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

/*
 *  linux/arch/arm/kernel/signal.c
 *
 *  Copyright (C) 1995-2002 Russell King
 *
 * 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/config.h>
#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/ptrace.h>
#include <linux/personality.h>

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

#include "ptrace.h"
#include "signal.h"

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

/*
 * For ARM syscalls, we encode the syscall number into the instruction.
 */
#define SWI_SYS_SIGRETURN	(0xef000000|(__NR_sigreturn))
#define SWI_SYS_RT_SIGRETURN	(0xef000000|(__NR_rt_sigreturn))

/*
 * With EABI, the syscall number has to be loaded into r7.
 */
#define MOV_R7_NR_SIGRETURN	(0xe3a07000 | (__NR_sigreturn - __NR_SYSCALL_BASE))
#define MOV_R7_NR_RT_SIGRETURN	(0xe3a07000 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))

/*
 * For Thumb syscalls, we pass the syscall number via r7.  We therefore
 * need two 16-bit instructions.
 */
#define SWI_THUMB_SIGRETURN	(0xdf00 << 16 | 0x2700 | (__NR_sigreturn - __NR_SYSCALL_BASE))
#define SWI_THUMB_RT_SIGRETURN	(0xdf00 << 16 | 0x2700 | (__NR_rt_sigreturn - __NR_SYSCALL_BASE))

const unsigned long sigreturn_codes[7] = {
	MOV_R7_NR_SIGRETURN,    SWI_SYS_SIGRETURN,    SWI_THUMB_SIGRETURN,
	MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
};

static int do_signal(sigset_t *oldset, struct pt_regs * regs, int syscall);

/*
 * atomically swap in the new signal mask, and wait for a signal.
 */
asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
{
	sigset_t saveset;

	mask &= _BLOCKABLE;
	spin_lock_irq(&current->sighand->siglock);
	saveset = current->blocked;
	siginitset(&current->blocked, mask);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	regs->ARM_r0 = -EINTR;

	while (1) {
		current->state = TASK_INTERRUPTIBLE;
		schedule();
		if (do_signal(&saveset, regs, 0))
			return regs->ARM_r0;
	}
}

asmlinkage int
sys_rt_sigsuspend(sigset_t __user *unewset, size_t sigsetsize, struct pt_regs *regs)
{
	sigset_t saveset, newset;

	/* XXX: Don't preclude handling different sized sigset_t's. */
	if (sigsetsize != sizeof(sigset_t))
		return -EINVAL;

	if (copy_from_user(&newset, unewset, sizeof(newset)))
		return -EFAULT;
	sigdelsetmask(&newset, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);
	saveset = current->blocked;
	current->blocked = newset;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
	regs->ARM_r0 = -EINTR;

	while (1) {
		current->state = TASK_INTERRUPTIBLE;
		schedule();
		if (do_signal(&saveset, regs, 0))
			return regs->ARM_r0;
	}
}

asmlinkage int 
sys_sigaction(int sig, const struct old_sigaction __user *act,
	      struct old_sigaction __user *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

	if (act) {
		old_sigset_t mask;
		if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
		    __get_user(new_ka.sa.sa_handler, &act->sa_handler) ||
		    __get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
			return -EFAULT;
		__get_user(new_ka.sa.sa_flags, &act->sa_flags);
		__get_user(mask, &act->sa_mask);
		siginitset(&new_ka.sa.sa_mask, mask);
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);

	if (!ret && oact) {
		if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) ||
		    __put_user(old_ka.sa.sa_handler, &oact->sa_handler) ||
		    __put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
			return -EFAULT;
		__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
	}

	return ret;
}

#ifdef CONFIG_IWMMXT

/* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */
#define IWMMXT_STORAGE_SIZE	(0x98 + 8)
#define IWMMXT_MAGIC0		0x12ef842a
#define IWMMXT_MAGIC1		0x1c07ca71

struct iwmmxt_sigframe {
	unsigned long	magic0;
	unsigned long	magic1;
	unsigned long	storage[0x98/4];
};

static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
{
	char kbuf[sizeof(*frame) + 8];
	struct iwmmxt_sigframe *kframe;

	/* the iWMMXt context must be 64 bit aligned */
	kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
	kframe->magic0 = IWMMXT_MAGIC0;
	kframe->magic1 = IWMMXT_MAGIC1;
	iwmmxt_task_copy(current_thread_info(), &kframe->storage);
	return __copy_to_user(frame, kframe, sizeof(*frame));
}

static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
{
	char kbuf[sizeof(*frame) + 8];
	struct iwmmxt_sigframe *kframe;

	/* the iWMMXt context must be 64 bit aligned */
	kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
	if (__copy_from_user(kframe, frame, sizeof(*frame)))
		return -1;
	if (kframe->magic0 != IWMMXT_MAGIC0 ||
	    kframe->magic1 != IWMMXT_MAGIC1)
		return -1;
	iwmmxt_task_restore(current_thread_info(), &kframe->storage);
	return 0;
}

