[GitHub/mt8127/android_kernel_alcatel_ttab.git] / arch / alpha / kernel / signal.c

/*
 *  linux/arch/alpha/kernel/signal.c
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  1997-11-02  Modified for POSIX.1b signals by Richard Henderson
 */

#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/wait.h>
#include <linux/ptrace.h>
#include <linux/unistd.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/stddef.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
#include <linux/bitops.h>
#include <linux/syscalls.h>
#include <linux/tracehook.h>

#include <asm/uaccess.h>
#include <asm/sigcontext.h>
#include <asm/ucontext.h>

#include "proto.h"


#define DEBUG_SIG 0

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

asmlinkage void ret_from_sys_call(void);

/*
 * The OSF/1 sigprocmask calling sequence is different from the
 * C sigprocmask() sequence..
 */
SYSCALL_DEFINE2(osf_sigprocmask, int, how, unsigned long, newmask)
{
	sigset_t oldmask;
	sigset_t mask;
	unsigned long res;

	siginitset(&mask, newmask & _BLOCKABLE);
	res = sigprocmask(how, &mask, &oldmask);
	if (!res) {
		force_successful_syscall_return();
		res = oldmask.sig[0];
	}
	return res;
}

SYSCALL_DEFINE3(osf_sigaction, int, sig,
		const struct osf_sigaction __user *, act,
		struct osf_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_flags, &act->sa_flags) ||
		    __get_user(mask, &act->sa_mask))
			return -EFAULT;
		siginitset(&new_ka.sa.sa_mask, mask);
		new_ka.ka_restorer = NULL;
	}

	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_flags, &oact->sa_flags) ||
		    __put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
			return -EFAULT;
	}

	return ret;
}

SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
		struct sigaction __user *, oact,
		size_t, sigsetsize, void __user *, restorer)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

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

	if (act) {
		new_ka.ka_restorer = restorer;
		if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
			return -EFAULT;
	}

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

	if (!ret && oact) {
		if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
			return -EFAULT;
	}

	return ret;
}

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

#if _NSIG_WORDS > 1
# error "Non SA_SIGINFO frame needs rearranging"
#endif

struct sigframe
{
	struct sigcontext sc;
	unsigned int retcode[3];
};

struct rt_sigframe
{
	struct siginfo info;
	struct ucontext uc;
	unsigned int retcode[3];
};

/* If this changes, userland unwinders that Know Things about our signal
   frame will break.  Do not undertake lightly.  It also implies an ABI
   change wrt the size of siginfo_t, which may cause some pain.  */
extern char compile_time_assert
        [offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1];

#define INSN_MOV_R30_R16	0x47fe0410
#define INSN_LDI_R0		0x201f0000
#define INSN_CALLSYS		0x00000083

static long
restore_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs)
{
	unsigned long usp;
	struct switch_stack *sw = (struct switch_stack *)regs - 1;
	long i, err = __get_user(regs->pc, &sc->sc_pc);

	current_thread_info()->restart_block.fn = do_no_restart_syscall;

	sw->r26 = (unsigned long) ret_from_sys_call;

	err |= __get_user(regs->r0, sc->sc_regs+0);
	err |= __get_user(regs->r1, sc->sc_regs+1);
	err |= __get_user(regs->r2, sc->sc_regs+2);
	err |= __get_user(regs->r3, sc->sc_regs+3);
	err |= __get_user(regs->r4, sc->sc_regs+4);
	err |= __get_user(regs->r5, sc->sc_regs+5);
	err |= __get_user(regs->r6, sc->sc_regs+6);
	err |= __get_user(regs->r7, sc->sc_regs+7);
	err |= __get_user(regs->r8, sc->sc_regs+8);
	err |= __get_user(sw->r9, sc->sc_regs+9);
	err |= __get_user(sw->r10, sc->sc_regs+10);
	err |= __get_user(sw->r11, sc->sc_regs+11);
	err |= __get_user(sw->r12, sc->sc_regs+12);
	err |= __get_user(sw->r13, sc->sc_regs+13);
	err |= __get_user(sw->r14, sc->sc_regs+14);
	err |= __get_user(sw->r15, sc->sc_regs+15);
	err |= __get_user(regs->r16, sc->sc_regs+16);
	err |= __get_user(regs->r17, sc->sc_regs+17);
	err |= __get_user(regs->r18, sc->sc_regs+18);
	err |= __get_user(regs->r19, sc->sc_regs+19);
	err |= __get_user(regs->r20, sc->sc_regs+20);
	err |= __get_user(regs->r21, sc->sc_regs+21);
	err |= __get_user(regs->r22, sc->sc_regs+22);
	err |= __get_user(regs->r23, sc->sc_regs+23);
	err |= __get_user(regs->r24, sc->sc_regs+24);
	err |= __get_user(regs->r25, sc->sc_regs+25);
	err |= __get_user(regs->r26, sc->sc_regs+26);
	err |= __get_user(regs->r27, sc->sc_regs+27);
	err |= __get_user(regs->r28, sc->sc_regs+28);
	err |= __get_user(regs->gp, sc->sc_regs+29);
	err |= __get_user(usp, sc->sc_regs+30);
	wrusp(usp);

