[mirror_ubuntu-artful-kernel.git] / arch / unicore32 / kernel / signal.c

/*
 * linux/arch/unicore32/kernel/signal.c
 *
 * Code specific to PKUnity SoC and UniCore ISA
 *
 * Copyright (C) 2001-2010 GUAN Xue-tao
 *
 * 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/errno.h>
#include <linux/signal.h>
#include <linux/personality.h>
#include <linux/uaccess.h>
#include <linux/tracehook.h>
#include <linux/elf.h>
#include <linux/unistd.h>

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

/*
 * For UniCore syscalls, we encode the syscall number into the instruction.
 */
#define SWI_SYS_SIGRETURN	(0xff000000) /* error number for new abi */
#define SWI_SYS_RT_SIGRETURN	(0xff000000 | (__NR_rt_sigreturn))
#define SWI_SYS_RESTART		(0xff000000 | (__NR_restart_syscall))

#define KERN_SIGRETURN_CODE	(KUSER_VECPAGE_BASE + 0x00000500)
#define KERN_RESTART_CODE	(KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))

const unsigned long sigreturn_codes[3] = {
	SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN,
};

const unsigned long syscall_restart_code[2] = {
	SWI_SYS_RESTART,	/* swi	__NR_restart_syscall */
	0x69efc004,		/* ldr	pc, [sp], #4 */
};

/*
 * Do a signal return; undo the signal stack.  These are aligned to 64-bit.
 */
struct sigframe {
	struct ucontext uc;
	unsigned long retcode[2];
};

struct rt_sigframe {
	struct siginfo info;
	struct sigframe sig;
};

static int restore_sigframe(struct pt_regs *regs, struct 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);

	err |= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
	err |= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
	err |= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
	err |= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
	err |= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
	err |= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
	err |= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
	err |= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
	err |= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
	err |= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
	err |= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
	err |= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
	err |= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
	err |= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
	err |= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
	err |= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
	err |= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
	err |= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
	err |= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
	err |= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
	err |= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
	err |= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
	err |= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
	err |= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
	err |= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
	err |= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
	err |= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
	err |= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
	err |= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
	err |= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
	err |= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
	err |= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
	err |= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);

	err |= !valid_user_regs(regs);

	return err;
}

asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs)
{
	struct rt_sigframe __user *frame;

	/* 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 64-bit boundary,
	 * then 'sp' should be word aligned here.  If it's
	 * not, then the user is trying to mess with us.
	 */
	if (regs->UCreg_sp & 7)
		goto badframe;

	frame = (struct rt_sigframe __user *)regs->UCreg_sp;

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

	if (restore_sigframe(regs, &frame->sig))
		goto badframe;

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

	return regs->UCreg_00;

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

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

	err |= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
	err |= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
	err |= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
	err |= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
	err |= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
	err |= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
	err |= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
	err |= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
	err |= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
	err |= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
	err |= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
	err |= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
	err |= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
	err |= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
	err |= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
	err |= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
	err |= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
	err |= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
	err |= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
	err |= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
	err |= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
	err |= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
	err |= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
	err |= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
	err |= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
	err |= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
	err |= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
	err |= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
	err |= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
	err |= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
	err |= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
	err |= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
	err |= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);

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

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

	return err;
}

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

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

	/*
	 * ATPCS B01 mandates 8-byte alignment
	 */
	frame = (void __user *)((sp - framesize) & ~7);

