arch/m32r/kernel/signal.c - maze/linux - Git at Google

 /*
  *  linux/arch/m32r/kernel/signal.c
  *
  *  Copyright (c) 2003  Hitoshi Yamamoto
  *
  *  Taken from i386 version.
  *  Copyright (C) 1991, 1992  Linus Torvalds
  *
  *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
  *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
  */

 #include <linux/sched.h>
 #include <linux/mm.h>
 #include <linux/smp.h>
 #include <linux/kernel.h>
 #include <linux/signal.h>
 #include <linux/errno.h>
 #include <linux/wait.h>
 #include <linux/unistd.h>
 #include <linux/stddef.h>
 #include <linux/personality.h>
 #include <linux/freezer.h>
 #include <linux/tracehook.h>
 #include <asm/cacheflush.h>
 #include <asm/ucontext.h>
 #include <asm/uaccess.h>

 #define DEBUG_SIG 0

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

 asmlinkage int
 sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss,
 		unsigned long r2, unsigned long r3, unsigned long r4,
 		unsigned long r5, unsigned long r6, struct pt_regs *regs)
 {
 	return do_sigaltstack(uss, uoss, regs->spu);
 }


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

 struct rt_sigframe
 {
 	int sig;
 	struct siginfo __user *pinfo;
 	void __user *puc;
 	struct siginfo info;
 	struct ucontext uc;
 //	struct _fpstate fpstate;
 };

 static int
 restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
 		   int *r0_p)
 {
 	unsigned int err = 0;

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

 #define COPY(x)		err |= __get_user(regs->x, &sc->sc_##x)
 	COPY(r4);
 	COPY(r5);
 	COPY(r6);
 	COPY(pt_regs);
 	/* COPY(r0); Skip r0 */
 	COPY(r1);
 	COPY(r2);
 	COPY(r3);
 	COPY(r7);
 	COPY(r8);
 	COPY(r9);
 	COPY(r10);
 	COPY(r11);
 	COPY(r12);
 	COPY(acc0h);
 	COPY(acc0l);
 	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
 	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
 	COPY(psw);
 	COPY(bpc);
 	COPY(bbpsw);
 	COPY(bbpc);
 	COPY(spu);
 	COPY(fp);
 	COPY(lr);
 	COPY(spi);
 #undef COPY

 	regs->syscall_nr = -1;	/* disable syscall checks */
 	err |= __get_user(*r0_p, &sc->sc_r0);

 	return err;
 }

 asmlinkage int
 sys_rt_sigreturn(unsigned long r0, unsigned long r1,
 		 unsigned long r2, unsigned long r3, unsigned long r4,
 		 unsigned long r5, unsigned long r6, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame = (struct rt_sigframe __user *)regs->spu;
 	sigset_t set;
 	int result;

 	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);
 	spin_lock_irq(&current->sighand->siglock);
 	current->blocked = set;
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);

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

 	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
 		goto badframe;

 	return result;

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

 /*
  * Set up a signal frame.
  */

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

 #define COPY(x)	err |= __put_user(regs->x, &sc->sc_##x)
 	COPY(r4);
 	COPY(r5);
 	COPY(r6);
 	COPY(pt_regs);
 	COPY(r0);
 	COPY(r1);
 	COPY(r2);
 	COPY(r3);
 	COPY(r7);
 	COPY(r8);
 	COPY(r9);
 	COPY(r10);
 	COPY(r11);
 	COPY(r12);
 	COPY(acc0h);
 	COPY(acc0l);
 	COPY(acc1h);		/* ISA_DSP_LEVEL2 only */
 	COPY(acc1l);		/* ISA_DSP_LEVEL2 only */
 	COPY(psw);
 	COPY(bpc);
 	COPY(bbpsw);
 	COPY(bbpc);
 	COPY(spu);
 	COPY(fp);
 	COPY(lr);
 	COPY(spi);
 #undef COPY

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

 	return err;
 }

 /*
  * Determine which stack to use..
  */
 static inline void __user *
 get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
 {
 	/* This is the X/Open sanctioned signal stack switching.  */
 	if (ka->sa.sa_flags & SA_ONSTACK) {
 		if (sas_ss_flags(sp) == 0)
 			sp = current->sas_ss_sp + current->sas_ss_size;
 	}

 	return (void __user *)((sp - frame_size) & -8ul);
 }

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

 	frame = get_sigframe(ka, regs->spu, sizeof(*frame));

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

 	signal = current_thread_info()->exec_domain
 		&& current_thread_info()->exec_domain->signal_invmap
 		&& sig < 32
 		? current_thread_info()->exec_domain->signal_invmap[sig]
 		: sig;

 	err |= __put_user(signal, &frame->sig);
 	if (err)
 		goto give_sigsegv;

