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x86: signal: move {setup|restore}_sigcontext()
[linux-block.git] / arch / x86 / kernel / signal_32.c
CommitLineData
1da177e4 1/*
1da177e4
LT		 2 * Copyright (C) 1991, 1992 Linus Torvalds
3 *
4 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
5 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
6 */
7
5c9b3a0c
HS		 8#include <linux/sched.h>
9#include <linux/mm.h>
10#include <linux/smp.h>
1da177e4
LT		 11#include <linux/kernel.h>
12#include <linux/signal.h>
13#include <linux/errno.h>
14#include <linux/wait.h>
5c9b3a0c 15#include <linux/ptrace.h>
36a03308 16#include <linux/tracehook.h>
5c9b3a0c
HS		 17#include <linux/unistd.h>
18#include <linux/stddef.h>
19#include <linux/personality.h>
20#include <linux/uaccess.h>
7e907f48 21
1da177e4
LT		 22#include <asm/processor.h>
23#include <asm/ucontext.h>
1da177e4 24#include <asm/i387.h>
6c3652ef 25#include <asm/vdso.h>
5c9b3a0c
HS		 26
27#ifdef CONFIG_X86_64
28#include <asm/proto.h>
29#include <asm/ia32_unistd.h>
30#include <asm/mce.h>
31#endif /* CONFIG_X86_64 */
32
bb57925f 33#include <asm/syscall.h>
bbc1f698 34#include <asm/syscalls.h>
7e907f48 35
123a6347 36#include "sigframe.h"
1da177e4 37
1da177e4
LT		 38#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
39
1a176803
HH		 40#define __FIX_EFLAGS (X86_EFLAGS_AC | X86_EFLAGS_OF | \
41 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
42 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
43 X86_EFLAGS_CF)
44
45#ifdef CONFIG_X86_32
46# define FIX_EFLAGS (__FIX_EFLAGS | X86_EFLAGS_RF)
47#else
48# define FIX_EFLAGS __FIX_EFLAGS
49#endif
50
4a612048
HS		 51static const struct {
52 u16 poplmovl;
53 u32 val;
54 u16 int80;
55} __attribute__((packed)) retcode = {
56 0xb858, /* popl %eax; movl $..., %eax */
57 __NR_sigreturn,
58 0x80cd, /* int $0x80 */
59};
60
61static const struct {
62 u8 movl;
63 u32 val;
64 u16 int80;
65 u8 pad;
66} __attribute__((packed)) rt_retcode = {
67 0xb8, /* movl $..., %eax */
68 __NR_rt_sigreturn,
69 0x80cd, /* int $0x80 */
70 0
71};
72
2601657d
HS		 73#define COPY(x) { \
74 err |= __get_user(regs->x, &sc->x); \
75}
76
77#define COPY_SEG(seg) { \
78 unsigned short tmp; \
79 err |= __get_user(tmp, &sc->seg); \
80 regs->seg = tmp; \
81}
82
83#define COPY_SEG_CPL3(seg) { \
84 unsigned short tmp; \
85 err |= __get_user(tmp, &sc->seg); \
86 regs->seg = tmp | 3; \
87}
88
89#define GET_SEG(seg) { \
90 unsigned short tmp; \
91 err |= __get_user(tmp, &sc->seg); \
92 loadsegment(seg, tmp); \
93}
94
95static int
96restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
97 unsigned long *pax)
98{
99 void __user *buf;
100 unsigned int tmpflags;
101 unsigned int err = 0;
102
103 /* Always make any pending restarted system calls return -EINTR */
104 current_thread_info()->restart_block.fn = do_no_restart_syscall;
105
106#ifdef CONFIG_X86_32
107 GET_SEG(gs);
108 COPY_SEG(fs);
109 COPY_SEG(es);
110 COPY_SEG(ds);
111#endif /* CONFIG_X86_32 */
112
113 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
114 COPY(dx); COPY(cx); COPY(ip);
115
116#ifdef CONFIG_X86_64
117 COPY(r8);
118 COPY(r9);
119 COPY(r10);
120 COPY(r11);
121 COPY(r12);
122 COPY(r13);
123 COPY(r14);
124 COPY(r15);
125#endif /* CONFIG_X86_64 */
126
127#ifdef CONFIG_X86_32
128 COPY_SEG_CPL3(cs);
129 COPY_SEG_CPL3(ss);
130#else /* !CONFIG_X86_32 */
131 /* Kernel saves and restores only the CS segment register on signals,
132 * which is the bare minimum needed to allow mixed 32/64-bit code.
