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> |
bbc1f698 | 30 | #include <asm/syscalls.h> |
7e907f48 | 31 | |
123a6347 | 32 | #include "sigframe.h" |
1da177e4 | 33 | |
1da177e4 LT |
34 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
35 | ||
1a176803 HH |
36 | #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \ |
37 | X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \ | |
38 | X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \ | |
39 | X86_EFLAGS_CF) | |
40 | ||
41 | #ifdef CONFIG_X86_32 | |
42 | # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF) | |
43 | #else | |
44 | # define FIX_EFLAGS __FIX_EFLAGS | |
45 | #endif | |
46 | ||
1da177e4 LT |
47 | /* |
48 | * Atomically swap in the new signal mask, and wait for a signal. | |
49 | */ | |
50 | asmlinkage int | |
51 | sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
52 | { | |
1da177e4 LT |
53 | mask &= _BLOCKABLE; |
54 | spin_lock_irq(¤t->sighand->siglock); | |
283828f3 | 55 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
56 | siginitset(¤t->blocked, mask); |
57 | recalc_sigpending(); | |
58 | spin_unlock_irq(¤t->sighand->siglock); | |
59 | ||
283828f3 DH |
60 | current->state = TASK_INTERRUPTIBLE; |
61 | schedule(); | |
5a8da0ea | 62 | set_restore_sigmask(); |
7e907f48 | 63 | |
283828f3 | 64 | return -ERESTARTNOHAND; |
1da177e4 LT |
65 | } |
66 | ||
7e907f48 | 67 | asmlinkage int |
1da177e4 LT |
68 | sys_sigaction(int sig, const struct old_sigaction __user *act, |
69 | struct old_sigaction __user *oact) | |
70 | { | |
71 | struct k_sigaction new_ka, old_ka; | |
72 | int ret; | |
73 | ||
74 | if (act) { | |
75 | old_sigset_t mask; | |
7e907f48 | 76 | |
1da177e4 LT |
77 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
78 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
79 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
80 | return -EFAULT; | |
7e907f48 | 81 | |
1da177e4 LT |
82 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
83 | __get_user(mask, &act->sa_mask); | |
84 | siginitset(&new_ka.sa.sa_mask, mask); | |
85 | } | |
86 | ||
87 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
88 | ||
89 | if (!ret && oact) { | |
90 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
91 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
92 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
93 | return -EFAULT; | |
7e907f48 | 94 | |
1da177e4 LT |
95 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
96 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
97 | } | |
98 | ||
99 | return ret; | |
100 | } | |
101 | ||
7e907f48 | 102 | asmlinkage int sys_sigaltstack(unsigned long bx) |
1da177e4 | 103 | { |
7e907f48 IM |
104 | /* |
105 | * This is needed to make gcc realize it doesn't own the | |
106 | * "struct pt_regs" | |
107 | */ | |
65ea5b03 PA |
108 | struct pt_regs *regs = (struct pt_regs *)&bx; |
109 | const stack_t __user *uss = (const stack_t __user *)bx; | |
110 | stack_t __user *uoss = (stack_t __user *)regs->cx; | |
1da177e4 | 111 | |
65ea5b03 | 112 | return do_sigaltstack(uss, uoss, regs->sp); |
1da177e4 LT |
113 | } |
114 | ||
115 | ||
116 | /* | |
117 | * Do a signal return; undo the signal stack. | |
118 | */ | |
1da177e4 | 119 | static int |
866bc13f HH |
120 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
121 | unsigned long *pax) | |
1da177e4 LT |
122 | { |
123 | unsigned int err = 0; | |
124 | ||
125 | /* Always make any pending restarted system calls return -EINTR */ | |
126 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
127 | ||
742fa54a | 128 | #define COPY(x) err |= __get_user(regs->x, &sc->x) |
1da177e4 LT |
129 | |
130 | #define COPY_SEG(seg) \ | |
131 | { unsigned short tmp; \ | |
132 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 133 | regs->seg = tmp; } |
1da177e4 LT |
134 | |
135 | #define COPY_SEG_STRICT(seg) \ | |
136 | { unsigned short tmp; \ | |
137 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 138 | regs->seg = tmp|3; } |
1da177e4 LT |
139 | |
140 | #define GET_SEG(seg) \ | |
141 | { unsigned short tmp; \ | |
