xref: /openbmc/linux/arch/sparc/kernel/signal_64.c (revision 9c1f8594)
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 
620