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v3.1
 
  1/*
  2 * OpenRISC signal.c
  3 *
  4 * Linux architectural port borrowing liberally from similar works of
  5 * others.  All original copyrights apply as per the original source
  6 * declaration.
  7 *
  8 * Modifications for the OpenRISC architecture:
  9 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 10 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 11 *
 12 *      This program is free software; you can redistribute it and/or
 13 *      modify it under the terms of the GNU General Public License
 14 *      as published by the Free Software Foundation; either version
 15 *      2 of the License, or (at your option) any later version.
 16 */
 17
 18#include <linux/sched.h>
 19#include <linux/mm.h>
 20#include <linux/smp.h>
 21#include <linux/kernel.h>
 22#include <linux/signal.h>
 23#include <linux/errno.h>
 24#include <linux/wait.h>
 25#include <linux/ptrace.h>
 26#include <linux/unistd.h>
 27#include <linux/stddef.h>
 28#include <linux/tracehook.h>
 29
 30#include <asm/processor.h>
 
 31#include <asm/ucontext.h>
 32#include <asm/uaccess.h>
 33
 34#define DEBUG_SIG 0
 35
 36#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))
 37
 38asmlinkage long
 39_sys_sigaltstack(const stack_t *uss, stack_t *uoss, struct pt_regs *regs)
 40{
 41	return do_sigaltstack(uss, uoss, regs->sp);
 42}
 43
 44struct rt_sigframe {
 45	struct siginfo *pinfo;
 46	void *puc;
 47	struct siginfo info;
 48	struct ucontext uc;
 49	unsigned char retcode[16];	/* trampoline code */
 50};
 51
 52static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
 
 53{
 54	unsigned int err = 0;
 55
 56	/* Alwys make any pending restarted system call return -EINTR */
 57	current_thread_info()->restart_block.fn = do_no_restart_syscall;
 58
 59	/*
 60	 * Restore the regs from &sc->regs.
 61	 * (sc is already checked for VERIFY_READ since the sigframe was
 62	 *  checked in sys_sigreturn previously)
 63	 */
 64	if (__copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long)))
 65		goto badframe;
 66	if (__copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long)))
 67		goto badframe;
 68	if (__copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long)))
 69		goto badframe;
 70
 71	/* make sure the SM-bit is cleared so user-mode cannot fool us */
 72	regs->sr &= ~SPR_SR_SM;
 73
 
 
 74	/* TODO: the other ports use regs->orig_XX to disable syscall checks
 75	 * after this completes, but we don't use that mechanism. maybe we can
 76	 * use it now ?
 77	 */
 78
 79	return err;
 80
 81badframe:
 82	return 1;
 83}
 84
 85asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
 86{
 87	struct rt_sigframe *frame = (struct rt_sigframe __user *)regs->sp;
 88	sigset_t set;
 89	stack_t st;
 90
 91	/*
 92	 * Since we stacked the signal on a dword boundary,
 93	 * then frame should be dword aligned here.  If it's
 94	 * not, then the user is trying to mess with us.
 95	 */
 96	if (((long)frame) & 3)
 97		goto badframe;
 98
 99	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
100		goto badframe;
101	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
102		goto badframe;
103
104	sigdelsetmask(&set, ~_BLOCKABLE);
105	spin_lock_irq(&current->sighand->siglock);
106	current->blocked = set;
107	recalc_sigpending();
108	spin_unlock_irq(&current->sighand->siglock);
109
110	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
111		goto badframe;
112
113	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
114		goto badframe;
115	/* It is more difficult to avoid calling this function than to
116	   call it and ignore errors.  */
117	do_sigaltstack(&st, NULL, regs->sp);
118
119	return regs->gpr[11];
120
121badframe:
122	force_sig(SIGSEGV, current);
123	return 0;
124}
125
126/*
127 * Set up a signal frame.
128 */
129
130static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
131			    unsigned long mask)
132{
133	int err = 0;
134
135	/* copy the regs */
136
 