133 * App's signal handler can save/restore other segments if needed. */
134 COPY_SEG_CPL3(cs);
135#endif /* CONFIG_X86_32 */
136
137 err |= __get_user(tmpflags, &sc->flags);
138 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
139 regs->orig_ax = -1; /* disable syscall checks */
140
141 err |= __get_user(buf, &sc->fpstate);
142 err |= restore_i387_xstate(buf);
143
144 err |= __get_user(*pax, &sc->ax);
145 return err;
146}
147
148static int
149setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
150 struct pt_regs *regs, unsigned long mask)
151{
152 int err = 0;
153
154#ifdef CONFIG_X86_32
155 {
156 unsigned int tmp;
157
158 savesegment(gs, tmp);
159 err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
160 }
161 err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
162 err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
163 err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
164#endif /* CONFIG_X86_32 */
165
166 err |= __put_user(regs->di, &sc->di);
167 err |= __put_user(regs->si, &sc->si);
168 err |= __put_user(regs->bp, &sc->bp);
169 err |= __put_user(regs->sp, &sc->sp);
170 err |= __put_user(regs->bx, &sc->bx);
171 err |= __put_user(regs->dx, &sc->dx);
172 err |= __put_user(regs->cx, &sc->cx);
173 err |= __put_user(regs->ax, &sc->ax);
174#ifdef CONFIG_X86_64
175 err |= __put_user(regs->r8, &sc->r8);
176 err |= __put_user(regs->r9, &sc->r9);
177 err |= __put_user(regs->r10, &sc->r10);
178 err |= __put_user(regs->r11, &sc->r11);
179 err |= __put_user(regs->r12, &sc->r12);
180 err |= __put_user(regs->r13, &sc->r13);
181 err |= __put_user(regs->r14, &sc->r14);
182 err |= __put_user(regs->r15, &sc->r15);
183#endif /* CONFIG_X86_64 */
184
185 err |= __put_user(current->thread.trap_no, &sc->trapno);
186 err |= __put_user(current->thread.error_code, &sc->err);
187 err |= __put_user(regs->ip, &sc->ip);
188#ifdef CONFIG_X86_32
189 err |= __put_user(regs->cs, (unsigned int __user *)&sc->cs);
190 err |= __put_user(regs->flags, &sc->flags);
191 err |= __put_user(regs->sp, &sc->sp_at_signal);
192 err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);
193#else /* !CONFIG_X86_32 */
194 err |= __put_user(regs->flags, &sc->flags);
195 err |= __put_user(regs->cs, &sc->cs);
196 err |= __put_user(0, &sc->gs);
197 err |= __put_user(0, &sc->fs);
198#endif /* CONFIG_X86_32 */
199
200 err |= __put_user(fpstate, &sc->fpstate);
201
202 /* non-iBCS2 extensions.. */
203 err |= __put_user(mask, &sc->oldmask);
204 err |= __put_user(current->thread.cr2, &sc->cr2);
205
206 return err;
207}
208
1da177e4
LT		 209/*
210 * Atomically swap in the new signal mask, and wait for a signal.
