Merge git://bedivere.hansenpartnership.com/git/scsi-rc-fixes-2.6
[linux-2.6.git] / arch / sparc / kernel / signal_64.c
1 /*
2  *  arch/sparc64/kernel/signal.c
3  *
4  *  Copyright (C) 1991, 1992  Linus Torvalds
5  *  Copyright (C) 1995, 2008 David S. Miller (davem@davemloft.net)
6  *  Copyright (C) 1996 Miguel de Icaza (miguel@nuclecu.unam.mx)
7  *  Copyright (C) 1997 Eddie C. Dost   (ecd@skynet.be)
8  *  Copyright (C) 1997,1998 Jakub Jelinek   (jj@sunsite.mff.cuni.cz)
9  */
10
11 #ifdef CONFIG_COMPAT
12 #include <linux/compat.h>       /* for compat_old_sigset_t */
13 #endif
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
16 #include <linux/signal.h>
17 #include <linux/errno.h>
18 #include <linux/wait.h>
19 #include <linux/ptrace.h>
20 #include <linux/tracehook.h>
21 #include <linux/unistd.h>
22 #include <linux/mm.h>
23 #include <linux/tty.h>
24 #include <linux/binfmts.h>
25 #include <linux/bitops.h>
26
27 #include <asm/uaccess.h>
28 #include <asm/ptrace.h>
29 #include <asm/pgtable.h>
30 #include <asm/fpumacro.h>
31 #include <asm/uctx.h>
32 #include <asm/siginfo.h>
33 #include <asm/visasm.h>
34
35 #include "entry.h"
36 #include "systbls.h"
37 #include "sigutil.h"
38
39 #define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
40
41 /* {set, get}context() needed for 64-bit SparcLinux userland. */
42 asmlinkage void sparc64_set_context(struct pt_regs *regs)
43 {
44         struct ucontext __user *ucp = (struct ucontext __user *)
45                 regs->u_regs[UREG_I0];
46         mc_gregset_t __user *grp;
47         unsigned long pc, npc, tstate;
48         unsigned long fp, i7;
49         unsigned char fenab;
50         int err;
51
52         flush_user_windows();
53         if (get_thread_wsaved()                                 ||
54             (((unsigned long)ucp) & (sizeof(unsigned long)-1))  ||
55             (!__access_ok(ucp, sizeof(*ucp))))
56                 goto do_sigsegv;
57         grp  = &ucp->uc_mcontext.mc_gregs;
58         err  = __get_user(pc, &((*grp)[MC_PC]));
59         err |= __get_user(npc, &((*grp)[MC_NPC]));
60         if (err || ((pc | npc) & 3))
61                 goto do_sigsegv;
62         if (regs->u_regs[UREG_I1]) {
63                 sigset_t set;
64
65                 if (_NSIG_WORDS == 1) {
66                         if (__get_user(set.sig[0], &ucp->uc_sigmask.sig[0]))
67                                 goto do_sigsegv;
68                 } else {
69                         if (__copy_from_user(&set, &ucp->uc_sigmask, sizeof(sigset_t)))
70                                 goto do_sigsegv;
71                 }
72                 sigdelsetmask(&set, ~_BLOCKABLE);
73                 spin_lock_irq(&current->sighand->siglock);
74                 current->blocked = set;
75                 recalc_sigpending();
76                 spin_unlock_irq(&current->sighand->siglock);
77         }
78         if (test_thread_flag(TIF_32BIT)) {
79                 pc &= 0xffffffff;
80                 npc &= 0xffffffff;
81         }
82         regs->tpc = pc;
83         regs->tnpc = npc;
84         err |= __get_user(regs->y, &((*grp)[MC_Y]));
85         err |= __get_user(tstate, &((*grp)[MC_TSTATE]));
86         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
87         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
88         err |= __get_user(regs->u_regs[UREG_G1], (&(*grp)[MC_G1]));
89         err |= __get_user(regs->u_regs[UREG_G2], (&(*grp)[MC_G2]));
90         err |= __get_user(regs->u_regs[UREG_G3], (&(*grp)[MC_G3]));
91         err |= __get_user(regs->u_regs[UREG_G4], (&(*grp)[MC_G4]));
92         err |= __get_user(regs->u_regs[UREG_G5], (&(*grp)[MC_G5]));
93         err |= __get_user(regs->u_regs[UREG_G6], (&(*grp)[MC_G6]));
94
95         /* Skip %g7 as that's the thread register in userspace.  */
96
97         err |= __get_user(regs->u_regs[UREG_I0], (&(*grp)[MC_O0]));
