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 | */ | |
7e907f48 | 7 | #include <linux/list.h> |
1da177e4 | 8 | |
7e907f48 IM |
9 | #include <linux/personality.h> |
10 | #include <linux/binfmts.h> | |
11 | #include <linux/suspend.h> | |
1da177e4 | 12 | #include <linux/kernel.h> |
7e907f48 | 13 | #include <linux/ptrace.h> |
1da177e4 | 14 | #include <linux/signal.h> |
7e907f48 IM |
15 | #include <linux/stddef.h> |
16 | #include <linux/unistd.h> | |
1da177e4 | 17 | #include <linux/errno.h> |
7e907f48 | 18 | #include <linux/sched.h> |
1da177e4 | 19 | #include <linux/wait.h> |
36a03308 | 20 | #include <linux/tracehook.h> |
1da177e4 | 21 | #include <linux/elf.h> |
7e907f48 IM |
22 | #include <linux/smp.h> |
23 | #include <linux/mm.h> | |
24 | ||
1da177e4 LT |
25 | #include <asm/processor.h> |
26 | #include <asm/ucontext.h> | |
27 | #include <asm/uaccess.h> | |
28 | #include <asm/i387.h> | |
6c3652ef | 29 | #include <asm/vdso.h> |
bb57925f | 30 | #include <asm/syscall.h> |
bbc1f698 | 31 | #include <asm/syscalls.h> |
7e907f48 | 32 | |
123a6347 | 33 | #include "sigframe.h" |
1da177e4 | 34 | |
1da177e4 LT |
35 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
36 | ||
1a176803 HH |
37 | #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \ |
38 | X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \ | |
39 | X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \ | |
40 | X86_EFLAGS_CF) | |
41 | ||
42 | #ifdef CONFIG_X86_32 | |
43 | # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF) | |
44 | #else | |
45 | # define FIX_EFLAGS __FIX_EFLAGS | |
46 | #endif | |
47 | ||
1da177e4 LT |
48 | /* |
49 | * Atomically swap in the new signal mask, and wait for a signal. | |
50 | */ | |
51 | asmlinkage int | |
52 | sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
53 | { | |
1da177e4 LT |
54 | mask &= _BLOCKABLE; |
55 | spin_lock_irq(¤t->sighand->siglock); | |
283828f3 | 56 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
57 | siginitset(¤t->blocked, mask); |
58 | recalc_sigpending(); | |
59 | spin_unlock_irq(¤t->sighand->siglock); | |
60 | ||
283828f3 DH |
61 | current->state = TASK_INTERRUPTIBLE; |
62 | schedule(); | |
5a8da0ea | 63 | set_restore_sigmask(); |
7e907f48 | 64 | |
283828f3 | 65 | return -ERESTARTNOHAND; |
1da177e4 LT |
66 | } |
67 | ||
7e907f48 | 68 | asmlinkage int |
1da177e4 LT |
69 | sys_sigaction(int sig, const struct old_sigaction __user *act, |
70 | struct old_sigaction __user *oact) | |
71 | { | |
72 | struct k_sigaction new_ka, old_ka; | |
73 | int ret; | |
74 | ||
75 | if (act) { | |
76 | old_sigset_t mask; | |
7e907f48 | 77 | |
1da177e4 LT |
78 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
79 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
80 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
81 | return -EFAULT; | |
7e907f48 | 82 | |
1da177e4 LT |
83 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
84 | __get_user(mask, &act->sa_mask); | |
85 | siginitset(&new_ka.sa.sa_mask, mask); | |
86 | } | |
87 | ||
88 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
89 | ||
90 | if (!ret && oact) { | |
91 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
92 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
93 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
94 | return -EFAULT; | |
7e907f48 | 95 | |
1da177e4 LT |
96 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
97 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
98 | } | |
99 | ||
100 | return ret; | |
101 | } | |
102 | ||