142 | err |= __get_user(tmp, &sc->seg); \ | |
7e907f48 | 143 | loadsegment(seg, tmp); } |
1da177e4 | 144 | |
464d1a78 JF |
145 | GET_SEG(gs); |
146 | COPY_SEG(fs); | |
1da177e4 LT |
147 | COPY_SEG(es); |
148 | COPY_SEG(ds); | |
ac66f3fd HH |
149 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
150 | COPY(dx); COPY(cx); COPY(ip); | |
1da177e4 LT |
151 | COPY_SEG_STRICT(cs); |
152 | COPY_SEG_STRICT(ss); | |
7e907f48 | 153 | |
1da177e4 LT |
154 | { |
155 | unsigned int tmpflags; | |
7e907f48 | 156 | |
742fa54a | 157 | err |= __get_user(tmpflags, &sc->flags); |
7e907f48 IM |
158 | regs->flags = (regs->flags & ~FIX_EFLAGS) | |
159 | (tmpflags & FIX_EFLAGS); | |
65ea5b03 | 160 | regs->orig_ax = -1; /* disable syscall checks */ |
1da177e4 LT |
161 | } |
162 | ||
163 | { | |
ab513701 | 164 | void __user *buf; |
7e907f48 | 165 | |
1da177e4 | 166 | err |= __get_user(buf, &sc->fpstate); |
ab513701 | 167 | err |= restore_i387_xstate(buf); |
1da177e4 LT |
168 | } |
169 | ||
866bc13f | 170 | err |= __get_user(*pax, &sc->ax); |
1da177e4 | 171 | return err; |
1da177e4 LT |
172 | } |
173 | ||
866bc13f | 174 | asmlinkage unsigned long sys_sigreturn(unsigned long __unused) |
1da177e4 | 175 | { |
7e907f48 IM |
176 | struct sigframe __user *frame; |
177 | struct pt_regs *regs; | |
866bc13f | 178 | unsigned long ax; |
7e907f48 IM |
179 | sigset_t set; |
180 | ||
181 | regs = (struct pt_regs *) &__unused; | |
182 | frame = (struct sigframe __user *)(regs->sp - 8); | |
1da177e4 LT |
183 | |
184 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
185 | goto badframe; | |
7e907f48 | 186 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 |
1da177e4 LT |
187 | && __copy_from_user(&set.sig[1], &frame->extramask, |
188 | sizeof(frame->extramask)))) | |
189 | goto badframe; | |
190 | ||
191 | sigdelsetmask(&set, ~_BLOCKABLE); | |
192 | spin_lock_irq(¤t->sighand->siglock); | |
193 | current->blocked = set; | |
194 | recalc_sigpending(); | |
195 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 196 | |
65ea5b03 | 197 | if (restore_sigcontext(regs, &frame->sc, &ax)) |
1da177e4 | 198 | goto badframe; |
65ea5b03 | 199 | return ax; |
1da177e4 LT |
200 | |
201 | badframe: | |
03252919 | 202 | if (show_unhandled_signals && printk_ratelimit()) { |
1181f8b5 | 203 | printk("%s%s[%d] bad frame in sigreturn frame:" |
97b44ae6 | 204 | "%p ip:%lx sp:%lx oeax:%lx", |
19c5870c | 205 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
65ea5b03 PA |
206 | current->comm, task_pid_nr(current), frame, regs->ip, |
207 | regs->sp, regs->orig_ax); | |
03252919 | 208 | print_vma_addr(" in ", regs->ip); |
97b44ae6 | 209 | printk(KERN_CONT "\n"); |
03252919 | 210 | } |
abd4f750 | 211 | |
1da177e4 | 212 | force_sig(SIGSEGV, current); |
7e907f48 | 213 | |
1da177e4 | 214 | return 0; |
7e907f48 | 215 | } |
1da177e4 LT |
216 | |
217 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
218 | { | |
2d19c458 HH |
219 | struct pt_regs *regs = (struct pt_regs *)&__unused; |
220 | struct rt_sigframe __user *frame; | |
866bc13f | 221 | unsigned long ax; |
1da177e4 | 222 | sigset_t set; |
1da177e4 | 223 | |
2d19c458 | 224 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); |
1da177e4 LT |
225 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
226 | goto badframe; | |
227 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
228 | goto badframe; | |
229 | ||
230 | sigdelsetmask(&set, ~_BLOCKABLE); | |
231 | spin_lock_irq(¤t->sighand->siglock); | |
232 | current->blocked = set; | |
233 | recalc_sigpending(); | |
234 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 235 | |
65ea5b03 | 236 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
1da177e4 LT |
237 | goto badframe; |
238 | ||
65ea5b03 | 239 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
1da177e4 LT |
240 | goto badframe; |
241 | ||
65ea5b03 | 242 | return ax; |
1da177e4 LT |
243 | |
244 | badframe: | |
245 | force_sig(SIGSEGV, current); | |
246 | return 0; | |
7e907f48 | 247 | } |
1da177e4 LT |
248 | |
249 | /* | |
250 | * Set up a signal frame. | |