211 */
212asmlinkage int
213sys_sigsuspend(int history0, int history1, old_sigset_t mask)
214{
1da177e4
LT		 215 mask &= _BLOCKABLE;
216 spin_lock_irq(&current->sighand->siglock);
283828f3 217 current->saved_sigmask = current->blocked;
1da177e4
LT		 218 siginitset(&current->blocked, mask);
219 recalc_sigpending();
220 spin_unlock_irq(&current->sighand->siglock);
221
283828f3
DH		 222 current->state = TASK_INTERRUPTIBLE;
223 schedule();
5a8da0ea 224 set_restore_sigmask();
7e907f48 225
283828f3 226 return -ERESTARTNOHAND;
1da177e4
LT		 227}
228
7e907f48 229asmlinkage int
1da177e4
LT		 230sys_sigaction(int sig, const struct old_sigaction __user *act,
231 struct old_sigaction __user *oact)
232{
233 struct k_sigaction new_ka, old_ka;
234 int ret;
235
236 if (act) {
237 old_sigset_t mask;
7e907f48 238
1da177e4
LT		 239 if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
240 __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
241 __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
242 return -EFAULT;
7e907f48 243
1da177e4
LT		 244 __get_user(new_ka.sa.sa_flags, &act->sa_flags);
245 __get_user(mask, &act->sa_mask);
246 siginitset(&new_ka.sa.sa_mask, mask);
247 }
248
249 ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
250
251 if (!ret && oact) {
252 if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
253 __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
254 __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
255 return -EFAULT;
7e907f48 256
1da177e4
LT		 257 __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
258 __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
259 }
260
261 return ret;
262}
263
666ac7be 264#ifdef CONFIG_X86_32
7e907f48 265asmlinkage int sys_sigaltstack(unsigned long bx)
1da177e4 266{
7e907f48
IM		 267 /*
268 * This is needed to make gcc realize it doesn't own the
269 * "struct pt_regs"
270 */
65ea5b03
PA		 271 struct pt_regs *regs = (struct pt_regs *)&bx;
272 const stack_t __user *uss = (const stack_t __user *)bx;
273 stack_t __user *uoss = (stack_t __user *)regs->cx;
1da177e4 274
65ea5b03 275 return do_sigaltstack(uss, uoss, regs->sp);
1da177e4 276}
666ac7be
HS		 277#else /* !CONFIG_X86_32 */
278asmlinkage long
279sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
280 struct pt_regs *regs)
281{
282 return do_sigaltstack(uss, uoss, regs->sp);
283}
284#endif /* CONFIG_X86_32 */
1da177e4 285
1da177e4
LT		 286/*
287 * Do a signal return; undo the signal stack.
288 */
866bc13f 289asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
1da177e4 290{
7e907f48
IM		 291 struct sigframe __user *frame;
292 struct pt_regs *regs;
866bc13f 293 unsigned long ax;
7e907f48
IM		 294 sigset_t set;
295
296 regs = (struct pt_regs *) &__unused;
297 frame = (struct sigframe __user *)(regs->sp - 8);
1da177e4
LT		 298
299 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
300 goto badframe;
7e907f48 301 if (__get_user(set.sig[0], &frame->sc.oldmask) || (_NSIG_WORDS > 1
1da177e4
LT		 302 && __copy_from_user(&set.sig[1], &frame->extramask,
303 sizeof(frame->extramask))))
304 goto badframe;
305
306 sigdelsetmask(&set, ~_BLOCKABLE);
307 spin_lock_irq(&current->sighand->siglock);
308 current->blocked = set;
309 recalc_sigpending();
310 spin_unlock_irq(&current->sighand->siglock);
7e907f48 311
65ea5b03 312 if (restore_sigcontext(regs, &frame->sc, &ax))
1da177e4 313 goto badframe;
65ea5b03 314 return ax;
1da177e4
LT		 315
316badframe:
03252919 317 if (show_unhandled_signals && printk_ratelimit()) {
