arch/nds32/kernel/signal.c - linux-mtk - Git at Google

 // SPDX-License-Identifier: GPL-2.0
 // Copyright (C) 2005-2017 Andes Technology Corporation

 #include <linux/errno.h>
 #include <linux/signal.h>
 #include <linux/ptrace.h>
 #include <linux/personality.h>
 #include <linux/freezer.h>
 #include <linux/tracehook.h>
 #include <linux/uaccess.h>

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

 #include <asm/ptrace.h>
 #include <asm/vdso.h>

 struct rt_sigframe {
 	struct siginfo info;
 	struct ucontext uc;
 };

 static int restore_sigframe(struct pt_regs *regs,
 			    struct rt_sigframe __user * sf)
 {
 	sigset_t set;
 	int err;

 	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
 	if (err == 0) {
 		set_current_blocked(&set);
 	}

 	__get_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err);
 	__get_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err);
 	__get_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err);
 	__get_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err);
 	__get_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err);
 	__get_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err);
 	__get_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err);
 	__get_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err);
 	__get_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err);
 	__get_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err);
 	__get_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err);
 	__get_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err);
 	__get_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err);
 	__get_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err);
 	__get_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err);
 	__get_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err);
 	__get_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err);
 	__get_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err);
 	__get_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err);
 	__get_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err);
 	__get_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err);
 	__get_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err);
 	__get_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err);
 	__get_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err);
 	__get_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err);
 	__get_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err);

 	__get_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err);
 	__get_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err);
 	__get_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err);
 	__get_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err);
 	__get_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err);
 #if defined(CONFIG_HWZOL)
 	__get_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err);
 	__get_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err);
 	__get_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err);
 #endif

 	/*
 	 * Avoid sys_rt_sigreturn() restarting.
 	 */
 	forget_syscall(regs);
 	return err;
 }

 asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame;

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

 	/*
 	 * Since we stacked the signal on a 64-bit boundary,
 	 * then 'sp' should be two-word 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 *)regs->sp;

 	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
 		goto badframe;

 	if (restore_sigframe(regs, frame))
 		goto badframe;

 	if (restore_altstack(&frame->uc.uc_stack))
 		goto badframe;

 	return regs->uregs[0];

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

 static int
 setup_sigframe(struct rt_sigframe __user * sf, struct pt_regs *regs,
 	       sigset_t * set)
 {
 	int err = 0;

 	__put_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err);
 	__put_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err);
 	__put_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err);
 	__put_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err);
 	__put_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err);
 	__put_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err);
 	__put_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err);
 	__put_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err);
 	__put_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err);
 	__put_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err);
 	__put_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err);
 	__put_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err);
 	__put_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err);
 	__put_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err);
 	__put_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err);
 	__put_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err);
 	__put_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err);
 	__put_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err);
 	__put_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err);
 	__put_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err);
 	__put_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err);

 	__put_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err);
 	__put_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err);
 	__put_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err);
 	__put_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err);
 	__put_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err);
 	__put_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err);
 	__put_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err);
 	__put_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err);
 	__put_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err);
 	__put_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err);
 #if defined(CONFIG_HWZOL)
 	__put_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err);
 	__put_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err);
 	__put_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err);
 #endif

 	__put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no,
 			 err);
 	__put_user_error(current->thread.error_code,
 			 &sf->uc.uc_mcontext.error_code, err);
 	__put_user_error(current->thread.address,
 			 &sf->uc.uc_mcontext.fault_address, err);
 	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);

 	err |= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));

 	return err;
 }

 static inline void __user *get_sigframe(struct ksignal *ksig,
 					struct pt_regs *regs, int framesize)
 {
 	unsigned long sp;

 	/* Default to using normal stack */
 	sp = regs->sp;

 	/*
 	 * If we are on the alternate signal stack and would overflow it, don't.
 	 * Return an always-bogus address instead so we will die with SIGSEGV.
 	 */
 	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
 		return (void __user __force *)(-1UL);

 	/* This is the X/Open sanctioned signal stack switching. */
 	sp = (sigsp(sp, ksig) - framesize);

 	/*
 	 * nds32 mandates 8-byte alignment
 	 */
 	sp &= ~0x7UL;

 	return (void __user *)sp;
 }

 static int
 setup_return(struct pt_regs *regs, struct ksignal *ksig, void __user * frame)
 {
 	unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler;
 	unsigned long retcode;

 	retcode = VDSO_SYMBOL(current->mm->context.vdso, rt_sigtramp);
 	regs->uregs[0] = ksig->sig;
 	regs->sp = (unsigned long)frame;
 	regs->lp = retcode;
 	regs->ipc = handler;

 	return 0;
 }

 static int
 setup_rt_frame(struct ksignal *ksig, sigset_t * set, struct pt_regs *regs)
 {
 	struct rt_sigframe __user *frame =
 	    get_sigframe(ksig, regs, sizeof(*frame));
 	int err = 0;