	/*
	 * Check that we can actually write to the signal frame.
	 */
	if (!access_ok(VERIFY_WRITE, frame, framesize))
		frame = NULL;

	return frame;
}

static int setup_return(struct pt_regs *regs, struct k_sigaction *ka,
	     unsigned long __user *rc, void __user *frame, int usig)
{
	unsigned long handler = (unsigned long)ka->sa.sa_handler;
	unsigned long retcode;
	unsigned long asr = regs->UCreg_asr & ~PSR_f;

	unsigned int idx = 0;

	if (ka->sa.sa_flags & SA_SIGINFO)
		idx += 1;

	if (__put_user(sigreturn_codes[idx],   rc) ||
	    __put_user(sigreturn_codes[idx+1], rc+1))
		return 1;

	retcode = KERN_SIGRETURN_CODE + (idx << 2);

	regs->UCreg_00 = usig;
	regs->UCreg_sp = (unsigned long)frame;
	regs->UCreg_lr = retcode;
	regs->UCreg_pc = handler;
	regs->UCreg_asr = asr;

	return 0;
}

static int setup_frame(int usig, struct k_sigaction *ka,
		sigset_t *set, struct pt_regs *regs)
{
	struct sigframe __user *frame = get_sigframe(ka, regs, sizeof(*frame));
	int err = 0;

	if (!frame)
		return 1;

	/*
	 * Set uc.uc_flags to a value which sc.trap_no would never have.
	 */
	err |= __put_user(0x5ac3c35a, &frame->uc.uc_flags);

	err |= setup_sigframe(frame, regs, set);
	if (err == 0)
		err |= setup_return(regs, ka, frame->retcode, frame, usig);

	return err;
}

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

	if (!frame)
		return 1;

	err |= copy_siginfo_to_user(&frame->info, info);

	err |= __put_user(0, &frame->sig.uc.uc_flags);
	err |= __put_user(NULL, &frame->sig.uc.uc_link);
	err |= __save_altstack(&frame->sig.uc.uc_stack, regs->UCreg_sp);
	err |= setup_sigframe(&frame->sig, regs, set);
	if (err == 0)
		err |= setup_return(regs, ka, frame->sig.retcode, frame, usig);

	if (err == 0) {
		/*
		 * For realtime signals we must also set the second and third
		 * arguments for the signal handler.
		 */
		regs->UCreg_01 = (unsigned long)&frame->info;
		regs->UCreg_02 = (unsigned long)&frame->sig.uc;
	}

	return err;
}

static inline void setup_syscall_restart(struct pt_regs *regs)
{
	regs->UCreg_00 = regs->UCreg_ORIG_00;
	regs->UCreg_pc -= 4;
}

/*
 * OK, we're invoking a handler
 */
static void handle_signal(unsigned long sig, struct k_sigaction *ka,
	      siginfo_t *info, struct pt_regs *regs, int syscall)
{
	struct thread_info *thread = current_thread_info();
	struct task_struct *tsk = current;
	sigset_t *oldset = sigmask_to_save();
	int usig = sig;
	int ret;

	/*
	 * If we were from a system call, check for system call restarting...
	 */
	if (syscall) {
		switch (regs->UCreg_00) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			regs->UCreg_00 = -EINTR;
			break;
		case -ERESTARTSYS:
			if (!(ka->sa.sa_flags & SA_RESTART)) {
				regs->UCreg_00 = -EINTR;
				break;
			}
			/* fallthrough */
		case -ERESTARTNOINTR:
			setup_syscall_restart(regs);
		}
	}

	/*
	 * translate the signal
	 */
	if (usig < 32 && thread->exec_domain
			&& thread->exec_domain->signal_invmap)
		usig = thread->exec_domain->signal_invmap[usig];

	/*
	 * Set up the stack frame
	 */
	if (ka->sa.sa_flags & SA_SIGINFO)
		ret = setup_rt_frame(usig, ka, info, oldset, regs);
	else
		ret = setup_frame(usig, ka, oldset, regs);

	/*
	 * Check that the resulting registers are actually sane.
	 */
	ret |= !valid_user_regs(regs);

	if (ret != 0) {
		force_sigsegv(sig, tsk);
		return;
	}

	signal_delivered(sig, info, ka, regs, 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, int syscall)
{
	struct k_sigaction ka;
	siginfo_t info;
	int signr;

	/*
	 * 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;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		handle_signal(signr, &ka, &info, regs, syscall);
		return;
	}

