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> |
1da177e4 | 20 | #include <linux/elf.h> |
7e907f48 IM |
21 | #include <linux/smp.h> |
22 | #include <linux/mm.h> | |
23 | ||
1da177e4 LT |
24 | #include <asm/processor.h> |
25 | #include <asm/ucontext.h> | |
26 | #include <asm/uaccess.h> | |
27 | #include <asm/i387.h> | |
6c3652ef | 28 | #include <asm/vdso.h> |
7e907f48 | 29 | |
123a6347 | 30 | #include "sigframe.h" |
1da177e4 | 31 | |
1da177e4 LT |
32 | #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP))) |
33 | ||
1a176803 HH |
34 | #define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \ |
35 | X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \ | |
36 | X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \ | |
37 | X86_EFLAGS_CF) | |
38 | ||
39 | #ifdef CONFIG_X86_32 | |
40 | # define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF) | |
41 | #else | |
42 | # define FIX_EFLAGS __FIX_EFLAGS | |
43 | #endif | |
44 | ||
1da177e4 LT |
45 | /* |
46 | * Atomically swap in the new signal mask, and wait for a signal. | |
47 | */ | |
48 | asmlinkage int | |
49 | sys_sigsuspend(int history0, int history1, old_sigset_t mask) | |
50 | { | |
1da177e4 LT |
51 | mask &= _BLOCKABLE; |
52 | spin_lock_irq(¤t->sighand->siglock); | |
283828f3 | 53 | current->saved_sigmask = current->blocked; |
1da177e4 LT |
54 | siginitset(¤t->blocked, mask); |
55 | recalc_sigpending(); | |
56 | spin_unlock_irq(¤t->sighand->siglock); | |
57 | ||
283828f3 DH |
58 | current->state = TASK_INTERRUPTIBLE; |
59 | schedule(); | |
5a8da0ea | 60 | set_restore_sigmask(); |
7e907f48 | 61 | |
283828f3 | 62 | return -ERESTARTNOHAND; |
1da177e4 LT |
63 | } |
64 | ||
7e907f48 | 65 | asmlinkage int |
1da177e4 LT |
66 | sys_sigaction(int sig, const struct old_sigaction __user *act, |
67 | struct old_sigaction __user *oact) | |
68 | { | |
69 | struct k_sigaction new_ka, old_ka; | |
70 | int ret; | |
71 | ||
72 | if (act) { | |
73 | old_sigset_t mask; | |
7e907f48 | 74 | |
1da177e4 LT |
75 | if (!access_ok(VERIFY_READ, act, sizeof(*act)) || |
76 | __get_user(new_ka.sa.sa_handler, &act->sa_handler) || | |
77 | __get_user(new_ka.sa.sa_restorer, &act->sa_restorer)) | |
78 | return -EFAULT; | |
7e907f48 | 79 | |
1da177e4 LT |
80 | __get_user(new_ka.sa.sa_flags, &act->sa_flags); |
81 | __get_user(mask, &act->sa_mask); | |
82 | siginitset(&new_ka.sa.sa_mask, mask); | |
83 | } | |
84 | ||
85 | ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL); | |
86 | ||
87 | if (!ret && oact) { | |
88 | if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) || | |
89 | __put_user(old_ka.sa.sa_handler, &oact->sa_handler) || | |
90 | __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer)) | |
91 | return -EFAULT; | |
7e907f48 | 92 | |
1da177e4 LT |
93 | __put_user(old_ka.sa.sa_flags, &oact->sa_flags); |
94 | __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask); | |
95 | } | |
96 | ||
97 | return ret; | |
98 | } | |
99 | ||
7e907f48 | 100 | asmlinkage int sys_sigaltstack(unsigned long bx) |
1da177e4 | 101 | { |
7e907f48 IM |
102 | /* |
103 | * This is needed to make gcc realize it doesn't own the | |
104 | * "struct pt_regs" | |
105 | */ | |
65ea5b03 PA |
106 | struct pt_regs *regs = (struct pt_regs *)&bx; |
107 | const stack_t __user *uss = (const stack_t __user *)bx; | |
108 | stack_t __user *uoss = (stack_t __user *)regs->cx; | |
1da177e4 | 109 | |