 	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
 		return -EFAULT;

 	__put_user_error(0, &frame->uc.uc_flags, err);
 	__put_user_error(NULL, &frame->uc.uc_link, err);

 	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
 	err |= setup_sigframe(frame, regs, set);
 	if (err == 0) {
 		setup_return(regs, ksig, frame);
 		if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
 			err |= copy_siginfo_to_user(&frame->info, &ksig->info);
 			regs->uregs[1] = (unsigned long)&frame->info;
 			regs->uregs[2] = (unsigned long)&frame->uc;
 		}
 	}
 	return err;
 }

 /*
  * OK, we're invoking a handler
  */
 static void handle_signal(struct ksignal *ksig, struct pt_regs *regs)
 {
 	int ret;
 	sigset_t *oldset = sigmask_to_save();

 	if (in_syscall(regs)) {
 		/* Avoid additional syscall restarting via ret_slow_syscall. */
 		forget_syscall(regs);

 		switch (regs->uregs[0]) {
 		case -ERESTART_RESTARTBLOCK:
 		case -ERESTARTNOHAND:
 			regs->uregs[0] = -EINTR;
 			break;
 		case -ERESTARTSYS:
 			if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
 				regs->uregs[0] = -EINTR;
 				break;
 			}
 		case -ERESTARTNOINTR:
 			regs->uregs[0] = regs->orig_r0;
 			regs->ipc -= 4;
 			break;
 		}
 	}
 	/*
 	 * Set up the stack frame
 	 */
 	ret = setup_rt_frame(ksig, oldset, regs);

 	signal_setup_done(ret, ksig, 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.
  *
  * Note that we go through the signals twice: once to check the signals that
  * the kernel can handle, and then we build all the user-level signal handling
  * stack-frames in one go after that.
  */
 static void do_signal(struct pt_regs *regs)
 {
 	struct ksignal ksig;

 	if (get_signal(&ksig)) {
 		handle_signal(&ksig, regs);
 		return;
 	}

 	/*
 	 * If we were from a system call, check for system call restarting...
 	 */
 	if (in_syscall(regs)) {
 		/* Restart the system call - no handlers present */

 		/* Avoid additional syscall restarting via ret_slow_syscall. */
 		forget_syscall(regs);

 		switch (regs->uregs[0]) {
 		case -ERESTART_RESTARTBLOCK:
 			regs->uregs[15] = __NR_restart_syscall;
 		case -ERESTARTNOHAND:
 		case -ERESTARTSYS:
 		case -ERESTARTNOINTR:
 			regs->uregs[0] = regs->orig_r0;
 			regs->ipc -= 0x4;
 			break;
 		}
 	}
 	restore_saved_sigmask();
 }

 asmlinkage void
 do_notify_resume(struct pt_regs *regs, unsigned int thread_flags)
 {
 	if (thread_flags & _TIF_SIGPENDING)
 		do_signal(regs);

 	if (thread_flags & _TIF_NOTIFY_RESUME) {
 		clear_thread_flag(TIF_NOTIFY_RESUME);
 		tracehook_notify_resume(regs);
 	}
 }
	// SPDX-License-Identifier: GPL-2.0
	// Copyright (C) 2005-2017 Andes Technology Corporation

	#include <linux/errno.h>
	#include <linux/signal.h>
	#include <linux/ptrace.h>
	#include <linux/personality.h>
	#include <linux/freezer.h>
	#include <linux/tracehook.h>
	#include <linux/uaccess.h>

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

	#include <asm/ptrace.h>
	#include <asm/vdso.h>

	struct rt_sigframe {
	struct siginfo info;
	struct ucontext uc;
	};

	static int restore_sigframe(struct pt_regs *regs,
	struct rt_sigframe __user * sf)
	{
	sigset_t set;
	int err;

	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
	if (err == 0) {
	set_current_blocked(&set);
	}

	__get_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err);
	__get_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err);
	__get_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err);
	__get_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err);
	__get_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err);
	__get_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err);
	__get_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err);
	__get_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err);
	__get_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err);
	__get_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err);
	__get_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err);
	__get_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err);
	__get_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err);
	__get_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err);
	__get_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err);
	__get_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err);
	__get_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err);
	__get_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err);
	__get_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err);
	__get_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err);
	__get_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err);
	__get_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err);
	__get_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err);
	__get_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err);
	__get_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err);
	__get_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err);

