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 | ||
a2e8d3dc HS |
116 | #define COPY(x) { \ |
117 | err |= __get_user(regs->x, &sc->x); \ | |
118 | } | |
119 | ||
120 | #define COPY_SEG(seg) { \ | |
121 | unsigned short tmp; \ | |
122 | err |= __get_user(tmp, &sc->seg); \ | |
123 | regs->seg = tmp; \ | |
124 | } | |
125 | ||
126 | #define COPY_SEG_STRICT(seg) { \ | |
127 | unsigned short tmp; \ | |
128 | err |= __get_user(tmp, &sc->seg); \ | |
129 | regs->seg = tmp | 3; \ | |
130 | } | |
131 | ||
132 | #define GET_SEG(seg) { \ | |
133 | unsigned short tmp; \ | |
134 | err |= __get_user(tmp, &sc->seg); \ | |
135 | loadsegment(seg, tmp); \ | |
136 | } | |
1da177e4 LT |
137 | |
138 | /* | |
139 | * Do a signal return; undo the signal stack. | |
140 | */ | |
1da177e4 | 141 | static int |
866bc13f HH |
142 | restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, |
143 | unsigned long *pax) | |
1da177e4 | 144 | { |
69e13ad5 HS |
145 | void __user *buf; |
146 | unsigned int tmpflags; | |
1da177e4 LT |
147 | unsigned int err = 0; |
148 | ||
149 | /* Always make any pending restarted system calls return -EINTR */ | |
150 | current_thread_info()->restart_block.fn = do_no_restart_syscall; | |
151 | ||
464d1a78 JF |
152 | GET_SEG(gs); |
153 | COPY_SEG(fs); | |
1da177e4 LT |
154 | COPY_SEG(es); |
155 | COPY_SEG(ds); | |
ac66f3fd HH |
156 | COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx); |
157 | COPY(dx); COPY(cx); COPY(ip); | |
1da177e4 LT |
158 | COPY_SEG_STRICT(cs); |
159 | COPY_SEG_STRICT(ss); | |
7e907f48 | 160 | |
69e13ad5 HS |
161 | err |= __get_user(tmpflags, &sc->flags); |
162 | regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS); | |
163 | regs->orig_ax = -1; /* disable syscall checks */ | |
7e907f48 | 164 | |
69e13ad5 HS |
165 | err |= __get_user(buf, &sc->fpstate); |
166 | err |= restore_i387_xstate(buf); | |
1da177e4 | 167 | |
866bc13f | 168 | err |= __get_user(*pax, &sc->ax); |
1da177e4 | 169 | return err; |
1da177e4 LT |
170 | } |
171 | ||
866bc13f | 172 | asmlinkage unsigned long sys_sigreturn(unsigned long __unused) |
1da177e4 | 173 | { |
7e907f48 IM |
174 | struct sigframe __user *frame; |
175 | struct pt_regs *regs; | |
866bc13f | 176 | unsigned long ax; |
7e907f48 IM |
177 | sigset_t set; |
178 | ||
179 | regs = (struct pt_regs *) &__unused; | |
180 | frame = (struct sigframe __user *)(regs->sp - 8); | |
1da177e4 LT |
181 | |
182 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) | |
183 | goto badframe; | |
7e907f48 | 184 | if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1 |
1da177e4 LT |
185 | && __copy_from_user(&set.sig[1], &frame->extramask, |
186 | sizeof(frame->extramask)))) | |
187 | goto badframe; | |
188 | ||
189 | sigdelsetmask(&set, ~_BLOCKABLE); | |
190 | spin_lock_irq(¤t->sighand->siglock); | |
191 | current->blocked = set; | |
192 | recalc_sigpending(); | |
193 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 194 | |
65ea5b03 | 195 | if (restore_sigcontext(regs, &frame->sc, &ax)) |
1da177e4 | 196 | goto badframe; |
65ea5b03 | 197 | return ax; |
1da177e4 LT |
198 | |
199 | badframe: | |
03252919 | 200 | if (show_unhandled_signals && printk_ratelimit()) { |
1181f8b5 | 201 | printk("%s%s[%d] bad frame in sigreturn frame:" |
97b44ae6 | 202 | "%p ip:%lx sp:%lx oeax:%lx", |
19c5870c | 203 | task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG, |
65ea5b03 PA |
