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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}
v3.5.6
  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
 
 
 36asmlinkage long
 37_sys_sigaltstack(const stack_t *uss, stack_t *uoss, struct pt_regs *regs)
 38{
 39	return do_sigaltstack(uss, uoss, regs->sp);
 40}
 41
 42struct rt_sigframe {
 43	struct siginfo *pinfo;
 44	void *puc;
 45	struct siginfo info;
 46	struct ucontext uc;
 47	unsigned char retcode[16];	/* trampoline code */
 48};
 49
 50static int restore_sigcontext(struct pt_regs *regs, struct sigcontext *sc)
 51{
 52	unsigned int err = 0;
 53
 54	/* Alwys make any pending restarted system call return -EINTR */
 55	current_thread_info()->restart_block.fn = do_no_restart_syscall;
 56
 57	/*
 58	 * Restore the regs from &sc->regs.
 59	 * (sc is already checked for VERIFY_READ since the sigframe was
 60	 *  checked in sys_sigreturn previously)
 61	 */
 62	if (__copy_from_user(regs, sc->regs.gpr, 32 * sizeof(unsigned long)))
 63		goto badframe;
 64	if (__copy_from_user(&regs->pc, &sc->regs.pc, sizeof(unsigned long)))
 65		goto badframe;
 66	if (__copy_from_user(&regs->sr, &sc->regs.sr, sizeof(unsigned long)))
 67		goto badframe;
 68
 69	/* make sure the SM-bit is cleared so user-mode cannot fool us */
 70	regs->sr &= ~SPR_SR_SM;
 71
 72	/* TODO: the other ports use regs->orig_XX to disable syscall checks
 73	 * after this completes, but we don't use that mechanism. maybe we can
 74	 * use it now ?
 75	 */
 76
 77	return err;
 78
 79badframe:
 80	return 1;
 81}
 82
 83asmlinkage long _sys_rt_sigreturn(struct pt_regs *regs)
 84{
 85	struct rt_sigframe *frame = (struct rt_sigframe __user *)regs->sp;
 86	sigset_t set;
 87	stack_t st;
 88
 89	/*
 90	 * Since we stacked the signal on a dword boundary,
 91	 * then frame should be dword aligned here.  If it's
 92	 * not, then the user is trying to mess with us.
 93	 */
 94	if (((long)frame) & 3)
 95		goto badframe;
 96
 97	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 98		goto badframe;
 99	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
100		goto badframe;
101
102	set_current_blocked(&set);
 
 
 
 
103
104	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
105		goto badframe;
106
107	if (__copy_from_user(&st, &frame->uc.uc_stack, sizeof(st)))
108		goto badframe;
109	/* It is more difficult to avoid calling this function than to
110	   call it and ignore errors.  */
111	do_sigaltstack(&st, NULL, regs->sp);
112
113	return regs->gpr[11];
114
115badframe:
116	force_sig(SIGSEGV, current);
117	return 0;
118}
119
120/*
121 * Set up a signal frame.
122 */
123
124static int setup_sigcontext(struct sigcontext *sc, struct pt_regs *regs,
125			    unsigned long mask)
126{
127	int err = 0;
128
129	/* copy the regs */
130
131	err |= __copy_to_user(sc->regs.gpr, regs, 32 * sizeof(unsigned long));
132	err |= __copy_to_user(&sc->regs.pc, &regs->pc, sizeof(unsigned long));
133	err |= __copy_to_user(&sc->regs.sr, &regs->sr, sizeof(unsigned long));
134
135	/* then some other stuff */
136
137	err |= __put_user(mask, &sc->oldmask);
138
139	return err;
140}
141
142static inline unsigned long align_sigframe(unsigned long sp)
143{
144	return sp & ~3UL;
145}
146
147/*
148 * Work out where the signal frame should go.  It's either on the user stack
149 * or the alternate stack.
150 */
151
152static inline void __user *get_sigframe(struct k_sigaction *ka,
153					struct pt_regs *regs, size_t frame_size)
154{
155	unsigned long sp = regs->sp;
156	int onsigstack = on_sig_stack(sp);
157
158	/* redzone */
159	sp -= STACK_FRAME_OVERHEAD;
160
161	/* This is the X/Open sanctioned signal stack switching.  */
162	if ((ka->sa.sa_flags & SA_ONSTACK) && !onsigstack) {
163		if (current->sas_ss_size)
164			sp = current->sas_ss_sp + current->sas_ss_size;
165	}
166
167	sp = align_sigframe(sp - frame_size);
168
169	/*
170	 * If we are on the alternate signal stack and would overflow it, don't.
171	 * Return an always-bogus address instead so we will die with SIGSEGV.
172	 */
173	if (onsigstack && !likely(on_sig_stack(sp)))
174		return (void __user *)-1L;
175
176	return (void __user *)sp;
177}
178
179/* grab and setup a signal frame.
180 *
181 * basically we stack a lot of state info, and arrange for the
182 * user-mode program to return to the kernel using either a
183 * trampoline which performs the syscall sigreturn, or a provided
184 * user-mode trampoline.
185 */
186static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info,
187			  sigset_t *set, struct pt_regs *regs)
188{
189	struct rt_sigframe *frame;
190	unsigned long return_ip;
191	int err = 0;
192
193	frame = get_sigframe(ka, regs, sizeof(*frame));
194
195	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
196		goto give_sigsegv;
197
198	err |= __put_user(&frame->info, &frame->pinfo);
199	err |= __put_user(&frame->uc, &frame->puc);
200
201	if (ka->sa.sa_flags & SA_SIGINFO)
202		err |= copy_siginfo_to_user(&frame->info, info);
203	if (err)
204		goto give_sigsegv;
205
206	/* Clear all the bits of the ucontext we don't use.  */
207	err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
208	err |= __put_user(0, &frame->uc.uc_flags);
209	err |= __put_user(NULL, &frame->uc.uc_link);
210	err |= __put_user((void *)current->sas_ss_sp,
211			  &frame->uc.uc_stack.ss_sp);
212	err |= __put_user(sas_ss_flags(regs->sp), &frame->uc.uc_stack.ss_flags);
213	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
214	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
215
216	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
217
218	if (err)
219		goto give_sigsegv;
220
221	/* trampoline - the desired return ip is the retcode itself */
222	return_ip = (unsigned long)&frame->retcode;
223	/* This is l.ori r11,r0,__NR_sigreturn, l.sys 1 */
224	err |= __put_user(0xa960, (short *)(frame->retcode + 0));
225	err |= __put_user(__NR_rt_sigreturn, (short *)(frame->retcode + 2));
226	err |= __put_user(0x20000001, (unsigned long *)(frame->retcode + 4));
227	err |= __put_user(0x15000000, (unsigned long *)(frame->retcode + 8));
228
229	if (err)
230		goto give_sigsegv;
231
232	/* TODO what is the current->exec_domain stuff and invmap ? */
233
234	/* Set up registers for signal handler */
235	regs->pc = (unsigned long)ka->sa.sa_handler; /* what we enter NOW */
236	regs->gpr[9] = (unsigned long)return_ip;     /* what we enter LATER */
237	regs->gpr[3] = (unsigned long)sig;           /* arg 1: signo */
238	regs->gpr[4] = (unsigned long)&frame->info;  /* arg 2: (siginfo_t*) */
239	regs->gpr[5] = (unsigned long)&frame->uc;    /* arg 3: ucontext */
240
241	/* actually move the usp to reflect the stacked frame */
242	regs->sp = (unsigned long)frame;
243
244	return 0;
245
246give_sigsegv:
247	force_sigsegv(sig, current);
248	return -EFAULT;
 