65ea5b03 | 110 | return do_sigaltstack(uss, uoss, regs->sp); |
1da177e4 LT |
111 | } |
112 | ||
113 | ||
114 | /* | |
115 | * Do a signal return; undo the signal stack. | |
116 | */ | |
1da177e4 | 117 | static int |
866bc13f HH |
118 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
119 | unsigned long *pax) | |
1da177e4 LT |
120 | { |
121 | unsigned int err = 0; | |
122 | ||
123 | /* Always make any pending restarted system calls return -EINTR */ | |
124 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
125 | ||
742fa54a | 126 | #define COPY(x) err |= __get_user(regs->x, &sc->x) |
1da177e4 LT |
127 | |
128 | #define COPY_SEG(seg) \ | |
129 | { unsigned short tmp; \ | |
130 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 131 | regs->seg = tmp; } |
1da177e4 LT |
132 | |
133 | #define COPY_SEG_STRICT(seg) \ | |
134 | { unsigned short tmp; \ | |
135 | err |= __get_user(tmp, &sc->seg); \ | |
65ea5b03 | 136 | regs->seg = tmp|3; } |
1da177e4 LT |
137 | |
138 | #define GET_SEG(seg) \ | |
139 | { unsigned short tmp; \ | |
140 | err |= __get_user(tmp, &sc->seg); \ | |
7e907f48 | 141 | loadsegment(seg, tmp); } |
1da177e4 | 142 | |
464d1a78 JF |
143 | GET_SEG(gs); |
144 | COPY_SEG(fs); | |
1da177e4 LT |
145 | COPY_SEG(es); |
146 | COPY_SEG(ds); | |
ac66f3fd HH |
147 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
148 | COPY(dx); COPY(cx); COPY(ip); | |
1da177e4 LT |
149 | COPY_SEG_STRICT(cs); |
150 | COPY_SEG_STRICT(ss); | |
7e907f48 | 151 | |
1da177e4 LT |
152 | { |
153 | unsigned int tmpflags; | |
7e907f48 | 154 | |
742fa54a | 155 | err |= __get_user(tmpflags, &sc->flags); |
7e907f48 IM |
156 | regs->flags = (regs->flags & ~FIX_EFLAGS) | |
157 | (tmpflags & FIX_EFLAGS); | |
65ea5b03 | 158 | regs->orig_ax = -1; /* disable syscall checks */ |
1da177e4 LT |
159 | } |
160 | ||
161 | { | |
7e907f48 IM |
162 | struct _fpstate __user *buf; |
163 | ||
1da177e4 LT |
164 | err |= __get_user(buf, &sc->fpstate); |
165 | if (buf) { | |
166 | if (!access_ok(VERIFY_READ, buf, sizeof(*buf))) | |
167 | goto badframe; | |
168 | err |= restore_i387(buf); | |
169 | } else { | |
170 | struct task_struct *me = current; | |
7e907f48 | 171 | |
1da177e4 LT |
172 | if (used_math()) { |
173 | clear_fpu(me); | |
174 | clear_used_math(); | |
175 | } | |
176 | } | |
177 | } | |
178 | ||
866bc13f | 179 | err |= __get_user(*pax, &sc->ax); |
1da177e4 LT |
180 | return err; |
181 | ||
182 | badframe: | |
183 | return 1; | |
184 | } | |
185 | ||
866bc13f | 186 | asmlinkage unsigned long sys_sigreturn(unsigned long __unused) |
1da177e4 | 187 | { |
7e907f48 IM |
188 | struct sigframe __user *frame; |
189 | struct pt_regs *regs; | |
866bc13f | 190 | unsigned long ax; |
7e907f48 IM |
191 | sigset_t set; |
192 | ||
193 | regs = (struct pt_regs *) &__unused; | |
194 | frame = (struct sigframe __user *)(regs->sp - 8); | |
1da177e4 LT |
195 | |
196 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
197 | goto badframe; | |
7e907f48 | 198 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 |
1da177e4 LT |
199 | && __copy_from_user(&set.sig[1], &frame->extramask, |
200 | sizeof(frame->extramask)))) | |
201 | goto badframe; | |
202 | ||
203 | sigdelsetmask(&set, ~_BLOCKABLE); | |
204 | spin_lock_irq(¤t->sighand->siglock); | |
205 | current->blocked = set; | |
206 | recalc_sigpending(); | |
207 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 208 | |