#endif

/*
 * Auxiliary signal frame.  This saves stuff like FP state.
 * The layout of this structure is not part of the user ABI.
 */
struct aux_sigframe {
#ifdef CONFIG_IWMMXT
	struct iwmmxt_sigframe	iwmmxt;
#endif
#ifdef CONFIG_VFP
	union vfp_state		vfp;
#endif
};

/*
 * Do a signal return; undo the signal stack.  These are aligned to 64-bit.
 */
struct sigframe {
	struct ucontext uc;
	unsigned long retcode[2];
	struct aux_sigframe aux __attribute__((aligned(8)));
};

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) {
		sigdelsetmask(&set, ~_BLOCKABLE);
		spin_lock_irq(&current->sighand->siglock);
		current->blocked = set;
		recalc_sigpending();
		spin_unlock_irq(&current->sighand->siglock);
	}

	__get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
	__get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
	__get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
	__get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
	__get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
	__get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
	__get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
	__get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
	__get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
	__get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
	__get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
	__get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
	__get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
	__get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
	__get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
	__get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
	__get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);

	err |= !valid_user_regs(regs);

#ifdef CONFIG_IWMMXT
	if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
		err |= restore_iwmmxt_context(&sf->aux.iwmmxt);
#endif
#ifdef CONFIG_VFP
//	if (err == 0)
//		err |= vfp_restore_state(&sf->aux.vfp);
#endif

	return err;
}

asmlinkage int sys_sigreturn(struct pt_regs *regs)
{
	struct 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->ARM_sp & 7)
		goto badframe;

	frame = (struct sigframe __user *)regs->ARM_sp;

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

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

	/* Send SIGTRAP if we're single-stepping */
	if (current->ptrace & PT_SINGLESTEP) {
		ptrace_cancel_bpt(current);
		send_sig(SIGTRAP, current, 1);
	}

	return regs->ARM_r0;

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

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->ARM_sp & 7)
		goto badframe;

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

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

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

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

	/* Send SIGTRAP if we're single-stepping */
	if (current->ptrace & PT_SINGLESTEP) {
		ptrace_cancel_bpt(current);
		send_sig(SIGTRAP, current, 1);
	}

	return regs->ARM_r0;

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;

	__put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
	__put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
	__put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
	__put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
	__put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
	__put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
	__put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
	__put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
	__put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
	__put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
	__put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
	__put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
	__put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
	__put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
	__put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
	__put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
	__put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);

	__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));

#ifdef CONFIG_IWMMXT
	if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
		err |= preserve_iwmmxt_context(&sf->aux.iwmmxt);
#endif
#ifdef CONFIG_VFP
//	if (err == 0)
//		err |= vfp_save_state(&sf->aux.vfp);
#endif

	return err;
}

static inline void __user *
get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, int framesize)
{
	unsigned long sp = regs->ARM_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;
	int thumb = 0;
	unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;

	/*
	 * Maybe we need to deliver a 32-bit signal to a 26-bit task.
	 */
	if (ka->sa.sa_flags & SA_THIRTYTWO)
		cpsr = (cpsr & ~MODE_MASK) | USR_MODE;

#ifdef CONFIG_ARM_THUMB
	if (elf_hwcap & HWCAP_THUMB) {
		/*
		 * The LSB of the handler determines if we're going to
		 * be using THUMB or ARM mode for this signal handler.
		 */
		thumb = handler & 1;

		if (thumb)
			cpsr |= PSR_T_BIT;
		else
			cpsr &= ~PSR_T_BIT;
	}
#endif

	if (ka->sa.sa_flags & SA_RESTORER) {
		retcode = (unsigned long)ka->sa.sa_restorer;
	} else {
		unsigned int idx = thumb << 1;

		if (ka->sa.sa_flags & SA_SIGINFO)
			idx += 3;

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

		if (cpsr & MODE32_BIT) {
			/*
			 * 32-bit code can use the new high-page
			 * signal return code support.
			 */
			retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
		} else {
			/*
			 * Ensure that the instruction cache sees
			 * the return code written onto the stack.
			 */
			flush_icache_range((unsigned long)rc,
					   (unsigned long)(rc + 2));

			retcode = ((unsigned long)rc) + thumb;
		}
	}

	regs->ARM_r0 = usig;
	regs->ARM_sp = (unsigned long)frame;
	regs->ARM_lr = retcode;
	regs->ARM_pc = handler;
	regs->ARM_cpsr = cpsr;

	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;

	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));
	stack_t stack;
	int err = 0;

	if (!frame)
		return 1;

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

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

	memset(&stack, 0, sizeof(stack));
	stack.ss_sp = (void __user *)current->sas_ss_sp;
	stack.ss_flags = sas_ss_flags(regs->ARM_sp);
	stack.ss_size = current->sas_ss_size;
	err |= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));

	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.
		 *   -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
		 */
		regs->ARM_r1 = (unsigned long)&frame->info;
		regs->ARM_r2 = (unsigned long)&frame->sig.uc;
	}

	return err;
}

static inline void restart_syscall(struct pt_regs *regs)
{
	regs->ARM_r0 = regs->ARM_ORIG_r0;
	regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
}