 
137	err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
138	err |= __copy_to_user(&sc->regs.pc, &regs->pc, sizeof(unsigned long));
139	err |= __copy_to_user(&sc->regs.sr, &regs->sr, sizeof(unsigned long));
140
141	/* then some other stuff */
142
143	err |= __put_user(mask, &sc->oldmask);
144
145	return err;
146}
147
148static inline unsigned long align_sigframe(unsigned long sp)
149{
150	return sp & ~3UL;
151}
152
153/*
154 * Work out where the signal frame should go.  It's either on the user stack
155 * or the alternate stack.
156 */
157
158static inline void __user *get_sigframe(struct k_sigaction *ka,
159					struct pt_regs *regs, size_t frame_size)
160{
161	unsigned long sp = regs->sp;
162	int onsigstack = on_sig_stack(sp);
163
164	/* redzone */
165	sp -= STACK_FRAME_OVERHEAD;
166
167	/* This is the X/Open sanctioned signal stack switching.  */
168	if ((ka->sa.sa_flags & SA_ONSTACK) && !onsigstack) {
169		if (current->sas_ss_size)
170			sp = current->sas_ss_sp + current->sas_ss_size;
171	}
172
173	sp = align_sigframe(sp - frame_size);
174
175	/*
176	 * If we are on the alternate signal stack and would overflow it, don't.
177	 * Return an always-bogus address instead so we will die with SIGSEGV.
178	 */
179	if (onsigstack && !likely(on_sig_stack(sp)))
180		return (void __user *)-1L;
181
182	return (void __user *)sp;
183}
184
185/* grab and setup a signal frame.
186 *
187 * basically we stack a lot of state info, and arrange for the
188 * user-mode program to return to the kernel using either a
189 * trampoline which performs the syscall sigreturn, or a provided
190 * user-mode trampoline.
191 */
192static void setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
193			   sigset_t *set, struct pt_regs *regs)
194{
195	struct rt_sigframe *frame;
196	unsigned long return_ip;
197	int err = 0;
198
199	frame = get_sigframe(ka, regs, sizeof(*frame));
200
201	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
202		goto give_sigsegv;
203
204	err |= __put_user(&frame->info, &frame->pinfo);
205	err |= __put_user(&frame->uc, &frame->puc);
206
207	if (ka->sa.sa_flags & SA_SIGINFO)
208		err |= copy_siginfo_to_user(&frame->info, info);
209	if (err)
210		goto give_sigsegv;
211
212	/* Clear all the bits of the ucontext we don't use.  */
213	err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
214	err |= __put_user(0, &frame->uc.uc_flags);
215	err |= __put_user(NULL, &frame->uc.uc_link);
216	err |= __put_user((void *)current->sas_ss_sp,
217			  &frame->uc.uc_stack.ss_sp);
218	err |= __put_user(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags);
219	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
220	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
221
222	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
223
224	if (err)
225		goto give_sigsegv;
226
227	/* trampoline - the desired return ip is the retcode itself */
228	return_ip = (unsigned long)&frame->retcode;
229	/* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
230	err |= __put_user(0xa960, (short *)(frame->retcode + 0));
231	err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2));
232	err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
233	err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
 
 
 