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

 	/* Create the ucontext.  */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(0, &frame->uc.uc_link);
 	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
 	err |= __put_user(sas_ss_flags(regs->spu),
 			  &frame->uc.uc_stack.ss_flags);
 	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
 	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
 	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
 	if (err)
 		goto give_sigsegv;

 	/* Set up to return from userspace.  */
 	regs->lr = (unsigned long)ka->sa.sa_restorer;

 	/* Set up registers for signal handler */
 	regs->spu = (unsigned long)frame;
 	regs->r0 = signal;	/* Arg for signal handler */
 	regs->r1 = (unsigned long)&frame->info;
 	regs->r2 = (unsigned long)&frame->uc;
 	regs->bpc = (unsigned long)ka->sa.sa_handler;

 	set_fs(USER_DS);

 #if DEBUG_SIG
 	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
 		current->comm, current->pid, frame, regs->pc);
 #endif

 	return 0;

 give_sigsegv:
 	force_sigsegv(sig, current);
 	return -EFAULT;
 }

 static int prev_insn(struct pt_regs *regs)
 {
 	u16 inst;
 	if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
 		return -EFAULT;
 	if ((inst & 0xfff0) == 0x10f0)	/* trap ? */
 		regs->bpc -= 2;
 	else
 		regs->bpc -= 4;
 	regs->syscall_nr = -1;
 	return 0;
 }

 /*
  * OK, we're invoking a handler
  */

 static int
 handle_signal(unsigned long sig, struct k_sigaction *ka, siginfo_t *info,
 	      sigset_t *oldset, struct pt_regs *regs)
 {
 	/* Are we from a system call? */
 	if (regs->syscall_nr >= 0) {
 		/* If so, check system call restarting.. */
 		switch (regs->r0) {
 		        case -ERESTART_RESTARTBLOCK:
 			case -ERESTARTNOHAND:
 				regs->r0 = -EINTR;
 				break;

 			case -ERESTARTSYS:
 				if (!(ka->sa.sa_flags & SA_RESTART)) {
 					regs->r0 = -EINTR;
 					break;
 				}
 			/* fallthrough */
 			case -ERESTARTNOINTR:
 				regs->r0 = regs->orig_r0;
 				if (prev_insn(regs) < 0)
 					return -EFAULT;
 		}
 	}

 	/* Set up the stack frame */
 	if (setup_rt_frame(sig, ka, info, oldset, regs))
 		return -EFAULT;

 	spin_lock_irq(&current->sighand->siglock);
 	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
 	if (!(ka->sa.sa_flags & SA_NODEFER))
 		sigaddset(&current->blocked,sig);
 	recalc_sigpending();
 	spin_unlock_irq(&current->sighand->siglock);
 	return 0;
 }

 /*
  * Note that 'init' is a special process: it doesn't get signals it doesn't
  * want to handle. Thus you cannot kill init even with a SIGKILL even by
  * mistake.
  */
 static void do_signal(struct pt_regs *regs)
 {
 	siginfo_t info;
 	int signr;
 	struct k_sigaction ka;
 	sigset_t *oldset;

 	/*
 	 * We want the common case to go fast, which
 	 * is why we may in certain cases get here from
 	 * kernel mode. Just return without doing anything
 	 * if so.
 	 */
 	if (!user_mode(regs))
 		return;

 	if (try_to_freeze())
 		goto no_signal;

 	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) {
 		/* Re-enable any watchpoints before delivering the
 		 * signal to user space. The processor register will
 		 * have been cleared if the watchpoint triggered
 		 * inside the kernel.
 		 */

 		/* Whee!  Actually deliver the signal.  */
 		if (handle_signal(signr, &ka, &info, oldset, regs) == 0)
 			clear_thread_flag(TIF_RESTORE_SIGMASK);

 		return;
 	}

  no_signal:
 	/* Did we come from a system call? */
 	if (regs->syscall_nr >= 0) {
 		/* Restart the system call - no handlers present */
 		if (regs->r0 == -ERESTARTNOHAND ||
 		    regs->r0 == -ERESTARTSYS ||
 		    regs->r0 == -ERESTARTNOINTR) {
 			regs->r0 = regs->orig_r0;
 			prev_insn(regs);
 		} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
 			regs->r0 = regs->orig_r0;
 			regs->r7 = __NR_restart_syscall;
 			prev_insn(regs);
 		}
 	}
 	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
  */
 void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
 {
 	/* Pending single-step? */
 	if (thread_info_flags & _TIF_SINGLESTEP)
 		clear_thread_flag(TIF_SINGLESTEP);

