[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / c6x / kernel / signal.c

/*
 *  Port on Texas Instruments TMS320C6x architecture
 *
 *  Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
 *  Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
 *
 *  Updated for 2.6.34: Mark Salter <msalter@redhat.com>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2 as
 *  published by the Free Software Foundation.
 */

#include <linux/kernel.h>
#include <linux/uaccess.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>

#include <asm/ucontext.h>
#include <asm/cacheflush.h>


#define _BLOCKABLE (~(sigmask(SIGKILL) | sigmask(SIGSTOP)))

/*
 * Do a signal return, undo the signal stack.
 */

#define RETCODE_SIZE (9 << 2)	/* 9 instructions = 36 bytes */

struct rt_sigframe {
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
	unsigned long retcode[RETCODE_SIZE >> 2];
};

static int restore_sigcontext(struct pt_regs *regs,
			      struct sigcontext __user *sc)
{
	int err = 0;

	/* The access_ok check was done by caller, so use __get_user here */
#define COPY(x)  (err |= __get_user(regs->x, &sc->sc_##x))

	COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
	COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
	COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);

	COPY(a16); COPY(a17); COPY(a18); COPY(a19);
	COPY(a20); COPY(a21); COPY(a22); COPY(a23);
	COPY(a24); COPY(a25); COPY(a26); COPY(a27);
	COPY(a28); COPY(a29); COPY(a30); COPY(a31);
	COPY(b16); COPY(b17); COPY(b18); COPY(b19);
	COPY(b20); COPY(b21); COPY(b22); COPY(b23);
	COPY(b24); COPY(b25); COPY(b26); COPY(b27);
	COPY(b28); COPY(b29); COPY(b30); COPY(b31);

	COPY(csr); COPY(pc);

#undef COPY

	return err;
}

asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;
	sigset_t set;

	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	/*
	 * Since we stacked the signal on a dword boundary,
	 * 'sp' should be dword aligned here.  If it's
	 * not, then the user is trying to mess with us.
	 */
	if (regs->sp & 7)
		goto badframe;

	frame = (struct rt_sigframe __user *) ((unsigned long) regs->sp + 8);

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto badframe;

	sigdelsetmask(&set, ~_BLOCKABLE);
	set_current_blocked(&set);

	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
		goto badframe;

	return regs->a4;

badframe:
	force_sig(SIGSEGV, current);
	return 0;
}

static int setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
			    unsigned long mask)
{
	int err = 0;

	err |= __put_user(mask, &sc->sc_mask);

	/* The access_ok check was done by caller, so use __put_user here */
#define COPY(x) (err |= __put_user(regs->x, &sc->sc_##x))

	COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
	COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
	COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);

	COPY(a16); COPY(a17); COPY(a18); COPY(a19);
	COPY(a20); COPY(a21); COPY(a22); COPY(a23);
	COPY(a24); COPY(a25); COPY(a26); COPY(a27);
	COPY(a28); COPY(a29); COPY(a30); COPY(a31);
	COPY(b16); COPY(b17); COPY(b18); COPY(b19);
	COPY(b20); COPY(b21); COPY(b22); COPY(b23);
	COPY(b24); COPY(b25); COPY(b26); COPY(b27);
	COPY(b28); COPY(b29); COPY(b30); COPY(b31);

	COPY(csr); COPY(pc);

#undef COPY

	return err;
}

static inline void __user *get_sigframe(struct k_sigaction *ka,
					struct pt_regs *regs,
					unsigned long framesize)
{
	unsigned long sp = regs->sp;

	/*
	 * This is the X/Open sanctioned signal stack switching.
	 */
	if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(sp) == 0)
		sp = current->sas_ss_sp + current->sas_ss_size;

	/*
	 * No matter what happens, 'sp' must be dword
	 * aligned. Otherwise, nasty things will happen
	 */
	return (void __user *)((sp - framesize) & ~7);
}

static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
			   sigset_t *set, struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;
	unsigned long __user *retcode;
	int err = 0;

	frame = get_sigframe(ka, regs, sizeof(*frame));

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		goto segv_and_exit;

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);

	/* Clear all the bits of the ucontext we don't use.  */
	err |= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));

	err |= setup_sigcontext(&frame->uc.uc_mcontext,	regs, set->sig[0]);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	/* Set up to return from userspace */
	retcode = (unsigned long __user *) &frame->retcode;

	/* The access_ok check was done above, so use __put_user here */
#define COPY(x) (err |= __put_user(x, retcode++))