204 | current->comm, task_pid_nr(current), frame, regs->ip, |
205 | regs->sp, regs->orig_ax); | |
03252919 | 206 | print_vma_addr(" in ", regs->ip); |
97b44ae6 | 207 | printk(KERN_CONT "\n"); |
03252919 | 208 | } |
abd4f750 | 209 | |
1da177e4 | 210 | force_sig(SIGSEGV, current); |
7e907f48 | 211 | |
1da177e4 | 212 | return 0; |
7e907f48 | 213 | } |
1da177e4 | 214 | |
e6babb6b | 215 | static long do_rt_sigreturn(struct pt_regs *regs) |
1da177e4 | 216 | { |
2d19c458 | 217 | struct rt_sigframe __user *frame; |
866bc13f | 218 | unsigned long ax; |
1da177e4 | 219 | sigset_t set; |
1da177e4 | 220 | |
2d19c458 | 221 | frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long)); |
1da177e4 LT |
222 | if (!access_ok(VERIFY_READ, frame, sizeof(*frame))) |
223 | goto badframe; | |
224 | if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set))) | |
225 | goto badframe; | |
226 | ||
227 | sigdelsetmask(&set, ~_BLOCKABLE); | |
228 | spin_lock_irq(¤t->sighand->siglock); | |
229 | current->blocked = set; | |
230 | recalc_sigpending(); | |
231 | spin_unlock_irq(¤t->sighand->siglock); | |
7e907f48 | 232 | |
65ea5b03 | 233 | if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax)) |
1da177e4 LT |
234 | goto badframe; |
235 | ||
65ea5b03 | 236 | if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT) |
1da177e4 LT |
237 | goto badframe; |
238 | ||
65ea5b03 | 239 | return ax; |
1da177e4 LT |
240 | |
241 | badframe: | |
e6babb6b | 242 | signal_fault(regs, frame, "rt_sigreturn"); |
1da177e4 | 243 | return 0; |
7e907f48 | 244 | } |
1da177e4 | 245 | |
e6babb6b HS |
246 | asmlinkage int sys_rt_sigreturn(unsigned long __unused) |
247 | { | |
248 | struct pt_regs *regs = (struct pt_regs *)&__unused; | |
249 | ||
250 | return do_rt_sigreturn(regs); | |
251 | } | |
252 | ||
1da177e4 LT |
253 | /* |
254 | * Set up a signal frame. | |
255 | */ | |
1da177e4 | 256 | static int |
ab513701 | 257 | setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate, |
1da177e4 LT |
258 | struct pt_regs *regs, unsigned long mask) |
259 | { | |
260 | int tmp, err = 0; | |
261 | ||
65ea5b03 | 262 | err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs); |
464d1a78 JF |
263 | savesegment(gs, tmp); |
264 | err |= __put_user(tmp, (unsigned int __user *)&sc->gs); | |
1da177e4 | 265 | |
65ea5b03 PA |
266 | err |= __put_user(regs->es, (unsigned int __user *)&sc->es); |
267 | err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds); | |
742fa54a PA |
268 | err |= __put_user(regs->di, &sc->di); |
269 | err |= __put_user(regs->si, &sc->si); | |
270 | err |= __put_user(regs->bp, &sc->bp); | |
271 | err |= __put_user(regs->sp, &sc->sp); | |
272 | err |= __put_user(regs->bx, &sc->bx); | |
273 | err |= __put_user(regs->dx, &sc->dx); | |
274 | err |= __put_user(regs->cx, &sc->cx); | |
275 | err |= __put_user(regs->ax, &sc->ax); | |
1da177e4 LT |
276 | err |= __put_user(current->thread.trap_no, &sc->trapno); |
277 | err |= __put_user(current->thread.error_code, &sc->err); | |
742fa54a | 278 | err |= __put_user(regs->ip, &sc->ip); |
65ea5b03 | 279 | err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs); |
742fa54a PA |
280 | err |= __put_user(regs->flags, &sc->flags); |
281 | err |= __put_user(regs->sp, &sc->sp_at_signal); | |
65ea5b03 | 282 | err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss); |
1da177e4 | 283 | |
ab513701 | 284 | tmp = save_i387_xstate(fpstate); |