98         err |= __get_user(regs->u_regs[UREG_I1], (&(*grp)[MC_O1]));
99         err |= __get_user(regs->u_regs[UREG_I2], (&(*grp)[MC_O2]));
100         err |= __get_user(regs->u_regs[UREG_I3], (&(*grp)[MC_O3]));
101         err |= __get_user(regs->u_regs[UREG_I4], (&(*grp)[MC_O4]));
102         err |= __get_user(regs->u_regs[UREG_I5], (&(*grp)[MC_O5]));
103         err |= __get_user(regs->u_regs[UREG_I6], (&(*grp)[MC_O6]));
104         err |= __get_user(regs->u_regs[UREG_I7], (&(*grp)[MC_O7]));
105
106         err |= __get_user(fp, &(ucp->uc_mcontext.mc_fp));
107         err |= __get_user(i7, &(ucp->uc_mcontext.mc_i7));
108         err |= __put_user(fp,
109               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
110         err |= __put_user(i7,
111               (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
112
113         err |= __get_user(fenab, &(ucp->uc_mcontext.mc_fpregs.mcfpu_enab));
114         if (fenab) {
115                 unsigned long *fpregs = current_thread_info()->fpregs;
116                 unsigned long fprs;
117                 
118                 fprs_write(0);
119                 err |= __get_user(fprs, &(ucp->uc_mcontext.mc_fpregs.mcfpu_fprs));
120                 if (fprs & FPRS_DL)
121                         err |= copy_from_user(fpregs,
122                                               &(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs),
123                                               (sizeof(unsigned int) * 32));
124                 if (fprs & FPRS_DU)
125                         err |= copy_from_user(fpregs+16,
126                          ((unsigned long __user *)&(ucp->uc_mcontext.mc_fpregs.mcfpu_fregs))+16,
127                          (sizeof(unsigned int) * 32));
128                 err |= __get_user(current_thread_info()->xfsr[0],
129                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_fsr));
130                 err |= __get_user(current_thread_info()->gsr[0],
131                                   &(ucp->uc_mcontext.mc_fpregs.mcfpu_gsr));
132                 regs->tstate &= ~TSTATE_PEF;
133         }
134         if (err)
135                 goto do_sigsegv;
136
137         return;
138 do_sigsegv:
139         force_sig(SIGSEGV, current);
140 }
141
142 asmlinkage void sparc64_get_context(struct pt_regs *regs)
143 {
144         struct ucontext __user *ucp = (struct ucontext __user *)
145                 regs->u_regs[UREG_I0];
146         mc_gregset_t __user *grp;
147         mcontext_t __user *mcp;
148         unsigned long fp, i7;
149         unsigned char fenab;
150         int err;
151
152         synchronize_user_stack();
153         if (get_thread_wsaved() || clear_user(ucp, sizeof(*ucp)))
154                 goto do_sigsegv;
155
156 #if 1
157         fenab = 0; /* IMO get_context is like any other system call, thus modifies FPU state -jj */
158 #else
159         fenab = (current_thread_info()->fpsaved[0] & FPRS_FEF);
160 #endif
161                 
162         mcp = &ucp->uc_mcontext;
163         grp = &mcp->mc_gregs;
164
165         /* Skip over the trap instruction, first. */
166         if (test_thread_flag(TIF_32BIT)) {
167                 regs->tpc   = (regs->tnpc & 0xffffffff);
168                 regs->tnpc  = (regs->tnpc + 4) & 0xffffffff;
169         } else {
170                 regs->tpc   = regs->tnpc;
171                 regs->tnpc += 4;
172         }
173         err = 0;
174         if (_NSIG_WORDS == 1)
175                 err |= __put_user(current->blocked.sig[0],
176                                   (unsigned long __user *)&ucp->uc_sigmask);
177         else
178                 err |= __copy_to_user(&ucp->uc_sigmask, &current->blocked,
179                                       sizeof(sigset_t));
180
181         err |= __put_user(regs->tstate, &((*grp)[MC_TSTATE]));