	__get_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err);
	__get_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err);
	__get_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err);
	__get_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err);
	__get_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err);
	#if defined(CONFIG_HWZOL)
	__get_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err);
	__get_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err);
	__get_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err);
	#endif

	/*
	* Avoid sys_rt_sigreturn() restarting.
	*/
	forget_syscall(regs);
	return err;
	}

	asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
	{
	struct rt_sigframe __user *frame;

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

	/*
	* Since we stacked the signal on a 64-bit boundary,
	* then 'sp' should be two-word 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 *)regs->sp;

	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	goto badframe;

	if (restore_sigframe(regs, frame))
	goto badframe;

	if (restore_altstack(&frame->uc.uc_stack))
	goto badframe;

	return regs->uregs[0];

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

	static int
	setup_sigframe(struct rt_sigframe __user * sf, struct pt_regs *regs,
	sigset_t * set)
	{
	int err = 0;

	__put_user_error(regs->uregs[0], &sf->uc.uc_mcontext.nds32_r0, err);
	__put_user_error(regs->uregs[1], &sf->uc.uc_mcontext.nds32_r1, err);
	__put_user_error(regs->uregs[2], &sf->uc.uc_mcontext.nds32_r2, err);
	__put_user_error(regs->uregs[3], &sf->uc.uc_mcontext.nds32_r3, err);
	__put_user_error(regs->uregs[4], &sf->uc.uc_mcontext.nds32_r4, err);
	__put_user_error(regs->uregs[5], &sf->uc.uc_mcontext.nds32_r5, err);
	__put_user_error(regs->uregs[6], &sf->uc.uc_mcontext.nds32_r6, err);
	__put_user_error(regs->uregs[7], &sf->uc.uc_mcontext.nds32_r7, err);
	__put_user_error(regs->uregs[8], &sf->uc.uc_mcontext.nds32_r8, err);
	__put_user_error(regs->uregs[9], &sf->uc.uc_mcontext.nds32_r9, err);
	__put_user_error(regs->uregs[10], &sf->uc.uc_mcontext.nds32_r10, err);
	__put_user_error(regs->uregs[11], &sf->uc.uc_mcontext.nds32_r11, err);
	__put_user_error(regs->uregs[12], &sf->uc.uc_mcontext.nds32_r12, err);
	__put_user_error(regs->uregs[13], &sf->uc.uc_mcontext.nds32_r13, err);
	__put_user_error(regs->uregs[14], &sf->uc.uc_mcontext.nds32_r14, err);
	__put_user_error(regs->uregs[15], &sf->uc.uc_mcontext.nds32_r15, err);
	__put_user_error(regs->uregs[16], &sf->uc.uc_mcontext.nds32_r16, err);
	__put_user_error(regs->uregs[17], &sf->uc.uc_mcontext.nds32_r17, err);
	__put_user_error(regs->uregs[18], &sf->uc.uc_mcontext.nds32_r18, err);
	__put_user_error(regs->uregs[19], &sf->uc.uc_mcontext.nds32_r19, err);
	__put_user_error(regs->uregs[20], &sf->uc.uc_mcontext.nds32_r20, err);

	__put_user_error(regs->uregs[21], &sf->uc.uc_mcontext.nds32_r21, err);
	__put_user_error(regs->uregs[22], &sf->uc.uc_mcontext.nds32_r22, err);
	__put_user_error(regs->uregs[23], &sf->uc.uc_mcontext.nds32_r23, err);
	__put_user_error(regs->uregs[24], &sf->uc.uc_mcontext.nds32_r24, err);
	__put_user_error(regs->uregs[25], &sf->uc.uc_mcontext.nds32_r25, err);
	__put_user_error(regs->fp, &sf->uc.uc_mcontext.nds32_fp, err);
	__put_user_error(regs->gp, &sf->uc.uc_mcontext.nds32_gp, err);
	__put_user_error(regs->lp, &sf->uc.uc_mcontext.nds32_lp, err);
	__put_user_error(regs->sp, &sf->uc.uc_mcontext.nds32_sp, err);
	__put_user_error(regs->ipc, &sf->uc.uc_mcontext.nds32_ipc, err);
	#if defined(CONFIG_HWZOL)
	__put_user_error(regs->lc, &sf->uc.uc_mcontext.zol.nds32_lc, err);
	__put_user_error(regs->le, &sf->uc.uc_mcontext.zol.nds32_le, err);
	__put_user_error(regs->lb, &sf->uc.uc_mcontext.zol.nds32_lb, err);
	#endif