1181f8b5 318 printk("%s%s[%d] bad frame in sigreturn frame:"
97b44ae6 319 "%p ip:%lx sp:%lx oeax:%lx",
19c5870c 320 task_pid_nr(current) > 1 ? KERN_INFO : KERN_EMERG,
65ea5b03
PA		 321 current->comm, task_pid_nr(current), frame, regs->ip,
322 regs->sp, regs->orig_ax);
03252919 323 print_vma_addr(" in ", regs->ip);
97b44ae6 324 printk(KERN_CONT "\n");
03252919 325 }
abd4f750 326
1da177e4 327 force_sig(SIGSEGV, current);
7e907f48 328
1da177e4 329 return 0;
7e907f48 330}
1da177e4 331
e6babb6b 332static long do_rt_sigreturn(struct pt_regs *regs)
1da177e4 333{
2d19c458 334 struct rt_sigframe __user *frame;
866bc13f 335 unsigned long ax;
1da177e4 336 sigset_t set;
1da177e4 337
2d19c458 338 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
1da177e4
LT		 339 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
340 goto badframe;
341 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
342 goto badframe;
343
344 sigdelsetmask(&set, ~_BLOCKABLE);
345 spin_lock_irq(&current->sighand->siglock);
346 current->blocked = set;
347 recalc_sigpending();
348 spin_unlock_irq(&current->sighand->siglock);
7e907f48 349
65ea5b03 350 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
1da177e4
LT		 351 goto badframe;
352
65ea5b03 353 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
1da177e4
LT		 354 goto badframe;
355
65ea5b03 356 return ax;
1da177e4
LT		 357
358badframe:
e6babb6b 359 signal_fault(regs, frame, "rt_sigreturn");
1da177e4 360 return 0;
7e907f48 361}
1da177e4 362
2456d738 363#ifdef CONFIG_X86_32
e6babb6b
HS		 364asmlinkage int sys_rt_sigreturn(unsigned long __unused)
365{
366 struct pt_regs *regs = (struct pt_regs *)&__unused;
367
368 return do_rt_sigreturn(regs);
369}
2456d738
HS		 370#else /* !CONFIG_X86_32 */
371asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
372{
373 return do_rt_sigreturn(regs);
374}
375#endif /* CONFIG_X86_32 */
e6babb6b 376
1da177e4
LT		 377/*
378 * Set up a signal frame.
379 */
1da177e4
LT		 380
381/*
382 * Determine which stack to use..
383 */
384static inline void __user *
3c1c7f10 385get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,
ab513701 386 void **fpstate)
1da177e4 387{
65ea5b03 388 unsigned long sp;
1da177e4
LT		 389
390 /* Default to using normal stack */
65ea5b03 391 sp = regs->sp;
1da177e4 392
83bd0102
RM		 393 /*
394 * If we are on the alternate signal stack and would overflow it, don't.
395 * Return an always-bogus address instead so we will die with SIGSEGV.
396 */
65ea5b03 397 if (on_sig_stack(sp) && !likely(on_sig_stack(sp - frame_size)))
83bd0102
RM		 398 return (void __user *) -1L;
399
1da177e4
LT		 400 /* This is the X/Open sanctioned signal stack switching. */
401 if (ka->sa.sa_flags & SA_ONSTACK) {
65ea5b03
PA		 402 if (sas_ss_flags(sp) == 0)
403 sp = current->sas_ss_sp + current->sas_ss_size;
7e907f48
IM		 404 } else {
405 /* This is the legacy signal stack switching. */
406 if ((regs->ss & 0xffff) != __USER_DS &&
407 !(ka->sa.sa_flags & SA_RESTORER) &&
408 ka->sa.sa_restorer)
409 sp = (unsigned long) ka->sa.sa_restorer;
1da177e4
LT		 410 }
411
3c1c7f10
SS		 412 if (used_math()) {
413 sp = sp - sig_xstate_size;
414 *fpstate = (struct _fpstate *) sp;
4b33669e
HS		 415 if (save_i387_xstate(*fpstate) < 0)
416 return (void __user *)-1L;
3c1c7f10
SS		 417 }
418
65ea5b03 419 sp -= frame_size;
7e907f48
IM		 420 /*
421 * Align the stack pointer according to the i386 ABI,
422 * i.e. so that on function entry ((sp + 4) & 15) == 0.
