arch/nios2/kernel/signal.c - third_party/kernel - Git at Google

 /*
  * Copyright (C) 2013-2014 Altera Corporation
  * Copyright (C) 2011-2012 Tobias Klauser <tklauser@distanz.ch>
  * Copyright (C) 2004 Microtronix Datacom Ltd
  * Copyright (C) 1991, 1992 Linus Torvalds
  *
  * This file is subject to the terms and conditions of the GNU General Public
  * License.  See the file COPYING in the main directory of this archive
  * for more details.
  */

 #include <linux/signal.h>
 #include <linux/errno.h>
 #include <linux/ptrace.h>
 #include <linux/uaccess.h>
 #include <linux/unistd.h>
 #include <linux/personality.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.
  *
  * Keep the return code on the stack quadword aligned!
  * That makes the cache flush below easier.
  */

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

 static inline int rt_restore_ucontext(struct pt_regs *regs,
 					struct switch_stack *sw,
 					struct ucontext __user *uc, int *pr2)
 {
 	int temp;
 	unsigned long __user *gregs = uc->uc_mcontext.gregs;
 	int err;

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

 	err = __get_user(temp, &uc->uc_mcontext.version);
 	if (temp != MCONTEXT_VERSION)
 		goto badframe;
 	/* restore passed registers */
 	err |= __get_user(regs->r1, &gregs[0]);
 	err |= __get_user(regs->r2, &gregs[1]);
 	err |= __get_user(regs->r3, &gregs[2]);
 	err |= __get_user(regs->r4, &gregs[3]);
 	err |= __get_user(regs->r5, &gregs[4]);
 	err |= __get_user(regs->r6, &gregs[5]);
 	err |= __get_user(regs->r7, &gregs[6]);
 	err |= __get_user(regs->r8, &gregs[7]);
 	err |= __get_user(regs->r9, &gregs[8]);
 	err |= __get_user(regs->r10, &gregs[9]);
 	err |= __get_user(regs->r11, &gregs[10]);
 	err |= __get_user(regs->r12, &gregs[11]);
 	err |= __get_user(regs->r13, &gregs[12]);
 	err |= __get_user(regs->r14, &gregs[13]);
 	err |= __get_user(regs->r15, &gregs[14]);
 	err |= __get_user(sw->r16, &gregs[15]);
 	err |= __get_user(sw->r17, &gregs[16]);
 	err |= __get_user(sw->r18, &gregs[17]);
 	err |= __get_user(sw->r19, &gregs[18]);
 	err |= __get_user(sw->r20, &gregs[19]);
 	err |= __get_user(sw->r21, &gregs[20]);
 	err |= __get_user(sw->r22, &gregs[21]);
 	err |= __get_user(sw->r23, &gregs[22]);
 	/* gregs[23] is handled below */
 	err |= __get_user(sw->fp, &gregs[24]);  /* Verify, should this be
 							settable */
 	err |= __get_user(sw->gp, &gregs[25]);  /* Verify, should this be
 							settable */

 	err |= __get_user(temp, &gregs[26]);  /* Not really necessary no user
 							settable bits */
 	err |= __get_user(regs->ea, &gregs[27]);

 	err |= __get_user(regs->ra, &gregs[23]);
 	err |= __get_user(regs->sp, &gregs[28]);

 	regs->orig_r2 = -1;		/* disable syscall checks */

 	err |= restore_altstack(&uc->uc_stack);
 	if (err)
 		goto badframe;

 	*pr2 = regs->r2;
 	return err;

 badframe:
 	return 1;
 }

 asmlinkage int do_rt_sigreturn(struct switch_stack *sw)
 {
 	struct pt_regs *regs = (struct pt_regs *)(sw + 1);
 	/* Verify, can we follow the stack back */
 	struct rt_sigframe __user *frame;
 	sigset_t set;
 	int rval;

 	frame = (struct rt_sigframe __user *) regs->sp;
 	if (!access_ok(frame, sizeof(*frame)))
 		goto badframe;

