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Diffstat (limited to 'arch/x86/kernel/signal_64.c')
-rw-r--r--arch/x86/kernel/signal_64.c516
1 files changed, 0 insertions, 516 deletions
diff --git a/arch/x86/kernel/signal_64.c b/arch/x86/kernel/signal_64.c
deleted file mode 100644
index a5c9627f4db9..000000000000
--- a/arch/x86/kernel/signal_64.c
+++ /dev/null
@@ -1,516 +0,0 @@
1/*
2 * Copyright (C) 1991, 1992 Linus Torvalds
3 * Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
4 *
5 * 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
6 * 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
7 * 2000-2002 x86-64 support by Andi Kleen
8 */
9
10#include <linux/sched.h>
11#include <linux/mm.h>
12#include <linux/smp.h>
13#include <linux/kernel.h>
14#include <linux/signal.h>
15#include <linux/errno.h>
16#include <linux/wait.h>
17#include <linux/ptrace.h>
18#include <linux/tracehook.h>
19#include <linux/unistd.h>
20#include <linux/stddef.h>
21#include <linux/personality.h>
22#include <linux/compiler.h>
23#include <linux/uaccess.h>
24
25#include <asm/processor.h>
26#include <asm/ucontext.h>
27#include <asm/i387.h>
28#include <asm/proto.h>
29#include <asm/ia32_unistd.h>
30#include <asm/mce.h>
31#include <asm/syscall.h>
32#include <asm/syscalls.h>
33#include "sigframe.h"
34
35#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
36
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
48asmlinkage long
49sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
50 struct pt_regs *regs)
51{
52 return do_sigaltstack(uss, uoss, regs->sp);
53}
54
55#define COPY(x) { \
56 err |= __get_user(regs->x, &sc->x); \
57}
58
59#define COPY_SEG_STRICT(seg) { \
60 unsigned short tmp; \
61 err |= __get_user(tmp, &sc->seg); \
62 regs->seg = tmp | 3; \
63}
64
65/*
66 * Do a signal return; undo the signal stack.
67 */
68static int
69restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
70 unsigned long *pax)
71{
72 void __user *buf;
73 unsigned int tmpflags;
74 unsigned int err = 0;
75
76 /* Always make any pending restarted system calls return -EINTR */
77 current_thread_info()->restart_block.fn = do_no_restart_syscall;
78
79 COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
80 COPY(dx); COPY(cx); COPY(ip);
81 COPY(r8);
82 COPY(r9);
83 COPY(r10);
84 COPY(r11);
85 COPY(r12);
86 COPY(r13);
87 COPY(r14);
88 COPY(r15);
89
90 /* Kernel saves and restores only the CS segment register on signals,
91 * which is the bare minimum needed to allow mixed 32/64-bit code.
92 * App's signal handler can save/restore other segments if needed. */
93 COPY_SEG_STRICT(cs);
94
95 err |= __get_user(tmpflags, &sc->flags);
96 regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
97 regs->orig_ax = -1; /* disable syscall checks */
98
99 err |= __get_user(buf, &sc->fpstate);
100 err |= restore_i387_xstate(buf);
101
102 err |= __get_user(*pax, &sc->ax);
103 return err;
104}
105
106static long do_rt_sigreturn(struct pt_regs *regs)
107{
108 struct rt_sigframe __user *frame;
109 unsigned long ax;
110 sigset_t set;
111
112 frame = (struct rt_sigframe __user *)(regs->sp - sizeof(long));
113 if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
114 goto badframe;
115 if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
116 goto badframe;
117
118 sigdelsetmask(&set, ~_BLOCKABLE);
119 spin_lock_irq(&current->sighand->siglock);
120 current->blocked = set;
121 recalc_sigpending();
122 spin_unlock_irq(&current->sighand->siglock);
123
124 if (restore_sigcontext(regs, &frame->uc.uc_mcontext, &ax))
125 goto badframe;
126
127 if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->sp) == -EFAULT)
128 goto badframe;
129
130 return ax;
131
132badframe:
133 signal_fault(regs, frame, "rt_sigreturn");
134 return 0;
135}
136
137asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
138{
139 return do_rt_sigreturn(regs);
140}
141
142/*
143 * Set up a signal frame.