423 */
65ea5b03 424 sp = ((sp + 4) & -16ul) - 4;
7e907f48 425
65ea5b03 426 return (void __user *) sp;
1da177e4
LT		 427}
428
7e907f48 429static int
1d13024e
HS		 430__setup_frame(int sig, struct k_sigaction *ka, sigset_t *set,
431 struct pt_regs *regs)
1da177e4 432{
1da177e4 433 struct sigframe __user *frame;
7e907f48 434 void __user *restorer;
1da177e4 435 int err = 0;
ab513701 436 void __user *fpstate = NULL;
1da177e4 437
3c1c7f10 438 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
1da177e4
LT		 439
440 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
3d0aedd9 441 return -EFAULT;
1da177e4 442
2ba48e16 443 if (__put_user(sig, &frame->sig))
3d0aedd9 444 return -EFAULT;
1da177e4 445
2ba48e16 446 if (setup_sigcontext(&frame->sc, fpstate, regs, set->sig[0]))
3d0aedd9 447 return -EFAULT;
1da177e4
LT		 448
449 if (_NSIG_WORDS > 1) {
2ba48e16
HS		 450 if (__copy_to_user(&frame->extramask, &set->sig[1],
451 sizeof(frame->extramask)))
3d0aedd9 452 return -EFAULT;
1da177e4
LT		 453 }
454
1a3e4ca4 455 if (current->mm->context.vdso)
6c3652ef 456 restorer = VDSO32_SYMBOL(current->mm->context.vdso, sigreturn);
9fbbd4dd 457 else
ade1af77 458 restorer = &frame->retcode;
1da177e4
LT		 459 if (ka->sa.sa_flags & SA_RESTORER)
460 restorer = ka->sa.sa_restorer;
461
462 /* Set up to return from userspace. */
463 err |= __put_user(restorer, &frame->pretcode);
7e907f48 464
1da177e4 465 /*
7e907f48 466 * This is popl %eax ; movl $__NR_sigreturn, %eax ; int $0x80
1da177e4
LT		 467 *
468 * WE DO NOT USE IT ANY MORE! It's only left here for historical
469 * reasons and because gdb uses it as a signature to notice
470 * signal handler stack frames.
471 */
4a612048 472 err |= __put_user(*((u64 *)&retcode), (u64 *)frame->retcode);
1da177e4
LT		 473
474 if (err)
3d0aedd9 475 return -EFAULT;
1da177e4
LT		 476
477 /* Set up registers for signal handler */
7e907f48
IM		 478 regs->sp = (unsigned long)frame;
479 regs->ip = (unsigned long)ka->sa.sa_handler;
480 regs->ax = (unsigned long)sig;
92bc2056
HH		 481 regs->dx = 0;
482 regs->cx = 0;
1da177e4 483
65ea5b03
PA		 484 regs->ds = __USER_DS;
485 regs->es = __USER_DS;
486 regs->ss = __USER_DS;
487 regs->cs = __USER_CS;
1da177e4 488
283828f3 489 return 0;
1da177e4
LT		 490}
491
1d13024e
HS		 492static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
493 sigset_t *set, struct pt_regs *regs)
1da177e4 494{
1da177e4 495 struct rt_sigframe __user *frame;
7e907f48 496 void __user *restorer;
1da177e4 497 int err = 0;
ab513701 498 void __user *fpstate = NULL;
1da177e4 499
3c1c7f10 500 frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
1da177e4
LT		 501
502 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
3d0aedd9 503 return -EFAULT;
1da177e4 504
13ad7725 505 err |= __put_user(sig, &frame->sig);
1da177e4
LT		 506 err |= __put_user(&frame->info, &frame->pinfo);
507 err |= __put_user(&frame->uc, &frame->puc);
508 err |= copy_siginfo_to_user(&frame->info, info);
509 if (err)
3d0aedd9 510 return -EFAULT;
1da177e4
LT		 511
512 /* Create the ucontext. */
c37b5efe
SS		 513 if (cpu_has_xsave)
514 err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
515 else
516 err |= __put_user(0, &frame->uc.uc_flags);
1da177e4