7e907f48 | 103 | asmlinkage int sys_sigaltstack(unsigned long bx) |
1da177e4 | 104 | { |
7e907f48 IM |
105 | /* |
106 | * This is needed to make gcc realize it doesn't own the | |
107 | * "struct pt_regs" | |
108 | */ | |
65ea5b03 PA |
109 | struct pt_regs *regs = (struct pt_regs *)&bx; |
110 | const stack_t __user *uss = (const stack_t __user *)bx; | |
111 | stack_t __user *uoss = (stack_t __user *)regs->cx; | |
1da177e4 | 112 | |
65ea5b03 | 113 | return do_sigaltstack(uss, uoss, regs->sp); |
1da177e4 LT |
114 | } |
115 | ||
116 | ||
117 | /* | |
118 | * Do a signal return; undo the signal stack. | |
119 | */ | |
1da177e4 | 120 | static int |
866bc13f HH |
121 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
122 | unsigned long *pax) | |
1da177e4 LT |
123 | { |
124 | unsigned int err = 0; | |
125 | ||
126 | /* Always make any pending restarted system calls return -EINTR */ | |
127 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
128 | ||
742fa54a | 129 | #define COPY(x) err |= __get_user(regs->x, &sc->x) |
1da177e4 LT |
130 | |
131 | #define COPY_SEG(seg) \ | |
132 | { unsigned short tmp; \ | |
133 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 134 | regs->seg = tmp; } |
1da177e4 LT |
135 | |
136 | #define COPY_SEG_STRICT(seg) \ | |
137 | { unsigned short tmp; \ | |
138 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 139 | regs->seg = tmp|3; } |
1da177e4 LT |
140 | |
141 | #define GET_SEG(seg) \ | |
142 | { unsigned short tmp; \ | |
143 | err |= __get_user(tmp, &sc->seg); \ | |
7e907f48 | 144 | loadsegment(seg, tmp); } |
1da177e4 | 145 | |
464d1a78 JF |
146 | GET_SEG(gs); |
147 | COPY_SEG(fs); | |
1da177e4 LT |
148 | COPY_SEG(es); |
149 | COPY_SEG(ds); | |
ac66f3fd HH |
150 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
151 | COPY(dx); COPY(cx); COPY(ip); | |
1da177e4 LT |
152 | COPY_SEG_STRICT(cs); |
153 | COPY_SEG_STRICT(ss); | |
7e907f48 | 154 | |
1da177e4 LT |
155 | { |
156 | unsigned int tmpflags; | |
7e907f48 | 157 | |
742fa54a | 158 | err |= __get_user(tmpflags, &sc->flags); |
7e907f48 IM |
159 | regs->flags = (regs->flags & ~FIX_EFLAGS) | |
160 | (tmpflags & FIX_EFLAGS); | |
65ea5b03 | 161 | regs->orig_ax = -1; /* disable syscall checks */ |
1da177e4 LT |
162 | } |
163 | ||
164 | { | |
ab513701 | 165 | void __user *buf; |
7e907f48 | 166 | |
1da177e4 | 167 | err |= __get_user(buf, &sc->fpstate); |
ab513701 | 168 | err |= restore_i387_xstate(buf); |
1da177e4 LT |
169 | } |
170 | ||
866bc13f | 171 | err |= __get_user(*pax, &sc->ax); |
1da177e4 | 172 | return err; |
1da177e4 LT |
173 | } |
174 | ||
866bc13f | 175 | asmlinkage unsigned long sys_sigreturn(unsigned long __unused) |
1da177e4 | 176 | { |
7e907f48 IM |
177 | struct sigframe __user *frame; |
178 | struct pt_regs *regs; | |
866bc13f | 179 | unsigned long ax; |
7e907f48 IM |
180 | sigset_t set; |
181 | ||
182 | regs = (struct pt_regs *) &__unused; | |
183 | frame = (struct sigframe __user *)(regs->sp - 8); | |
1da177e4 LT |
184 | |
185 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
186 | goto badframe; | |
7e907f48 | 187 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 |
1da177e4 LT |
188 | && __copy_from_user(&set.sig[1], &frame->extramask, |
189 | sizeof(frame->extramask)))) | |
190 | goto badframe; | |
191 | ||
192 | sigdelsetmask(&set, ~_BLOCKABLE); | |
193 | spin_lock_irq(¤t->sighand->siglock); | |
194 | current->blocked = set; | |
195 | recalc_sigpending(); | |
196 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 197 | |
65ea5b03 | 198 | if (restore_sigcontext(regs, &frame->sc, &ax)) |