144 */
145
146static inline int
147setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
148 unsigned long mask, struct task_struct *me)
149{
150 int err = 0;
151
152 err |= __put_user(regs->cs, &sc->cs);
153 err |= __put_user(0, &sc->gs);
154 err |= __put_user(0, &sc->fs);
155
156 err |= __put_user(regs->di, &sc->di);
157 err |= __put_user(regs->si, &sc->si);
158 err |= __put_user(regs->bp, &sc->bp);
159 err |= __put_user(regs->sp, &sc->sp);
160 err |= __put_user(regs->bx, &sc->bx);
161 err |= __put_user(regs->dx, &sc->dx);
162 err |= __put_user(regs->cx, &sc->cx);
163 err |= __put_user(regs->ax, &sc->ax);
164 err |= __put_user(regs->r8, &sc->r8);
165 err |= __put_user(regs->r9, &sc->r9);
166 err |= __put_user(regs->r10, &sc->r10);
167 err |= __put_user(regs->r11, &sc->r11);
168 err |= __put_user(regs->r12, &sc->r12);
169 err |= __put_user(regs->r13, &sc->r13);
170 err |= __put_user(regs->r14, &sc->r14);
171 err |= __put_user(regs->r15, &sc->r15);
172 err |= __put_user(me->thread.trap_no, &sc->trapno);
173 err |= __put_user(me->thread.error_code, &sc->err);
174 err |= __put_user(regs->ip, &sc->ip);
175 err |= __put_user(regs->flags, &sc->flags);
176 err |= __put_user(mask, &sc->oldmask);
177 err |= __put_user(me->thread.cr2, &sc->cr2);
178
179 return err;
180}
181
182/*
183 * Determine which stack to use..
184 */
185
186static void __user *
187get_stack(struct k_sigaction *ka, struct pt_regs *regs, unsigned long size)
188{
189 unsigned long sp;
190
191 /* Default to using normal stack - redzone*/
192 sp = regs->sp - 128;
193
194 /* This is the X/Open sanctioned signal stack switching. */
195 if (ka->sa.sa_flags & SA_ONSTACK) {
196 if (sas_ss_flags(sp) == 0)
197 sp = current->sas_ss_sp + current->sas_ss_size;
198 }
199
200 return (void __user *)round_down(sp - size, 64);
201}
202
203static int __setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
204 sigset_t *set, struct pt_regs *regs)
205{
206 struct rt_sigframe __user *frame;
207 void __user *fp = NULL;
208 int err = 0;
209 struct task_struct *me = current;
210
211 if (used_math()) {
212 fp = get_stack(ka, regs, sig_xstate_size);
213 frame = (void __user *)round_down(
214 (unsigned long)fp - sizeof(struct rt_sigframe), 16) - 8;
215
216 if (save_i387_xstate(fp) < 0)
217 return -EFAULT;
218 } else
219 frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;
220
221 if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
222 return -EFAULT;
223
224 if (ka->sa.sa_flags & SA_SIGINFO) {
225 if (copy_siginfo_to_user(&frame->info, info))
226 return -EFAULT;
227 }
228
229 /* Create the ucontext. */
230 if (cpu_has_xsave)
231 err |= __put_user(UC_FP_XSTATE, &frame->uc.uc_flags);
232 else
233 err |= __put_user(0, &frame->uc.uc_flags);
234 err |= __put_user(0, &frame->uc.uc_link);
235 err |= __put_user(me->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
236 err |= __put_user(sas_ss_flags(regs->sp),
237 &frame->uc.uc_stack.ss_flags);
238 err |= __put_user(me->sas_ss_size, &frame->uc.uc_stack.ss_size);
239 err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0], me);
240 err |= __put_user(fp, &frame->uc.uc_mcontext.fpstate);
241 if (sizeof(*set) == 16) {
242 __put_user(set->sig[0], &frame->uc.uc_sigmask.sig[0]);
243 __put_user(set->sig[1], &frame->uc.uc_sigmask.sig[1]);
244 } else
245 err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
246