182         err |= __put_user(regs->tpc, &((*grp)[MC_PC]));
183         err |= __put_user(regs->tnpc, &((*grp)[MC_NPC]));
184         err |= __put_user(regs->y, &((*grp)[MC_Y]));
185         err |= __put_user(regs->u_regs[UREG_G1], &((*grp)[MC_G1]));
186         err |= __put_user(regs->u_regs[UREG_G2], &((*grp)[MC_G2]));
187         err |= __put_user(regs->u_regs[UREG_G3], &((*grp)[MC_G3]));
188         err |= __put_user(regs->u_regs[UREG_G4], &((*grp)[MC_G4]));
189         err |= __put_user(regs->u_regs[UREG_G5], &((*grp)[MC_G5]));
190         err |= __put_user(regs->u_regs[UREG_G6], &((*grp)[MC_G6]));
191         err |= __put_user(regs->u_regs[UREG_G7], &((*grp)[MC_G7]));
192         err |= __put_user(regs->u_regs[UREG_I0], &((*grp)[MC_O0]));
193         err |= __put_user(regs->u_regs[UREG_I1], &((*grp)[MC_O1]));
194         err |= __put_user(regs->u_regs[UREG_I2], &((*grp)[MC_O2]));
195         err |= __put_user(regs->u_regs[UREG_I3], &((*grp)[MC_O3]));
196         err |= __put_user(regs->u_regs[UREG_I4], &((*grp)[MC_O4]));
197         err |= __put_user(regs->u_regs[UREG_I5], &((*grp)[MC_O5]));
198         err |= __put_user(regs->u_regs[UREG_I6], &((*grp)[MC_O6]));
199         err |= __put_user(regs->u_regs[UREG_I7], &((*grp)[MC_O7]));
200
201         err |= __get_user(fp,
202                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[6])));
203         err |= __get_user(i7,
204                  (&(((struct reg_window __user *)(STACK_BIAS+regs->u_regs[UREG_I6]))->ins[7])));
205         err |= __put_user(fp, &(mcp->mc_fp));
206         err |= __put_user(i7, &(mcp->mc_i7));
207
208         err |= __put_user(fenab, &(mcp->mc_fpregs.mcfpu_enab));
209         if (fenab) {
210                 unsigned long *fpregs = current_thread_info()->fpregs;
211                 unsigned long fprs;
212                 
213                 fprs = current_thread_info()->fpsaved[0];
214                 if (fprs & FPRS_DL)
215                         err |= copy_to_user(&(mcp->mc_fpregs.mcfpu_fregs), fpregs,
216                                             (sizeof(unsigned int) * 32));
217                 if (fprs & FPRS_DU)
218                         err |= copy_to_user(
219                           ((unsigned long __user *)&(mcp->mc_fpregs.mcfpu_fregs))+16, fpregs+16,
220                           (sizeof(unsigned int) * 32));
221                 err |= __put_user(current_thread_info()->xfsr[0], &(mcp->mc_fpregs.mcfpu_fsr));
222                 err |= __put_user(current_thread_info()->gsr[0], &(mcp->mc_fpregs.mcfpu_gsr));
223                 err |= __put_user(fprs, &(mcp->mc_fpregs.mcfpu_fprs));
224         }
225         if (err)
226                 goto do_sigsegv;
227
228         return;
229 do_sigsegv:
230         force_sig(SIGSEGV, current);
231 }
232
233 struct rt_signal_frame {
234         struct sparc_stackf     ss;
235         siginfo_t               info;
236         struct pt_regs          regs;
237         __siginfo_fpu_t __user  *fpu_save;
238         stack_t                 stack;
239         sigset_t                mask;
240         __siginfo_rwin_t        *rwin_save;
241 };
242
243 static long _sigpause_common(old_sigset_t set)
244 {
245         set &= _BLOCKABLE;
246         spin_lock_irq(&current->sighand->siglock);
247         current->saved_sigmask = current->blocked;
248         siginitset(&current->blocked, set);
249         recalc_sigpending();
250         spin_unlock_irq(&current->sighand->siglock);
251
252         current->state = TASK_INTERRUPTIBLE;
253         schedule();
254
255         set_restore_sigmask();
256
257         return -ERESTARTNOHAND;
258 }
259
260 asmlinkage long sys_sigpause(unsigned int set)
261 {
262         return _sigpause_common(set);
263 }
264
265 asmlinkage long sys_sigsuspend(old_sigset_t set)
266 {
267         return _sigpause_common(set);
268 }
269