	for (i = 0; i < 31; i++)
		err |= __get_user(sw->fp[i], sc->sc_fpregs+i);
	err |= __get_user(sw->fp[31], &sc->sc_fpcr);

	return err;
}

/* Note that this syscall is also used by setcontext(3) to install
   a given sigcontext.  This because it's impossible to set *all*
   registers and transfer control from userland.  */

asmlinkage void
do_sigreturn(struct sigcontext __user *sc)
{
	struct pt_regs *regs = current_pt_regs();
	sigset_t set;

	/* Verify that it's a good sigcontext before using it */
	if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
		goto give_sigsegv;
	if (__get_user(set.sig[0], &sc->sc_mask))
		goto give_sigsegv;

	set_current_blocked(&set);

	if (restore_sigcontext(sc, regs))
		goto give_sigsegv;

	/* Send SIGTRAP if we're single-stepping: */
	if (ptrace_cancel_bpt (current)) {
		siginfo_t info;

		info.si_signo = SIGTRAP;
		info.si_errno = 0;
		info.si_code = TRAP_BRKPT;
		info.si_addr = (void __user *) regs->pc;
		info.si_trapno = 0;
		send_sig_info(SIGTRAP, &info, current);
	}
	return;

give_sigsegv:
	force_sig(SIGSEGV, current);
}

asmlinkage void
do_rt_sigreturn(struct rt_sigframe __user *frame)
{
	struct pt_regs *regs = current_pt_regs();
	sigset_t set;

	/* Verify that it's a good ucontext_t before using it */
	if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc)))
		goto give_sigsegv;
	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
		goto give_sigsegv;

	set_current_blocked(&set);

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

	/* Send SIGTRAP if we're single-stepping: */
	if (ptrace_cancel_bpt (current)) {
		siginfo_t info;

		info.si_signo = SIGTRAP;
		info.si_errno = 0;
		info.si_code = TRAP_BRKPT;
		info.si_addr = (void __user *) regs->pc;
		info.si_trapno = 0;
		send_sig_info(SIGTRAP, &info, current);
	}
	return;

give_sigsegv:
	force_sig(SIGSEGV, current);
}


/*
 * Set up a signal frame.
 */

static inline void __user *
get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
{
	return (void __user *)((sigsp(sp, ksig) - frame_size) & -32ul);
}

static long
setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs, 
		 unsigned long mask, unsigned long sp)
{
	struct switch_stack *sw = (struct switch_stack *)regs - 1;
	long i, err = 0;

	err |= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack);
	err |= __put_user(mask, &sc->sc_mask);
	err |= __put_user(regs->pc, &sc->sc_pc);
	err |= __put_user(8, &sc->sc_ps);