1da177e4 | 199 | goto badframe; |
65ea5b03 | 200 | return ax; |
1da177e4 LT |
201 | |
202 | badframe: | |
03252919 | 203 | if (show_unhandled_signals && printk_ratelimit()) { |
1181f8b5 | 204 | printk("%s%s[%d] bad frame in sigreturn frame:" |
97b44ae6 | 205 | "%p ip:%lx sp:%lx oeax:%lx", |
19c5870c | 206 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
65ea5b03 PA |
207 | current->comm, task_pid_nr(current), frame, regs->ip, |
208 | regs->sp, regs->orig_ax); | |
03252919 | 209 | print_vma_addr(" in ", regs->ip); |
97b44ae6 | 210 | printk(KERN_CONT "\n"); |
03252919 | 211 | } |
abd4f750 | 212 | |
1da177e4 | 213 | force_sig(SIGSEGV, current); |
7e907f48 | 214 | |
1da177e4 | 215 | return 0; |
7e907f48 | 216 | } |
1da177e4 LT |
217 | |
218 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
219 | { | |
2d19c458 HH |
220 | struct pt_regs *regs = (struct pt_regs *)&__unused; |
221 | struct rt_sigframe __user *frame; | |
866bc13f | 222 | unsigned long ax; |
1da177e4 | 223 | sigset_t set; |
1da177e4 | 224 | |
2d19c458 | 225 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); |
1da177e4 LT |
226 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
227 | goto badframe; | |
228 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
229 | goto badframe; | |
230 | ||
231 | sigdelsetmask(&set, ~_BLOCKABLE); | |
232 | spin_lock_irq(¤t->sighand->siglock); | |
233 | current->blocked = set; | |
234 | recalc_sigpending(); | |
235 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 236 | |
65ea5b03 | 237 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
1da177e4 LT |
238 | goto badframe; |
239 | ||
65ea5b03 | 240 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
1da177e4 LT |
241 | goto badframe; |
242 | ||
65ea5b03 | 243 | return ax; |
1da177e4 LT |
244 | |
245 | badframe: | |
246 | force_sig(SIGSEGV, current); | |
247 | return 0; | |
7e907f48 | 248 | } |
1da177e4 LT |
249 | |
250 | /* | |
251 | * Set up a signal frame. | |
252 | */ | |
1da177e4 | 253 | static int |
ab513701 | 254 | setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
1da177e4 LT |
255 | struct pt_regs *regs, unsigned long mask) |
256 | { | |
257 | int tmp, err = 0; | |
258 | ||
65ea5b03 | 259 | err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
464d1a78 JF |
260 | savesegment(gs, tmp); |
261 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 | 262 | |
65ea5b03 PA |
263 | err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
264 | err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); | |
742fa54a PA |
265 | err |= __put_user(regs->di, &sc->di); |
266 | err |= __put_user(regs->si, &sc->si); | |
267 | err |= __put_user(regs->bp, &sc->bp); | |
268 | err |= __put_user(regs->sp, &sc->sp); | |
269 | err |= __put_user(regs->bx, &sc->bx); | |
270 | err |= __put_user(regs->dx, &sc->dx); | |
271 | err |= __put_user(regs->cx, &sc->cx); | |
272 | err |= __put_user(regs->ax, &sc->ax); | |
1da177e4 LT |
273 | err |= __put_user(current->thread.trap_no, &sc->trapno); |
274 | err |= __put_user(current->thread.error_code, &sc->err); | |
742fa54a | 275 | err |= __put_user(regs->ip, &sc->ip); |
65ea5b03 | 276 | err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
742fa54a PA |
277 | err |= __put_user(regs->flags, &sc->flags); |
278 | err |= __put_user(regs->sp, &sc->sp_at_signal); | |
65ea5b03 | 279 | err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
1da177e4 | 280 | |
ab513701 | 281 | tmp = save_i387_xstate(fpstate); |
1da177e4 | 282 | if (tmp < 0) |