1da177e4 | 285 | if (tmp < 0) |
7e907f48 | 286 | err = 1; |
1da177e4 | 287 | else |
7e907f48 | 288 | err |= __put_user(tmp ? fpstate : NULL, &sc->fpstate); |
1da177e4 LT |
289 | |
290 | /* non-iBCS2 extensions.. */ | |
291 | err |= __put_user(mask, &sc->oldmask); | |
292 | err |= __put_user(current->thread.cr2, &sc->cr2); | |
293 | ||
294 | return err; | |
295 | } | |
296 | ||
297 | /* | |
298 | * Determine which stack to use.. | |
299 | */ | |
300 | static inline void __user * | |
3c1c7f10 | 301 | get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size, |
ab513701 | 302 | void **fpstate) |
1da177e4 | 303 | { |
65ea5b03 | 304 | unsigned long sp; |
1da177e4 LT |
305 | |
306 | /* Default to using normal stack */ | |
65ea5b03 | 307 | sp = regs->sp; |
1da177e4 | 308 | |
83bd0102 RM |
309 | /* |
310 | * If we are on the alternate signal stack and would overflow it, don't. | |
311 | * Return an always-bogus address instead so we will die with SIGSEGV. | |
312 | */ | |
65ea5b03 | 313 | if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size))) |
83bd0102 RM |
314 | return (void __user *) -1L; |
315 | ||
1da177e4 LT |
316 | /* This is the X/Open sanctioned signal stack switching. */ |
317 | if (ka->sa.sa_flags & SA_ONSTACK) { | |
65ea5b03 PA |
318 | if (sas_ss_flags(sp) == 0) |
319 | sp = current->sas_ss_sp + current->sas_ss_size; | |
7e907f48 IM |
320 | } else { |
321 | /* This is the legacy signal stack switching. */ | |
322 | if ((regs->ss & 0xffff) != __USER_DS && | |
323 | !(ka->sa.sa_flags & SA_RESTORER) && | |
324 | ka->sa.sa_restorer) | |
325 | sp = (unsigned long) ka->sa.sa_restorer; | |
1da177e4 LT |
326 | } |
327 | ||
3c1c7f10 SS |
328 | if (used_math()) { |
329 | sp = sp - sig_xstate_size; | |
330 | *fpstate = (struct _fpstate *) sp; | |
331 | } | |
332 | ||
65ea5b03 | 333 | sp -= frame_size; |
7e907f48 IM |
334 | /* |
335 | * Align the stack pointer according to the i386 ABI, | |
336 | * i.e. so that on function entry ((sp + 4) & 15) == 0. | |
337 | */ | |
65ea5b03 | 338 | sp = ((sp + 4) & -16ul) - 4; |
7e907f48 | 339 | |
65ea5b03 | 340 | return (void __user *) sp; |
1da177e4 LT |
341 | } |
342 | ||
7e907f48 | 343 | static int |
1d13024e HS |
344 | __setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, |
345 | struct pt_regs *regs) | |
1da177e4 | 346 | { |
1da177e4 | 347 | struct sigframe __user *frame; |
7e907f48 | 348 | void __user *restorer; |
1da177e4 | 349 | int err = 0; |
ab513701 | 350 | void __user *fpstate = NULL; |
1da177e4 | 351 | |
3c1c7f10 | 352 | frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
353 | |
354 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 355 | return -EFAULT; |
1da177e4 | 356 | |
2ba48e16 | 357 | if (__put_user(sig, &frame->sig)) |
3d0aedd9 | 358 | return -EFAULT; |
1da177e4 | 359 | |
2ba48e16 | 360 | if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0])) |
3d0aedd9 | 361 | return -EFAULT; |
1da177e4 LT |
362 | |
363 | if (_NSIG_WORDS > 1) { | |
2ba48e16 HS |
364 | if (__copy_to_user(&frame->extramask, &set->sig[1], |
365 | sizeof(frame->extramask))) | |
3d0aedd9 | 366 | return -EFAULT; |
1da177e4 LT |
367 | } |
368 | ||
1a3e4ca4 | 369 | if (current->mm->context.vdso) |
6c3652ef | 370 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn); |
9fbbd4dd | 371 | else |
ade1af77 | 372 | restorer = &frame->retcode; |
1da177e4 LT |