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

 	set_current_blocked(&set);

 	if (rt_restore_ucontext(regs, sw, &frame->uc, &rval))
 		goto badframe;

 	return rval;

 badframe:
 	force_sig(SIGSEGV);
 	return 0;
 }

 static inline int rt_setup_ucontext(struct ucontext __user *uc, struct pt_regs *regs)
 {
 	struct switch_stack *sw = (struct switch_stack *)regs - 1;
 	unsigned long __user *gregs = uc->uc_mcontext.gregs;
 	int err = 0;

 	err |= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
 	err |= __put_user(regs->r1, &gregs[0]);
 	err |= __put_user(regs->r2, &gregs[1]);
 	err |= __put_user(regs->r3, &gregs[2]);
 	err |= __put_user(regs->r4, &gregs[3]);
 	err |= __put_user(regs->r5, &gregs[4]);
 	err |= __put_user(regs->r6, &gregs[5]);
 	err |= __put_user(regs->r7, &gregs[6]);
 	err |= __put_user(regs->r8, &gregs[7]);
 	err |= __put_user(regs->r9, &gregs[8]);
 	err |= __put_user(regs->r10, &gregs[9]);
 	err |= __put_user(regs->r11, &gregs[10]);
 	err |= __put_user(regs->r12, &gregs[11]);
 	err |= __put_user(regs->r13, &gregs[12]);
 	err |= __put_user(regs->r14, &gregs[13]);
 	err |= __put_user(regs->r15, &gregs[14]);
 	err |= __put_user(sw->r16, &gregs[15]);
 	err |= __put_user(sw->r17, &gregs[16]);
 	err |= __put_user(sw->r18, &gregs[17]);
 	err |= __put_user(sw->r19, &gregs[18]);
 	err |= __put_user(sw->r20, &gregs[19]);
 	err |= __put_user(sw->r21, &gregs[20]);
 	err |= __put_user(sw->r22, &gregs[21]);
 	err |= __put_user(sw->r23, &gregs[22]);
 	err |= __put_user(regs->ra, &gregs[23]);
 	err |= __put_user(sw->fp, &gregs[24]);
 	err |= __put_user(sw->gp, &gregs[25]);
 	err |= __put_user(regs->ea, &gregs[27]);
 	err |= __put_user(regs->sp, &gregs[28]);
 	return err;
 }

 static inline void __user *get_sigframe(struct ksignal *ksig,
 					struct pt_regs *regs,
 					size_t frame_size)
 {
 	unsigned long usp;

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

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

 	/* Verify, is it 32 or 64 bit aligned */
 	return (void __user *)((usp - frame_size) & -8UL);
 }

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

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

 	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
 		err |= copy_siginfo_to_user(&frame->info, &ksig->info);

 	/* Create the ucontext.  */
 	err |= __put_user(0, &frame->uc.uc_flags);
 	err |= __put_user(0, &frame->uc.uc_link);
 	err |= __save_altstack(&frame->uc.uc_stack, regs->sp);
 	err |= rt_setup_ucontext(&frame->uc, regs);
 	err |= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

 	if (err)
 		goto give_sigsegv;

 	/* Set up to return from userspace; jump to fixed address sigreturn
 	   trampoline on kuser page.  */
 	regs->ra = (unsigned long) (0x1044);

 	/* Set up registers for signal handler */
 	regs->sp = (unsigned long) frame;
 	regs->r4 = (unsigned long) ksig->sig;
 	regs->r5 = (unsigned long) &frame->info;
 	regs->r6 = (unsigned long) &frame->uc;
 	regs->ea = (unsigned long) ksig->ka.sa.sa_handler;
 	return 0;

 give_sigsegv:
 	force_sigsegv(ksig->sig);
 	return -EFAULT;
 }

 /*
  * 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();

 	/* set up the stack frame */
 	ret = setup_rt_frame(ksig, oldset, regs);

 	signal_setup_done(ret, ksig, 0);
 }

 static int do_signal(struct pt_regs *regs)
 {
 	unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
 	int restart = 0;
 	struct ksignal ksig;

 	current->thread.kregs = regs;

 	/*
 	 * If we were from a system call, check for system call restarting...
 	 */
 	if (regs->orig_r2 >= 0 && regs->r1) {
 		continue_addr = regs->ea;
 		restart_addr = continue_addr - 4;
 		retval = regs->r2;