7e907f48 | 283 | err = 1; |
1da177e4 | 284 | else |
7e907f48 | 285 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); |
1da177e4 LT |
286 | |
287 | /* non-iBCS2 extensions.. */ | |
288 | err |= __put_user(mask, &sc->oldmask); | |
289 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
290 | ||
291 | return err; | |
292 | } | |
293 | ||
294 | /* | |
295 | * Determine which stack to use.. | |
296 | */ | |
297 | static inline void __user * | |
3c1c7f10 | 298 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
ab513701 | 299 | void **fpstate) |
1da177e4 | 300 | { |
65ea5b03 | 301 | unsigned long sp; |
1da177e4 LT |
302 | |
303 | /* Default to using normal stack */ | |
65ea5b03 | 304 | sp = regs->sp; |
1da177e4 | 305 | |
83bd0102 RM |
306 | /* |
307 | * If we are on the alternate signal stack and would overflow it, don't. | |
308 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
309 | */ | |
65ea5b03 | 310 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
83bd0102 RM |
311 | return (void __user *) -1L; |
312 | ||
1da177e4 LT |
313 | /* This is the X/Open sanctioned signal stack switching. */ |
314 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
65ea5b03 PA |
315 | if (sas_ss_flags(sp) == 0) |
316 | sp = current->sas_ss_sp + current->sas_ss_size; | |
7e907f48 IM |
317 | } else { |
318 | /* This is the legacy signal stack switching. */ | |
319 | if ((regs->ss & 0xffff) != __USER_DS && | |
320 | !(ka->sa.sa_flags & SA_RESTORER) && | |
321 | ka->sa.sa_restorer) | |
322 | sp = (unsigned long) ka->sa.sa_restorer; | |
1da177e4 LT |
323 | } |
324 | ||
3c1c7f10 SS |
325 | if (used_math()) { |
326 | sp = sp - sig_xstate_size; | |
327 | *fpstate = (struct _fpstate *) sp; | |
328 | } | |
329 | ||
65ea5b03 | 330 | sp -= frame_size; |
7e907f48 IM |
331 | /* |
332 | * Align the stack pointer according to the i386 ABI, | |
333 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
334 | */ | |
65ea5b03 | 335 | sp = ((sp + 4) & -16ul) - 4; |
7e907f48 | 336 | |
65ea5b03 | 337 | return (void __user *) sp; |
1da177e4 LT |
338 | } |
339 | ||
7e907f48 IM |
340 | static int |
341 | setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, | |
342 | struct pt_regs *regs) | |
1da177e4 | 343 | { |
1da177e4 | 344 | struct sigframe __user *frame; |
7e907f48 | 345 | void __user *restorer; |
1da177e4 LT |
346 | int err = 0; |
347 | int usig; | |
ab513701 | 348 | void __user *fpstate = NULL; |
1da177e4 | 349 | |
3c1c7f10 | 350 | frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
351 | |
352 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
353 | goto give_sigsegv; | |
354 | ||
355 | usig = current_thread_info()->exec_domain | |
356 | && current_thread_info()->exec_domain->signal_invmap | |
357 | && sig < 32 | |
358 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
359 | : sig; | |
360 | ||
361 | err = __put_user(usig, &frame->sig); | |
362 | if (err) | |
363 | goto give_sigsegv; | |
364 | ||
3c1c7f10 | 365 | err = setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]); |
1da177e4 LT |
366 | if (err) |
367 | goto give_sigsegv; | |
368 | ||
369 | if (_NSIG_WORDS > 1) { | |
370 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
371 | sizeof(frame->extramask)); | |
372 | if (err) | |
373 | goto give_sigsegv; | |
374 | } | |
375 | ||
1a3e4ca4 | 376 | if (current->mm->context.vdso) |
6c3652ef | 377 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
9fbbd4dd | 378 | else |
ade1af77 | 379 | restorer = &frame->retcode; |
1da177e4 LT |
380 | if (ka->sa.sa_flags & SA_RESTORER) |