	/*
	 * No signal to deliver to the process - restart the syscall.
	 */
	if (syscall) {
		if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) {
				u32 __user *usp;

				regs->UCreg_sp -= 4;
				usp = (u32 __user *)regs->UCreg_sp;

				if (put_user(regs->UCreg_pc, usp) == 0) {
					regs->UCreg_pc = KERN_RESTART_CODE;
				} else {
					regs->UCreg_sp += 4;
					force_sigsegv(0, current);
				}
		}
		if (regs->UCreg_00 == -ERESTARTNOHAND ||
		    regs->UCreg_00 == -ERESTARTSYS ||
		    regs->UCreg_00 == -ERESTARTNOINTR) {
			setup_syscall_restart(regs);
		}
	}
	/* If there's no signal to deliver, we just put the saved
	 * sigmask back.
	 */
	restore_saved_sigmask();
}

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

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

/*
 * Copy signal return handlers into the vector page, and
 * set sigreturn to be a pointer to these.
 */
void __init early_signal_init(void)
{
	memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE),
			sigreturn_codes, sizeof(sigreturn_codes));
	memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE),
			syscall_restart_code, sizeof(syscall_restart_code));
	/* Need not to flush icache, since early_trap_init will do it last. */
}
Commit	Line	Data
f864d2f8 G	1	/*
	2	* linux/arch/unicore32/kernel/signal.c
	3	*
	4	* Code specific to PKUnity SoC and UniCore ISA
	5	*
	6	* Copyright (C) 2001-2010 GUAN Xue-tao
	7	*
	8	* This program is free software; you can redistribute it and/or modify
	9	* it under the terms of the GNU General Public License version 2 as
	10	* published by the Free Software Foundation.
	11	*/
	12	#include <linux/errno.h>
	13	#include <linux/signal.h>
	14	#include <linux/personality.h>
f864d2f8 G	15	#include <linux/uaccess.h>
	16	#include <linux/tracehook.h>
	17	#include <linux/elf.h>
	18	#include <linux/unistd.h>
	19
	20	#include <asm/cacheflush.h>
	21	#include <asm/ucontext.h>
	22
f864d2f8 G	23	/*
	24	* For UniCore syscalls, we encode the syscall number into the instruction.
	25	*/
	26	#define SWI_SYS_SIGRETURN (0xff000000) /* error number for new abi */
	27	#define SWI_SYS_RT_SIGRETURN (0xff000000 \| (__NR_rt_sigreturn))
	28	#define SWI_SYS_RESTART (0xff000000 \| (__NR_restart_syscall))
	29
	30	#define KERN_SIGRETURN_CODE (KUSER_VECPAGE_BASE + 0x00000500)
	31	#define KERN_RESTART_CODE (KERN_SIGRETURN_CODE + sizeof(sigreturn_codes))
	32
	33	const unsigned long sigreturn_codes[3] = {
	34	SWI_SYS_SIGRETURN, SWI_SYS_RT_SIGRETURN,
	35	};
	36
	37	const unsigned long syscall_restart_code[2] = {
	38	SWI_SYS_RESTART, /* swi __NR_restart_syscall */
	39	0x69efc004, /* ldr pc, [sp], #4 */
	40	};
	41
	42	/*
	43	* Do a signal return; undo the signal stack. These are aligned to 64-bit.
	44	*/
	45	struct sigframe {
	46	struct ucontext uc;
	47	unsigned long retcode[2];
	48	};
	49
	50	struct rt_sigframe {
	51	struct siginfo info;
	52	struct sigframe sig;
	53	};
	54
	55	static int restore_sigframe(struct pt_regs regs, struct sigframe __user sf)
	56	{
	57	sigset_t set;
	58	int err;
	59
	60	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
77097ae5	61	if (err == 0)
7037bd80	62	set_current_blocked(&set);
f864d2f8 G	63
	64	err \|= __get_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
	65	err \|= __get_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
	66	err \|= __get_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