251 | */ | |
1da177e4 | 252 | static int |
ab513701 | 253 | setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
1da177e4 LT |
254 | struct pt_regs *regs, unsigned long mask) |
255 | { | |
256 | int tmp, err = 0; | |
257 | ||
65ea5b03 | 258 | err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
464d1a78 JF |
259 | savesegment(gs, tmp); |
260 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 | 261 | |
65ea5b03 PA |
262 | err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
263 | err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); | |
742fa54a PA |
264 | err |= __put_user(regs->di, &sc->di); |
265 | err |= __put_user(regs->si, &sc->si); | |
266 | err |= __put_user(regs->bp, &sc->bp); | |
267 | err |= __put_user(regs->sp, &sc->sp); | |
268 | err |= __put_user(regs->bx, &sc->bx); | |
269 | err |= __put_user(regs->dx, &sc->dx); | |
270 | err |= __put_user(regs->cx, &sc->cx); | |
271 | err |= __put_user(regs->ax, &sc->ax); | |
1da177e4 LT |
272 | err |= __put_user(current->thread.trap_no, &sc->trapno); |
273 | err |= __put_user(current->thread.error_code, &sc->err); | |
742fa54a | 274 | err |= __put_user(regs->ip, &sc->ip); |
65ea5b03 | 275 | err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
742fa54a PA |
276 | err |= __put_user(regs->flags, &sc->flags); |
277 | err |= __put_user(regs->sp, &sc->sp_at_signal); | |
65ea5b03 | 278 | err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
1da177e4 | 279 | |
ab513701 | 280 | tmp = save_i387_xstate(fpstate); |
1da177e4 | 281 | if (tmp < 0) |
7e907f48 | 282 | err = 1; |
1da177e4 | 283 | else |
7e907f48 | 284 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); |
1da177e4 LT |
285 | |
286 | /* non-iBCS2 extensions.. */ | |
287 | err |= __put_user(mask, &sc->oldmask); | |
288 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
289 | ||
290 | return err; | |
291 | } | |
292 | ||
293 | /* | |
294 | * Determine which stack to use.. | |
295 | */ | |
296 | static inline void __user * | |
3c1c7f10 | 297 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
ab513701 | 298 | void **fpstate) |
1da177e4 | 299 | { |
65ea5b03 | 300 | unsigned long sp; |
1da177e4 LT |
301 | |
302 | /* Default to using normal stack */ | |
65ea5b03 | 303 | sp = regs->sp; |
1da177e4 | 304 | |
83bd0102 RM |
305 | /* |
306 | * If we are on the alternate signal stack and would overflow it, don't. | |
307 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
308 | */ | |
65ea5b03 | 309 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
83bd0102 RM |
310 | return (void __user *) -1L; |
311 | ||
1da177e4 LT |
312 | /* This is the X/Open sanctioned signal stack switching. */ |
313 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
65ea5b03 PA |
314 | if (sas_ss_flags(sp) == 0) |
315 | sp = current->sas_ss_sp + current->sas_ss_size; | |
7e907f48 IM |
316 | } else { |
317 | /* This is the legacy signal stack switching. */ | |
318 | if ((regs->ss & 0xffff) != __USER_DS && | |
319 | !(ka->sa.sa_flags & SA_RESTORER) && | |
320 | ka->sa.sa_restorer) | |
321 | sp = (unsigned long) ka->sa.sa_restorer; | |
1da177e4 LT |
322 | } |
323 | ||
3c1c7f10 SS |
324 | if (used_math()) { |
325 | sp = sp - sig_xstate_size; | |
326 | *fpstate = (struct _fpstate *) sp; | |
327 | } | |
328 | ||
65ea5b03 | 329 | sp -= frame_size; |
7e907f48 IM |
330 | /* |
331 | * Align the stack pointer according to the i386 ABI, | |
332 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
333 | */ | |
65ea5b03 | 334 | sp = ((sp + 4) & -16ul) - 4; |
7e907f48 | 335 | |
65ea5b03 | 336 | return (void __user *) sp; |
1da177e4 LT |
337 | } |
338 | ||
7e907f48 IM |
339 | static int |
340 | setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, | |
341 | struct pt_regs *regs) | |
1da177e4 | 342 | { |
1da177e4 | 343 | struct sigframe __user *frame; |
7e907f48 | 344 | void __user *restorer; |
1da177e4 LT |
345 | int err = 0; |
346 | int usig; | |
ab513701 | 347 | void __user *fpstate = NULL; |
1da177e4 | 348 | |
3c1c7f10 | 349 | frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