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

	/*
	 * If we were from a system call, check for system call restarting...
	 */
	if (syscall) {
		switch (regs->ARM_r0) {
		case -ERESTART_RESTARTBLOCK:
		case -ERESTARTNOHAND:
			regs->ARM_r0 = -EINTR;
			break;
		case -ERESTARTSYS:
			if (!(ka->sa.sa_flags & SA_RESTART)) {
				regs->ARM_r0 = -EINTR;
				break;
			}
			/* fallthrough */
		case -ERESTARTNOINTR:
			restart_syscall(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;
	}

	/*
	 * Block the signal if we were successful.
	 */
	spin_lock_irq(&tsk->sighand->siglock);
	sigorsets(&tsk->blocked, &tsk->blocked,
		  &ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NODEFER))
		sigaddset(&tsk->blocked, sig);
	recalc_sigpending();
	spin_unlock_irq(&tsk->sighand->siglock);

}

/*
 * 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 int do_signal(sigset_t *oldset, 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 0;

	if (try_to_freeze())
		goto no_signal;

	if (current->ptrace & PT_SINGLESTEP)
		ptrace_cancel_bpt(current);

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		handle_signal(signr, &ka, &info, oldset, regs, syscall);
		if (current->ptrace & PT_SINGLESTEP)
			ptrace_set_bpt(current);
		return 1;
	}

 no_signal:
	/*
	 * No signal to deliver to the process - restart the syscall.
	 */
	if (syscall) {
		if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
			if (thumb_mode(regs)) {
				regs->ARM_r7 = __NR_restart_syscall;
				regs->ARM_pc -= 2;
			} else {
				u32 __user *usp;

				regs->ARM_sp -= 12;
				usp = (u32 __user *)regs->ARM_sp;

				put_user(regs->ARM_pc, &usp[0]);
				/* swi __NR_restart_syscall */
				put_user(0xef000000 | __NR_restart_syscall, &usp[1]);
				/* ldr	pc, [sp], #12 */
				put_user(0xe49df00c, &usp[2]);

				flush_icache_range((unsigned long)usp,
						   (unsigned long)(usp + 3));

				regs->ARM_pc = regs->ARM_sp + 4;
			}
		}
		if (regs->ARM_r0 == -ERESTARTNOHAND ||
		    regs->ARM_r0 == -ERESTARTSYS ||
		    regs->ARM_r0 == -ERESTARTNOINTR) {
			restart_syscall(regs);
		}
	}
	if (current->ptrace & PT_SINGLESTEP)
		ptrace_set_bpt(current);
	return 0;
}