270 void do_rt_sigreturn(struct pt_regs *regs)
271 {
272         struct rt_signal_frame __user *sf;
273         unsigned long tpc, tnpc, tstate;
274         __siginfo_fpu_t __user *fpu_save;
275         __siginfo_rwin_t __user *rwin_save;
276         sigset_t set;
277         int err;
278
279         /* Always make any pending restarted system calls return -EINTR */
280         current_thread_info()->restart_block.fn = do_no_restart_syscall;
281
282         synchronize_user_stack ();
283         sf = (struct rt_signal_frame __user *)
284                 (regs->u_regs [UREG_FP] + STACK_BIAS);
285
286         /* 1. Make sure we are not getting garbage from the user */
287         if (((unsigned long) sf) & 3)
288                 goto segv;
289
290         err = get_user(tpc, &sf->regs.tpc);
291         err |= __get_user(tnpc, &sf->regs.tnpc);
292         if (test_thread_flag(TIF_32BIT)) {
293                 tpc &= 0xffffffff;
294                 tnpc &= 0xffffffff;
295         }
296         err |= ((tpc | tnpc) & 3);
297
298         /* 2. Restore the state */
299         err |= __get_user(regs->y, &sf->regs.y);
300         err |= __get_user(tstate, &sf->regs.tstate);
301         err |= copy_from_user(regs->u_regs, sf->regs.u_regs, sizeof(regs->u_regs));
302
303         /* User can only change condition codes and %asi in %tstate. */
304         regs->tstate &= ~(TSTATE_ASI | TSTATE_ICC | TSTATE_XCC);
305         regs->tstate |= (tstate & (TSTATE_ASI | TSTATE_ICC | TSTATE_XCC));
306
307         err |= __get_user(fpu_save, &sf->fpu_save);
308         if (!err && fpu_save)
309                 err |= restore_fpu_state(regs, fpu_save);
310
311         err |= __copy_from_user(&set, &sf->mask, sizeof(sigset_t));
312         err |= do_sigaltstack(&sf->stack, NULL, (unsigned long)sf);
313
314         if (err)
315                 goto segv;
316
317         err |= __get_user(rwin_save, &sf->rwin_save);
318         if (!err && rwin_save) {
319                 if (restore_rwin_state(rwin_save))
320                         goto segv;
321         }
322
323         regs->tpc = tpc;
324         regs->tnpc = tnpc;
325
326         /* Prevent syscall restart.  */
327         pt_regs_clear_syscall(regs);
328
329         sigdelsetmask(&set, ~_BLOCKABLE);
330         spin_lock_irq(&current->sighand->siglock);
331         current->blocked = set;
332         recalc_sigpending();
333         spin_unlock_irq(&current->sighand->siglock);
334         return;
335 segv:
336         force_sig(SIGSEGV, current);
337 }
338
339 /* Checks if the fp is valid */
340 static int invalid_frame_pointer(void __user *fp)
341 {
342         if (((unsigned long) fp) & 15)
343                 return 1;
344         return 0;
345 }
346
347 static inline void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, unsigned long framesize)
348 {
349         unsigned long sp = regs->u_regs[UREG_FP] + STACK_BIAS;
350
351         /*
352          * If we are on the alternate signal stack and would overflow it, don't.
353          * Return an always-bogus address instead so we will die with SIGSEGV.
354          */
355         if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
356                 return (void __user *) -1L;
357
358         /* This is the X/Open sanctioned signal stack switching.  */
359         if (ka->sa.sa_flags & SA_ONSTACK) {
360                 if (sas_ss_flags(sp) == 0)
361                         sp = current->sas_ss_sp + current->sas_ss_size;
362         }
363
364         sp -= framesize;
365
366         /* Always align the stack frame.  This handles two cases.  First,
367          * sigaltstack need not be mindful of platform specific stack
368          * alignment.  Second, if we took this signal because the stack
369          * is not aligned properly, we'd like to take the signal cleanly
370          * and report that.