350 | |
351 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
352 | goto give_sigsegv; | |
353 | ||
354 | usig = current_thread_info()->exec_domain | |
355 | && current_thread_info()->exec_domain->signal_invmap | |
356 | && sig < 32 | |
357 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
358 | : sig; | |
359 | ||
360 | err = __put_user(usig, &frame->sig); | |
361 | if (err) | |
362 | goto give_sigsegv; | |
363 | ||
3c1c7f10 | 364 | err = setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]); |
1da177e4 LT |
365 | if (err) |
366 | goto give_sigsegv; | |
367 | ||
368 | if (_NSIG_WORDS > 1) { | |
369 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
370 | sizeof(frame->extramask)); | |
371 | if (err) | |
372 | goto give_sigsegv; | |
373 | } | |
374 | ||
1a3e4ca4 | 375 | if (current->mm->context.vdso) |
6c3652ef | 376 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
9fbbd4dd | 377 | else |
ade1af77 | 378 | restorer = &frame->retcode; |
1da177e4 LT |
379 | if (ka->sa.sa_flags & SA_RESTORER) |
380 | restorer = ka->sa.sa_restorer; | |
381 | ||
382 | /* Set up to return from userspace. */ | |
383 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 384 | |
1da177e4 | 385 | /* |
7e907f48 | 386 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
387 | * |
388 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
389 | * reasons and because gdb uses it as a signature to notice | |
390 | * signal handler stack frames. | |
391 | */ | |
392 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
393 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
394 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
395 | ||
396 | if (err) | |
397 | goto give_sigsegv; | |
398 | ||
399 | /* Set up registers for signal handler */ | |
7e907f48 IM |
400 | regs->sp = (unsigned long)frame; |
401 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
402 | regs->ax = (unsigned long)sig; | |
92bc2056 HH |
403 | regs->dx = 0; |
404 | regs->cx = 0; | |
1da177e4 | 405 | |
65ea5b03 PA |
406 | regs->ds = __USER_DS; |
407 | regs->es = __USER_DS; | |
408 | regs->ss = __USER_DS; | |
409 | regs->cs = __USER_CS; | |
1da177e4 | 410 | |
283828f3 | 411 | return 0; |
1da177e4 LT |
412 | |
413 | give_sigsegv: | |
414 | force_sigsegv(sig, current); | |
283828f3 | 415 | return -EFAULT; |
1da177e4 LT |
416 | } |
417 | ||
7c1def16 | 418 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
7e907f48 | 419 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 420 | { |
1da177e4 | 421 | struct rt_sigframe __user *frame; |
7e907f48 | 422 | void __user *restorer; |
1da177e4 LT |
423 | int err = 0; |
424 | int usig; | |
ab513701 | 425 | void __user *fpstate = NULL; |
1da177e4 | 426 | |
3c1c7f10 | 427 | frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
428 | |
429 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
430 | goto give_sigsegv; | |
431 | ||
432 | usig = current_thread_info()->exec_domain | |
433 | && current_thread_info()->exec_domain->signal_invmap | |
434 | && sig < 32 | |
435 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
436 | : sig; | |
437 | ||
438 | err |= __put_user(usig, &frame->sig); | |
439 | err |= __put_user(&frame->info, &frame->pinfo); | |
440 | err |= __put_user(&frame->uc, &frame->puc); | |
441 | err |= copy_siginfo_to_user(&frame->info, info); | |
442 | if (err) | |
443 | goto give_sigsegv; | |
444 | ||
445 | /* Create the ucontext. */ | |
c37b5efe SS |
446 | if (cpu_has_xsave) |
447 | err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); | |
448 | else | |
449 | err |= __put_user(0, &frame->uc.uc_flags); | |
1da177e4 LT |
450 | err |= __put_user(0, &frame->uc.uc_link); |
451 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
65ea5b03 | 452 | err |= __put_user(sas_ss_flags(regs->sp), |
1da177e4 LT |
453 | &frame->uc.uc_stack.ss_flags); |
454 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
3c1c7f10 | 455 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
7e907f48 | 456 | regs, set->sig[0]); |
1da177e4 LT |