247 /* Set up to return from userspace. If provided, use a stub
248 already in userspace. */
249 /* x86-64 should always use SA_RESTORER. */
250 if (ka->sa.sa_flags & SA_RESTORER) {
251 err |= __put_user(ka->sa.sa_restorer, &frame->pretcode);
252 } else {
253 /* could use a vstub here */
254 return -EFAULT;
255 }
256
257 if (err)
258 return -EFAULT;
259
260 /* Set up registers for signal handler */
261 regs->di = sig;
262 /* In case the signal handler was declared without prototypes */
263 regs->ax = 0;
264
265 /* This also works for non SA_SIGINFO handlers because they expect the
266 next argument after the signal number on the stack. */
267 regs->si = (unsigned long)&frame->info;
268 regs->dx = (unsigned long)&frame->uc;
269 regs->ip = (unsigned long) ka->sa.sa_handler;
270
271 regs->sp = (unsigned long)frame;
272
273 /* Set up the CS register to run signal handlers in 64-bit mode,
274 even if the handler happens to be interrupting 32-bit code. */
275 regs->cs = __USER_CS;
276
277 return 0;
278}
279
280/*
281 * OK, we're invoking a handler
282 */
283static int signr_convert(int sig)
284{
285 return sig;
286}
287
288#ifdef CONFIG_IA32_EMULATION
289#define is_ia32 test_thread_flag(TIF_IA32)
290#else
291#define is_ia32 0
292#endif
293
294static int
295setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
296 sigset_t *set, struct pt_regs *regs)
297{
298 int usig = signr_convert(sig);
299 int ret;
300
301 /* Set up the stack frame */
302 if (is_ia32) {
303 if (ka->sa.sa_flags & SA_SIGINFO)
304 ret = ia32_setup_rt_frame(usig, ka, info, set, regs);
305 else
306 ret = ia32_setup_frame(usig, ka, set, regs);
307 } else
308 ret = __setup_rt_frame(sig, ka, info, set, regs);
309
310 if (ret) {
311 force_sigsegv(sig, current);
312 return -EFAULT;
313 }
314
315 return ret;
316}
317
318static int
319handle_signal(unsigned long sig, siginfo_t *info, struct k_sigaction *ka,
320 sigset_t *oldset, struct pt_regs *regs)
321{
322 int ret;
323
324 /* Are we from a system call? */
325 if (syscall_get_nr(current, regs) >= 0) {
326 /* If so, check system call restarting.. */
327 switch (syscall_get_error(current, regs)) {
328 case -ERESTART_RESTARTBLOCK:
329 case -ERESTARTNOHAND:
330 regs->ax = -EINTR;
331 break;
332
333 case -ERESTARTSYS:
334 if (!(ka->sa.sa_flags & SA_RESTART)) {
335 regs->ax = -EINTR;
336 break;
337 }
338 /* fallthrough */
339 case -ERESTARTNOINTR:
340 regs->ax = regs->orig_ax;
341 regs->ip -= 2;
342 break;
343 }
344 }
345
346 /*
347 * If TF is set due to a debugger (TIF_FORCED_TF), clear the TF
348 * flag so that register information in the sigcontext is correct.
349 */
350 if (unlikely(regs->flags & X86_EFLAGS_TF) &&
351 likely(test_and_clear_thread_flag(TIF_FORCED_TF)))
352 regs->flags &= ~X86_EFLAGS_TF;
353
354 ret = setup_rt_frame(sig, ka, info, oldset, regs);
355
356 if (ret)
357 return ret;
358
359#ifdef CONFIG_X86_64
360 /*
361 * This has nothing to do with segment registers,
362 * despite the name. This magic affects uaccess.h
363 * macros' behavior. Reset it to the normal setting.
364 */
365 set_fs(USER_DS);
366#endif
367
368 /*
369 * Clear the direction flag as per the ABI for function entry.
370 */
371 regs->flags &= ~X86_EFLAGS_DF;
372
373 /*
374 * Clear TF when entering the signal handler, but
375 * notify any tracer that was single-stepping it.
376 * The tracer may want to single-step inside the
377 * handler too.