asmlinkage void
do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
{
	if (thread_flags & _TIF_SIGPENDING)
		do_signal(&current->blocked, regs, syscall);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/arm/kernel/signal.c
	3	*
	4	* Copyright (C) 1995-2002 Russell King
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License version 2 as
	8	* published by the Free Software Foundation.
	9	*/
	10	#include <linux/config.h>
	11	#include <linux/errno.h>
	12	#include <linux/signal.h>
	13	#include <linux/ptrace.h>
	14	#include <linux/personality.h>
	15
	16	#include <asm/cacheflush.h>
	17	#include <asm/ucontext.h>
	18	#include <asm/uaccess.h>
	19	#include <asm/unistd.h>
	20
	21	#include "ptrace.h"
e00d349e	22	#include "signal.h"
1da177e4 LT	23
	24	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	25
	26	/*
	27	* For ARM syscalls, we encode the syscall number into the instruction.
	28	*/
	29	#define SWI_SYS_SIGRETURN (0xef000000\|(__NR_sigreturn))
	30	#define SWI_SYS_RT_SIGRETURN (0xef000000\|(__NR_rt_sigreturn))
	31
fcca538b NP	32	/*
	33	* With EABI, the syscall number has to be loaded into r7.
	34	*/
	35	#define MOV_R7_NR_SIGRETURN (0xe3a07000 \| (__NR_sigreturn - __NR_SYSCALL_BASE))
	36	#define MOV_R7_NR_RT_SIGRETURN (0xe3a07000 \| (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
	37
1da177e4 LT	38	/*
	39	* For Thumb syscalls, we pass the syscall number via r7. We therefore
	40	* need two 16-bit instructions.
	41	*/
	42	#define SWI_THUMB_SIGRETURN (0xdf00 << 16 \| 0x2700 \| (__NR_sigreturn - __NR_SYSCALL_BASE))
	43	#define SWI_THUMB_RT_SIGRETURN (0xdf00 << 16 \| 0x2700 \| (__NR_rt_sigreturn - __NR_SYSCALL_BASE))
	44
fcca538b NP	45	const unsigned long sigreturn_codes[7] = {
	46	MOV_R7_NR_SIGRETURN, SWI_SYS_SIGRETURN, SWI_THUMB_SIGRETURN,
	47	MOV_R7_NR_RT_SIGRETURN, SWI_SYS_RT_SIGRETURN, SWI_THUMB_RT_SIGRETURN,
1da177e4 LT	48	};
	49
	50	static int do_signal(sigset_t oldset, struct pt_regs regs, int syscall);
	51
	52	/*
	53	* atomically swap in the new signal mask, and wait for a signal.
	54	*/
	55	asmlinkage int sys_sigsuspend(int restart, unsigned long oldmask, old_sigset_t mask, struct pt_regs *regs)
	56	{
	57	sigset_t saveset;
	58
	59	mask &= _BLOCKABLE;
	60	spin_lock_irq(&current->sighand->siglock);
	61	saveset = current->blocked;
	62	siginitset(&current->blocked, mask);
	63	recalc_sigpending();
	64	spin_unlock_irq(&current->sighand->siglock);
	65	regs->ARM_r0 = -EINTR;
	66
	67	while (1) {
	68	current->state = TASK_INTERRUPTIBLE;
	69	schedule();
	70	if (do_signal(&saveset, regs, 0))
	71	return regs->ARM_r0;
	72	}
	73	}
	74
	75	asmlinkage int
	76	sys_rt_sigsuspend(sigset_t __user unewset, size_t sigsetsize, struct pt_regs regs)
	77	{
	78	sigset_t saveset, newset;
	79
	80	/* XXX: Don't preclude handling different sized sigset_t's. */
	81	if (sigsetsize != sizeof(sigset_t))
	82	return -EINVAL;
	83
	84	if (copy_from_user(&newset, unewset, sizeof(newset)))
	85	return -EFAULT;
	86	sigdelsetmask(&newset, ~_BLOCKABLE);
	87
	88	spin_lock_irq(&current->sighand->siglock);
	89	saveset = current->blocked;
	90	current->blocked = newset;
	91	recalc_sigpending();
	92	spin_unlock_irq(&current->sighand->siglock);
	93	regs->ARM_r0 = -EINTR;
	94
	95	while (1) {
	96	current->state = TASK_INTERRUPTIBLE;
	97	schedule();
	98	if (do_signal(&saveset, regs, 0))
	99	return regs->ARM_r0;
	100	}
	101	}
	102
	103	asmlinkage int
	104	sys_sigaction(int sig, const struct old_sigaction __user *act,
	105	struct old_sigaction __user *oact)
	106	{
	107	struct k_sigaction new_ka, old_ka;
	108	int ret;
	109
	110	if (act) {
	111	old_sigset_t mask;
112	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
113	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
114	__get_user(new_ka.sa.sa_restorer, &act->sa_restorer))
115	return -EFAULT;
116	__get_user(new_ka.sa.sa_flags, &act->sa_flags);
117	__get_user(mask, &act->sa_mask);
118	siginitset(&new_ka.sa.sa_mask, mask);
119	}
120
121	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
122
123	if (!ret && oact) {
124	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
125	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
126	__put_user(old_ka.sa.sa_restorer, &oact->sa_restorer))
127	return -EFAULT;
128	__put_user(old_ka.sa.sa_flags, &oact->sa_flags);
129	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask);