381 | restorer = ka->sa.sa_restorer; | |
382 | ||
383 | /* Set up to return from userspace. */ | |
384 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 385 | |
1da177e4 | 386 | /* |
7e907f48 | 387 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
388 | * |
389 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
390 | * reasons and because gdb uses it as a signature to notice | |
391 | * signal handler stack frames. | |
392 | */ | |
393 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
394 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
395 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
396 | ||
397 | if (err) | |
398 | goto give_sigsegv; | |
399 | ||
400 | /* Set up registers for signal handler */ | |
7e907f48 IM |
401 | regs->sp = (unsigned long)frame; |
402 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
403 | regs->ax = (unsigned long)sig; | |
92bc2056 HH |
404 | regs->dx = 0; |
405 | regs->cx = 0; | |
1da177e4 | 406 | |
65ea5b03 PA |
407 | regs->ds = __USER_DS; |
408 | regs->es = __USER_DS; | |
409 | regs->ss = __USER_DS; | |
410 | regs->cs = __USER_CS; | |
1da177e4 | 411 | |
283828f3 | 412 | return 0; |
1da177e4 LT |
413 | |
414 | give_sigsegv: | |
415 | force_sigsegv(sig, current); | |
283828f3 | 416 | return -EFAULT; |
1da177e4 LT |
417 | } |
418 | ||
7c1def16 | 419 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
7e907f48 | 420 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 421 | { |
1da177e4 | 422 | struct rt_sigframe __user *frame; |
7e907f48 | 423 | void __user *restorer; |
1da177e4 LT |
424 | int err = 0; |
425 | int usig; | |
ab513701 | 426 | void __user *fpstate = NULL; |
1da177e4 | 427 | |
3c1c7f10 | 428 | frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
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. */ | |
c37b5efe SS |
447 | if (cpu_has_xsave) |
448 | err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); | |
449 | else | |
450 | err |= __put_user(0, &frame->uc.uc_flags); | |
1da177e4 LT |
451 | err |= __put_user(0, &frame->uc.uc_link); |
452 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
65ea5b03 | 453 | err |= __put_user(sas_ss_flags(regs->sp), |
1da177e4 LT |
454 | &frame->uc.uc_stack.ss_flags); |
455 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
3c1c7f10 | 456 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
7e907f48 | 457 | regs, set->sig[0]); |
1da177e4 LT |
458 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
459 | if (err) | |
460 | goto give_sigsegv; | |
461 | ||
462 | /* Set up to return from userspace. */ | |
6c3652ef | 463 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); |
1da177e4 LT |
464 | if (ka->sa.sa_flags & SA_RESTORER) |
465 | restorer = ka->sa.sa_restorer; | |
466 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 467 | |
1da177e4 | 468 | /* |
7e907f48 | 469 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 |
1da177e4 LT |
470 | * |
471 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
472 | * reasons and because gdb uses it as a signature to notice | |
473 | * signal handler stack frames. | |
474 | */ | |
475 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); | |
476 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); | |
477 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); | |
478 | ||
479 | if (err) | |
480 | goto give_sigsegv; | |
481 | ||
482 | /* Set up registers for signal handler */ | |
7e907f48 IM |
483 | regs->sp = (unsigned long)frame; |
484 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