373 | if (ka->sa.sa_flags & SA_RESTORER) |
374 | restorer = ka->sa.sa_restorer; | |
375 | ||
376 | /* Set up to return from userspace. */ | |
377 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 378 | |
1da177e4 | 379 | /* |
7e907f48 | 380 | * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80 |
1da177e4 LT |
381 | * |
382 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
383 | * reasons and because gdb uses it as a signature to notice | |
384 | * signal handler stack frames. | |
385 | */ | |
386 | err |= __put_user(0xb858, (short __user *)(frame->retcode+0)); | |
387 | err |= __put_user(__NR_sigreturn, (int __user *)(frame->retcode+2)); | |
388 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+6)); | |
389 | ||
390 | if (err) | |
3d0aedd9 | 391 | return -EFAULT; |
1da177e4 LT |
392 | |
393 | /* Set up registers for signal handler */ | |
7e907f48 IM |
394 | regs->sp = (unsigned long)frame; |
395 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
396 | regs->ax = (unsigned long)sig; | |
92bc2056 HH |
397 | regs->dx = 0; |
398 | regs->cx = 0; | |
1da177e4 | 399 | |
65ea5b03 PA |
400 | regs->ds = __USER_DS; |
401 | regs->es = __USER_DS; | |
402 | regs->ss = __USER_DS; | |
403 | regs->cs = __USER_CS; | |
1da177e4 | 404 | |
283828f3 | 405 | return 0; |
1da177e4 LT |
406 | } |
407 | ||
1d13024e HS |
408 | static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, |
409 | sigset_t *set, struct pt_regs *regs) | |
1da177e4 | 410 | { |
1da177e4 | 411 | struct rt_sigframe __user *frame; |
7e907f48 | 412 | void __user *restorer; |
1da177e4 | 413 | int err = 0; |
ab513701 | 414 | void __user *fpstate = NULL; |
1da177e4 | 415 | |
3c1c7f10 | 416 | frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate); |
1da177e4 LT |
417 | |
418 | if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame))) | |
3d0aedd9 | 419 | return -EFAULT; |
1da177e4 | 420 | |
13ad7725 | 421 | err |= __put_user(sig, &frame->sig); |
1da177e4 LT |
422 | err |= __put_user(&frame->info, &frame->pinfo); |
423 | err |= __put_user(&frame->uc, &frame->puc); | |
424 | err |= copy_siginfo_to_user(&frame->info, info); | |
425 | if (err) | |
3d0aedd9 | 426 | return -EFAULT; |
1da177e4 LT |
427 | |
428 | /* Create the ucontext. */ | |
c37b5efe SS |
429 | if (cpu_has_xsave) |
430 | err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags); | |
431 | else | |
432 | err |= __put_user(0, &frame->uc.uc_flags); | |
1da177e4 LT |
433 | err |= __put_user(0, &frame->uc.uc_link); |
434 | err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp); | |
65ea5b03 | 435 | err |= __put_user(sas_ss_flags(regs->sp), |
1da177e4 LT |
436 | &frame->uc.uc_stack.ss_flags); |
437 | err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size); | |
3c1c7f10 | 438 | err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate, |
7e907f48 | 439 | regs, set->sig[0]); |
1da177e4 LT |
440 | err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set)); |
441 | if (err) | |
3d0aedd9 | 442 | return -EFAULT; |
1da177e4 LT |
443 | |
444 | /* Set up to return from userspace. */ | |
6c3652ef | 445 | restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn); |
1da177e4 LT |
446 | if (ka->sa.sa_flags & SA_RESTORER) |
447 | restorer = ka->sa.sa_restorer; | |
448 | err |= __put_user(restorer, &frame->pretcode); | |
7e907f48 | 449 | |
1da177e4 | 450 | /* |
7e907f48 | 451 | * This is movl $__NR_rt_sigreturn, %ax ; int $0x80 |