	67	err \|= __get_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
	68	err \|= __get_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
	69	err \|= __get_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
	70	err \|= __get_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
	71	err \|= __get_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
	72	err \|= __get_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
	73	err \|= __get_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
	74	err \|= __get_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
	75	err \|= __get_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
	76	err \|= __get_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
	77	err \|= __get_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
	78	err \|= __get_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
	79	err \|= __get_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
	80	err \|= __get_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
	81	err \|= __get_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
	82	err \|= __get_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
	83	err \|= __get_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
	84	err \|= __get_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
	85	err \|= __get_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
	86	err \|= __get_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
	87	err \|= __get_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
	88	err \|= __get_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
	89	err \|= __get_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
	90	err \|= __get_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
	91	err \|= __get_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
	92	err \|= __get_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
	93	err \|= __get_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
	94	err \|= __get_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
	95	err \|= __get_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
	96	err \|= __get_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);
	97
	98	err \|= !valid_user_regs(regs);
	99
	100	return err;
	101	}
	102
	103	asmlinkage int __sys_rt_sigreturn(struct pt_regs *regs)
	104	{
	105	struct rt_sigframe __user *frame;
	106
	107	/* Always make any pending restarted system calls return -EINTR */
	108	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	109
	110	/*
	111	* Since we stacked the signal on a 64-bit boundary,
	112	* then 'sp' should be word aligned here. If it's
	113	* not, then the user is trying to mess with us.
	114	*/
	115	if (regs->UCreg_sp & 7)
	116	goto badframe;
	117
	118	frame = (struct rt_sigframe __user *)regs->UCreg_sp;
	119
	120	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	121	goto badframe;
	122
	123	if (restore_sigframe(regs, &frame->sig))
	124	goto badframe;
	125
50b3c9e3	126	if (restore_altstack(&frame->sig.uc.uc_stack))
f864d2f8 G	127	goto badframe;
	128
	129	return regs->UCreg_00;
	130
	131	badframe:
	132	force_sig(SIGSEGV, current);
	133	return 0;
	134	}
	135
	136	static int setup_sigframe(struct sigframe __user sf, struct pt_regs regs,
	137	sigset_t *set)
	138	{
	139	int err = 0;
	140
	141	err \|= __put_user(regs->UCreg_00, &sf->uc.uc_mcontext.regs.UCreg_00);