	COPY(0x0000002AUL | (__NR_rt_sigreturn << 7));
				/* MVK __NR_rt_sigreturn,B0 */
	COPY(0x10000000UL);	/* SWE */
	COPY(0x00006000UL);	/* NOP 4 */
	COPY(0x00006000UL);	/* NOP 4 */
	COPY(0x00006000UL);	/* NOP 4 */
	COPY(0x00006000UL);	/* NOP 4 */
	COPY(0x00006000UL);	/* NOP 4 */
	COPY(0x00006000UL);	/* NOP 4 */
	COPY(0x00006000UL);	/* NOP 4 */

#undef COPY

	if (err)
		goto segv_and_exit;

	flush_icache_range((unsigned long) &frame->retcode,
			   (unsigned long) &frame->retcode + RETCODE_SIZE);

	retcode = (unsigned long __user *) &frame->retcode;

	/* Change user context to branch to signal handler */
	regs->sp = (unsigned long) frame - 8;
	regs->b3 = (unsigned long) retcode;
	regs->pc = (unsigned long) ka->sa.sa_handler;

	/* Give the signal number to the handler */
	regs->a4 = signr;

	/*
	 * For realtime signals we must also set the second and third
	 * arguments for the signal handler.
	 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
	 */
	regs->b4 = (unsigned long)&frame->info;
	regs->a6 = (unsigned long)&frame->uc;

	return 0;

segv_and_exit:
	force_sigsegv(signr, current);
	return -EFAULT;
}

static inline void
handle_restart(struct pt_regs *regs, struct k_sigaction *ka, int has_handler)
{
	switch (regs->a4) {
	case -ERESTARTNOHAND:
		if (!has_handler)
			goto do_restart;
		regs->a4 = -EINTR;
		break;

	case -ERESTARTSYS:
		if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
			regs->a4 = -EINTR;
			break;
		}
	/* fallthrough */
	case -ERESTARTNOINTR:
do_restart:
		regs->a4 = regs->orig_a4;
		regs->pc -= 4;
		break;
	}
}

/*
 * handle the actual delivery of a signal to userspace
 */
static int handle_signal(int sig,
			 siginfo_t *info, struct k_sigaction *ka,
			 sigset_t *oldset, struct pt_regs *regs,
			 int syscall)
{
	int ret;

	/* Are we from a system call? */
	if (syscall) {
		/* If so, check system call restarting.. */
		switch (regs->a4) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			regs->a4 = -EINTR;
			break;

		case -ERESTARTSYS:
			if (!(ka->sa.sa_flags & SA_RESTART)) {
				regs->a4 = -EINTR;
				break;
			}

			/* fallthrough */
		case -ERESTARTNOINTR:
			regs->a4 = regs->orig_a4;
			regs->pc -= 4;
		}
	}

	/* Set up the stack frame */
	ret = setup_rt_frame(sig, ka, info, oldset, regs);
	if (ret == 0)
		block_sigmask(ka, sig);

	return ret;
}

/*
 * handle a potential signal
 */
static void do_signal(struct pt_regs *regs, int syscall)
{
	struct k_sigaction ka;
	siginfo_t info;
	sigset_t *oldset;
	int signr;

	/* we want the common case to go fast, which is why we may in certain
	 * cases get here from kernel mode */
	if (!user_mode(regs))
		return;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		if (handle_signal(signr, &info, &ka, oldset,
				  regs, syscall) == 0) {
			/* a signal was successfully delivered; the saved
			 * sigmask will have been stored in the signal frame,
			 * and will be restored by sigreturn, so we can simply
			 * clear the TIF_RESTORE_SIGMASK flag */
			if (test_thread_flag(TIF_RESTORE_SIGMASK))
				clear_thread_flag(TIF_RESTORE_SIGMASK);

			tracehook_signal_handler(signr, &info, &ka, regs, 0);
		}

		return;
	}

	/* did we come from a system call? */
	if (syscall) {
		/* restart the system call - no handlers present */
		switch (regs->a4) {
		case -ERESTARTNOHAND:
		case -ERESTARTSYS:
		case -ERESTARTNOINTR:
			regs->a4 = regs->orig_a4;
			regs->pc -= 4;
			break;

		case -ERESTART_RESTARTBLOCK:
			regs->a4 = regs->orig_a4;
			regs->b0 = __NR_restart_syscall;
			regs->pc -= 4;
			break;
		}
	}

	/* if there's no signal to deliver, we just put the saved sigmask
	 * back */
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}
}