130	}
131
132	return ret;
133	}
134
135	#ifdef CONFIG_IWMMXT
136
137	/* iwmmxt_area is 0x98 bytes long, preceeded by 8 bytes of signature */
138	#define IWMMXT_STORAGE_SIZE (0x98 + 8)
139	#define IWMMXT_MAGIC0 0x12ef842a
140	#define IWMMXT_MAGIC1 0x1c07ca71
141
142	struct iwmmxt_sigframe {
143	unsigned long magic0;
144	unsigned long magic1;
145	unsigned long storage[0x98/4];
146	};
147
1da177e4 LT	148	static int preserve_iwmmxt_context(struct iwmmxt_sigframe *frame)
1da177e4 LT	149	{
69b04754 HD	150	char kbuf[sizeof(*frame) + 8];
69b04754 HD	151	struct iwmmxt_sigframe *kframe;
1da177e4 LT	152
1da177e4 LT	153	/* the iWMMXt context must be 64 bit aligned */
69b04754 HD	154	kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
	155	kframe->magic0 = IWMMXT_MAGIC0;
	156	kframe->magic1 = IWMMXT_MAGIC1;
	157	iwmmxt_task_copy(current_thread_info(), &kframe->storage);
	158	return __copy_to_user(frame, kframe, sizeof(*frame));
1da177e4 LT	159	}
	160
	161	static int restore_iwmmxt_context(struct iwmmxt_sigframe *frame)
	162	{
69b04754 HD	163	char kbuf[sizeof(*frame) + 8];
	164	struct iwmmxt_sigframe *kframe;
	165
	166	/* the iWMMXt context must be 64 bit aligned */
	167	kframe = (struct iwmmxt_sigframe *)((unsigned long)(kbuf + 8) & ~7);
	168	if (__copy_from_user(kframe, frame, sizeof(*frame)))
	169	return -1;
	170	if (kframe->magic0 != IWMMXT_MAGIC0 \|\|
	171	kframe->magic1 != IWMMXT_MAGIC1)
	172	return -1;
	173	iwmmxt_task_restore(current_thread_info(), &kframe->storage);
	174	return 0;
1da177e4 LT	175	}
	176
	177	#endif
	178
	179	/*
	180	* Auxiliary signal frame. This saves stuff like FP state.
	181	* The layout of this structure is not part of the user ABI.
	182	*/
	183	struct aux_sigframe {
	184	#ifdef CONFIG_IWMMXT
	185	struct iwmmxt_sigframe iwmmxt;
	186	#endif
	187	#ifdef CONFIG_VFP
	188	union vfp_state vfp;
	189	#endif
	190	};
	191
	192	/*
	193	* Do a signal return; undo the signal stack. These are aligned to 64-bit.
	194	*/
	195	struct sigframe {
7d4fdc19	196	struct ucontext uc;
fcca538b	197	unsigned long retcode[2];
1da177e4 LT	198	struct aux_sigframe aux __attribute__((aligned(8)));
	199	};
	200
	201	struct rt_sigframe {
1da177e4	202	struct siginfo info;
cb3504e8	203	struct sigframe sig;
1da177e4 LT	204	};
1da177e4 LT	205
68071484	206	static int restore_sigframe(struct pt_regs regs, struct sigframe __user sf)
1da177e4	207	{
68071484 RK	208	sigset_t set;
	209	int err;
	210
	211	err = __copy_from_user(&set, &sf->uc.uc_sigmask, sizeof(set));
	212	if (err == 0) {
	213	sigdelsetmask(&set, ~_BLOCKABLE);
	214	spin_lock_irq(&current->sighand->siglock);
	215	current->blocked = set;
	216	recalc_sigpending();
	217	spin_unlock_irq(&current->sighand->siglock);
	218	}
	219
	220	__get_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
	221	__get_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
	222	__get_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
	223	__get_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
	224	__get_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
	225	__get_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
	226	__get_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
	227	__get_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
	228	__get_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
	229	__get_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
	230	__get_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
	231	__get_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
	232	__get_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
	233	__get_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
	234	__get_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
	235	__get_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
	236	__get_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
1da177e4 LT	237
	238	err \|= !valid_user_regs(regs);
	239
	240	#ifdef CONFIG_IWMMXT
	241	if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
68071484	242	err \|= restore_iwmmxt_context(&sf->aux.iwmmxt);
1da177e4 LT	243	#endif
	244	#ifdef CONFIG_VFP
	245	// if (err == 0)
68071484	246	// err \|= vfp_restore_state(&sf->aux.vfp);
1da177e4 LT	247	#endif
	248
	249	return err;
	250	}
	251
	252	asmlinkage int sys_sigreturn(struct pt_regs *regs)
	253	{