457 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
458 | if (err) | |
459 | goto give_sigsegv; | |
460 | ||
461 | /* Set up to return from userspace. */ | |
6c3652ef | 462 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); |
1da177e4 LT |
463 | if (ka->sa.sa_flags & SA_RESTORER) |
464 | restorer = ka->sa.sa_restorer; | |
465 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 466 | |
1da177e4 | 467 | /* |
7e907f48 | 468 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 |
1da177e4 LT |
469 | * |
470 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
471 | * reasons and because gdb uses it as a signature to notice | |
472 | * signal handler stack frames. | |
473 | */ | |
474 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); | |
475 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); | |
476 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); | |
477 | ||
478 | if (err) | |
479 | goto give_sigsegv; | |
480 | ||
481 | /* Set up registers for signal handler */ | |
7e907f48 IM |
482 | regs->sp = (unsigned long)frame; |
483 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
484 | regs->ax = (unsigned long)usig; | |
485 | regs->dx = (unsigned long)&frame->info; | |
486 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 487 | |
65ea5b03 PA |
488 | regs->ds = __USER_DS; |
489 | regs->es = __USER_DS; | |
490 | regs->ss = __USER_DS; | |
491 | regs->cs = __USER_CS; | |
1da177e4 | 492 | |
283828f3 | 493 | return 0; |
1da177e4 LT |
494 | |
495 | give_sigsegv: | |
496 | force_sigsegv(sig, current); | |
283828f3 | 497 | return -EFAULT; |
1da177e4 LT |
498 | } |
499 | ||
500 | /* | |
7e907f48 IM |
501 | * OK, we're invoking a handler: |
502 | */ | |
7c1def16 | 503 | static int |
1da177e4 | 504 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
ac66f3fd | 505 | sigset_t *oldset, struct pt_regs *regs) |
1da177e4 | 506 | { |
7c1def16 RM |
507 | int ret; |
508 | ||
1da177e4 | 509 | /* Are we from a system call? */ |
9902a702 | 510 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 511 | /* If so, check system call restarting.. */ |
65ea5b03 | 512 | switch (regs->ax) { |
ac66f3fd HH |
513 | case -ERESTART_RESTARTBLOCK: |
514 | case -ERESTARTNOHAND: | |
515 | regs->ax = -EINTR; | |
516 | break; | |
517 | ||
518 | case -ERESTARTSYS: | |
519 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
65ea5b03 | 520 | regs->ax = -EINTR; |
1da177e4 | 521 | break; |
ac66f3fd HH |
522 | } |
523 | /* fallthrough */ | |
524 | case -ERESTARTNOINTR: | |
525 | regs->ax = regs->orig_ax; | |
526 | regs->ip -= 2; | |
527 | break; | |
1da177e4 LT |
528 | } |
529 | } | |
530 | ||
531 | /* | |
e1f28773 RM |
532 | * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
533 | * flag so that register information in the sigcontext is correct. | |
1da177e4 | 534 | */ |
65ea5b03 | 535 | if (unlikely(regs->flags & X86_EFLAGS_TF) && |
e1f28773 | 536 | likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
65ea5b03 | 537 | regs->flags &= ~X86_EFLAGS_TF; |
1da177e4 LT |
538 | |
539 | /* Set up the stack frame */ | |
540 | if (ka->sa.sa_flags & SA_SIGINFO) | |
7c1def16 | 541 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 542 | else |
7c1def16 | 543 | ret = setup_frame(sig, ka, oldset, regs); |
1da177e4 | 544 | |
7e907f48 IM |
545 | if (ret) |
546 | return ret; | |
7c1def16 | 547 | |
8b9c5ff3 RM |
548 | /* |
549 | * Clear the direction flag as per the ABI for function entry. | |
550 | */ | |
551 | regs->flags &= ~X86_EFLAGS_DF; | |
552 | ||
553 | /* | |
554 | * Clear TF when entering the signal handler, but | |
555 | * notify any tracer that was single-stepping it. | |
556 | * The tracer may want to single-step inside the | |
557 | * handler too. | |
558 | */ | |
559 | regs->flags &= ~X86_EFLAGS_TF; | |
8b9c5ff3 | 560 | |
7e907f48 IM |
561 | spin_lock_irq(¤t->sighand->siglock); |
562 | sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); | |
563 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
564 | sigaddset(¤t->blocked, sig); | |
565 | recalc_sigpending(); | |
566 | spin_unlock_irq(¤t->sighand->siglock); | |