234
235	if (err)
236		goto give_sigsegv;
237
238	/* TODO what is the current->exec_domain stuff and invmap ? */
239
240	/* Set up registers for signal handler */
241	regs->pc = (unsigned long)ka->sa.sa_handler; /* what we enter NOW */
242	regs->gpr[9] = (unsigned long)return_ip;     /* what we enter LATER */
243	regs->gpr[3] = (unsigned long)sig;           /* arg 1: signo */
244	regs->gpr[4] = (unsigned long)&frame->info;  /* arg 2: (siginfo_t*) */
245	regs->gpr[5] = (unsigned long)&frame->uc;    /* arg 3: ucontext */
246
247	/* actually move the usp to reflect the stacked frame */
248	regs->sp = (unsigned long)frame;
249
250	return;
251
252give_sigsegv:
253	if (sig == SIGSEGV)
254		ka->sa.sa_handler = SIG_DFL;
255	force_sig(SIGSEGV, current);
256}
257
258static inline void
259handle_signal(unsigned long sig,
260	      siginfo_t *info, struct k_sigaction *ka,
261	      sigset_t *oldset, struct pt_regs *regs)
262{
263	setup_rt_frame(sig, ka, info, oldset, regs);
264
265	if (ka->sa.sa_flags & SA_ONESHOT)
266		ka->sa.sa_handler = SIG_DFL;
267
268	spin_lock_irq(&current->sighand->siglock);
269	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
270	if (!(ka->sa.sa_flags & SA_NODEFER))
271		sigaddset(&current->blocked, sig);
272	recalc_sigpending();
273
274	spin_unlock_irq(&current->sighand->siglock);
275}
276
277/*
278 * Note that 'init' is a special process: it doesn't get signals it doesn't
279 * want to handle. Thus you cannot kill init even with a SIGKILL even by
280 * mistake.
281 *
282 * Also note that the regs structure given here as an argument, is the latest
283 * pushed pt_regs. It may or may not be the same as the first pushed registers
284 * when the initial usermode->kernelmode transition took place. Therefore
285 * we can use user_mode(regs) to see if we came directly from kernel or user
286 * mode below.
287 */
288
289void do_signal(struct pt_regs *regs)
290{
291	siginfo_t info;
292	int signr;
293	struct k_sigaction ka;
294
295	/*
296	 * We want the common case to go fast, which
297	 * is why we may in certain cases get here from
298	 * kernel mode. Just return without doing anything
299	 * if so.
300	 */
301	if (!user_mode(regs))
302		return;
303
304	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
305
306	/* If we are coming out of a syscall then we need
307	 * to check if the syscall was interrupted and wants to be
308	 * restarted after handling the signal.  If so, the original
309	 * syscall number is put back into r11 and the PC rewound to
310	 * point at the l.sys instruction that resulted in the
311	 * original syscall.  Syscall results other than the four
312	 * below mean that the syscall executed to completion and no
313	 * restart is necessary.
314	 */
315	if (regs->syscallno) {
316		int restart = 0;
317
318		switch (regs->gpr[11]) {
319		case -ERESTART_RESTARTBLOCK:
 
 
320		case -ERESTARTNOHAND:
321			/* Restart if there is no signal handler */
322			restart = (signr <= 0);
323			break;
324		case -ERESTARTSYS:
325			/* Restart if there no signal handler or
326			 * SA_RESTART flag is set */
327			restart = (signr <= 0 || (ka.sa.sa_flags & SA_RESTART));
328			break;
329		case -ERESTARTNOINTR:
330			/* Always restart */
331			restart = 1;
 
332			break;
333		}
334
335		if (restart) {
336			if (regs->gpr[11] == -ERESTART_RESTARTBLOCK)
337				regs->gpr[11] = __NR_restart_syscall;
338			else
339				regs->gpr[11] = regs->orig_gpr11;
340			regs->pc -= 4;
341		} else {
342			regs->gpr[11] = -EINTR;
343		}
344	}
345
346	if (signr <= 0) {
347		/* no signal to deliver so we just put the saved sigmask
348		 * back */
349		if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
350			clear_thread_flag(TIF_RESTORE_SIGMASK);
351			sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
352		}
353
354	} else {		/* signr > 0 */
355		sigset_t *oldset;
356
357		if (current_thread_info()->flags & _TIF_RESTORE_SIGMASK)
358			oldset = &current->saved_sigmask;
359		else
360			oldset = &current->blocked;
361
362		/* Whee!  Actually deliver the signal.  */
363		handle_signal(signr, &info, &ka, oldset, regs);
364		/* a signal was successfully delivered; the saved
365		 * sigmask will have been stored in the signal frame,
366		 * and will be restored by sigreturn, so we can simply
367		 * clear the TIF_RESTORE_SIGMASK flag */
368		if (test_thread_flag(TIF_RESTORE_SIGMASK))
369			clear_thread_flag(TIF_RESTORE_SIGMASK);
370
371		tracehook_signal_handler(signr, &info, &ka, regs,
372					 test_thread_flag(TIF_SINGLESTEP));
373	}
374
375	return;
376}
377
378asmlinkage void do_notify_resume(struct pt_regs *regs)
 