 	/* deal with pending signal delivery */
 	if (thread_info_flags & _TIF_SIGPENDING)
 		do_signal(regs);

 	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
 		if (current->replacement_session_keyring)
 			key_replace_session_keyring();
 	}

 	clear_thread_flag(TIF_IRET);
 }
	/*
	* linux/arch/m32r/kernel/signal.c
	*
	* Copyright (c) 2003 Hitoshi Yamamoto
	*
	* Taken from i386 version.
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	* 2000-06-20 Pentium III FXSR, SSE support by Gareth Hughes
	*/

	#include <linux/sched.h>
	#include <linux/mm.h>
	#include <linux/smp.h>
	#include <linux/kernel.h>
	#include <linux/signal.h>
	#include <linux/errno.h>
	#include <linux/wait.h>
	#include <linux/unistd.h>
	#include <linux/stddef.h>
	#include <linux/personality.h>
	#include <linux/freezer.h>
	#include <linux/tracehook.h>
	#include <asm/cacheflush.h>
	#include <asm/ucontext.h>
	#include <asm/uaccess.h>

	#define DEBUG_SIG 0

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

	asmlinkage int
	sys_sigaltstack(const stack_t __user uss, stack_t __user uoss,
	unsigned long r2, unsigned long r3, unsigned long r4,
	unsigned long r5, unsigned long r6, struct pt_regs *regs)
	{
	return do_sigaltstack(uss, uoss, regs->spu);
	}


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

	struct rt_sigframe
	{
	int sig;
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	struct ucontext uc;
	// struct _fpstate fpstate;
	};

	static int
	restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc,
	int *r0_p)
	{
	unsigned int err = 0;

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

	#define COPY(x) err \|= __get_user(regs->x, &sc->sc_##x)
	COPY(r4);
	COPY(r5);
	COPY(r6);
	COPY(pt_regs);
	/* COPY(r0); Skip r0 */
	COPY(r1);
	COPY(r2);
	COPY(r3);
	COPY(r7);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(acc0h);
	COPY(acc0l);
	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
	COPY(psw);
	COPY(bpc);
	COPY(bbpsw);
	COPY(bbpc);
	COPY(spu);
	COPY(fp);
	COPY(lr);
	COPY(spi);
	#undef COPY

	regs->syscall_nr = -1; /* disable syscall checks */
	err \|= __get_user(*r0_p, &sc->sc_r0);

	return err;
	}

	asmlinkage int
	sys_rt_sigreturn(unsigned long r0, unsigned long r1,
	unsigned long r2, unsigned long r3, unsigned long r4,
	unsigned long r5, unsigned long r6, struct pt_regs *regs)
	{
	struct rt_sigframe __user frame = (struct rt_sigframe __user )regs->spu;
	sigset_t set;
	int result;

	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);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

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

	if (do_sigaltstack(&frame->uc.uc_stack, NULL, regs->spu) == -EFAULT)
	goto badframe;

	return result;

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

	/*
	* Set up a signal frame.
	*/

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

	#define COPY(x) err \|= __put_user(regs->x, &sc->sc_##x)
	COPY(r4);
	COPY(r5);
	COPY(r6);
	COPY(pt_regs);
	COPY(r0);
	COPY(r1);
	COPY(r2);
	COPY(r3);
	COPY(r7);
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(acc0h);
	COPY(acc0l);
	COPY(acc1h); /* ISA_DSP_LEVEL2 only */
	COPY(acc1l); /* ISA_DSP_LEVEL2 only */
	COPY(psw);
	COPY(bpc);
	COPY(bbpsw);
	COPY(bbpc);
	COPY(spu);
	COPY(fp);
	COPY(lr);
	COPY(spi);
	#undef COPY

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

	return err;
	}

	/*
	* Determine which stack to use..
	*/
	static inline void __user *
	get_sigframe(struct k_sigaction *ka, unsigned long sp, size_t frame_size)
	{
	/* This is the X/Open sanctioned signal stack switching. */
	if (ka->sa.sa_flags & SA_ONSTACK) {
	if (sas_ss_flags(sp) == 0)
	sp = current->sas_ss_sp + current->sas_ss_size;
	}

	return (void __user *)((sp - frame_size) & -8ul);
	}

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

	frame = get_sigframe(ka, regs->spu, sizeof(*frame));

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

	signal = current_thread_info()->exec_domain
	&& current_thread_info()->exec_domain->signal_invmap
	&& sig < 32
	? current_thread_info()->exec_domain->signal_invmap[sig]
	: sig;

	err \|= __put_user(signal, &frame->sig);
	if (err)
	goto give_sigsegv;