LT		 517 err |= __put_user(0, &frame->uc.uc_link);
518 err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
65ea5b03 519 err |= __put_user(sas_ss_flags(regs->sp),
1da177e4
LT		 520 &frame->uc.uc_stack.ss_flags);
521 err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
3c1c7f10 522 err |= setup_sigcontext(&frame->uc.uc_mcontext, fpstate,
7e907f48 523 regs, set->sig[0]);
1da177e4
LT		 524 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
525 if (err)
3d0aedd9 526 return -EFAULT;
1da177e4
LT		 527
528 /* Set up to return from userspace. */
6c3652ef 529 restorer = VDSO32_SYMBOL(current->mm->context.vdso, rt_sigreturn);
1da177e4
LT		 530 if (ka->sa.sa_flags & SA_RESTORER)
531 restorer = ka->sa.sa_restorer;
532 err |= __put_user(restorer, &frame->pretcode);
7e907f48 533
1da177e4 534 /*
7e907f48 535 * This is movl $__NR_rt_sigreturn, %ax ; int $0x80
1da177e4
LT		 536 *
537 * WE DO NOT USE IT ANY MORE! It's only left here for historical
538 * reasons and because gdb uses it as a signature to notice
539 * signal handler stack frames.
540 */
4a612048 541 err |= __put_user(*((u64 *)&rt_retcode), (u64 *)frame->retcode);
1da177e4
LT		 542
543 if (err)
3d0aedd9 544 return -EFAULT;
1da177e4
LT		 545
546 /* Set up registers for signal handler */
7e907f48
IM		 547 regs->sp = (unsigned long)frame;
548 regs->ip = (unsigned long)ka->sa.sa_handler;
13ad7725 549 regs->ax = (unsigned long)sig;
7e907f48
IM		 550 regs->dx = (unsigned long)&frame->info;
551 regs->cx = (unsigned long)&frame->uc;
1da177e4 552
65ea5b03
PA		 553 regs->ds = __USER_DS;
554 regs->es = __USER_DS;
555 regs->ss = __USER_DS;
556 regs->cs = __USER_CS;
1da177e4 557
283828f3 558 return 0;
1da177e4
LT		 559}
560
561/*
7e907f48
IM		 562 * OK, we're invoking a handler:
563 */
8d8c13bd
HS		 564static int signr_convert(int sig)
565{
96bf84b7 566#ifdef CONFIG_X86_32
8d8c13bd
HS		 567 struct thread_info *info = current_thread_info();
568
569 if (info->exec_domain && info->exec_domain->signal_invmap && sig < 32)
570 return info->exec_domain->signal_invmap[sig];
96bf84b7 571#endif /* CONFIG_X86_32 */
8d8c13bd
HS		 572 return sig;
573}
574
cabf5035
HS		 575#ifdef CONFIG_X86_32
576
455edbc4 577#define is_ia32 1
4694d239
HS		 578#define ia32_setup_frame __setup_frame
579#define ia32_setup_rt_frame __setup_rt_frame
455edbc4 580
cabf5035
HS		 581#else /* !CONFIG_X86_32 */
582
583#ifdef CONFIG_IA32_EMULATION
584#define is_ia32 test_thread_flag(TIF_IA32)
585#else /* !CONFIG_IA32_EMULATION */
586#define is_ia32 0
587#endif /* CONFIG_IA32_EMULATION */
588
589#endif /* CONFIG_X86_32 */
590
1d13024e
HS		 591static int
592setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
593 sigset_t *set, struct pt_regs *regs)
594{
8d8c13bd 595 int usig = signr_convert(sig);
1d13024e
HS		 596 int ret;
597
598 /* Set up the stack frame */
455edbc4
HS		 599 if (is_ia32) {
600 if (ka->sa.sa_flags & SA_SIGINFO)
4694d239 601 ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
455edbc4 602 else
4694d239 603 ret = ia32_setup_frame(usig, ka, set, regs);
455edbc4
HS		 604 } else
605 ret = __setup_rt_frame(sig, ka, info, set, regs);
1d13024e 606
3d0aedd9
HS		 607 if (ret) {
608 force_sigsegv(sig, current);
609 return -EFAULT;
610 }
611
1d13024e