371          */
372         sp &= ~15UL;
373
374         return (void __user *) sp;
375 }
376
377 static inline int
378 setup_rt_frame(struct k_sigaction *ka, struct pt_regs *regs,
379                int signo, sigset_t *oldset, siginfo_t *info)
380 {
381         struct rt_signal_frame __user *sf;
382         int wsaved, err, sf_size;
383         void __user *tail;
384
385         /* 1. Make sure everything is clean */
386         synchronize_user_stack();
387         save_and_clear_fpu();
388         
389         wsaved = get_thread_wsaved();
390
391         sf_size = sizeof(struct rt_signal_frame);
392         if (current_thread_info()->fpsaved[0] & FPRS_FEF)
393                 sf_size += sizeof(__siginfo_fpu_t);
394         if (wsaved)
395                 sf_size += sizeof(__siginfo_rwin_t);
396         sf = (struct rt_signal_frame __user *)
397                 get_sigframe(ka, regs, sf_size);
398
399         if (invalid_frame_pointer (sf))
400                 goto sigill;
401
402         tail = (sf + 1);
403
404         /* 2. Save the current process state */
405         err = copy_to_user(&sf->regs, regs, sizeof (*regs));
406
407         if (current_thread_info()->fpsaved[0] & FPRS_FEF) {
408                 __siginfo_fpu_t __user *fpu_save = tail;
409                 tail += sizeof(__siginfo_fpu_t);
410                 err |= save_fpu_state(regs, fpu_save);
411                 err |= __put_user((u64)fpu_save, &sf->fpu_save);
412         } else {
413                 err |= __put_user(0, &sf->fpu_save);
414         }
415         if (wsaved) {
416                 __siginfo_rwin_t __user *rwin_save = tail;
417                 tail += sizeof(__siginfo_rwin_t);
418                 err |= save_rwin_state(wsaved, rwin_save);
419                 err |= __put_user((u64)rwin_save, &sf->rwin_save);
420                 set_thread_wsaved(0);
421         } else {
422                 err |= __put_user(0, &sf->rwin_save);
423         }
424         
425         /* Setup sigaltstack */
426         err |= __put_user(current->sas_ss_sp, &sf->stack.ss_sp);
427         err |= __put_user(sas_ss_flags(regs->u_regs[UREG_FP]), &sf->stack.ss_flags);
428         err |= __put_user(current->sas_ss_size, &sf->stack.ss_size);
429
430         err |= copy_to_user(&sf->mask, oldset, sizeof(sigset_t));
431
432         if (!wsaved) {
433                 err |= copy_in_user((u64 __user *)sf,
434                                     (u64 __user *)(regs->u_regs[UREG_FP] +
435                                                    STACK_BIAS),
436                                     sizeof(struct reg_window));
437         } else {
438                 struct reg_window *rp;
439
440                 rp = &current_thread_info()->reg_window[wsaved - 1];
441                 err |= copy_to_user(sf, rp, sizeof(struct reg_window));
442         }
443         if (info)
444                 err |= copy_siginfo_to_user(&sf->info, info);
445         else {
446                 err |= __put_user(signo, &sf->info.si_signo);
447                 err |= __put_user(SI_NOINFO, &sf->info.si_code);
448         }
449         if (err)
450                 goto sigsegv;
451         
452         /* 3. signal handler back-trampoline and parameters */
453         regs->u_regs[UREG_FP] = ((unsigned long) sf) - STACK_BIAS;
454         regs->u_regs[UREG_I0] = signo;
455         regs->u_regs[UREG_I1] = (unsigned long) &sf->info;
456
457         /* The sigcontext is passed in this way because of how it
458          * is defined in GLIBC's /usr/include/bits/sigcontext.h
459          * for sparc64.  It includes the 128 bytes of siginfo_t.
460          */
461         regs->u_regs[UREG_I2] = (unsigned long) &sf->info;
462
463         /* 5. signal handler */
464         regs->tpc = (unsigned long) ka->sa.sa_handler;
465         regs->tnpc = (regs->tpc + 4);
466         if (test_thread_flag(TIF_32BIT)) {
467                 regs->tpc &= 0xffffffff;
468                 regs->tnpc &= 0xffffffff;
469         }
470         /* 4. return to kernel instructions */
471         regs->u_regs[UREG_I7] = (unsigned long)ka->ka_restorer;
472         return 0;
473
474 sigill:
475         do_exit(SIGILL);
476         return -EINVAL;
477
478 sigsegv:
479         force_sigsegv(signo, current);
480         return -EFAULT;
481 }
482
483 static inline int handle_signal(unsigned long signr, struct k_sigaction *ka,
484                                 siginfo_t *info,
485                                 sigset_t *oldset, struct pt_regs *regs)
486 {
487         int err;
488
489         err = setup_rt_frame(ka, regs, signr, oldset,
490                              (ka->sa.sa_flags & SA_SIGINFO) ? info : NULL);
491         if (err)
492                 return err;
493         spin_lock_irq(&current->sighand->siglock);
494         sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
495         if (!(ka->sa.sa_flags & SA_NOMASK))
496                 sigaddset(&current->blocked,signr);
497         recalc_sigpending();
498         spin_unlock_irq(&current->sighand->siglock);
499
500         tracehook_signal_handler(signr, info, ka, regs, 0);
501
502         return 0;
503 }
504
505 static inline void syscall_restart(unsigned long orig_i0, struct pt_regs *regs,
506                                    struct sigaction *sa)
507 {
508         switch (regs->u_regs[UREG_I0]) {
509         case ERESTART_RESTARTBLOCK:
510         case ERESTARTNOHAND:
511         no_system_call_restart:
512                 regs->u_regs[UREG_I0] = EINTR;
513                 regs->tstate |= (TSTATE_ICARRY|TSTATE_XCARRY);
514                 break;
515         case ERESTARTSYS:
516                 if (!(sa->sa_flags & SA_RESTART))
517                         goto no_system_call_restart;
518                 /* fallthrough */
519         case ERESTARTNOINTR:
520                 regs->u_regs[UREG_I0] = orig_i0;
521                 regs->tpc -= 4;
522                 regs->tnpc -= 4;
523         }
524 }
525
526 /* Note that 'init' is a special process: it doesn't get signals it doesn't
527  * want to handle. Thus you cannot kill init even with a SIGKILL even by
528  * mistake.