379{
380	if (current_thread_info()->flags & _TIF_SIGPENDING)
381		do_signal(regs);
382
383	if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) {
384		clear_thread_flag(TIF_NOTIFY_RESUME);
385		tracehook_notify_resume(regs);
386		if (current->replacement_session_keyring)
387			key_replace_session_keyring();
388	}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
389}
v6.2
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * OpenRISC signal.c
  4 *
  5 * Linux architectural port borrowing liberally from similar works of
  6 * others.  All original copyrights apply as per the original source
  7 * declaration.
  8 *
  9 * Modifications for the OpenRISC architecture:
 10 * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
 11 * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
 
 
 
 
 
 12 */
 13
 14#include <linux/sched.h>
 15#include <linux/mm.h>
 16#include <linux/smp.h>
 17#include <linux/kernel.h>
 18#include <linux/signal.h>
 19#include <linux/errno.h>
 20#include <linux/wait.h>
 21#include <linux/ptrace.h>
 22#include <linux/unistd.h>
 23#include <linux/stddef.h>
 24#include <linux/resume_user_mode.h>
 25
 26#include <asm/processor.h>
 27#include <asm/syscall.h>
 28#include <asm/ucontext.h>
 29#include <linux/uaccess.h>
 
 
 
 
 
 
 
 
 
 
 30
 31struct rt_sigframe {
 
 
 32	struct siginfo info;
 33	struct ucontext uc;
 34	unsigned char retcode[16];	/* trampoline code */
 35};
 36
 37static int restore_sigcontext(struct pt_regs *regs,
 38			      struct sigcontext __user *sc)
 39{
 40	int err = 0;
 41
 42	/* Always make any pending restarted system calls return -EINTR */
 43	current->restart_block.fn = do_no_restart_syscall;
 44
 45	/*
 46	 * Restore the regs from &sc->regs.
 47	 * (sc is already checked since the sigframe was
 48	 *  checked in sys_sigreturn previously)
 49	 */
 50	err |= __copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long));
 51	err |= __copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long));
 52	err |= __copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long));
 
 
 
 53
 54	/* make sure the SM-bit is cleared so user-mode cannot fool us */
 55	regs->sr &= ~SPR_SR_SM;
 56
 57	regs->orig_gpr11 = -1;	/* Avoid syscall restart checks */
 58
 59	/* TODO: the other ports use regs->orig_XX to disable syscall checks
 60	 * after this completes, but we don't use that mechanism. maybe we can
 61	 * use it now ?
 62	 */
 63
 64	return err;
 
 
 
 65}
 66
 67asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
 68{
 69	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->sp;
 70	sigset_t set;
 
 71
 72	/*
 73	 * Since we stacked the signal on a dword boundary,
 74	 * then frame should be dword aligned here.  If it's
 75	 * not, then the user is trying to mess with us.
 76	 */
 77	if (((unsigned long)frame) & 3)
 78		goto badframe;
 79
 80	if (!access_ok(frame, sizeof(*frame)))
 81		goto badframe;
 82	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
 83		goto badframe;
 84
 85	set_current_blocked(&set);
 
 
 
 
 86
 87	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
 88		goto badframe;
 89
 90	if (restore_altstack(&frame->uc.uc_stack))
 91		goto badframe;
 
 
 