1da177e4 LT |
452 | * |
453 | * WE DO NOT USE IT ANY MORE! It's only left here for historical | |
454 | * reasons and because gdb uses it as a signature to notice | |
455 | * signal handler stack frames. | |
456 | */ | |
457 | err |= __put_user(0xb8, (char __user *)(frame->retcode+0)); | |
458 | err |= __put_user(__NR_rt_sigreturn, (int __user *)(frame->retcode+1)); | |
459 | err |= __put_user(0x80cd, (short __user *)(frame->retcode+5)); | |
460 | ||
461 | if (err) | |
3d0aedd9 | 462 | return -EFAULT; |
1da177e4 LT |
463 | |
464 | /* Set up registers for signal handler */ | |
7e907f48 IM |
465 | regs->sp = (unsigned long)frame; |
466 | regs->ip = (unsigned long)ka->sa.sa_handler; | |
13ad7725 | 467 | regs->ax = (unsigned long)sig; |
7e907f48 IM |
468 | regs->dx = (unsigned long)&frame->info; |
469 | regs->cx = (unsigned long)&frame->uc; | |
1da177e4 | 470 | |
65ea5b03 PA |
471 | regs->ds = __USER_DS; |
472 | regs->es = __USER_DS; | |
473 | regs->ss = __USER_DS; | |
474 | regs->cs = __USER_CS; | |
1da177e4 | 475 | |
283828f3 | 476 | return 0; |
1da177e4 LT |
477 | } |
478 | ||
479 | /* | |
7e907f48 IM |
480 | * OK, we're invoking a handler: |
481 | */ | |
8d8c13bd HS |
482 | static int signr_convert(int sig) |
483 | { | |
484 | struct thread_info *info = current_thread_info(); | |
485 | ||
486 | if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32) | |
487 | return info->exec_domain->signal_invmap[sig]; | |
488 | return sig; | |
489 | } | |
490 | ||
455edbc4 | 491 | #define is_ia32 1 |
4694d239 HS |
492 | #define ia32_setup_frame __setup_frame |
493 | #define ia32_setup_rt_frame __setup_rt_frame | |
455edbc4 | 494 | |
1d13024e HS |
495 | static int |
496 | setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, | |
497 | sigset_t *set, struct pt_regs *regs) | |
498 | { | |
8d8c13bd | 499 | int usig = signr_convert(sig); |
1d13024e HS |
500 | int ret; |
501 | ||
502 | /* Set up the stack frame */ | |
455edbc4 HS |
503 | if (is_ia32) { |
504 | if (ka->sa.sa_flags & SA_SIGINFO) | |
4694d239 | 505 | ret = ia32_setup_rt_frame(usig, ka, info, set, regs); |
455edbc4 | 506 | else |
4694d239 | 507 | ret = ia32_setup_frame(usig, ka, set, regs); |
455edbc4 HS |
508 | } else |
509 | ret = __setup_rt_frame(sig, ka, info, set, regs); | |
1d13024e | 510 | |
3d0aedd9 HS |
511 | if (ret) { |
512 | force_sigsegv(sig, current); | |
513 | return -EFAULT; | |
514 | } | |
515 | ||
1d13024e HS |
516 | return ret; |
517 | } | |
518 | ||
7c1def16 | 519 | static int |
1da177e4 | 520 | handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka, |
ac66f3fd | 521 | sigset_t *oldset, struct pt_regs *regs) |
1da177e4 | 522 | { |
7c1def16 RM |
523 | int ret; |
524 | ||
1da177e4 | 525 | /* Are we from a system call? */ |
bb57925f | 526 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 527 | /* If so, check system call restarting.. */ |
bb57925f | 528 | switch (syscall_get_error(current, regs)) { |
ac66f3fd HH |
529 | case -ERESTART_RESTARTBLOCK: |
530 | case -ERESTARTNOHAND: | |
531 | regs->ax = -EINTR; | |
532 | break; | |
533 | ||
534 | case -ERESTARTSYS: | |
535 | if (!(ka->sa.sa_flags & SA_RESTART)) { | |
65ea5b03 | 536 | regs->ax = -EINTR; |
1da177e4 | 537 | break; |
ac66f3fd HH |
538 | } |
539 | /* fallthrough */ | |
540 | case -ERESTARTNOINTR: | |
541 | regs->ax = regs->orig_ax; | |
542 | regs->ip -= 2; | |