65ea5b03 | 209 | if (restore_sigcontext(regs, &frame->sc, &ax)) |
1da177e4 | 210 | goto badframe; |
65ea5b03 | 211 | return ax; |
1da177e4 LT |
212 | |
213 | badframe: | |
03252919 | 214 | if (show_unhandled_signals && printk_ratelimit()) { |
1181f8b5 | 215 | printk("%s%s[%d] bad frame in sigreturn frame:" |
97b44ae6 | 216 | "%p ip:%lx sp:%lx oeax:%lx", |
19c5870c | 217 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
65ea5b03 PA |
218 | current->comm, task_pid_nr(current), frame, regs->ip, |
219 | regs->sp, regs->orig_ax); | |
03252919 | 220 | print_vma_addr(" in ", regs->ip); |
97b44ae6 | 221 | printk(KERN_CONT "\n"); |
03252919 | 222 | } |
abd4f750 | 223 | |
1da177e4 | 224 | force_sig(SIGSEGV, current); |
7e907f48 | 225 | |
1da177e4 | 226 | return 0; |
7e907f48 | 227 | } |
1da177e4 LT |
228 | |
229 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) | |
230 | { | |
2d19c458 HH |
231 | struct pt_regs *regs = (struct pt_regs *)&__unused; |
232 | struct rt_sigframe __user *frame; | |
866bc13f | 233 | unsigned long ax; |
1da177e4 | 234 | sigset_t set; |
1da177e4 | 235 | |
2d19c458 | 236 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); |
1da177e4 LT |
237 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
238 | goto badframe; | |
239 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
240 | goto badframe; | |
241 | ||
242 | sigdelsetmask(&set, ~_BLOCKABLE); | |
243 | spin_lock_irq(¤t->sighand->siglock); | |
244 | current->blocked = set; | |
245 | recalc_sigpending(); | |
246 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 247 | |
65ea5b03 | 248 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
1da177e4 LT |
249 | goto badframe; |
250 | ||
65ea5b03 | 251 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
1da177e4 LT |
252 | goto badframe; |
253 | ||
65ea5b03 | 254 | return ax; |
1da177e4 LT |
255 | |
256 | badframe: | |
257 | force_sig(SIGSEGV, current); | |
258 | return 0; | |
7e907f48 | 259 | } |
1da177e4 LT |
260 | |
261 | /* | |
262 | * Set up a signal frame. | |
263 | */ | |
1da177e4 LT |
264 | static int |
265 | setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, | |
266 | struct pt_regs *regs, unsigned long mask) | |
267 | { | |
268 | int tmp, err = 0; | |
269 | ||
65ea5b03 | 270 | err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
464d1a78 JF |
271 | savesegment(gs, tmp); |
272 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 | 273 | |
65ea5b03 PA |
274 | err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
275 | err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); | |
742fa54a PA |
276 | err |= __put_user(regs->di, &sc->di); |
277 | err |= __put_user(regs->si, &sc->si); | |
278 | err |= __put_user(regs->bp, &sc->bp); | |
279 | err |= __put_user(regs->sp, &sc->sp); | |
280 | err |= __put_user(regs->bx, &sc->bx); | |
281 | err |= __put_user(regs->dx, &sc->dx); | |
282 | err |= __put_user(regs->cx, &sc->cx); | |
283 | err |= __put_user(regs->ax, &sc->ax); | |
1da177e4 LT |
284 | err |= __put_user(current->thread.trap_no, &sc->trapno); |
285 | err |= __put_user(current->thread.error_code, &sc->err); | |
742fa54a | 286 | err |= __put_user(regs->ip, &sc->ip); |
65ea5b03 | 287 | err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
742fa54a PA |
288 | err |= __put_user(regs->flags, &sc->flags); |
289 | err |= __put_user(regs->sp, &sc->sp_at_signal); | |
65ea5b03 | 290 | err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