	142	err \|= __put_user(regs->UCreg_01, &sf->uc.uc_mcontext.regs.UCreg_01);
	143	err \|= __put_user(regs->UCreg_02, &sf->uc.uc_mcontext.regs.UCreg_02);
	144	err \|= __put_user(regs->UCreg_03, &sf->uc.uc_mcontext.regs.UCreg_03);
	145	err \|= __put_user(regs->UCreg_04, &sf->uc.uc_mcontext.regs.UCreg_04);
	146	err \|= __put_user(regs->UCreg_05, &sf->uc.uc_mcontext.regs.UCreg_05);
	147	err \|= __put_user(regs->UCreg_06, &sf->uc.uc_mcontext.regs.UCreg_06);
	148	err \|= __put_user(regs->UCreg_07, &sf->uc.uc_mcontext.regs.UCreg_07);
	149	err \|= __put_user(regs->UCreg_08, &sf->uc.uc_mcontext.regs.UCreg_08);
	150	err \|= __put_user(regs->UCreg_09, &sf->uc.uc_mcontext.regs.UCreg_09);
	151	err \|= __put_user(regs->UCreg_10, &sf->uc.uc_mcontext.regs.UCreg_10);
	152	err \|= __put_user(regs->UCreg_11, &sf->uc.uc_mcontext.regs.UCreg_11);
	153	err \|= __put_user(regs->UCreg_12, &sf->uc.uc_mcontext.regs.UCreg_12);
	154	err \|= __put_user(regs->UCreg_13, &sf->uc.uc_mcontext.regs.UCreg_13);
	155	err \|= __put_user(regs->UCreg_14, &sf->uc.uc_mcontext.regs.UCreg_14);
	156	err \|= __put_user(regs->UCreg_15, &sf->uc.uc_mcontext.regs.UCreg_15);
	157	err \|= __put_user(regs->UCreg_16, &sf->uc.uc_mcontext.regs.UCreg_16);
	158	err \|= __put_user(regs->UCreg_17, &sf->uc.uc_mcontext.regs.UCreg_17);
	159	err \|= __put_user(regs->UCreg_18, &sf->uc.uc_mcontext.regs.UCreg_18);
	160	err \|= __put_user(regs->UCreg_19, &sf->uc.uc_mcontext.regs.UCreg_19);
	161	err \|= __put_user(regs->UCreg_20, &sf->uc.uc_mcontext.regs.UCreg_20);
	162	err \|= __put_user(regs->UCreg_21, &sf->uc.uc_mcontext.regs.UCreg_21);
	163	err \|= __put_user(regs->UCreg_22, &sf->uc.uc_mcontext.regs.UCreg_22);
	164	err \|= __put_user(regs->UCreg_23, &sf->uc.uc_mcontext.regs.UCreg_23);
	165	err \|= __put_user(regs->UCreg_24, &sf->uc.uc_mcontext.regs.UCreg_24);
	166	err \|= __put_user(regs->UCreg_25, &sf->uc.uc_mcontext.regs.UCreg_25);
	167	err \|= __put_user(regs->UCreg_26, &sf->uc.uc_mcontext.regs.UCreg_26);
	168	err \|= __put_user(regs->UCreg_fp, &sf->uc.uc_mcontext.regs.UCreg_fp);
	169	err \|= __put_user(regs->UCreg_ip, &sf->uc.uc_mcontext.regs.UCreg_ip);
	170	err \|= __put_user(regs->UCreg_sp, &sf->uc.uc_mcontext.regs.UCreg_sp);
	171	err \|= __put_user(regs->UCreg_lr, &sf->uc.uc_mcontext.regs.UCreg_lr);
	172	err \|= __put_user(regs->UCreg_pc, &sf->uc.uc_mcontext.regs.UCreg_pc);
	173	err \|= __put_user(regs->UCreg_asr, &sf->uc.uc_mcontext.regs.UCreg_asr);
	174
	175	err \|= __put_user(current->thread.trap_no,
	176	&sf->uc.uc_mcontext.trap_no);
	177	err \|= __put_user(current->thread.error_code,
	178	&sf->uc.uc_mcontext.error_code);
	179	err \|= __put_user(current->thread.address,
	180	&sf->uc.uc_mcontext.fault_address);
	181	err \|= __put_user(set->sig[0], &sf->uc.uc_mcontext.oldmask);
	182
	183	err \|= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
	184
	185	return err;
	186	}
	187
	188	static inline void __user get_sigframe(struct k_sigaction ka,
	189	struct pt_regs *regs, int framesize)
	190	{
191	unsigned long sp = regs->UCreg_sp;
192	void __user *frame;
193
194	/*
195	* This is the X/Open sanctioned signal stack switching.
196	*/
197	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
198	sp = current->sas_ss_sp + current->sas_ss_size;
199
200	/*
201	* ATPCS B01 mandates 8-byte alignment
202	*/
203	frame = (void __user *)((sp - framesize) & ~7);