 		/*
 		 * Prepare for system call restart. We do this here so that a
 		 * debugger will see the already changed PC.
 		 */
 		switch (retval) {
 		case ERESTART_RESTARTBLOCK:
 			restart = -2;
 			fallthrough;
 		case ERESTARTNOHAND:
 		case ERESTARTSYS:
 		case ERESTARTNOINTR:
 			restart++;
 			regs->r2 = regs->orig_r2;
 			regs->r7 = regs->orig_r7;
 			regs->ea = restart_addr;
 			break;
 		}
 		regs->orig_r2 = -1;
 	}

 	if (get_signal(&ksig)) {
 		/* handler */
 		if (unlikely(restart && regs->ea == restart_addr)) {
 			if (retval == ERESTARTNOHAND ||
 			    retval == ERESTART_RESTARTBLOCK ||
 			     (retval == ERESTARTSYS
 				&& !(ksig.ka.sa.sa_flags & SA_RESTART))) {
 				regs->r2 = EINTR;
 				regs->r7 = 1;
 				regs->ea = continue_addr;
 			}
 		}
 		handle_signal(&ksig, regs);
 		return 0;
 	}

 	/*
 	 * No handler present
 	 */
 	if (unlikely(restart) && regs->ea == restart_addr) {
 		regs->ea = continue_addr;
 		regs->r2 = __NR_restart_syscall;
 	}

 	/*
 	* If there's no signal to deliver, we just put the saved sigmask back.
 	*/
 	restore_saved_sigmask();

 	return restart;
 }

 asmlinkage int do_notify_resume(struct pt_regs *regs)
 {
 	/*
 	 * 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 0;

 	if (test_thread_flag(TIF_SIGPENDING) ||
 	    test_thread_flag(TIF_NOTIFY_SIGNAL)) {
 		int restart = do_signal(regs);

 		if (unlikely(restart)) {
 			/*
 			 * Restart without handlers.
 			 * Deal with it without leaving
 			 * the kernel space.
 			 */
 			return restart;
 		}
 	} else if (test_thread_flag(TIF_NOTIFY_RESUME))
 		tracehook_notify_resume(regs);

 	return 0;
 }
	/*
	* Copyright (C) 2013-2014 Altera Corporation
	* Copyright (C) 2011-2012 Tobias Klauser <tklauser@distanz.ch>
	* Copyright (C) 2004 Microtronix Datacom Ltd
	* Copyright (C) 1991, 1992 Linus Torvalds
	*
	* This file is subject to the terms and conditions of the GNU General Public
	* License. See the file COPYING in the main directory of this archive
	* for more details.
	*/

	#include <linux/signal.h>
	#include <linux/errno.h>
	#include <linux/ptrace.h>
	#include <linux/uaccess.h>
	#include <linux/unistd.h>
	#include <linux/personality.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.
	*
	* Keep the return code on the stack quadword aligned!
	* That makes the cache flush below easier.
	*/

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

	static inline int rt_restore_ucontext(struct pt_regs *regs,
	struct switch_stack *sw,
	struct ucontext __user uc, int pr2)
	{
	int temp;
	unsigned long __user *gregs = uc->uc_mcontext.gregs;
	int err;