HS		 612 return ret;
613}
614
7c1def16 615static int
1da177e4 616handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
ac66f3fd 617 sigset_t *oldset, struct pt_regs *regs)
1da177e4 618{
7c1def16
RM		 619 int ret;
620
1da177e4 621 /* Are we from a system call? */
bb57925f 622 if (syscall_get_nr(current, regs) >= 0) {
1da177e4 623 /* If so, check system call restarting.. */
bb57925f 624 switch (syscall_get_error(current, regs)) {
ac66f3fd
HH		 625 case -ERESTART_RESTARTBLOCK:
626 case -ERESTARTNOHAND:
627 regs->ax = -EINTR;
628 break;
629
630 case -ERESTARTSYS:
631 if (!(ka->sa.sa_flags & SA_RESTART)) {
65ea5b03 632 regs->ax = -EINTR;
1da177e4 633 break;
ac66f3fd
HH		 634 }
635 /* fallthrough */
636 case -ERESTARTNOINTR:
637 regs->ax = regs->orig_ax;
638 regs->ip -= 2;
639 break;
1da177e4
LT		 640 }
641 }
642
643 /*
e1f28773
RM		 644 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
645 * flag so that register information in the sigcontext is correct.
1da177e4 646 */
65ea5b03 647 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
e1f28773 648 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
65ea5b03 649 regs->flags &= ~X86_EFLAGS_TF;
1da177e4 650
1d13024e 651 ret = setup_rt_frame(sig, ka, info, oldset, regs);
1da177e4 652
7e907f48
IM		 653 if (ret)
654 return ret;
7c1def16 655
86d3237c
HS		 656#ifdef CONFIG_X86_64
657 /*
658 * This has nothing to do with segment registers,
659 * despite the name. This magic affects uaccess.h
660 * macros' behavior. Reset it to the normal setting.
661 */
662 set_fs(USER_DS);
663#endif
664
8b9c5ff3
RM		 665 /*
666 * Clear the direction flag as per the ABI for function entry.
667 */
668 regs->flags &= ~X86_EFLAGS_DF;
669
670 /*
671 * Clear TF when entering the signal handler, but
672 * notify any tracer that was single-stepping it.
673 * The tracer may want to single-step inside the
674 * handler too.
675 */
676 regs->flags &= ~X86_EFLAGS_TF;
8b9c5ff3 677
7e907f48
IM		 678 spin_lock_irq(&current->sighand->siglock);
679 sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
680 if (!(ka->sa.sa_flags & SA_NODEFER))
681 sigaddset(&current->blocked, sig);
682 recalc_sigpending();
683 spin_unlock_irq(&current->sighand->siglock);
684
36a03308
RM		 685 tracehook_signal_handler(sig, info, ka, regs,
686 test_thread_flag(TIF_SINGLESTEP));
687
7e907f48 688 return 0;
1da177e4
LT		 689}
690
57917752 691#ifdef CONFIG_X86_32
8fcd8e20 692#define NR_restart_syscall __NR_restart_syscall
57917752
HS		 693#else /* !CONFIG_X86_32 */
694#define NR_restart_syscall \
695 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
696#endif /* CONFIG_X86_32 */
697
1da177e4
LT		 698/*
699 * Note that 'init' is a special process: it doesn't get signals it doesn't
700 * want to handle. Thus you cannot kill init even with a SIGKILL even by
701 * mistake.
702 */
75604d7f 703static void do_signal(struct pt_regs *regs)
1da177e4 704{
ac66f3fd 705 struct k_sigaction ka;
1da177e4
LT		 706 siginfo_t info;
707 int signr;
283828f3 708 sigset_t *oldset;
1da177e4
LT		 709
710 /*
ac66f3fd
HH		 711 * We want the common case to go fast, which is why we may in certain
712 * cases get here from kernel mode. Just return without doing anything
713 * if so.