204
205	/*
206	* Check that we can actually write to the signal frame.
207	*/
208	if (!access_ok(VERIFY_WRITE, frame, framesize))
209	frame = NULL;
210
211	return frame;
212	}
213
214	static int setup_return(struct pt_regs regs, struct k_sigaction ka,
215	unsigned long __user rc, void __user frame, int usig)
216	{
217	unsigned long handler = (unsigned long)ka->sa.sa_handler;
218	unsigned long retcode;
219	unsigned long asr = regs->UCreg_asr & ~PSR_f;
220
221	unsigned int idx = 0;
222
223	if (ka->sa.sa_flags & SA_SIGINFO)
224	idx += 1;
225
226	if (__put_user(sigreturn_codes[idx], rc) \|\|
227	__put_user(sigreturn_codes[idx+1], rc+1))
228	return 1;
229
230	retcode = KERN_SIGRETURN_CODE + (idx << 2);
231
232	regs->UCreg_00 = usig;
233	regs->UCreg_sp = (unsigned long)frame;
234	regs->UCreg_lr = retcode;
235	regs->UCreg_pc = handler;
236	regs->UCreg_asr = asr;
237
238	return 0;
239	}
240
241	static int setup_frame(int usig, struct k_sigaction *ka,
242	sigset_t set, struct pt_regs regs)
243	{
244	struct sigframe __user frame = get_sigframe(ka, regs, sizeof(frame));
245	int err = 0;
246
247	if (!frame)
248	return 1;
249
250	/*
251	* Set uc.uc_flags to a value which sc.trap_no would never have.
252	*/
253	err \|= __put_user(0x5ac3c35a, &frame->uc.uc_flags);
254
255	err \|= setup_sigframe(frame, regs, set);
256	if (err == 0)
257	err \|= setup_return(regs, ka, frame->retcode, frame, usig);
258
259	return err;
260	}
261
262	static int setup_rt_frame(int usig, struct k_sigaction ka, siginfo_t info,
263	sigset_t set, struct pt_regs regs)
264	{
265	struct rt_sigframe __user *frame =
266	get_sigframe(ka, regs, sizeof(*frame));
f864d2f8 G	267	int err = 0;
	268
	269	if (!frame)
	270	return 1;
	271
	272	err \|= copy_siginfo_to_user(&frame->info, info);
	273
	274	err \|= __put_user(0, &frame->sig.uc.uc_flags);
	275	err \|= __put_user(NULL, &frame->sig.uc.uc_link);
50b3c9e3	276	err \|= __save_altstack(&frame->sig.uc.uc_stack, regs->UCreg_sp);
f864d2f8 G	277	err \|= setup_sigframe(&frame->sig, regs, set);
	278	if (err == 0)
	279	err \|= setup_return(regs, ka, frame->sig.retcode, frame, usig);
	280
	281	if (err == 0) {
	282	/*
	283	* For realtime signals we must also set the second and third
	284	* arguments for the signal handler.
	285	*/
	286	regs->UCreg_01 = (unsigned long)&frame->info;
	287	regs->UCreg_02 = (unsigned long)&frame->sig.uc;
	288	}
	289
	290	return err;
	291	}
	292
	293	static inline void setup_syscall_restart(struct pt_regs *regs)
	294	{
	295	regs->UCreg_00 = regs->UCreg_ORIG_00;
	296	regs->UCreg_pc -= 4;
	297	}
	298
	299	/*
	300	* OK, we're invoking a handler
	301	*/
a610d6e6	302	static void handle_signal(unsigned long sig, struct k_sigaction *ka,
b7f9a11a	303	siginfo_t info, struct pt_regs regs, int syscall)
f864d2f8 G	304	{
	305	struct thread_info *thread = current_thread_info();
	306	struct task_struct *tsk = current;
b7f9a11a	307	sigset_t *oldset = sigmask_to_save();
f864d2f8 G	308	int usig = sig;
	309	int ret;
	310
	311	/*
	312	* If we were from a system call, check for system call restarting...
	313	*/
	314	if (syscall) {
	315	switch (regs->UCreg_00) {
	316	case -ERESTART_RESTARTBLOCK:
	317	case -ERESTARTNOHAND:
	318	regs->UCreg_00 = -EINTR;
	319	break;
	320	case -ERESTARTSYS:
	321	if (!(ka->sa.sa_flags & SA_RESTART)) {
	322	regs->UCreg_00 = -EINTR;
	323	break;
	324	}
	325	/* fallthrough */