	err |= __put_user(regs->r0 , sc->sc_regs+0);
	err |= __put_user(regs->r1 , sc->sc_regs+1);
	err |= __put_user(regs->r2 , sc->sc_regs+2);
	err |= __put_user(regs->r3 , sc->sc_regs+3);
	err |= __put_user(regs->r4 , sc->sc_regs+4);
	err |= __put_user(regs->r5 , sc->sc_regs+5);
	err |= __put_user(regs->r6 , sc->sc_regs+6);
	err |= __put_user(regs->r7 , sc->sc_regs+7);
	err |= __put_user(regs->r8 , sc->sc_regs+8);
	err |= __put_user(sw->r9   , sc->sc_regs+9);
	err |= __put_user(sw->r10  , sc->sc_regs+10);
	err |= __put_user(sw->r11  , sc->sc_regs+11);
	err |= __put_user(sw->r12  , sc->sc_regs+12);
	err |= __put_user(sw->r13  , sc->sc_regs+13);
	err |= __put_user(sw->r14  , sc->sc_regs+14);
	err |= __put_user(sw->r15  , sc->sc_regs+15);
	err |= __put_user(regs->r16, sc->sc_regs+16);
	err |= __put_user(regs->r17, sc->sc_regs+17);
	err |= __put_user(regs->r18, sc->sc_regs+18);
	err |= __put_user(regs->r19, sc->sc_regs+19);
	err |= __put_user(regs->r20, sc->sc_regs+20);
	err |= __put_user(regs->r21, sc->sc_regs+21);
	err |= __put_user(regs->r22, sc->sc_regs+22);
	err |= __put_user(regs->r23, sc->sc_regs+23);
	err |= __put_user(regs->r24, sc->sc_regs+24);
	err |= __put_user(regs->r25, sc->sc_regs+25);
	err |= __put_user(regs->r26, sc->sc_regs+26);
	err |= __put_user(regs->r27, sc->sc_regs+27);
	err |= __put_user(regs->r28, sc->sc_regs+28);
	err |= __put_user(regs->gp , sc->sc_regs+29);
	err |= __put_user(sp, sc->sc_regs+30);
	err |= __put_user(0, sc->sc_regs+31);

	for (i = 0; i < 31; i++)
		err |= __put_user(sw->fp[i], sc->sc_fpregs+i);
	err |= __put_user(0, sc->sc_fpregs+31);
	err |= __put_user(sw->fp[31], &sc->sc_fpcr);

	err |= __put_user(regs->trap_a0, &sc->sc_traparg_a0);
	err |= __put_user(regs->trap_a1, &sc->sc_traparg_a1);
	err |= __put_user(regs->trap_a2, &sc->sc_traparg_a2);

	return err;
}

static int
setup_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
{
	unsigned long oldsp, r26, err = 0;
	struct sigframe __user *frame;

	oldsp = rdusp();
	frame = get_sigframe(ksig, oldsp, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	err |= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp);
	if (err)
		return -EFAULT;

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	r26 = (unsigned long) ksig->ka.ka_restorer;
	if (!r26) {
		err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
		err |= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1);
		err |= __put_user(INSN_CALLSYS, frame->retcode+2);
		imb();
		r26 = (unsigned long) frame->retcode;
	}

	/* Check that everything was written properly.  */
	if (err)
		return err;

	/* "Return" to the handler */
	regs->r26 = r26;
	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
	regs->r16 = ksig->sig;			/* a0: signal number */
	regs->r17 = 0;				/* a1: exception code */
	regs->r18 = (unsigned long) &frame->sc;	/* a2: sigcontext pointer */
	wrusp((unsigned long) frame);
	
#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
		current->comm, current->pid, frame, regs->pc, regs->r26);
#endif
	return 0;
}

static int
setup_rt_frame(struct ksignal *ksig, sigset_t *set, struct pt_regs *regs)
{
	unsigned long oldsp, r26, err = 0;
	struct rt_sigframe __user *frame;

	oldsp = rdusp();
	frame = get_sigframe(ksig, oldsp, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
		return -EFAULT;

	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 |= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask);
	err |= __save_altstack(&frame->uc.uc_stack, oldsp);
	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, 
				set->sig[0], oldsp);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		return -EFAULT;

	/* Set up to return from userspace.  If provided, use a stub
	   already in userspace.  */
	r26 = (unsigned long) ksig->ka.ka_restorer;
	if (!r26) {
		err |= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
		err |= __put_user(INSN_LDI_R0+__NR_rt_sigreturn,
				  frame->retcode+1);
		err |= __put_user(INSN_CALLSYS, frame->retcode+2);
		imb();
		r26 = (unsigned long) frame->retcode;
	}

	if (err)
		return -EFAULT;

	/* "Return" to the handler */
	regs->r26 = r26;
	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
	regs->r16 = ksig->sig;			  /* a0: signal number */
	regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */
	regs->r18 = (unsigned long) &frame->uc;	  /* a2: ucontext pointer */
	wrusp((unsigned long) frame);