	254	struct sigframe __user *frame;
1da177e4 LT	255
	256	/* Always make any pending restarted system calls return -EINTR */
	257	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	258
	259	/*
	260	* Since we stacked the signal on a 64-bit boundary,
	261	* then 'sp' should be word aligned here. If it's
	262	* not, then the user is trying to mess with us.
	263	*/
	264	if (regs->ARM_sp & 7)
	265	goto badframe;
	266
	267	frame = (struct sigframe __user *)regs->ARM_sp;
	268
	269	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
	270	goto badframe;
1da177e4	271
68071484	272	if (restore_sigframe(regs, frame))
1da177e4 LT	273	goto badframe;
	274
	275	/* Send SIGTRAP if we're single-stepping */
	276	if (current->ptrace & PT_SINGLESTEP) {
	277	ptrace_cancel_bpt(current);
	278	send_sig(SIGTRAP, current, 1);
	279	}
	280
	281	return regs->ARM_r0;
	282
	283	badframe:
	284	force_sig(SIGSEGV, current);
	285	return 0;
	286	}
	287
	288	asmlinkage int sys_rt_sigreturn(struct pt_regs *regs)
	289	{
	290	struct rt_sigframe __user *frame;
1da177e4 LT	291
	292	/* Always make any pending restarted system calls return -EINTR */
	293	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	294
	295	/*
	296	* Since we stacked the signal on a 64-bit boundary,
	297	* then 'sp' should be word aligned here. If it's
	298	* not, then the user is trying to mess with us.
	299	*/
	300	if (regs->ARM_sp & 7)
	301	goto badframe;
	302
	303	frame = (struct rt_sigframe __user *)regs->ARM_sp;
	304
	305	if (!access_ok(VERIFY_READ, frame, sizeof (*frame)))
	306	goto badframe;
1da177e4	307
68071484	308	if (restore_sigframe(regs, &frame->sig))
1da177e4 LT	309	goto badframe;
1da177e4 LT	310
cb3504e8	311	if (do_sigaltstack(&frame->sig.uc.uc_stack, NULL, regs->ARM_sp) == -EFAULT)
1da177e4 LT	312	goto badframe;
	313
	314	/* Send SIGTRAP if we're single-stepping */
	315	if (current->ptrace & PT_SINGLESTEP) {
	316	ptrace_cancel_bpt(current);
	317	send_sig(SIGTRAP, current, 1);
	318	}
	319
	320	return regs->ARM_r0;
	321
	322	badframe:
	323	force_sig(SIGSEGV, current);
	324	return 0;
	325	}
	326
	327	static int
aca6ca10	328	setup_sigframe(struct sigframe __user sf, struct pt_regs regs, sigset_t *set)
1da177e4 LT	329	{
	330	int err = 0;
	331
aca6ca10 RK	332	__put_user_error(regs->ARM_r0, &sf->uc.uc_mcontext.arm_r0, err);
	333	__put_user_error(regs->ARM_r1, &sf->uc.uc_mcontext.arm_r1, err);
	334	__put_user_error(regs->ARM_r2, &sf->uc.uc_mcontext.arm_r2, err);
	335	__put_user_error(regs->ARM_r3, &sf->uc.uc_mcontext.arm_r3, err);
	336	__put_user_error(regs->ARM_r4, &sf->uc.uc_mcontext.arm_r4, err);
	337	__put_user_error(regs->ARM_r5, &sf->uc.uc_mcontext.arm_r5, err);
	338	__put_user_error(regs->ARM_r6, &sf->uc.uc_mcontext.arm_r6, err);
	339	__put_user_error(regs->ARM_r7, &sf->uc.uc_mcontext.arm_r7, err);
	340	__put_user_error(regs->ARM_r8, &sf->uc.uc_mcontext.arm_r8, err);
	341	__put_user_error(regs->ARM_r9, &sf->uc.uc_mcontext.arm_r9, err);
	342	__put_user_error(regs->ARM_r10, &sf->uc.uc_mcontext.arm_r10, err);
	343	__put_user_error(regs->ARM_fp, &sf->uc.uc_mcontext.arm_fp, err);
	344	__put_user_error(regs->ARM_ip, &sf->uc.uc_mcontext.arm_ip, err);
	345	__put_user_error(regs->ARM_sp, &sf->uc.uc_mcontext.arm_sp, err);
	346	__put_user_error(regs->ARM_lr, &sf->uc.uc_mcontext.arm_lr, err);
	347	__put_user_error(regs->ARM_pc, &sf->uc.uc_mcontext.arm_pc, err);
	348	__put_user_error(regs->ARM_cpsr, &sf->uc.uc_mcontext.arm_cpsr, err);
	349
	350	__put_user_error(current->thread.trap_no, &sf->uc.uc_mcontext.trap_no, err);
	351	__put_user_error(current->thread.error_code, &sf->uc.uc_mcontext.error_code, err);
	352	__put_user_error(current->thread.address, &sf->uc.uc_mcontext.fault_address, err);
	353	__put_user_error(set->sig[0], &sf->uc.uc_mcontext.oldmask, err);
	354
	355	err \|= __copy_to_user(&sf->uc.uc_sigmask, set, sizeof(*set));
1da177e4 LT	356
	357	#ifdef CONFIG_IWMMXT
	358	if (err == 0 && test_thread_flag(TIF_USING_IWMMXT))
aca6ca10	359	err \|= preserve_iwmmxt_context(&sf->aux.iwmmxt);
1da177e4 LT	360	#endif
	361	#ifdef CONFIG_VFP
	362	// if (err == 0)
aca6ca10	363	// err \|= vfp_save_state(&sf->aux.vfp);
1da177e4 LT	364	#endif
	365
	366	return err;
	367	}
	368
	369	static inline void __user *
	370	get_sigframe(struct k_sigaction ka, struct pt_regs regs, int framesize)
	371	{