1da177e4 LT |
291 | |
292 | tmp = save_i387(fpstate); | |
293 | if (tmp < 0) | |
7e907f48 | 294 | err = 1; |
1da177e4 | 295 | else |
7e907f48 | 296 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); |
1da177e4 LT |
297 | |
298 | /* non-iBCS2 extensions.. */ | |
299 | err |= __put_user(mask, &sc->oldmask); | |
300 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
301 | ||
302 | return err; | |
303 | } | |
304 | ||
305 | /* | |
306 | * Determine which stack to use.. | |
307 | */ | |
308 | static inline void __user * | |
7e907f48 | 309 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size) |
1da177e4 | 310 | { |
65ea5b03 | 311 | unsigned long sp; |
1da177e4 LT |
312 | |
313 | /* Default to using normal stack */ | |
65ea5b03 | 314 | sp = regs->sp; |
1da177e4 | 315 | |
83bd0102 RM |
316 | /* |
317 | * If we are on the alternate signal stack and would overflow it, don't. | |
318 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
319 | */ | |
65ea5b03 | 320 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
83bd0102 RM |
321 | return (void __user *) -1L; |
322 | ||
1da177e4 LT |
323 | /* This is the X/Open sanctioned signal stack switching. */ |
324 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
65ea5b03 PA |
325 | if (sas_ss_flags(sp) == 0) |
326 | sp = current->sas_ss_sp + current->sas_ss_size; | |
7e907f48 IM |
327 | } else { |
328 | /* This is the legacy signal stack switching. */ | |
329 | if ((regs->ss & 0xffff) != __USER_DS && | |
330 | !(ka->sa.sa_flags & SA_RESTORER) && | |
331 | ka->sa.sa_restorer) | |
332 | sp = (unsigned long) ka->sa.sa_restorer; | |
1da177e4 LT |
333 | } |
334 | ||
65ea5b03 | 335 | sp -= frame_size; |
7e907f48 IM |
336 | /* |
337 | * Align the stack pointer according to the i386 ABI, | |
338 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
339 | */ | |
65ea5b03 | 340 | sp = ((sp + 4) & -16ul) - 4; |
7e907f48 | 341 | |
65ea5b03 | 342 | return (void __user *) sp; |
1da177e4 LT |
343 | } |
344 | ||
7e907f48 IM |
345 | static int |
346 | setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, | |
347 | struct pt_regs *regs) | |
1da177e4 | 348 | { |
1da177e4 | 349 | struct sigframe __user *frame; |
7e907f48 | 350 | void __user *restorer; |
1da177e4 LT |
351 | int err = 0; |
352 | int usig; | |
353 | ||
354 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
355 | ||
356 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
357 | goto give_sigsegv; | |
358 | ||
359 | usig = current_thread_info()->exec_domain | |
360 | && current_thread_info()->exec_domain->signal_invmap | |
361 | && sig < 32 | |
362 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
363 | : sig; | |
364 | ||
365 | err = __put_user(usig, &frame->sig); | |
366 | if (err) | |
367 | goto give_sigsegv; | |
368 | ||
369 | err = setup_sigcontext(&frame->sc, &frame->fpstate, regs, set->sig[0]); | |
370 | if (err) | |
371 | goto give_sigsegv; | |
372 | ||
373 | if (_NSIG_WORDS > 1) { | |
374 | err = __copy_to_user(&frame->extramask, &set->sig[1], | |
375 | sizeof(frame->extramask)); | |
376 | if (err) | |
377 | goto give_sigsegv; | |
378 | } | |
379 | ||
1a3e4ca4 | 380 | if (current->mm->context.vdso) |
6c3652ef | 381 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
9fbbd4dd | 382 | else |
ade1af77 | 383 | restorer = &frame->retcode; |
1da177e4 LT |
384 | if (ka->sa.sa_flags & SA_RESTORER) |