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
		current->comm, current->pid, frame, regs->pc, regs->r26);
#endif

	return 0;
}


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

	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
		ret = setup_rt_frame(ksig, oldset, regs);
	else
		ret = setup_frame(ksig, oldset, regs);

	signal_setup_done(ret, ksig, 0);
}

static inline void
syscall_restart(unsigned long r0, unsigned long r19,
		struct pt_regs *regs, struct k_sigaction *ka)
{
	switch (regs->r0) {
	case ERESTARTSYS:
		if (!(ka->sa.sa_flags & SA_RESTART)) {
		case ERESTARTNOHAND:
			regs->r0 = EINTR;
			break;
		}
		/* fallthrough */
	case ERESTARTNOINTR:
		regs->r0 = r0;	/* reset v0 and a3 and replay syscall */
		regs->r19 = r19;
		regs->pc -= 4;
		break;
	case ERESTART_RESTARTBLOCK:
		regs->r0 = EINTR;
		break;
	}
}


/*
 * 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.
 *
 * "r0" and "r19" are the registers we need to restore for system call
 * restart. "r0" is also used as an indicator whether we can restart at
 * all (if we get here from anything but a syscall return, it will be 0)
 */
static void
do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19)
{
	unsigned long single_stepping = ptrace_cancel_bpt(current);
	struct ksignal ksig;

	/* This lets the debugger run, ... */
	if (get_signal(&ksig)) {
		/* ... so re-check the single stepping. */
		single_stepping |= ptrace_cancel_bpt(current);
		/* Whee!  Actually deliver the signal.  */
		if (r0)
			syscall_restart(r0, r19, regs, &ksig.ka);
		handle_signal(&ksig, regs);
	} else {
		single_stepping |= ptrace_cancel_bpt(current);
		if (r0) {
			switch (regs->r0) {
			case ERESTARTNOHAND:
			case ERESTARTSYS:
			case ERESTARTNOINTR:
				/* Reset v0 and a3 and replay syscall.  */
				regs->r0 = r0;
				regs->r19 = r19;
				regs->pc -= 4;
				break;
			case ERESTART_RESTARTBLOCK:
				/* Set v0 to the restart_syscall and replay */
				regs->r0 = __NR_restart_syscall;
				regs->pc -= 4;
				break;
			}
		}
		restore_saved_sigmask();
	}
	if (single_stepping)
		ptrace_set_bpt(current);	/* re-set breakpoint */
}