	__put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no,
	err);
	__put_user_error(current->thread.error_code,
	&sf->uc.uc_mcontext.error_code, err);
	__put_user_error(current->thread.address,
	&sf->uc.uc_mcontext.fault_address, err);
	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);

	err \|= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));

	return err;
	}

	static inline void __user get_sigframe(struct ksignal ksig,
	struct pt_regs *regs, int framesize)
	{
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->sp;

	/*
	* If we are on the alternate signal stack and would overflow it, don't.
	* Return an always-bogus address instead so we will die with SIGSEGV.
	*/
	if (on_sig_stack(sp) && !likely(on_sig_stack(sp - framesize)))
	return (void __user __force *)(-1UL);

	/* This is the X/Open sanctioned signal stack switching. */
	sp = (sigsp(sp, ksig) - framesize);

	/*
	* nds32 mandates 8-byte alignment
	*/
	sp &= ~0x7UL;

	return (void __user *)sp;
	}

	static int
	setup_return(struct pt_regs regs, struct ksignal ksig, void __user * frame)
	{
	unsigned long handler = (unsigned long)ksig->ka.sa.sa_handler;
	unsigned long retcode;

	retcode = VDSO_SYMBOL(current->mm->context.vdso, rt_sigtramp);
	regs->uregs[0] = ksig->sig;
	regs->sp = (unsigned long)frame;
	regs->lp = retcode;
	regs->ipc = handler;

	return 0;
	}

	static int
	setup_rt_frame(struct ksignal ksig, sigset_t set, struct pt_regs *regs)
	{
	struct rt_sigframe __user *frame =
	get_sigframe(ksig, regs, sizeof(*frame));
	int err = 0;

	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	return -EFAULT;

	__put_user_error(0, &frame->uc.uc_flags, err);
	__put_user_error(NULL, &frame->uc.uc_link, err);

	err \|= __save_altstack(&frame->uc.uc_stack, regs->sp);
	err \|= setup_sigframe(frame, regs, set);
	if (err == 0) {
	setup_return(regs, ksig, frame);
	if (ksig->ka.sa.sa_flags & SA_SIGINFO) {
	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
	regs->uregs[1] = (unsigned long)&frame->info;
	regs->uregs[2] = (unsigned long)&frame->uc;
	}
	}
	return err;
	}

	/*
	* OK, we're invoking a handler
	*/
	static void handle_signal(struct ksignal ksig, struct pt_regs regs)
	{
	int ret;
	sigset_t *oldset = sigmask_to_save();

	if (in_syscall(regs)) {
	/* Avoid additional syscall restarting via ret_slow_syscall. */
	forget_syscall(regs);

	switch (regs->uregs[0]) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
	regs->uregs[0] = -EINTR;
	break;
	case -ERESTARTSYS:
	if (!(ksig->ka.sa.sa_flags & SA_RESTART)) {
	regs->uregs[0] = -EINTR;
	break;
	}
	case -ERESTARTNOINTR:
	regs->uregs[0] = regs->orig_r0;
	regs->ipc -= 4;
	break;
	}
	}
	/*
	* Set up the stack frame
	*/
	ret = setup_rt_frame(ksig, oldset, regs);

	signal_setup_done(ret, ksig, 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.
	*
	* Note that we go through the signals twice: once to check the signals that
	* the kernel can handle, and then we build all the user-level signal handling
	* stack-frames in one go after that.
	*/
	static void do_signal(struct pt_regs *regs)
	{
	struct ksignal ksig;

	if (get_signal(&ksig)) {
	handle_signal(&ksig, regs);
	return;
	}

	/*
	* If we were from a system call, check for system call restarting...
	*/
	if (in_syscall(regs)) {
	/* Restart the system call - no handlers present */

	/* Avoid additional syscall restarting via ret_slow_syscall. */
	forget_syscall(regs);

	switch (regs->uregs[0]) {
	case -ERESTART_RESTARTBLOCK:
	regs->uregs[15] = __NR_restart_syscall;
	case -ERESTARTNOHAND:
	case -ERESTARTSYS:
	case -ERESTARTNOINTR:
	regs->uregs[0] = regs->orig_r0;
	regs->ipc -= 0x4;
	break;
	}
	}
	restore_saved_sigmask();
	}

	asmlinkage void
	do_notify_resume(struct pt_regs *regs, unsigned int thread_flags)
	{
	if (thread_flags & _TIF_SIGPENDING)
	do_signal(regs);

	if (thread_flags & _TIF_NOTIFY_RESUME) {
	clear_thread_flag(TIF_NOTIFY_RESUME);
	tracehook_notify_resume(regs);
	}
	}