378 */
379 regs->flags &= ~X86_EFLAGS_TF;
380
381 spin_lock_irq(&current->sighand->siglock);
382 sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
383 if (!(ka->sa.sa_flags & SA_NODEFER))
384 sigaddset(&current->blocked, sig);
385 recalc_sigpending();
386 spin_unlock_irq(&current->sighand->siglock);
387
388 tracehook_signal_handler(sig, info, ka, regs,
389 test_thread_flag(TIF_SINGLESTEP));
390
391 return 0;
392}
393
394#define NR_restart_syscall \
395 test_thread_flag(TIF_IA32) ? __NR_ia32_restart_syscall : __NR_restart_syscall
396/*
397 * Note that 'init' is a special process: it doesn't get signals it doesn't
398 * want to handle. Thus you cannot kill init even with a SIGKILL even by
399 * mistake.
400 */
401static void do_signal(struct pt_regs *regs)
402{
403 struct k_sigaction ka;
404 siginfo_t info;
405 int signr;
406 sigset_t *oldset;
407
408 /*
409 * We want the common case to go fast, which is why we may in certain
410 * cases get here from kernel mode. Just return without doing anything
411 * if so.
412 * X86_32: vm86 regs switched out by assembly code before reaching
413 * here, so testing against kernel CS suffices.
414 */
415 if (!user_mode(regs))
416 return;
417
418 if (current_thread_info()->status & TS_RESTORE_SIGMASK)
419 oldset = &current->saved_sigmask;
420 else
421 oldset = &current->blocked;
422
423 signr = get_signal_to_deliver(&info, &ka, regs, NULL);
424 if (signr > 0) {
425 /*
426 * Re-enable any watchpoints before delivering the
427 * signal to user space. The processor register will
428 * have been cleared if the watchpoint triggered
429 * inside the kernel.
430 */
431 if (current->thread.debugreg7)
432 set_debugreg(current->thread.debugreg7, 7);
433
434 /* Whee! Actually deliver the signal. */
435 if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
436 /*
437 * A signal was successfully delivered; the saved
438 * sigmask will have been stored in the signal frame,
439 * and will be restored by sigreturn, so we can simply
440 * clear the TS_RESTORE_SIGMASK flag.
441 */
442 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
443 }
444 return;
445 }
446
447 /* Did we come from a system call? */
448 if (syscall_get_nr(current, regs) >= 0) {
449 /* Restart the system call - no handlers present */
450 switch (syscall_get_error(current, regs)) {
451 case -ERESTARTNOHAND:
452 case -ERESTARTSYS:
453 case -ERESTARTNOINTR:
454 regs->ax = regs->orig_ax;
455 regs->ip -= 2;
456 break;
457
458 case -ERESTART_RESTARTBLOCK:
459 regs->ax = NR_restart_syscall;
460 regs->ip -= 2;
461 break;
462 }
463 }
464
465 /*
466 * If there's no signal to deliver, we just put the saved sigmask
467 * back.
468 */
469 if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
470 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
471 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
472 }
473}
474
475/*
476 * notification of userspace execution resumption
477 * - triggered by the TIF_WORK_MASK flags
478 */
479void
480do_notify_resume(struct pt_regs *regs, void *unused, __u32 thread_info_flags)
481{
482#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
483 /* notify userspace of pending MCEs */
484 if (thread_info_flags & _TIF_MCE_NOTIFY)
485 mce_notify_user();
486#endif /* CONFIG_X86_64 && CONFIG_X86_MCE */
487
488 /* deal with pending signal delivery */
489 if (thread_info_flags & _TIF_SIGPENDING)
490 do_signal(regs);
491
492 if (thread_info_flags & _TIF_NOTIFY_RESUME) {
493 clear_thread_flag(TIF_NOTIFY_RESUME);
494 tracehook_notify_resume(regs);
495 }
496
497#ifdef CONFIG_X86_32
498 clear_thread_flag(TIF_IRET);
499#endif /* CONFIG_X86_32 */
500}
501
502void signal_fault(struct pt_regs *regs, void __user *frame, char *where)
503{
504 struct task_struct *me = current;
505
506 if (show_unhandled_signals && printk_ratelimit()) {
507 printk(KERN_INFO
508 "%s[%d] bad frame in %s frame:%p ip:%lx sp:%lx orax:%lx",
509 me->comm, me->pid, where, frame,
510 regs->ip, regs->sp, regs->orig_ax);
511 print_vma_addr(" in ", regs->ip);
512 printk(KERN_CONT "\n");
513 }
514
515 force_sig(SIGSEGV, me);
516}
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