249}
250
251static inline void
252handle_signal(unsigned long sig,
253	      siginfo_t *info, struct k_sigaction *ka,
254	      struct pt_regs *regs)
255{
256	int ret;
 
 
 
257
258	ret = setup_rt_frame(sig, ka, info, sigmask_to_save(), regs);
259	if (ret)
260		return;
 
 
261
262	signal_delivered(sig, info, ka, regs,
263				 test_thread_flag(TIF_SINGLESTEP));
264}
265
266/*
267 * Note that 'init' is a special process: it doesn't get signals it doesn't
268 * want to handle. Thus you cannot kill init even with a SIGKILL even by
269 * mistake.
270 *
271 * Also note that the regs structure given here as an argument, is the latest
272 * pushed pt_regs. It may or may not be the same as the first pushed registers
273 * when the initial usermode->kernelmode transition took place. Therefore
274 * we can use user_mode(regs) to see if we came directly from kernel or user
275 * mode below.
276 */
277
278void do_signal(struct pt_regs *regs)
279{
280	siginfo_t info;
281	int signr;
282	struct k_sigaction ka;
283
284	/*
285	 * We want the common case to go fast, which
286	 * is why we may in certain cases get here from
287	 * kernel mode. Just return without doing anything
288	 * if so.
289	 */
290	if (!user_mode(regs))
291		return;
292
293	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
294
295	/* If we are coming out of a syscall then we need
296	 * to check if the syscall was interrupted and wants to be
297	 * restarted after handling the signal.  If so, the original
298	 * syscall number is put back into r11 and the PC rewound to
299	 * point at the l.sys instruction that resulted in the
300	 * original syscall.  Syscall results other than the four
301	 * below mean that the syscall executed to completion and no
302	 * restart is necessary.
303	 */
304	if (regs->orig_gpr11) {
305		int restart = 0;
306
307		switch (regs->gpr[11]) {
308		case -ERESTART_RESTARTBLOCK:
309		case -ERESTARTNOHAND:
310			/* Restart if there is no signal handler */
311			restart = (signr <= 0);
312			break;
313		case -ERESTARTSYS:
314			/* Restart if there no signal handler or
315			 * SA_RESTART flag is set */
316			restart = (signr <= 0 || (ka.sa.sa_flags & SA_RESTART));
317			break;
318		case -ERESTARTNOINTR:
319			/* Always restart */
320			restart = 1;
321			break;
322		}
323
324		if (restart) {
325			if (regs->gpr[11] == -ERESTART_RESTARTBLOCK)
326				regs->gpr[11] = __NR_restart_syscall;
327			else
328				regs->gpr[11] = regs->orig_gpr11;
329			regs->pc -= 4;
330		} else {
331			regs->gpr[11] = -EINTR;
332		}
333	}
334
335	if (signr <= 0) {
336		/* no signal to deliver so we just put the saved sigmask
337		 * back */
338		restore_saved_sigmask();
 
 
 
 
339	} else {		/* signr > 0 */
 
 
 
 
 
 
 
340		/* Whee!  Actually deliver the signal.  */
341		handle_signal(signr, &info, &ka, regs);
 
 
 
 
 
 
 
 
 
342	}
343
344	return;
345}
346
347asmlinkage void do_notify_resume(struct pt_regs *regs)
348{
349	if (current_thread_info()->flags & _TIF_SIGPENDING)
350		do_signal(regs);
351
352	if (current_thread_info()->flags & _TIF_NOTIFY_RESUME) {
353		clear_thread_flag(TIF_NOTIFY_RESUME);
354		tracehook_notify_resume(regs);
 
 
355	}
356}