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

	err = __get_user(temp, &uc->uc_mcontext.version);
	if (temp != MCONTEXT_VERSION)
	goto badframe;
	/* restore passed registers */
	err \|= __get_user(regs->r1, &gregs[0]);
	err \|= __get_user(regs->r2, &gregs[1]);
	err \|= __get_user(regs->r3, &gregs[2]);
	err \|= __get_user(regs->r4, &gregs[3]);
	err \|= __get_user(regs->r5, &gregs[4]);
	err \|= __get_user(regs->r6, &gregs[5]);
	err \|= __get_user(regs->r7, &gregs[6]);
	err \|= __get_user(regs->r8, &gregs[7]);
	err \|= __get_user(regs->r9, &gregs[8]);
	err \|= __get_user(regs->r10, &gregs[9]);
	err \|= __get_user(regs->r11, &gregs[10]);
	err \|= __get_user(regs->r12, &gregs[11]);
	err \|= __get_user(regs->r13, &gregs[12]);
	err \|= __get_user(regs->r14, &gregs[13]);
	err \|= __get_user(regs->r15, &gregs[14]);
	err \|= __get_user(sw->r16, &gregs[15]);
	err \|= __get_user(sw->r17, &gregs[16]);
	err \|= __get_user(sw->r18, &gregs[17]);
	err \|= __get_user(sw->r19, &gregs[18]);
	err \|= __get_user(sw->r20, &gregs[19]);
	err \|= __get_user(sw->r21, &gregs[20]);
	err \|= __get_user(sw->r22, &gregs[21]);
	err \|= __get_user(sw->r23, &gregs[22]);
	/* gregs[23] is handled below */
	err \|= __get_user(sw->fp, &gregs[24]); /* Verify, should this be
	settable */
	err \|= __get_user(sw->gp, &gregs[25]); /* Verify, should this be
	settable */

	err \|= __get_user(temp, &gregs[26]); /* Not really necessary no user
	settable bits */
	err \|= __get_user(regs->ea, &gregs[27]);

	err \|= __get_user(regs->ra, &gregs[23]);
	err \|= __get_user(regs->sp, &gregs[28]);

	regs->orig_r2 = -1; /* disable syscall checks */

	err \|= restore_altstack(&uc->uc_stack);
	if (err)
	goto badframe;

	*pr2 = regs->r2;
	return err;

	badframe:
	return 1;
	}

	asmlinkage int do_rt_sigreturn(struct switch_stack *sw)
	{
	struct pt_regs regs = (struct pt_regs )(sw + 1);
	/* Verify, can we follow the stack back */
	struct rt_sigframe __user *frame;
	sigset_t set;
	int rval;

	frame = (struct rt_sigframe __user *) regs->sp;
	if (!access_ok(frame, sizeof(*frame)))
	goto badframe;

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

	set_current_blocked(&set);

	if (rt_restore_ucontext(regs, sw, &frame->uc, &rval))
	goto badframe;

	return rval;

	badframe:
	force_sig(SIGSEGV);
	return 0;
	}

	static inline int rt_setup_ucontext(struct ucontext __user uc, struct pt_regs regs)
	{
	struct switch_stack sw = (struct switch_stack )regs - 1;
	unsigned long __user *gregs = uc->uc_mcontext.gregs;
	int err = 0;

	err \|= __put_user(MCONTEXT_VERSION, &uc->uc_mcontext.version);
	err \|= __put_user(regs->r1, &gregs[0]);
	err \|= __put_user(regs->r2, &gregs[1]);
	err \|= __put_user(regs->r3, &gregs[2]);
	err \|= __put_user(regs->r4, &gregs[3]);
	err \|= __put_user(regs->r5, &gregs[4]);
	err \|= __put_user(regs->r6, &gregs[5]);
	err \|= __put_user(regs->r7, &gregs[6]);
	err \|= __put_user(regs->r8, &gregs[7]);
	err \|= __put_user(regs->r9, &gregs[8]);
	err \|= __put_user(regs->r10, &gregs[9]);
	err \|= __put_user(regs->r11, &gregs[10]);
	err \|= __put_user(regs->r12, &gregs[11]);
	err \|= __put_user(regs->r13, &gregs[12]);
	err \|= __put_user(regs->r14, &gregs[13]);
	err \|= __put_user(regs->r15, &gregs[14]);
	err \|= __put_user(sw->r16, &gregs[15]);
	err \|= __put_user(sw->r17, &gregs[16]);
	err \|= __put_user(sw->r18, &gregs[17]);
	err \|= __put_user(sw->r19, &gregs[18]);
	err \|= __put_user(sw->r20, &gregs[19]);
	err \|= __put_user(sw->r21, &gregs[20]);
	err \|= __put_user(sw->r22, &gregs[21]);
	err \|= __put_user(sw->r23, &gregs[22]);
	err \|= __put_user(regs->ra, &gregs[23]);
	err \|= __put_user(sw->fp, &gregs[24]);
	err \|= __put_user(sw->gp, &gregs[25]);
	err \|= __put_user(regs->ea, &gregs[27]);
	err \|= __put_user(regs->sp, &gregs[28]);
	return err;
	}

	static inline void __user get_sigframe(struct ksignal ksig,
	struct pt_regs *regs,
	size_t frame_size)
	{
	unsigned long usp;