543 | break; | |
1da177e4 LT |
544 | } |
545 | } | |
546 | ||
547 | /* | |
e1f28773 RM |
548 | * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF |
549 | * flag so that register information in the sigcontext is correct. | |
1da177e4 | 550 | */ |
65ea5b03 | 551 | if (unlikely(regs->flags & X86_EFLAGS_TF) && |
e1f28773 | 552 | likely(test_and_clear_thread_flag(TIF_FORCED_TF))) |
65ea5b03 | 553 | regs->flags &= ~X86_EFLAGS_TF; |
1da177e4 | 554 | |
1d13024e | 555 | ret = setup_rt_frame(sig, ka, info, oldset, regs); |
1da177e4 | 556 | |
7e907f48 IM |
557 | if (ret) |
558 | return ret; | |
7c1def16 | 559 | |
86d3237c HS |
560 | #ifdef CONFIG_X86_64 |
561 | /* | |
562 | * This has nothing to do with segment registers, | |
563 | * despite the name. This magic affects uaccess.h | |
564 | * macros' behavior. Reset it to the normal setting. | |
565 | */ | |
566 | set_fs(USER_DS); | |
567 | #endif | |
568 | ||
8b9c5ff3 RM |
569 | /* |
570 | * Clear the direction flag as per the ABI for function entry. | |
571 | */ | |
572 | regs->flags &= ~X86_EFLAGS_DF; | |
573 | ||
574 | /* | |
575 | * Clear TF when entering the signal handler, but | |
576 | * notify any tracer that was single-stepping it. | |
577 | * The tracer may want to single-step inside the | |
578 | * handler too. | |
579 | */ | |
580 | regs->flags &= ~X86_EFLAGS_TF; | |
8b9c5ff3 | 581 | |
7e907f48 IM |
582 | spin_lock_irq(¤t->sighand->siglock); |
583 | sigorsets(¤t->blocked, ¤t->blocked, &ka->sa.sa_mask); | |
584 | if (!(ka->sa.sa_flags & SA_NODEFER)) | |
585 | sigaddset(¤t->blocked, sig); | |
586 | recalc_sigpending(); | |
587 | spin_unlock_irq(¤t->sighand->siglock); | |
588 | ||
36a03308 RM |
589 | tracehook_signal_handler(sig, info, ka, regs, |
590 | test_thread_flag(TIF_SINGLESTEP)); | |
591 | ||
7e907f48 | 592 | return 0; |
1da177e4 LT |
593 | } |
594 | ||
8fcd8e20 | 595 | #define NR_restart_syscall __NR_restart_syscall |
1da177e4 LT |
596 | /* |
597 | * Note that 'init' is a special process: it doesn't get signals it doesn't | |
598 | * want to handle. Thus you cannot kill init even with a SIGKILL even by | |
599 | * mistake. | |
600 | */ | |
75604d7f | 601 | static void do_signal(struct pt_regs *regs) |
1da177e4 | 602 | { |
ac66f3fd | 603 | struct k_sigaction ka; |
1da177e4 LT |
604 | siginfo_t info; |
605 | int signr; | |
283828f3 | 606 | sigset_t *oldset; |
1da177e4 LT |
607 | |
608 | /* | |
ac66f3fd HH |
609 | * We want the common case to go fast, which is why we may in certain |
610 | * cases get here from kernel mode. Just return without doing anything | |
611 | * if so. | |
612 | * X86_32: vm86 regs switched out by assembly code before reaching | |
613 | * here, so testing against kernel CS suffices. | |
1da177e4 | 614 | */ |
717b594a | 615 | if (!user_mode(regs)) |
283828f3 | 616 | return; |
1da177e4 | 617 | |
5a8da0ea | 618 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) |
283828f3 DH |
619 | oldset = ¤t->saved_sigmask; |
620 | else | |
1da177e4 LT |
621 | oldset = ¤t->blocked; |
622 | ||
623 | signr = get_signal_to_deliver(&info, &ka, regs, NULL); | |
624 | if (signr > 0) { | |
7e907f48 IM |
625 | /* |
626 | * Re-enable any watchpoints before delivering the | |
1da177e4 LT |
627 | * signal to user space. The processor register will |
628 | * have been cleared if the watchpoint triggered | |
629 | * inside the kernel. | |
630 | */ | |