/*
 * notification of userspace execution resumption
 * - triggered by current->work.notify_resume
 */
asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
				 int syscall)
{
	/* deal with pending signal delivery */
	if (thread_info_flags & ((1 << TIF_SIGPENDING) |
				 (1 << TIF_RESTORE_SIGMASK)))
		do_signal(regs, syscall);

	if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
		clear_thread_flag(TIF_NOTIFY_RESUME);
		tracehook_notify_resume(regs);
	}
}
Commit	Line	Data
03a34755 AJ	1	/*
	2	* Port on Texas Instruments TMS320C6x architecture
	3	*
	4	* Copyright (C) 2004, 2006, 2009, 2010, 2011 Texas Instruments Incorporated
	5	* Author: Aurelien Jacquiot (aurelien.jacquiot@jaluna.com)
	6	*
	7	* Updated for 2.6.34: Mark Salter <msalter@redhat.com>
	8	*
	9	* This program is free software; you can redistribute it and/or modify
	10	* it under the terms of the GNU General Public License version 2 as
	11	* published by the Free Software Foundation.
	12	*/
	13
	14	#include <linux/kernel.h>
	15	#include <linux/uaccess.h>
	16	#include <linux/syscalls.h>
	17	#include <linux/tracehook.h>
	18
	19	#include <asm/ucontext.h>
	20	#include <asm/cacheflush.h>
	21
	22
	23	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	24
	25	/*
	26	* Do a signal return, undo the signal stack.
	27	*/
	28
	29	#define RETCODE_SIZE (9 << 2) /* 9 instructions = 36 bytes */
	30
	31	struct rt_sigframe {
	32	struct siginfo __user *pinfo;
	33	void __user *puc;
	34	struct siginfo info;
	35	struct ucontext uc;
	36	unsigned long retcode[RETCODE_SIZE >> 2];
	37	};
	38
	39	static int restore_sigcontext(struct pt_regs *regs,
	40	struct sigcontext __user *sc)
	41	{
	42	int err = 0;
	43
	44	/* The access_ok check was done by caller, so use __get_user here */
	45	#define COPY(x) (err \|= __get_user(regs->x, &sc->sc_##x))
	46
	47	COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
	48	COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
	49	COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
	50
	51	COPY(a16); COPY(a17); COPY(a18); COPY(a19);
	52	COPY(a20); COPY(a21); COPY(a22); COPY(a23);
	53	COPY(a24); COPY(a25); COPY(a26); COPY(a27);
	54	COPY(a28); COPY(a29); COPY(a30); COPY(a31);
	55	COPY(b16); COPY(b17); COPY(b18); COPY(b19);
	56	COPY(b20); COPY(b21); COPY(b22); COPY(b23);
	57	COPY(b24); COPY(b25); COPY(b26); COPY(b27);
	58	COPY(b28); COPY(b29); COPY(b30); COPY(b31);
	59
	60	COPY(csr); COPY(pc);
	61
	62	#undef COPY
	63
	64	return err;
65	}
66
67	asmlinkage int do_rt_sigreturn(struct pt_regs *regs)
68	{
69	struct rt_sigframe __user *frame;
70	sigset_t set;
71
2a3fdc11 AV	72	/* Always make any pending restarted system calls return -EINTR */
	73	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	74
03a34755 AJ	75	/*
	76	* Since we stacked the signal on a dword boundary,
	77	* 'sp' should be dword aligned here. If it's
	78	* not, then the user is trying to mess with us.
	79	*/
	80	if (regs->sp & 7)
	81	goto badframe;
	82
	83	frame = (struct rt_sigframe __user *) ((unsigned long) regs->sp + 8);
	84
	85	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	86	goto badframe;
	87	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	88	goto badframe;
	89
	90	sigdelsetmask(&set, ~_BLOCKABLE);
6e61ee3b	91	set_current_blocked(&set);
03a34755 AJ	92
	93	if (restore_sigcontext(regs, &frame->uc.uc_mcontext))
	94	goto badframe;
	95
	96	return regs->a4;
	97
	98	badframe:
	99	force_sig(SIGSEGV, current);
	100	return 0;
	101	}
	102
	103	static int setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	104	unsigned long mask)
	105	{
	106	int err = 0;
	107
	108	err \|= __put_user(mask, &sc->sc_mask);
	109
	110	/* The access_ok check was done by caller, so use __put_user here */