	372	unsigned long sp = regs->ARM_sp;
	373	void __user *frame;
	374
	375	/*
	376	* This is the X/Open sanctioned signal stack switching.
	377	*/
	378	if ((ka->sa.sa_flags & SA_ONSTACK) && !sas_ss_flags(sp))
	379	sp = current->sas_ss_sp + current->sas_ss_size;
	380
	381	/*
	382	* ATPCS B01 mandates 8-byte alignment
	383	*/
	384	frame = (void __user *)((sp - framesize) & ~7);
	385
	386	/*
	387	* Check that we can actually write to the signal frame.
	388	*/
	389	if (!access_ok(VERIFY_WRITE, frame, framesize))
	390	frame = NULL;
	391
	392	return frame;
	393	}
	394
	395	static int
	396	setup_return(struct pt_regs regs, struct k_sigaction ka,
	397	unsigned long __user rc, void __user frame, int usig)
	398	{
	399	unsigned long handler = (unsigned long)ka->sa.sa_handler;
	400	unsigned long retcode;
	401	int thumb = 0;
	402	unsigned long cpsr = regs->ARM_cpsr & ~PSR_f;
	403
	404	/*
	405	* Maybe we need to deliver a 32-bit signal to a 26-bit task.
	406	*/
	407	if (ka->sa.sa_flags & SA_THIRTYTWO)
	408	cpsr = (cpsr & ~MODE_MASK) \| USR_MODE;
	409
	410	#ifdef CONFIG_ARM_THUMB
	411	if (elf_hwcap & HWCAP_THUMB) {
	412	/*
	413	* The LSB of the handler determines if we're going to
	414	* be using THUMB or ARM mode for this signal handler.
	415	*/
	416	thumb = handler & 1;
	417
	418	if (thumb)
	419	cpsr \|= PSR_T_BIT;
	420	else
	421	cpsr &= ~PSR_T_BIT;
	422	}
	423	#endif
	424
	425	if (ka->sa.sa_flags & SA_RESTORER) {
	426	retcode = (unsigned long)ka->sa.sa_restorer;
	427	} else {
fcca538b	428	unsigned int idx = thumb << 1;
1da177e4 LT	429
1da177e4 LT	430	if (ka->sa.sa_flags & SA_SIGINFO)
fcca538b	431	idx += 3;
1da177e4	432
fcca538b NP	433	if (__put_user(sigreturn_codes[idx], rc) \|\|
fcca538b NP	434	__put_user(sigreturn_codes[idx+1], rc+1))
1da177e4 LT	435	return 1;
1da177e4 LT	436
e00d349e RK	437	if (cpsr & MODE32_BIT) {
	438	/*
	439	* 32-bit code can use the new high-page
	440	* signal return code support.
	441	*/
	442	retcode = KERN_SIGRETURN_CODE + (idx << 2) + thumb;
	443	} else {
	444	/*
	445	* Ensure that the instruction cache sees
	446	* the return code written onto the stack.
	447	*/
	448	flush_icache_range((unsigned long)rc,
fcca538b	449	(unsigned long)(rc + 2));
e00d349e RK	450
	451	retcode = ((unsigned long)rc) + thumb;
	452	}
1da177e4 LT	453	}
	454
	455	regs->ARM_r0 = usig;
	456	regs->ARM_sp = (unsigned long)frame;
	457	regs->ARM_lr = retcode;
	458	regs->ARM_pc = handler;
	459	regs->ARM_cpsr = cpsr;
	460
	461	return 0;
	462	}
	463
	464	static int
	465	setup_frame(int usig, struct k_sigaction ka, sigset_t set, struct pt_regs *regs)
	466	{
	467	struct sigframe __user frame = get_sigframe(ka, regs, sizeof(frame));
	468	int err = 0;
	469
	470	if (!frame)
	471	return 1;
	472
aca6ca10	473	err \|= setup_sigframe(frame, regs, set);
1da177e4	474	if (err == 0)
fcca538b	475	err = setup_return(regs, ka, frame->retcode, frame, usig);
1da177e4 LT	476
	477	return err;
	478	}
	479
	480	static int
	481	setup_rt_frame(int usig, struct k_sigaction ka, siginfo_t info,
	482	sigset_t set, struct pt_regs regs)
	483	{
	484	struct rt_sigframe __user frame = get_sigframe(ka, regs, sizeof(frame));
	485	stack_t stack;
	486	int err = 0;
	487
	488	if (!frame)
	489	return 1;
	490
1da177e4 LT	491	err \|= copy_siginfo_to_user(&frame->info, info);
1da177e4 LT	492
cb3504e8 RK	493	__put_user_error(0, &frame->sig.uc.uc_flags, err);
cb3504e8 RK	494	__put_user_error(NULL, &frame->sig.uc.uc_link, err);
1da177e4 LT	495
	496	memset(&stack, 0, sizeof(stack));
	497	stack.ss_sp = (void __user *)current->sas_ss_sp;
	498	stack.ss_flags = sas_ss_flags(regs->ARM_sp);
	499	stack.ss_size = current->sas_ss_size;
cb3504e8	500	err \|= __copy_to_user(&frame->sig.uc.uc_stack, &stack, sizeof(stack));
1da177e4	501
aca6ca10	502	err \|= setup_sigframe(&frame->sig, regs, set);
1da177e4	503	if (err == 0)
cb3504e8	504	err = setup_return(regs, ka, frame->sig.retcode, frame, usig);
1da177e4 LT	505
	506	if (err == 0) {
	507	/*
	508	* For realtime signals we must also set the second and third
	509	* arguments for the signal handler.
	510	* -- Peter Maydell <pmaydell@chiark.greenend.org.uk> 2000-12-06
	511	*/
	512	regs->ARM_r1 = (unsigned long)&frame->info;
cb3504e8	513	regs->ARM_r2 = (unsigned long)&frame->sig.uc;
1da177e4 LT	514	}
	515
	516	return err;
	517	}
	518