529  */
530 static void do_signal(struct pt_regs *regs, unsigned long orig_i0)
531 {
532         struct k_sigaction ka;
533         int restart_syscall;
534         sigset_t *oldset;
535         siginfo_t info;
536         int signr;
537         
538         if (pt_regs_is_syscall(regs) &&
539             (regs->tstate & (TSTATE_XCARRY | TSTATE_ICARRY))) {
540                 restart_syscall = 1;
541         } else
542                 restart_syscall = 0;
543
544         if (current_thread_info()->status & TS_RESTORE_SIGMASK)
545                 oldset = &current->saved_sigmask;
546         else
547                 oldset = &current->blocked;
548
549 #ifdef CONFIG_COMPAT
550         if (test_thread_flag(TIF_32BIT)) {
551                 extern void do_signal32(sigset_t *, struct pt_regs *,
552                                         int restart_syscall,
553                                         unsigned long orig_i0);
554                 do_signal32(oldset, regs, restart_syscall, orig_i0);
555                 return;
556         }
557 #endif  
558
559         signr = get_signal_to_deliver(&info, &ka, regs, NULL);
560
561         /* If the debugger messes with the program counter, it clears
562          * the software "in syscall" bit, directing us to not perform
563          * a syscall restart.
564          */
565         if (restart_syscall && !pt_regs_is_syscall(regs))
566                 restart_syscall = 0;
567
568         if (signr > 0) {
569                 if (restart_syscall)
570                         syscall_restart(orig_i0, regs, &ka.sa);
571                 if (handle_signal(signr, &ka, &info, oldset, regs) == 0) {
572                         /* A signal was successfully delivered; the saved
573                          * sigmask will have been stored in the signal frame,
574                          * and will be restored by sigreturn, so we can simply
575                          * clear the TS_RESTORE_SIGMASK flag.
576                          */
577                         current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
578                 }
579                 return;
580         }
581         if (restart_syscall &&
582             (regs->u_regs[UREG_I0] == ERESTARTNOHAND ||
583              regs->u_regs[UREG_I0] == ERESTARTSYS ||
584              regs->u_regs[UREG_I0] == ERESTARTNOINTR)) {
585                 /* replay the system call when we are done */
586                 regs->u_regs[UREG_I0] = orig_i0;
587                 regs->tpc -= 4;
588                 regs->tnpc -= 4;
589                 pt_regs_clear_syscall(regs);
590         }
591         if (restart_syscall &&
592             regs->u_regs[UREG_I0] == ERESTART_RESTARTBLOCK) {
593                 regs->u_regs[UREG_G1] = __NR_restart_syscall;
594                 regs->tpc -= 4;
595                 regs->tnpc -= 4;
596                 pt_regs_clear_syscall(regs);
597         }
598
599         /* If there's no signal to deliver, we just put the saved sigmask
600          * back
601          */
602         if (current_thread_info()->status & TS_RESTORE_SIGMASK) {
603                 current_thread_info()->status &= ~TS_RESTORE_SIGMASK;
604                 sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
605         }
606 }
607
608 void do_notify_resume(struct pt_regs *regs, unsigned long orig_i0, unsigned long thread_info_flags)
609 {
610         if (thread_info_flags & _TIF_SIGPENDING)
611                 do_signal(regs, orig_i0);
612         if (thread_info_flags & _TIF_NOTIFY_RESUME) {
613                 clear_thread_flag(TIF_NOTIFY_RESUME);
614                 tracehook_notify_resume(regs);
615                 if (current->replacement_session_keyring)
616                         key_replace_session_keyring();
617         }
618 }
619