567 | ||
36a03308 RM |
568 | tracehook_signal_handler(sig, info, ka, regs, |
569 | test_thread_flag(TIF_SINGLESTEP)); | |
570 | ||
7e907f48 | 571 | return 0; |
1da177e4 LT |
572 | } |
573 | ||
574 | /* | |
575 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
576 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
577 | * mistake. | |
578 | */ | |
75604d7f | 579 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 580 | { |
ac66f3fd | 581 | struct k_sigaction ka; |
1da177e4 LT |
582 | siginfo_t info; |
583 | int signr; | |
283828f3 | 584 | sigset_t *oldset; |
1da177e4 LT |
585 | |
586 | /* | |
ac66f3fd HH |
587 | * We want the common case to go fast, which is why we may in certain |
588 | * cases get here from kernel mode. Just return without doing anything | |
589 | * if so. | |
590 | * X86_32: vm86 regs switched out by assembly code before reaching | |
591 | * here, so testing against kernel CS suffices. | |
1da177e4 | 592 | */ |
717b594a | 593 | if (!user_mode(regs)) |
283828f3 | 594 | return; |
1da177e4 | 595 | |
5a8da0ea | 596 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) |
283828f3 DH |
597 | oldset = ¤t->saved_sigmask; |
598 | else | |
1da177e4 LT |
599 | oldset = ¤t->blocked; |
600 | ||
601 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
602 | if (signr > 0) { | |
7e907f48 IM |
603 | /* |
604 | * Re-enable any watchpoints before delivering the | |
1da177e4 LT |
605 | * signal to user space. The processor register will |
606 | * have been cleared if the watchpoint triggered | |
607 | * inside the kernel. | |
608 | */ | |
ac66f3fd | 609 | if (current->thread.debugreg7) |
0f534093 | 610 | set_debugreg(current->thread.debugreg7, 7); |
1da177e4 | 611 | |
7e907f48 | 612 | /* Whee! Actually deliver the signal. */ |
283828f3 | 613 | if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
7e907f48 | 614 | /* |
5a8da0ea | 615 | * A signal was successfully delivered; the saved |
283828f3 DH |
616 | * sigmask will have been stored in the signal frame, |
617 | * and will be restored by sigreturn, so we can simply | |
5a8da0ea | 618 | * clear the TS_RESTORE_SIGMASK flag. |
7e907f48 | 619 | */ |
5a8da0ea | 620 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
283828f3 | 621 | } |
283828f3 | 622 | return; |
1da177e4 LT |
623 | } |
624 | ||
1da177e4 | 625 | /* Did we come from a system call? */ |
9902a702 | 626 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 627 | /* Restart the system call - no handlers present */ |
65ea5b03 | 628 | switch (regs->ax) { |
283828f3 DH |
629 | case -ERESTARTNOHAND: |
630 | case -ERESTARTSYS: | |
631 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
632 | regs->ax = regs->orig_ax; |
633 | regs->ip -= 2; | |
283828f3 DH |
634 | break; |
635 | ||
636 | case -ERESTART_RESTARTBLOCK: | |
65ea5b03 PA |
637 | regs->ax = __NR_restart_syscall; |
638 | regs->ip -= 2; | |
283828f3 | 639 | break; |
1da177e4 LT |
640 | } |
641 | } | |
283828f3 | 642 | |
ac66f3fd HH |
643 | /* |
644 | * If there's no signal to deliver, we just put the saved sigmask | |
645 | * back. | |
646 | */ | |
5a8da0ea RM |
647 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) { |
648 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; | |
283828f3 DH |
649 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
650 | } | |
1da177e4 LT |
651 | } |
652 | ||
653 | /* | |
654 | * notification of userspace execution resumption | |
283828f3 | 655 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 656 | */ |
7e907f48 IM |
657 | void |
658 | do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) | |
1da177e4 | 659 | { |
1da177e4 | 660 | /* deal with pending signal delivery */ |
5a8da0ea | 661 | if (thread_info_flags & _TIF_SIGPENDING) |
283828f3 | 662 | do_signal(regs); |
8f4d37ec | 663 | |
59e52130 RM |
664 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
665 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
666 | tracehook_notify_resume(regs); | |
667 | } | |
668 | ||
1da177e4 LT |
669 | clear_thread_flag(TIF_IRET); |
670 | } |