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

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

	/* Verify, is it 32 or 64 bit aligned */
	return (void __user *)((usp - frame_size) & -8UL);
	}

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

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

	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);

	/* Create the ucontext. */
	err \|= __put_user(0, &frame->uc.uc_flags);
	err \|= __put_user(0, &frame->uc.uc_link);
	err \|= __save_altstack(&frame->uc.uc_stack, regs->sp);
	err \|= rt_setup_ucontext(&frame->uc, regs);
	err \|= copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));

	if (err)
	goto give_sigsegv;

	/* Set up to return from userspace; jump to fixed address sigreturn
	trampoline on kuser page. */
	regs->ra = (unsigned long) (0x1044);

	/* Set up registers for signal handler */
	regs->sp = (unsigned long) frame;
	regs->r4 = (unsigned long) ksig->sig;
	regs->r5 = (unsigned long) &frame->info;
	regs->r6 = (unsigned long) &frame->uc;
	regs->ea = (unsigned long) ksig->ka.sa.sa_handler;
	return 0;

	give_sigsegv:
	force_sigsegv(ksig->sig);
	return -EFAULT;
	}

	/*
	* 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();

	/* set up the stack frame */
	ret = setup_rt_frame(ksig, oldset, regs);

	signal_setup_done(ret, ksig, 0);
	}

	static int do_signal(struct pt_regs *regs)
	{
	unsigned int retval = 0, continue_addr = 0, restart_addr = 0;
	int restart = 0;
	struct ksignal ksig;

	current->thread.kregs = regs;

	/*
	* If we were from a system call, check for system call restarting...
	*/
	if (regs->orig_r2 >= 0 && regs->r1) {
	continue_addr = regs->ea;
	restart_addr = continue_addr - 4;
	retval = regs->r2;

	/*
	* Prepare for system call restart. We do this here so that a
	* debugger will see the already changed PC.
	*/
	switch (retval) {
	case ERESTART_RESTARTBLOCK:
	restart = -2;
	fallthrough;
	case ERESTARTNOHAND:
	case ERESTARTSYS:
	case ERESTARTNOINTR:
	restart++;
	regs->r2 = regs->orig_r2;
	regs->r7 = regs->orig_r7;
	regs->ea = restart_addr;
	break;
	}
	regs->orig_r2 = -1;
	}

	if (get_signal(&ksig)) {
	/* handler */
	if (unlikely(restart && regs->ea == restart_addr)) {
	if (retval == ERESTARTNOHAND \|\|
	retval == ERESTART_RESTARTBLOCK \|\|
	(retval == ERESTARTSYS
	&& !(ksig.ka.sa.sa_flags & SA_RESTART))) {
	regs->r2 = EINTR;
	regs->r7 = 1;
	regs->ea = continue_addr;
	}
	}
	handle_signal(&ksig, regs);
	return 0;
	}

	/*
	* No handler present
	*/
	if (unlikely(restart) && regs->ea == restart_addr) {
	regs->ea = continue_addr;
	regs->r2 = __NR_restart_syscall;
	}

	/*
	* If there's no signal to deliver, we just put the saved sigmask back.
	*/
	restore_saved_sigmask();

	return restart;
	}

	asmlinkage int do_notify_resume(struct pt_regs *regs)
	{
	/*
	* 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 0;

	if (test_thread_flag(TIF_SIGPENDING) \|\|
	test_thread_flag(TIF_NOTIFY_SIGNAL)) {
	int restart = do_signal(regs);

	if (unlikely(restart)) {
	/*
	* Restart without handlers.
	* Deal with it without leaving
	* the kernel space.
	*/
	return restart;
	}
	} else if (test_thread_flag(TIF_NOTIFY_RESUME))
	tracehook_notify_resume(regs);

	return 0;
	}