc->err); | |
742fa54a | 271 | err |= __put_user(regs->ip, &sc->ip); |
65ea5b03 | 272 | err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
742fa54a PA |
273 | err |= __put_user(regs->flags, &sc->flags); |
274 | err |= __put_user(regs->sp, &sc->sp_at_signal); | |
65ea5b03 | 275 | err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
1da177e4 LT |
276 | |
277 | tmp = save_i387(fpstate); | |
278 | if (tmp < 0) | |
279 | err = 1; | |
280 | else | |
281 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); | |
282 | ||
283 | /* non-iBCS2 extensions.. */ | |
284 | err |= __put_user(mask, &sc->oldmask); | |
285 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
286 | ||
287 | return err; | |
288 | } | |
289 | ||
290 | /* | |
291 | * Determine which stack to use.. | |
292 | */ | |
293 | static inline void __user * | |
294 | get_sigframe(struct k_sigaction *ka, struct pt_regs * regs, size_t frame_size) | |
295 | { | |
65ea5b03 | 296 | unsigned long sp; |
1da177e4 LT |
297 | |
298 | /* Default to using normal stack */ | |
65ea5b03 | 299 | sp = regs->sp; |
1da177e4 | 300 | |
83bd0102 RM |
301 | /* |
302 | * If we are on the alternate signal stack and would overflow it, don't. | |
303 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
304 | */ | |
65ea5b03 | 305 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
83bd0102 RM |
306 | return (void __user *) -1L; |
307 | ||
1da177e4 LT |
308 | /* This is the X/Open sanctioned signal stack switching. */ |
309 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
65ea5b03 PA |
310 | if (sas_ss_flags(sp) == 0) |
311 | sp = current->sas_ss_sp + current->sas_ss_size; | |
1da177e4 LT |
312 | } |
313 | ||
314 | /* This is the legacy signal stack switching. */ | |
65ea5b03 | 315 | else if ((regs->ss & 0xffff) != __USER_DS && |
1da177e4 LT |
316 | !(ka->sa.sa_flags & SA_RESTORER) && |
317 | ka->sa.sa_restorer) { | |
65ea5b03 | 318 | sp = (unsigned long) ka->sa.sa_restorer; |
1da177e4 LT |
319 | } |
320 | ||
65ea5b03 | 321 | sp -= frame_size; |
d347f372 MO |
322 | /* Align the stack pointer according to the i386 ABI, |
323 | * i.e. so that on function entry ((sp + 4) & 15) == 0. */ | |
65ea5b03 PA |
324 | sp = ((sp + 4) & -16ul) - 4; |
325 | return (void __user *) sp; | |
1da177e4 LT |
326 | } |
327 | ||
328 | /* These symbols are defined with the addresses in the vsyscall page. | |
329 | See vsyscall-sigreturn.S. */ | |
330 | extern void __user __kernel_sigreturn; | |
331 | extern void __user __kernel_rt_sigreturn; | |
332 | ||
7c1def16 RM |
333 | static int setup_frame(int sig, struct k_sigaction *ka, |
334 | sigset_t *set, struct pt_regs * regs) | |
1da177e4 LT |
335 | { |
336 | void __user *restorer; | |
337 | struct sigframe __user *frame; | |
338 | int err = 0; | |
339 | int usig; | |
340 | ||
341 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
342 | ||
343 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
344 | goto give_sigsegv; | |
345 | ||
346 | usig = current_thread_info()->exec_domain | |
347 | && current_thread_info()->exec_domain->signal_invmap | |
348 | && sig < 32 | |
349 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
350 | : sig; | |
351 | ||
352 | err = __put_user(usig, &frame->sig); | |
353 | if (err) | |
354 | goto give_sigsegv; | |
355 | ||
356 | err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); | |
357 | if (err) | |
358 | goto give_sigsegv; | |
359 | ||
360 | if (_NSIG_WORDS > 1) { | |
361 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
362 | sizeof(frame->extramask)); | |
363 | if (err) | |
364 | goto give_sigsegv; | |
365 | } | |
366 | ||
1a3e4ca4 | 367 | if (current->mm->context.vdso) |
6c3652ef | 368 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
9fbbd4dd | 369 | else |
ade1af77 | 370 | restorer = &frame->retcode; |
1da177e4 LT |