ac66f3fd | 631 | if (current->thread.debugreg7) |
0f534093 | 632 | set_debugreg(current->thread.debugreg7, 7); |
1da177e4 | 633 | |
7e907f48 | 634 | /* Whee! Actually deliver the signal. */ |
283828f3 | 635 | if (handle_signal(signr, &info, &ka, oldset, regs) == 0) { |
7e907f48 | 636 | /* |
5a8da0ea | 637 | * A signal was successfully delivered; the saved |
283828f3 DH |
638 | * sigmask will have been stored in the signal frame, |
639 | * and will be restored by sigreturn, so we can simply | |
5a8da0ea | 640 | * clear the TS_RESTORE_SIGMASK flag. |
7e907f48 | 641 | */ |
5a8da0ea | 642 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; |
283828f3 | 643 | } |
283828f3 | 644 | return; |
1da177e4 LT |
645 | } |
646 | ||
1da177e4 | 647 | /* Did we come from a system call? */ |
bb57925f | 648 | if (syscall_get_nr(current, regs) >= 0) { |
1da177e4 | 649 | /* Restart the system call - no handlers present */ |
bb57925f | 650 | switch (syscall_get_error(current, regs)) { |
283828f3 DH |
651 | case -ERESTARTNOHAND: |
652 | case -ERESTARTSYS: | |
653 | case -ERESTARTNOINTR: | |
65ea5b03 PA |
654 | regs->ax = regs->orig_ax; |
655 | regs->ip -= 2; | |
283828f3 DH |
656 | break; |
657 | ||
658 | case -ERESTART_RESTARTBLOCK: | |
8fcd8e20 | 659 | regs->ax = NR_restart_syscall; |
65ea5b03 | 660 | regs->ip -= 2; |
283828f3 | 661 | break; |
1da177e4 LT |
662 | } |
663 | } | |
283828f3 | 664 | |
ac66f3fd HH |
665 | /* |
666 | * If there's no signal to deliver, we just put the saved sigmask | |
667 | * back. | |
668 | */ | |
5a8da0ea RM |
669 | if (current_thread_info()->status & TS_RESTORE_SIGMASK) { |
670 | current_thread_info()->status &= ~TS_RESTORE_SIGMASK; | |
283828f3 DH |
671 | sigprocmask(SIG_SETMASK, ¤t->saved_sigmask, NULL); |
672 | } | |
1da177e4 LT |
673 | } |
674 | ||
675 | /* | |
676 | * notification of userspace execution resumption | |
283828f3 | 677 | * - triggered by the TIF_WORK_MASK flags |
1da177e4 | 678 | */ |
7e907f48 IM |
679 | void |
680 | do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags) | |
1da177e4 | 681 | { |
ee847c54 HS |
682 | #if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE) |
683 | /* notify userspace of pending MCEs */ | |
684 | if (thread_info_flags & _TIF_MCE_NOTIFY) | |
685 | mce_notify_user(); | |
686 | #endif /* CONFIG_X86_64 && CONFIG_X86_MCE */ | |
687 | ||
1da177e4 | 688 | /* deal with pending signal delivery */ |
5a8da0ea | 689 | if (thread_info_flags & _TIF_SIGPENDING) |
283828f3 | 690 | do_signal(regs); |
8f4d37ec | 691 | |
59e52130 RM |
692 | if (thread_info_flags & _TIF_NOTIFY_RESUME) { |
693 | clear_thread_flag(TIF_NOTIFY_RESUME); | |
694 | tracehook_notify_resume(regs); | |
695 | } | |
696 | ||
ee847c54 | 697 | #ifdef CONFIG_X86_32 |
1da177e4 | 698 | clear_thread_flag(TIF_IRET); |
ee847c54 | 699 | #endif /* CONFIG_X86_32 */ |
1da177e4 | 700 | } |
72fa50f4 HS |
701 | |
702 | void signal_fault(struct pt_regs *regs, void __user *frame, char *where) | |
703 | { | |
704 | struct task_struct *me = current; | |
705 | ||
706 | if (show_unhandled_signals && printk_ratelimit()) { | |
707 | printk(KERN_INFO | |
708 | "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx", | |
709 | me->comm, me->pid, where, frame, | |
710 | regs->ip, regs->sp, regs->orig_ax); | |
711 | print_vma_addr(" in ", regs->ip); | |
712 | printk(KERN_CONT "\n"); | |
713 | } | |
714 | ||
715 | force_sig(SIGSEGV, me); | |
716 | } |