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

	/* Create the ucontext. */
	err \|= __put_user(0, &frame->uc.uc_flags);
	err \|= __put_user(0, &frame->uc.uc_link);
	err \|= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err \|= __put_user(sas_ss_flags(regs->spu),
	&frame->uc.uc_stack.ss_flags);
	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, set->sig[0]);
	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
	goto give_sigsegv;

	/* Set up to return from userspace. */
	regs->lr = (unsigned long)ka->sa.sa_restorer;

	/* Set up registers for signal handler */
	regs->spu = (unsigned long)frame;
	regs->r0 = signal; /* Arg for signal handler */
	regs->r1 = (unsigned long)&frame->info;
	regs->r2 = (unsigned long)&frame->uc;
	regs->bpc = (unsigned long)ka->sa.sa_handler;

	set_fs(USER_DS);

	#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p\n",
	current->comm, current->pid, frame, regs->pc);
	#endif

	return 0;

	give_sigsegv:
	force_sigsegv(sig, current);
	return -EFAULT;
	}

	static int prev_insn(struct pt_regs *regs)
	{
	u16 inst;
	if (get_user(inst, (u16 __user *)(regs->bpc - 2)))
	return -EFAULT;
	if ((inst & 0xfff0) == 0x10f0) /* trap ? */
	regs->bpc -= 2;
	else
	regs->bpc -= 4;
	regs->syscall_nr = -1;
	return 0;
	}

	/*
	* OK, we're invoking a handler
	*/

	static int
	handle_signal(unsigned long sig, struct k_sigaction ka, siginfo_t info,
	sigset_t oldset, struct pt_regs regs)
	{
	/* Are we from a system call? */
	if (regs->syscall_nr >= 0) {
	/* If so, check system call restarting.. */
	switch (regs->r0) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
	regs->r0 = -EINTR;
	break;

	case -ERESTARTSYS:
	if (!(ka->sa.sa_flags & SA_RESTART)) {
	regs->r0 = -EINTR;
	break;
	}
	/* fallthrough */
	case -ERESTARTNOINTR:
	regs->r0 = regs->orig_r0;
	if (prev_insn(regs) < 0)
	return -EFAULT;
	}
	}

	/* Set up the stack frame */
	if (setup_rt_frame(sig, ka, info, oldset, regs))
	return -EFAULT;

	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NODEFER))
	sigaddset(&current->blocked,sig);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	return 0;
	}

	/*
	* Note that 'init' is a special process: it doesn't get signals it doesn't
	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	* mistake.
	*/
	static void do_signal(struct pt_regs *regs)
	{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;
	sigset_t *oldset;

	/*
	* We want the common case to go fast, which
	* is why we may in certain cases get here from
	* kernel mode. Just return without doing anything
	* if so.
	*/
	if (!user_mode(regs))
	return;

	if (try_to_freeze())
	goto no_signal;

	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) {
	/* Re-enable any watchpoints before delivering the
	* signal to user space. The processor register will
	* have been cleared if the watchpoint triggered
	* inside the kernel.
	*/

	/* Whee! Actually deliver the signal. */
	if (handle_signal(signr, &ka, &info, oldset, regs) == 0)
	clear_thread_flag(TIF_RESTORE_SIGMASK);

	return;
	}

	no_signal:
	/* Did we come from a system call? */
	if (regs->syscall_nr >= 0) {
	/* Restart the system call - no handlers present */
	if (regs->r0 == -ERESTARTNOHAND \|\|
	regs->r0 == -ERESTARTSYS \|\|
	regs->r0 == -ERESTARTNOINTR) {
	regs->r0 = regs->orig_r0;
	prev_insn(regs);
	} else if (regs->r0 == -ERESTART_RESTARTBLOCK){
	regs->r0 = regs->orig_r0;
	regs->r7 = __NR_restart_syscall;
	prev_insn(regs);
	}
	}
	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
	*/
	void do_notify_resume(struct pt_regs *regs, __u32 thread_info_flags)
	{
	/* Pending single-step? */
	if (thread_info_flags & _TIF_SINGLESTEP)
	clear_thread_flag(TIF_SINGLESTEP);

	/* deal with pending signal delivery */
	if (thread_info_flags & _TIF_SIGPENDING)
	do_signal(regs);

	if (thread_info_flags & _TIF_NOTIFY_RESUME) {
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(regs);
	if (current->replacement_session_keyring)
	key_replace_session_keyring();
	}

	clear_thread_flag(TIF_IRET);
	}