	111	#define COPY(x) (err \|= __put_user(regs->x, &sc->sc_##x))
	112
	113	COPY(sp); COPY(a4); COPY(b4); COPY(a6); COPY(b6); COPY(a8); COPY(b8);
	114	COPY(a0); COPY(a1); COPY(a2); COPY(a3); COPY(a5); COPY(a7); COPY(a9);
	115	COPY(b0); COPY(b1); COPY(b2); COPY(b3); COPY(b5); COPY(b7); COPY(b9);
	116
	117	COPY(a16); COPY(a17); COPY(a18); COPY(a19);
	118	COPY(a20); COPY(a21); COPY(a22); COPY(a23);
	119	COPY(a24); COPY(a25); COPY(a26); COPY(a27);
	120	COPY(a28); COPY(a29); COPY(a30); COPY(a31);
	121	COPY(b16); COPY(b17); COPY(b18); COPY(b19);
	122	COPY(b20); COPY(b21); COPY(b22); COPY(b23);
	123	COPY(b24); COPY(b25); COPY(b26); COPY(b27);
	124	COPY(b28); COPY(b29); COPY(b30); COPY(b31);
	125
	126	COPY(csr); COPY(pc);
	127
	128	#undef COPY
	129
	130	return err;
	131	}
	132
	133	static inline void __user get_sigframe(struct k_sigaction ka,
	134	struct pt_regs *regs,
	135	unsigned long framesize)
	136	{
	137	unsigned long sp = regs->sp;
	138
	139	/*
	140	* This is the X/Open sanctioned signal stack switching.
	141	*/
	142	if ((ka->sa.sa_flags & SA_ONSTACK) && sas_ss_flags(sp) == 0)
	143	sp = current->sas_ss_sp + current->sas_ss_size;
	144
	145	/*
	146	* No matter what happens, 'sp' must be dword
	147	* aligned. Otherwise, nasty things will happen
	148	*/
	149	return (void __user *)((sp - framesize) & ~7);
	150	}
	151
	152	static int setup_rt_frame(int signr, struct k_sigaction ka, siginfo_t info,
	153	sigset_t set, struct pt_regs regs)
	154	{
	155	struct rt_sigframe __user *frame;
156	unsigned long __user *retcode;
157	int err = 0;
158
159	frame = get_sigframe(ka, regs, sizeof(*frame));
160
161	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
162	goto segv_and_exit;
163
164	err \|= __put_user(&frame->info, &frame->pinfo);
165	err \|= __put_user(&frame->uc, &frame->puc);
166	err \|= copy_siginfo_to_user(&frame->info, info);
167
168	/* Clear all the bits of the ucontext we don't use. */
169	err \|= __clear_user(&frame->uc, offsetof(struct ucontext, uc_mcontext));
170
171	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
172	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
173
174	/* Set up to return from userspace */
175	retcode = (unsigned long __user *) &frame->retcode;
176
177	/* The access_ok check was done above, so use __put_user here */
178	#define COPY(x) (err \|= __put_user(x, retcode++))
179
180	COPY(0x0000002AUL \| (__NR_rt_sigreturn << 7));
181	/* MVK __NR_rt_sigreturn,B0 */
182	COPY(0x10000000UL); /* SWE */
183	COPY(0x00006000UL); /* NOP 4 */
184	COPY(0x00006000UL); /* NOP 4 */
185	COPY(0x00006000UL); /* NOP 4 */
186	COPY(0x00006000UL); /* NOP 4 */
187	COPY(0x00006000UL); /* NOP 4 */
188	COPY(0x00006000UL); /* NOP 4 */
189	COPY(0x00006000UL); /* NOP 4 */
190
191	#undef COPY
192
193	if (err)
194	goto segv_and_exit;
195
196	flush_icache_range((unsigned long) &frame->retcode,
197	(unsigned long) &frame->retcode + RETCODE_SIZE);
198
199	retcode = (unsigned long __user *) &frame->retcode;
200
201	/* Change user context to branch to signal handler */
202	regs->sp = (unsigned long) frame - 8;
203	regs->b3 = (unsigned long) retcode;
204	regs->pc = (unsigned long) ka->sa.sa_handler;
205
206	/* Give the signal number to the handler */
207	regs->a4 = signr;
208
209	/*
210	* For realtime signals we must also set the second and third
211	* arguments for the signal handler.
212	* -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
213	*/
214	regs->b4 = (unsigned long)&frame->info;
215	regs->a6 = (unsigned long)&frame->uc;
216
217	return 0;
218
219	segv_and_exit:
220	force_sigsegv(signr, current);
221	return -EFAULT;
222	}
223
224	static inline void