385 | restorer = ka->sa.sa_restorer; | |
386 | ||
387 | /* Set up to return from userspace. */ | |
388 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 389 | |
1da177e4 | 390 | /* |
7e907f48 | 391 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
392 | * |
393 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
394 | * reasons and because gdb uses it as a signature to notice | |
395 | * signal handler stack frames. | |
396 | */ | |
397 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
398 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
399 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
400 | ||
401 | if (err) | |
402 | goto give_sigsegv; | |
403 | ||
404 | /* Set up registers for signal handler */ | |
7e907f48 IM |
405 | regs->sp = (unsigned long)frame; |
406 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
407 | regs->ax = (unsigned long)sig; | |
92bc2056 HH |
408 | regs->dx = 0; |
409 | regs->cx = 0; | |
1da177e4 | 410 | |
65ea5b03 PA |
411 | regs->ds = __USER_DS; |
412 | regs->es = __USER_DS; | |
413 | regs->ss = __USER_DS; | |
414 | regs->cs = __USER_CS; | |
1da177e4 | 415 | |
283828f3 | 416 | return 0; |
1da177e4 LT |
417 | |
418 | give_sigsegv: | |
419 | force_sigsegv(sig, current); | |
283828f3 | 420 | return -EFAULT; |
1da177e4 LT |
421 | } |
422 | ||
7c1def16 | 423 | static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
7e907f48 | 424 | sigset_t *set, struct pt_regs *regs) |
1da177e4 | 425 | { |
1da177e4 | 426 | struct rt_sigframe __user *frame; |
7e907f48 | 427 | void __user *restorer; |
1da177e4 LT |
428 | int err = 0; |
429 | int usig; | |
430 | ||
431 | frame = get_sigframe(ka, regs, sizeof(*frame)); | |
432 | ||
433 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
434 | goto give_sigsegv; | |
435 | ||
436 | usig = current_thread_info()->exec_domain | |
437 | && current_thread_info()->exec_domain->signal_invmap | |
438 | && sig < 32 | |
439 | ? current_thread_info()->exec_domain->signal_invmap[sig] | |
440 | : sig; | |
441 | ||
442 | err |= __put_user(usig, &frame->sig); | |
443 | err |= __put_user(&frame->info, &frame->pinfo); | |
444 | err |= __put_user(&frame->uc, &frame->puc); | |
445 | err |= copy_siginfo_to_user(&frame->info, info); | |
446 | if (err) | |
447 | goto give_sigsegv; | |
448 | ||
449 | /* Create the ucontext. */ | |
450 | err |= __put_user(0, &frame->uc.uc_flags); | |
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); | |
456 | err |= setup_sigcontext(&frame->uc.uc_mcontext, &frame->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? */ |
9902a702 | 511 | if ((long)regs->orig_ax >= 0) { |
1da177e4 | 512 | /* If so, check system call restarting.. */ |
65ea5b03 | 513 | switch (regs->ax) { |
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; | |
561 | if (test_thread_flag(TIF_SINGLESTEP)) | |
562 | ptrace_notify(SIGTRAP); | |
563 | ||
7e907f48 IM |
564 | spin_lock_irq(¤t->sighand->siglock); |
565 | sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); | |
566 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
567 | sigaddset(¤t->blocked, sig); | |
568 | recalc_sigpending(); | |
569 | spin_unlock_irq(¤t->sighand->siglock); | |
570 | ||
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 PZ |
663 | |
664 | if (thread_info_flags & _TIF_HRTICK_RESCHED) | |
665 | hrtick_resched(); | |
7e907f48 | 666 | |
1da177e4 LT |
667 | clear_thread_flag(TIF_IRET); |
668 | } |