 92
 93	return regs->gpr[11];
 94
 95badframe:
 96	force_sig(SIGSEGV);
 97	return 0;
 98}
 99
100/*
101 * Set up a signal frame.
102 */
103
104static int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 
105{
106	int err = 0;
107
108	/* copy the regs */
109	/* There should be no need to save callee-saved registers here...
110	 * ...but we save them anyway.  Revisit this
111	 */
112	err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
113	err |= __copy_to_user(&sc->regs.pc, &regs->pc, sizeof(unsigned long));
114	err |= __copy_to_user(&sc->regs.sr, &regs->sr, sizeof(unsigned long));
115
 
 
 
 
116	return err;
117}
118
119static inline unsigned long align_sigframe(unsigned long sp)
120{
121	return sp & ~3UL;
122}
123
124/*
125 * Work out where the signal frame should go.  It's either on the user stack
126 * or the alternate stack.
127 */
128
129static inline void __user *get_sigframe(struct ksignal *ksig,
130					struct pt_regs *regs, size_t frame_size)
131{
132	unsigned long sp = regs->sp;
 
133
134	/* redzone */
135	sp -= STACK_FRAME_OVERHEAD;
136	sp = sigsp(sp, ksig);
 
 
 
 
 
 
137	sp = align_sigframe(sp - frame_size);
138
 
 
 
 
 
 
 
139	return (void __user *)sp;
140}
141
142/* grab and setup a signal frame.
143 *
144 * basically we stack a lot of state info, and arrange for the
145 * user-mode program to return to the kernel using either a
146 * trampoline which performs the syscall sigreturn, or a provided
147 * user-mode trampoline.
148 */
149static int setup_rt_frame(struct ksignal *ksig, sigset_t *set,
150			  struct pt_regs *regs)
151{
152	struct rt_sigframe __user *frame;
153	unsigned long return_ip;
154	int err = 0;
155
156	frame = get_sigframe(ksig, regs, sizeof(*frame));
 
 
 
157
158	if (!access_ok(frame, sizeof(*frame)))
159		return -EFAULT;
160
161	/* Create siginfo.  */
162	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
163		err |= copy_siginfo_to_user(&frame->info, &ksig->info);
 
164
165	/* Create the ucontext.  */
 
166	err |= __put_user(0, &frame->uc.uc_flags);
167	err |= __put_user(NULL, &frame->uc.uc_link);
168	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
169	err |= setup_sigcontext(regs, &frame->uc.uc_mcontext);
 
 
 
170
171	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
172
173	if (err)
174		return -EFAULT;
175
176	/* trampoline - the desired return ip is the retcode itself */
177	return_ip = (unsigned long)&frame->retcode;
178	/* This is:
179		l.ori r11,r0,__NR_sigreturn
180		l.sys 1
181	 */
182	err |= __put_user(0xa960,             (short __user *)(frame->retcode + 0));
183	err |= __put_user(__NR_rt_sigreturn,  (short __user *)(frame->retcode + 2));
184	err |= __put_user(0x20000001, (unsigned long __user *)(frame->retcode + 4));
185	err |= __put_user(0x15000000, (unsigned long __user *)(frame->retcode + 8));
186
187	if (err)
188		return -EFAULT;
 
 
189
190	/* Set up registers for signal handler */
191	regs->pc = (unsigned long)ksig->ka.sa.sa_handler; /* what we enter NOW */
192	regs->gpr[9] = (unsigned long)return_ip;     /* what we enter LATER */
193	regs->gpr[3] = (unsigned long)ksig->sig;           /* arg 1: signo */
194	regs->gpr[4] = (unsigned long)&frame->info;  /* arg 2: (siginfo_t*) */
195	regs->gpr[5] = (unsigned long)&frame->uc;    /* arg 3: ucontext */
196
197	/* actually move the usp to reflect the stacked frame */
198	regs->sp = (unsigned long)frame;
199
200	return 0;
 
 
 
 
 
201}
202
203static inline void
204handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 
 