485 | regs->ax = (unsigned long)usig; | |
486 | regs->dx = (unsigned long)&frame->info; | |
487 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 488 | |
65ea5b03 PA |
489 | regs->ds = __USER_DS; |
490 | regs->es = __USER_DS; | |
491 | regs->ss = __USER_DS; | |
492 | regs->cs = __USER_CS; | |
1da177e4 | 493 | |
283828f3 | 494 | return 0; |
1da177e4 LT |
495 | |
496 | give_sigsegv: | |
497 | force_sigsegv(sig, current); | |
283828f3 | 498 | return -EFAULT; |
1da177e4 LT |
499 | } |
500 | ||
501 | /* | |
7e907f48 IM |
502 | * OK, we're invoking a handler: |
503 | */ | |
7c1def16 | 504 | static int |
1da177e4 | 505 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
ac66f3fd | 506 | sigset_t *oldset, struct pt_regs *regs) |
1da177e4 | 507 | { |
7c1def16 RM |
508 | int ret; |
509 | ||
1da177e4 | 510 | /* Are we from a system call? */ |
bb57925f | 511 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 512 | /* If so, check system call restarting.. */ |
bb57925f | 513 | switch (syscall_get_error(current, regs)) { |
ac66f3fd HH |
514 | case -ERESTART_RESTARTBLOCK: |
515 | case -ERESTARTNOHAND: | |
516 | regs->ax = -EINTR; | |
517 | break; | |
518 | ||
519 | case -ERESTARTSYS: | |
520 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
65ea5b03 | 521 | regs->ax = -EINTR; |
1da177e4 | 522 | break; |
ac66f3fd HH |
523 | } |
524 | /* fallthrough */ | |
525 | case -ERESTARTNOINTR: | |
526 | regs->ax = regs->orig_ax; | |
527 | regs->ip -= 2; | |
528 | break; | |
1da177e4 LT |
529 | } |
530 | } | |
531 | ||
532 | /* | |
e1f28773 RM |
533 | * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
534 | * flag so that register information in the sigcontext is correct. | |
1da177e4 | 535 | */ |
65ea5b03 | 536 | if (unlikely(regs->flags & X86_EFLAGS_TF) && |
e1f28773 | 537 | likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
65ea5b03 | 538 | regs->flags &= ~X86_EFLAGS_TF; |
1da177e4 LT |
539 | |
540 | /* Set up the stack frame */ | |
541 | if (ka->sa.sa_flags & SA_SIGINFO) | |
7c1def16 | 542 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 543 | else |
7c1def16 | 544 | ret = setup_frame(sig, ka, oldset, regs); |
1da177e4 | 545 | |
7e907f48 IM |
546 | if (ret) |
547 | return ret; | |
7c1def16 | 548 | |
8b9c5ff3 RM |
549 | /* |
550 | * Clear the direction flag as per the ABI for function entry. | |
551 | */ | |
552 | regs->flags &= ~X86_EFLAGS_DF; | |
553 | ||
554 | /* | |
555 | * Clear TF when entering the signal handler, but | |
556 | * notify any tracer that was single-stepping it. | |
557 | * The tracer may want to single-step inside the | |
558 | * handler too. | |
559 | */ | |
560 | regs->flags &= ~X86_EFLAGS_TF; | |
8b9c5ff3 | 561 | |
7e907f48 IM |
562 | spin_lock_irq(¤t->sighand->siglock); |
563 | sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); | |
564 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
565 | sigaddset(¤t->blocked, sig); | |
566 | recalc_sigpending(); | |
567 | spin_unlock_irq(¤t->sighand->siglock); | |
568 | ||
36a03308 RM |
569 | tracehook_signal_handler(sig, info, ka, regs, |
570 | test_thread_flag(TIF_SINGLESTEP)); | |
571 | ||
7e907f48 | 572 | return 0; |
1da177e4 LT |
573 | } |
574 | ||
575 | /* | |
576 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
577 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
578 | * mistake. | |
579 | */ | |
75604d7f | 580 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 581 | { |
ac66f3fd | 582 | struct k_sigaction ka; |
1da177e4 LT |
583 | siginfo_t info; |