	326	case -ERESTARTNOINTR:
	327	setup_syscall_restart(regs);
	328	}
	329	}
	330
	331	/*
	332	* translate the signal
	333	*/
	334	if (usig < 32 && thread->exec_domain
	335	&& thread->exec_domain->signal_invmap)
	336	usig = thread->exec_domain->signal_invmap[usig];
	337
	338	/*
	339	* Set up the stack frame
	340	*/
	341	if (ka->sa.sa_flags & SA_SIGINFO)
	342	ret = setup_rt_frame(usig, ka, info, oldset, regs);
	343	else
	344	ret = setup_frame(usig, ka, oldset, regs);
	345
	346	/*
	347	* Check that the resulting registers are actually sane.
	348	*/
	349	ret \|= !valid_user_regs(regs);
	350
	351	if (ret != 0) {
	352	force_sigsegv(sig, tsk);
a610d6e6	353	return;
f864d2f8 G	354	}
f864d2f8 G	355
efee984c	356	signal_delivered(sig, info, ka, regs, 0);
f864d2f8 G	357	}
	358
	359	/*
	360	* Note that 'init' is a special process: it doesn't get signals it doesn't
	361	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	362	* mistake.
	363	*
	364	* Note that we go through the signals twice: once to check the signals that
	365	* the kernel can handle, and then we build all the user-level signal handling
	366	* stack-frames in one go after that.
	367	*/
	368	static void do_signal(struct pt_regs *regs, int syscall)
	369	{
	370	struct k_sigaction ka;
	371	siginfo_t info;
	372	int signr;
	373
	374	/*
	375	* We want the common case to go fast, which
	376	* is why we may in certain cases get here from
	377	* kernel mode. Just return without doing anything
	378	* if so.
	379	*/
	380	if (!user_mode(regs))
	381	return;
	382
f864d2f8 G	383	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
f864d2f8 G	384	if (signr > 0) {
a610d6e6	385	handle_signal(signr, &ka, &info, regs, syscall);
f864d2f8 G	386	return;
	387	}
	388
f864d2f8 G	389	/*
	390	* No signal to deliver to the process - restart the syscall.
	391	*/
	392	if (syscall) {
	393	if (regs->UCreg_00 == -ERESTART_RESTARTBLOCK) {
	394	u32 __user *usp;
	395
	396	regs->UCreg_sp -= 4;
	397	usp = (u32 __user *)regs->UCreg_sp;
	398
	399	if (put_user(regs->UCreg_pc, usp) == 0) {
	400	regs->UCreg_pc = KERN_RESTART_CODE;
	401	} else {
	402	regs->UCreg_sp += 4;
	403	force_sigsegv(0, current);
	404	}
	405	}
	406	if (regs->UCreg_00 == -ERESTARTNOHAND \|\|
	407	regs->UCreg_00 == -ERESTARTSYS \|\|
	408	regs->UCreg_00 == -ERESTARTNOINTR) {
	409	setup_syscall_restart(regs);
	410	}
f864d2f8	411	}
415d04d0 AV	412	/* If there's no signal to deliver, we just put the saved
	413	* sigmask back.
	414	*/
51a7b448	415	restore_saved_sigmask();
f864d2f8 G	416	}
	417
	418	asmlinkage void do_notify_resume(struct pt_regs *regs,
	419	unsigned int thread_flags, int syscall)
	420	{
	421	if (thread_flags & _TIF_SIGPENDING)
	422	do_signal(regs, syscall);
	423
	424	if (thread_flags & _TIF_NOTIFY_RESUME) {
	425	clear_thread_flag(TIF_NOTIFY_RESUME);
	426	tracehook_notify_resume(regs);
f864d2f8 G	427	}
	428	}
	429
	430	/*
	431	* Copy signal return handlers into the vector page, and
	432	* set sigreturn to be a pointer to these.
	433	*/
	434	void __init early_signal_init(void)
	435	{
	436	memcpy((void *)kuser_vecpage_to_vectors(KERN_SIGRETURN_CODE),
	437	sigreturn_codes, sizeof(sigreturn_codes));
	438	memcpy((void *)kuser_vecpage_to_vectors(KERN_RESTART_CODE),
	439	syscall_restart_code, sizeof(syscall_restart_code));
	440	/* Need not to flush icache, since early_trap_init will do it last. */
	441	}