225	handle_restart(struct pt_regs regs, struct k_sigaction ka, int has_handler)
226	{
227	switch (regs->a4) {
228	case -ERESTARTNOHAND:
229	if (!has_handler)
230	goto do_restart;
231	regs->a4 = -EINTR;
232	break;
233
234	case -ERESTARTSYS:
235	if (has_handler && !(ka->sa.sa_flags & SA_RESTART)) {
236	regs->a4 = -EINTR;
237	break;
238	}
239	/* fallthrough */
240	case -ERESTARTNOINTR:
241	do_restart:
242	regs->a4 = regs->orig_a4;
243	regs->pc -= 4;
244	break;
245	}
246	}
247
248	/*
249	* handle the actual delivery of a signal to userspace
250	*/
251	static int handle_signal(int sig,
252	siginfo_t info, struct k_sigaction ka,
253	sigset_t oldset, struct pt_regs regs,
254	int syscall)
255	{
256	int ret;
257
258	/* Are we from a system call? */
259	if (syscall) {
260	/* If so, check system call restarting.. */
261	switch (regs->a4) {
262	case -ERESTART_RESTARTBLOCK:
263	case -ERESTARTNOHAND:
264	regs->a4 = -EINTR;
265	break;
266
267	case -ERESTARTSYS:
268	if (!(ka->sa.sa_flags & SA_RESTART)) {
269	regs->a4 = -EINTR;
270	break;
271	}
272
273	/* fallthrough */
274	case -ERESTARTNOINTR:
275	regs->a4 = regs->orig_a4;
276	regs->pc -= 4;
277	}
278	}
279
280	/* Set up the stack frame */
281	ret = setup_rt_frame(sig, ka, info, oldset, regs);
6e61ee3b MF	282	if (ret == 0)
6e61ee3b MF	283	block_sigmask(ka, sig);
03a34755 AJ	284
	285	return ret;
	286	}
	287
	288	/*
	289	* handle a potential signal
	290	*/
	291	static void do_signal(struct pt_regs *regs, int syscall)
	292	{
	293	struct k_sigaction ka;
	294	siginfo_t info;
	295	sigset_t *oldset;
	296	int signr;
	297
	298	/* we want the common case to go fast, which is why we may in certain
	299	* cases get here from kernel mode */
	300	if (!user_mode(regs))
	301	return;
	302
	303	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	304	oldset = &current->saved_sigmask;
	305	else
	306	oldset = &current->blocked;
	307
	308	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	309	if (signr > 0) {
	310	if (handle_signal(signr, &info, &ka, oldset,
	311	regs, syscall) == 0) {
	312	/* a signal was successfully delivered; the saved
	313	* sigmask will have been stored in the signal frame,
	314	* and will be restored by sigreturn, so we can simply
	315	* clear the TIF_RESTORE_SIGMASK flag */
	316	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	317	clear_thread_flag(TIF_RESTORE_SIGMASK);
	318
	319	tracehook_signal_handler(signr, &info, &ka, regs, 0);
	320	}
	321
	322	return;
	323	}
	324
	325	/* did we come from a system call? */
	326	if (syscall) {
	327	/* restart the system call - no handlers present */
	328	switch (regs->a4) {
	329	case -ERESTARTNOHAND:
	330	case -ERESTARTSYS:
	331	case -ERESTARTNOINTR:
	332	regs->a4 = regs->orig_a4;
	333	regs->pc -= 4;
	334	break;
	335
	336	case -ERESTART_RESTARTBLOCK:
	337	regs->a4 = regs->orig_a4;
	338	regs->b0 = __NR_restart_syscall;
	339	regs->pc -= 4;
	340	break;
	341	}
	342	}
	343
	344	/* if there's no signal to deliver, we just put the saved sigmask
	345	* back */
	346	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	347	clear_thread_flag(TIF_RESTORE_SIGMASK);
348	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
349	}
350	}
351
352	/*
353	* notification of userspace execution resumption
354	* - triggered by current->work.notify_resume
355	*/
356	asmlinkage void do_notify_resume(struct pt_regs *regs, u32 thread_info_flags,
357	int syscall)
358	{
359	/* deal with pending signal delivery */
360	if (thread_info_flags & ((1 << TIF_SIGPENDING) \|
361	(1 << TIF_RESTORE_SIGMASK)))
362	do_signal(regs, syscall);
363
364	if (thread_info_flags & (1 << TIF_NOTIFY_RESUME)) {
365	clear_thread_flag(TIF_NOTIFY_RESUME);
366	tracehook_notify_resume(regs);
03a34755 AJ	367	}
03a34755 AJ	368	}