205{
206	int ret;
207
208	ret = setup_rt_frame(ksig, sigmask_to_save(), regs);
 
209
210	signal_setup_done(ret, ksig, test_thread_flag(TIF_SINGLESTEP));
 
 
 
 
 
 
211}
212
213/*
214 * Note that 'init' is a special process: it doesn't get signals it doesn't
215 * want to handle. Thus you cannot kill init even with a SIGKILL even by
216 * mistake.
217 *
218 * Also note that the regs structure given here as an argument, is the latest
219 * pushed pt_regs. It may or may not be the same as the first pushed registers
220 * when the initial usermode->kernelmode transition took place. Therefore
221 * we can use user_mode(regs) to see if we came directly from kernel or user
222 * mode below.
223 */
224
225int do_signal(struct pt_regs *regs, int syscall)
226{
227	struct ksignal ksig;
228	unsigned long continue_addr = 0;
229	unsigned long restart_addr = 0;
230	unsigned long retval = 0;
231	int restart = 0;
232
233	if (syscall) {
234		continue_addr = regs->pc;
235		restart_addr = continue_addr - 4;
236		retval = regs->gpr[11];
237
238		/*
239		 * Setup syscall restart here so that a debugger will
240		 * see the already changed PC.
241		 */
242		switch (retval) {
 
 
 
 
 
 
 
 
 
 
 
 
243		case -ERESTART_RESTARTBLOCK:
244			restart = -2;
245			fallthrough;
246		case -ERESTARTNOHAND:
 
 
 
247		case -ERESTARTSYS:
 
 
 
 
248		case -ERESTARTNOINTR:
249			restart++;
250			regs->gpr[11] = regs->orig_gpr11;
251			regs->pc = restart_addr;
252			break;
253		}
 
 
 
 
 
 
 
 
 
 
254	}
255
256	/*
257	 * Get the signal to deliver.  During the call to get_signal the
258	 * debugger may change all our registers so we may need to revert
259	 * the decision to restart the syscall; specifically, if the PC is
260	 * changed, don't restart the syscall.
261	 */
262	if (get_signal(&ksig)) {
263		if (unlikely(restart) && regs->pc == restart_addr) {
264			if (retval == -ERESTARTNOHAND ||
265			    retval == -ERESTART_RESTARTBLOCK
266			    || (retval == -ERESTARTSYS
267			        && !(ksig.ka.sa.sa_flags & SA_RESTART))) {
268				/* No automatic restart */
269				regs->gpr[11] = -EINTR;
270				regs->pc = continue_addr;
271			}
272		}
273		handle_signal(&ksig, regs);
274	} else {
275		/* no handler */
276		restore_saved_sigmask();
277		/*
278		 * Restore pt_regs PC as syscall restart will be handled by
279		 * kernel without return to userspace
280		 */
281		if (unlikely(restart) && regs->pc == restart_addr) {
282			regs->pc = continue_addr;
283			return restart;
284		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
285	}
286
287	return 0;
288}
289
290asmlinkage int
291do_work_pending(struct pt_regs *regs, unsigned int thread_flags, int syscall)
292{
293	do {
294		if (likely(thread_flags & _TIF_NEED_RESCHED)) {
295			schedule();
296		} else {
297			if (unlikely(!user_mode(regs)))
298				return 0;
299			local_irq_enable();
300			if (thread_flags & (_TIF_SIGPENDING|_TIF_NOTIFY_SIGNAL)) {
301				int restart = do_signal(regs, syscall);
302				if (unlikely(restart)) {
303					/*
304					 * Restart without handlers.
305					 * Deal with it without leaving
306					 * the kernel space.
307					 */
308					return restart;
309				}
310				syscall = 0;
311			} else {
312				resume_user_mode_work(regs);
313			}
314		}
315		local_irq_disable();
316		thread_flags = read_thread_flags();
317	} while (thread_flags & _TIF_WORK_MASK);
318	return 0;
319}