371 | if (ka->sa.sa_flags & SA_RESTORER) |
372 | restorer = ka->sa.sa_restorer; | |
373 | ||
374 | /* Set up to return from userspace. */ | |
375 | err |= __put_user(restorer, &frame->pretcode); | |
376 | ||
377 | /* | |
378 | * This is popl %eax ; movl $,%eax ; int $0x80 | |
379 | * | |
380 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
381 | * reasons and because gdb uses it as a signature to notice | |
382 | * signal handler stack frames. | |
383 | */ | |
384 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
385 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
386 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
387 | ||
388 | if (err) | |
389 | goto give_sigsegv; | |
390 | ||
391 | /* Set up registers for signal handler */ | |
65ea5b03 PA |
392 | regs->sp = (unsigned long) frame; |
393 | regs->ip = (unsigned long) ka->sa.sa_handler; | |
394 | regs->ax = (unsigned long) sig; | |
92bc2056 HH |
395 | regs->dx = 0; |
396 | regs->cx = 0; | |
1da177e4 | 397 | |
65ea5b03 PA |
398 | regs->ds = __USER_DS; |
399 | regs->es = __USER_DS; | |
400 | regs->ss = __USER_DS; | |
401 | regs->cs = __USER_CS; | |
1da177e4 LT |
402 | |
403 | /* | |
404 | * Clear TF when entering the signal handler, but | |
405 | * notify any tracer that was single-stepping it. | |
406 | * The tracer may want to single-step inside the | |
407 | * handler too. | |
408 | */ | |
e40cd10c | 409 | regs->flags &= ~(TF_MASK | X86_EFLAGS_DF); |
1da177e4 LT |
410 | if (test_thread_flag(TIF_SINGLESTEP)) |
411 | ptrace_notify(SIGTRAP); | |
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 | ||
283828f3 | 501 | return 0; |
1da177e4 LT |
502 | |
503 | give_sigsegv: | |
504 | force_sigsegv(sig, current); | |
283828f3 | 505 | return -EFAULT; |
1da177e4 LT |
506 | } |
507 | ||
508 | /* | |
509 | * OK, we're invoking a handler | |
510 | */ | |
511 | ||
7c1def16 | 512 | static int |
1da177e4 | 513 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
ac66f3fd | 514 | sigset_t *oldset, struct pt_regs *regs) |
1da177e4 | 515 | { |
7c1def16 RM |
516 | int ret; |
517 | ||
1da177e4 | 518 | /* Are we from a system call? */ |
9902a702 | 519 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 520 | /* If so, check system call restarting.. */ |
65ea5b03 | 521 | switch (regs->ax) { |
ac66f3fd HH |
522 | case -ERESTART_RESTARTBLOCK: |
523 | case -ERESTARTNOHAND: | |
524 | regs->ax = -EINTR; | |
525 | break; | |
526 | ||
527 | case -ERESTARTSYS: | |
528 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
65ea5b03 | 529 | regs->ax = -EINTR; |
1da177e4 | 530 | break; |
ac66f3fd HH |
531 | } |
532 | /* fallthrough */ | |
533 | case -ERESTARTNOINTR: | |
534 | regs->ax = regs->orig_ax; | |
535 | regs->ip -= 2; | |
536 | break; | |
1da177e4 LT |
537 | } |
538 | } | |
539 | ||
540 | /* | |
e1f28773 RM |
541 | * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
542 | * flag so that register information in the sigcontext is correct. | |
1da177e4 | 543 | */ |
65ea5b03 | 544 | if (unlikely(regs->flags & X86_EFLAGS_TF) && |
e1f28773 | 545 | likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
65ea5b03 | 546 | regs->flags &= ~X86_EFLAGS_TF; |
1da177e4 LT |
547 | |
548 | /* Set up the stack frame */ | |
549 | if (ka->sa.sa_flags & SA_SIGINFO) | |
7c1def16 | 550 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 551 | else |
7c1def16 | 552 | ret = setup_frame(sig, ka, oldset, regs); |
1da177e4 | 553 | |
283828f3 | 554 | if (ret == 0) { |
1da177e4 LT |
555 | spin_lock_irq(¤t->sighand->siglock); |
556 | sigorsets(¤t->blocked,¤t->blocked,&ka->sa.sa_mask); | |
69be8f18 SR |
557 | if (!(ka->sa.sa_flags & SA_NODEFER)) |
558 | sigaddset(¤t->blocked,sig); | |
1da177e4 LT |
559 | recalc_sigpending(); |
560 | spin_unlock_irq(¤t->sighand->siglock); | |
561 | } | |
7c1def16 RM |
562 | |
563 | return ret; | |
1da177e4 LT |