714 * X86_32: vm86 regs switched out by assembly code before reaching
715 * here, so testing against kernel CS suffices.
1da177e4 716 */
717b594a 717 if (!user_mode(regs))
283828f3 718 return;
1da177e4 719
5a8da0ea 720 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
283828f3
DH		 721 oldset = &current->saved_sigmask;
722 else
1da177e4
LT		 723 oldset = &current->blocked;
724
725 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
726 if (signr > 0) {
7e907f48
IM		 727 /*
728 * Re-enable any watchpoints before delivering the
1da177e4
LT		 729 * signal to user space. The processor register will
730 * have been cleared if the watchpoint triggered
731 * inside the kernel.
732 */
ac66f3fd 733 if (current->thread.debugreg7)
0f534093 734 set_debugreg(current->thread.debugreg7, 7);
1da177e4 735
7e907f48 736 /* Whee! Actually deliver the signal. */
283828f3 737 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
7e907f48 738 /*
5a8da0ea 739 * A signal was successfully delivered; the saved
283828f3
DH		 740 * sigmask will have been stored in the signal frame,
741 * and will be restored by sigreturn, so we can simply
5a8da0ea 742 * clear the TS_RESTORE_SIGMASK flag.
7e907f48 743 */
5a8da0ea 744 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
283828f3 745 }
283828f3 746 return;
1da177e4
LT		 747 }
748
1da177e4 749 /* Did we come from a system call? */
bb57925f 750 if (syscall_get_nr(current, regs) >= 0) {
1da177e4 751 /* Restart the system call - no handlers present */
bb57925f 752 switch (syscall_get_error(current, regs)) {
283828f3
DH		 753 case -ERESTARTNOHAND:
754 case -ERESTARTSYS:
755 case -ERESTARTNOINTR:
65ea5b03
PA		 756 regs->ax = regs->orig_ax;
757 regs->ip -= 2;
283828f3
DH		 758 break;
759
760 case -ERESTART_RESTARTBLOCK:
8fcd8e20 761 regs->ax = NR_restart_syscall;
65ea5b03 762 regs->ip -= 2;
283828f3 763 break;
1da177e4
LT		 764 }
765 }
283828f3 766
ac66f3fd
HH		 767 /*
768 * If there's no signal to deliver, we just put the saved sigmask
769 * back.
770 */
5a8da0ea
RM		 771 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
772 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
283828f3
DH		 773 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
774 }
1da177e4
LT		 775}
776
777/*
778 * notification of userspace execution resumption
283828f3 779 * - triggered by the TIF_WORK_MASK flags
1da177e4 780 */
7e907f48
IM		 781void
782do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
1da177e4 783{
ee847c54
HS		 784#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
785 /* notify userspace of pending MCEs */
786 if (thread_info_flags & _TIF_MCE_NOTIFY)
787 mce_notify_user();
788#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
789
1da177e4 790 /* deal with pending signal delivery */
5a8da0ea 791 if (thread_info_flags & _TIF_SIGPENDING)
283828f3 792 do_signal(regs);
8f4d37ec 793
59e52130
RM		 794 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
795 clear_thread_flag(TIF_NOTIFY_RESUME);
796 tracehook_notify_resume(regs);
797 }
798
ee847c54 799#ifdef CONFIG_X86_32
1da177e4 800 clear_thread_flag(TIF_IRET);
ee847c54 801#endif /* CONFIG_X86_32 */
1da177e4 802}
72fa50f4
HS		 803
804void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
805{
806 struct task_struct *me = current;
807
808 if (show_unhandled_signals && printk_ratelimit()) {
809 printk(KERN_INFO
810 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
811 me->comm, me->pid, where, frame,
812 regs->ip, regs->sp, regs->orig_ax);
813 print_vma_addr(" in ", regs->ip);
814 printk(KERN_CONT "\n");
815 }
816
817 force_sig(SIGSEGV, me);
818}
Linux 6.x block layer and io_uring tree(s)