584 | int signr; | |
283828f3 | 585 | sigset_t *oldset; |
1da177e4 LT |
586 | |
587 | /* | |
ac66f3fd HH |
588 | * We want the common case to go fast, which is why we may in certain |
589 | * cases get here from kernel mode. Just return without doing anything | |
590 | * if so. | |
591 | * X86_32: vm86 regs switched out by assembly code before reaching | |
592 | * here, so testing against kernel CS suffices. | |
1da177e4 | 593 | */ |
717b594a | 594 | if (!user_mode(regs)) |
283828f3 | 595 | return; |
1da177e4 | 596 | |
5a8da0ea | 597 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) |
283828f3 DH |
598 | oldset = ¤t->saved_sigmask; |
599 | else | |
1da177e4 LT |
600 | oldset = ¤t->blocked; |
601 | ||
602 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
603 | if (signr > 0) { | |
7e907f48 IM |
604 | /* |
605 | * Re-enable any watchpoints before delivering the | |
1da177e4 LT |
606 | * signal to user space. The processor register will |
607 | * have been cleared if the watchpoint triggered | |
608 | * inside the kernel. | |
609 | */ | |
ac66f3fd | 610 | if (current->thread.debugreg7) |
0f534093 | 611 | set_debugreg(current->thread.debugreg7, 7); |
1da177e4 | 612 | |
7e907f48 | 613 | /* Whee! Actually deliver the signal. */ |
283828f3 | 614 | if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
7e907f48 | 615 | /* |
5a8da0ea | 616 | * A signal was successfully delivered; the saved |
283828f3 DH |
617 | * sigmask will have been stored in the signal frame, |
618 | * and will be restored by sigreturn, so we can simply | |
5a8da0ea | 619 | * clear the TS_RESTORE_SIGMASK flag. |
7e907f48 | 620 | */ |
5a8da0ea | 621 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
283828f3 | 622 | } |
283828f3 | 623 | return; |
1da177e4 LT |
624 | } |
625 | ||
1da177e4 | 626 | /* Did we come from a system call? */ |
bb57925f | 627 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 628 | /* Restart the system call - no handlers present */ |
bb57925f | 629 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
630 | case -ERESTARTNOHAND: |
631 | case -ERESTARTSYS: | |
632 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
633 | regs->ax = regs->orig_ax; |
634 | regs->ip -= 2; | |
283828f3 DH |
635 | break; |
636 | ||
637 | case -ERESTART_RESTARTBLOCK: | |
65ea5b03 PA |
638 | regs->ax = __NR_restart_syscall; |
639 | regs->ip -= 2; | |
283828f3 | 640 | break; |
1da177e4 LT |
641 | } |
642 | } | |
283828f3 | 643 | |
ac66f3fd HH |
644 | /* |
645 | * If there's no signal to deliver, we just put the saved sigmask | |
646 | * back. | |
647 | */ | |
5a8da0ea RM |
648 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) { |
649 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; | |
283828f3 DH |
650 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
651 | } | |
1da177e4 LT |
652 | } |
653 | ||
654 | /* | |
655 | * notification of userspace execution resumption | |
283828f3 | 656 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 657 | */ |
7e907f48 IM |
658 | void |
659 | do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) | |
1da177e4 | 660 | { |
1da177e4 | 661 | /* deal with pending signal delivery */ |
5a8da0ea | 662 | if (thread_info_flags & _TIF_SIGPENDING) |
283828f3 | 663 | do_signal(regs); |
8f4d37ec | 664 | |
59e52130 RM |
665 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
666 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
667 | tracehook_notify_resume(regs); | |
668 | } | |
669 | ||
1da177e4 LT |
670 | clear_thread_flag(TIF_IRET); |
671 | } |