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 | */ | |
75604d7f | 571 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 572 | { |
ac66f3fd | 573 | struct k_sigaction ka; |
1da177e4 LT |
574 | siginfo_t info; |
575 | int signr; | |
283828f3 | 576 | sigset_t *oldset; |
1da177e4 LT |
577 | |
578 | /* | |
ac66f3fd HH |
579 | * We want the common case to go fast, which is why we may in certain |
580 | * cases get here from kernel mode. Just return without doing anything | |
581 | * if so. | |
582 | * X86_32: vm86 regs switched out by assembly code before reaching | |
583 | * here, so testing against kernel CS suffices. | |
1da177e4 | 584 | */ |
717b594a | 585 | if (!user_mode(regs)) |
283828f3 | 586 | return; |
1da177e4 | 587 | |
283828f3 DH |
588 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) |
589 | oldset = ¤t->saved_sigmask; | |
590 | else | |
1da177e4 LT |
591 | oldset = ¤t->blocked; |
592 | ||
593 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
594 | if (signr > 0) { | |
27b46d76 | 595 | /* Re-enable any watchpoints before delivering the |
1da177e4 LT |
596 | * signal to user space. The processor register will |
597 | * have been cleared if the watchpoint triggered | |
598 | * inside the kernel. | |
599 | */ | |
ac66f3fd | 600 | if (current->thread.debugreg7) |
0f534093 | 601 | set_debugreg(current->thread.debugreg7, 7); |
1da177e4 LT |
602 | |
603 | /* Whee! Actually deliver the signal. */ | |
283828f3 DH |
604 | if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
605 | /* a signal was successfully delivered; the saved | |
606 | * sigmask will have been stored in the signal frame, | |
607 | * and will be restored by sigreturn, so we can simply | |
608 | * clear the TIF_RESTORE_SIGMASK flag */ | |
609 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) | |
610 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
611 | } | |
612 | ||
613 | return; | |
1da177e4 LT |
614 | } |
615 | ||
1da177e4 | 616 | /* Did we come from a system call? */ |
9902a702 | 617 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 618 | /* Restart the system call - no handlers present */ |
65ea5b03 | 619 | switch (regs->ax) { |
283828f3 DH |
620 | case -ERESTARTNOHAND: |
621 | case -ERESTARTSYS: | |
622 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
623 | regs->ax = regs->orig_ax; |
624 | regs->ip -= 2; | |
283828f3 DH |
625 | break; |
626 | ||
627 | case -ERESTART_RESTARTBLOCK: | |
65ea5b03 PA |
628 | regs->ax = __NR_restart_syscall; |
629 | regs->ip -= 2; | |
283828f3 | 630 | break; |
1da177e4 LT |
631 | } |
632 | } | |
283828f3 | 633 | |
ac66f3fd HH |
634 | /* |
635 | * If there's no signal to deliver, we just put the saved sigmask | |
636 | * back. | |
637 | */ | |
283828f3 DH |
638 | if (test_thread_flag(TIF_RESTORE_SIGMASK)) { |
639 | clear_thread_flag(TIF_RESTORE_SIGMASK); | |
640 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); | |
641 | } | |
1da177e4 LT |
642 | } |
643 | ||
644 | /* | |
645 | * notification of userspace execution resumption | |
283828f3 | 646 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 647 | */ |
ac66f3fd | 648 | void do_notify_resume(struct pt_regs *regs, void *unused, |
1da177e4 LT |
649 | __u32 thread_info_flags) |
650 | { | |
651 | /* Pending single-step? */ | |
652 | if (thread_info_flags & _TIF_SINGLESTEP) { | |
ac66f3fd | 653 | regs->flags |= X86_EFLAGS_TF; |
1da177e4 LT |
654 | clear_thread_flag(TIF_SINGLESTEP); |
655 | } | |
283828f3 | 656 | |
1da177e4 | 657 | /* deal with pending signal delivery */ |
283828f3 DH |
658 | if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK)) |
659 | do_signal(regs); | |
8f4d37ec PZ |
660 | |
661 | if (thread_info_flags & _TIF_HRTICK_RESCHED) | |
662 | hrtick_resched(); | |
1da177e4 LT |
663 | |
664 | clear_thread_flag(TIF_IRET); | |
665 | } |