	519	static inline void restart_syscall(struct pt_regs *regs)
	520	{
	521	regs->ARM_r0 = regs->ARM_ORIG_r0;
	522	regs->ARM_pc -= thumb_mode(regs) ? 2 : 4;
	523	}
	524
	525	/*
	526	* OK, we're invoking a handler
	527	*/
	528	static void
	529	handle_signal(unsigned long sig, struct k_sigaction *ka,
	530	siginfo_t info, sigset_t oldset,
	531	struct pt_regs * regs, int syscall)
	532	{
	533	struct thread_info *thread = current_thread_info();
	534	struct task_struct *tsk = current;
	535	int usig = sig;
	536	int ret;
	537
	538	/*
	539	* If we were from a system call, check for system call restarting...
	540	*/
	541	if (syscall) {
	542	switch (regs->ARM_r0) {
	543	case -ERESTART_RESTARTBLOCK:
	544	case -ERESTARTNOHAND:
	545	regs->ARM_r0 = -EINTR;
	546	break;
	547	case -ERESTARTSYS:
	548	if (!(ka->sa.sa_flags & SA_RESTART)) {
	549	regs->ARM_r0 = -EINTR;
	550	break;
	551	}
	552	/* fallthrough */
	553	case -ERESTARTNOINTR:
	554	restart_syscall(regs);
	555	}
	556	}
	557
	558	/*
	559	* translate the signal
	560	*/
	561	if (usig < 32 && thread->exec_domain && thread->exec_domain->signal_invmap)
	562	usig = thread->exec_domain->signal_invmap[usig];
	563
	564	/*
	565	* Set up the stack frame
	566	*/
	567	if (ka->sa.sa_flags & SA_SIGINFO)
	568	ret = setup_rt_frame(usig, ka, info, oldset, regs);
	569	else
	570	ret = setup_frame(usig, ka, oldset, regs);
	571
	572	/*
	573	* Check that the resulting registers are actually sane.
	574	*/
	575	ret \|= !valid_user_regs(regs);
	576
69be8f18	577	if (ret != 0) {
a6c61e9d DJ	578	force_sigsegv(sig, tsk);
a6c61e9d DJ	579	return;
1da177e4 LT	580	}
1da177e4 LT	581
a6c61e9d DJ	582	/*
	583	* Block the signal if we were successful.
	584	*/
	585	spin_lock_irq(&tsk->sighand->siglock);
	586	sigorsets(&tsk->blocked, &tsk->blocked,
	587	&ka->sa.sa_mask);
	588	if (!(ka->sa.sa_flags & SA_NODEFER))
	589	sigaddset(&tsk->blocked, sig);
	590	recalc_sigpending();
	591	spin_unlock_irq(&tsk->sighand->siglock);
1da177e4	592
1da177e4 LT	593	}
	594
	595	/*
	596	* Note that 'init' is a special process: it doesn't get signals it doesn't
	597	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	598	* mistake.
	599	*
	600	* Note that we go through the signals twice: once to check the signals that
	601	* the kernel can handle, and then we build all the user-level signal handling
	602	* stack-frames in one go after that.
	603	*/
	604	static int do_signal(sigset_t oldset, struct pt_regs regs, int syscall)
	605	{
	606	struct k_sigaction ka;
	607	siginfo_t info;
	608	int signr;
	609
	610	/*
	611	* We want the common case to go fast, which
	612	* is why we may in certain cases get here from
	613	* kernel mode. Just return without doing anything
	614	* if so.
	615	*/
	616	if (!user_mode(regs))
	617	return 0;
	618
bdb94f3a	619	if (try_to_freeze())
1da177e4 LT	620	goto no_signal;
	621
	622	if (current->ptrace & PT_SINGLESTEP)
	623	ptrace_cancel_bpt(current);
	624
	625	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	626	if (signr > 0) {
	627	handle_signal(signr, &ka, &info, oldset, regs, syscall);
	628	if (current->ptrace & PT_SINGLESTEP)
	629	ptrace_set_bpt(current);
	630	return 1;
	631	}
	632
	633	no_signal:
	634	/*
	635	* No signal to deliver to the process - restart the syscall.
	636	*/
	637	if (syscall) {
	638	if (regs->ARM_r0 == -ERESTART_RESTARTBLOCK) {
	639	if (thumb_mode(regs)) {
	640	regs->ARM_r7 = __NR_restart_syscall;
	641	regs->ARM_pc -= 2;
	642	} else {
	643	u32 __user *usp;
	644
	645	regs->ARM_sp -= 12;
	646	usp = (u32 __user *)regs->ARM_sp;
	647
	648	put_user(regs->ARM_pc, &usp[0]);
	649	/* swi __NR_restart_syscall */
	650	put_user(0xef000000 \| __NR_restart_syscall, &usp[1]);
	651	/* ldr pc, [sp], #12 */
	652	put_user(0xe49df00c, &usp[2]);
	653
	654	flush_icache_range((unsigned long)usp,
	655	(unsigned long)(usp + 3));
	656
	657	regs->ARM_pc = regs->ARM_sp + 4;
	658	}
	659	}
	660	if (regs->ARM_r0 == -ERESTARTNOHAND \|\|
	661	regs->ARM_r0 == -ERESTARTSYS \|\|
	662	regs->ARM_r0 == -ERESTARTNOINTR) {
	663	restart_syscall(regs);
	664	}
	665	}
	666	if (current->ptrace & PT_SINGLESTEP)
	667	ptrace_set_bpt(current);
	668	return 0;
	669	}
	670
	671	asmlinkage void
	672	do_notify_resume(struct pt_regs *regs, unsigned int thread_flags, int syscall)
	673	{
	674	if (thread_flags & _TIF_SIGPENDING)
	675	do_signal(&current->blocked, regs, syscall);
	676	}