void
do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
		 unsigned long r0, unsigned long r19)
{
	do {
		if (thread_flags & _TIF_NEED_RESCHED) {
			schedule();
		} else {
			local_irq_enable();
			if (thread_flags & _TIF_SIGPENDING) {
				do_signal(regs, r0, r19);
				r0 = 0;
			} else {
				clear_thread_flag(TIF_NOTIFY_RESUME);
				tracehook_notify_resume(regs);
			}
		}
		local_irq_disable();
		thread_flags = current_thread_info()->flags;
	} while (thread_flags & _TIF_WORK_MASK);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/alpha/kernel/signal.c
	3	*
	4	* Copyright (C) 1995 Linus Torvalds
	5	*
	6	* 1997-11-02 Modified for POSIX.1b signals by Richard Henderson
	7	*/
	8
	9	#include <linux/sched.h>
	10	#include <linux/kernel.h>
	11	#include <linux/signal.h>
	12	#include <linux/errno.h>
	13	#include <linux/wait.h>
	14	#include <linux/ptrace.h>
	15	#include <linux/unistd.h>
	16	#include <linux/mm.h>
	17	#include <linux/smp.h>
1da177e4 LT	18	#include <linux/stddef.h>
	19	#include <linux/tty.h>
	20	#include <linux/binfmts.h>
	21	#include <linux/bitops.h>
e5d9a90c	22	#include <linux/syscalls.h>
733e5e4b	23	#include <linux/tracehook.h>
1da177e4 LT	24
	25	#include <asm/uaccess.h>
	26	#include <asm/sigcontext.h>
	27	#include <asm/ucontext.h>
	28
	29	#include "proto.h"
	30
	31
	32	#define DEBUG_SIG 0
	33
	34	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	35
	36	asmlinkage void ret_from_sys_call(void);
1da177e4 LT	37
	38	/*
	39	* The OSF/1 sigprocmask calling sequence is different from the
	40	* C sigprocmask() sequence..
1da177e4	41	*/
c52c2ddc	42	SYSCALL_DEFINE2(osf_sigprocmask, int, how, unsigned long, newmask)
1da177e4	43	{
c52c2ddc AV	44	sigset_t oldmask;
	45	sigset_t mask;
	46	unsigned long res;
1da177e4	47
87400e54	48	siginitset(&mask, newmask & _BLOCKABLE);
0f44fbd2	49	res = sigprocmask(how, &mask, &oldmask);
c52c2ddc AV	50	if (!res) {
c52c2ddc AV	51	force_successful_syscall_return();
0f44fbd2	52	res = oldmask.sig[0];
1da177e4	53	}
c52c2ddc	54	return res;
1da177e4 LT	55	}
1da177e4 LT	56
e5d9a90c IK	57	SYSCALL_DEFINE3(osf_sigaction, int, sig,
	58	const struct osf_sigaction __user *, act,
	59	struct osf_sigaction __user *, oact)
1da177e4 LT	60	{
	61	struct k_sigaction new_ka, old_ka;
	62	int ret;
	63
	64	if (act) {
	65	old_sigset_t mask;
	66	if (!access_ok(VERIFY_READ, act, sizeof(*act)) \|\|
	67	__get_user(new_ka.sa.sa_handler, &act->sa_handler) \|\|
18e6bfa9 AV	68	__get_user(new_ka.sa.sa_flags, &act->sa_flags) \|\|
18e6bfa9 AV	69	__get_user(mask, &act->sa_mask))
1da177e4	70	return -EFAULT;
1da177e4 LT	71	siginitset(&new_ka.sa.sa_mask, mask);
	72	new_ka.ka_restorer = NULL;
	73	}
	74
	75	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	76
	77	if (!ret && oact) {
	78	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)) \|\|
	79	__put_user(old_ka.sa.sa_handler, &oact->sa_handler) \|\|
18e6bfa9 AV	80	__put_user(old_ka.sa.sa_flags, &oact->sa_flags) \|\|
18e6bfa9 AV	81	__put_user(old_ka.sa.sa_mask.sig[0], &oact->sa_mask))
1da177e4	82	return -EFAULT;
1da177e4 LT	83	}
	84
	85	return ret;
	86	}
	87
e5d9a90c IK	88	SYSCALL_DEFINE5(rt_sigaction, int, sig, const struct sigaction __user *, act,
	89	struct sigaction __user *, oact,
	90	size_t, sigsetsize, void __user *, restorer)
1da177e4 LT	91	{
	92	struct k_sigaction new_ka, old_ka;
	93	int ret;
	94
	95	/* XXX: Don't preclude handling different sized sigset_t's. */
	96	if (sigsetsize != sizeof(sigset_t))
	97	return -EINVAL;
	98
	99	if (act) {
	100	new_ka.ka_restorer = restorer;
	101	if (copy_from_user(&new_ka.sa, act, sizeof(*act)))
	102	return -EFAULT;
	103	}
	104
	105	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	106
	107	if (!ret && oact) {
	108	if (copy_to_user(oact, &old_ka.sa, sizeof(*oact)))
	109	return -EFAULT;
	110	}
	111
	112	return ret;
	113	}
	114
1da177e4 LT	115	/*
	116	* Do a signal return; undo the signal stack.
	117	*/
	118
	119	#if _NSIG_WORDS > 1
	120	# error "Non SA_SIGINFO frame needs rearranging"
	121	#endif
	122
	123	struct sigframe
	124	{
	125	struct sigcontext sc;
	126	unsigned int retcode[3];
	127	};
	128
	129	struct rt_sigframe
	130	{
	131	struct siginfo info;
	132	struct ucontext uc;
	133	unsigned int retcode[3];
	134	};
	135
	136	/* If this changes, userland unwinders that Know Things about our signal
	137	frame will break. Do not undertake lightly. It also implies an ABI
	138	change wrt the size of siginfo_t, which may cause some pain. */
	139	extern char compile_time_assert
	140	[offsetof(struct rt_sigframe, uc.uc_mcontext) == 176 ? 1 : -1];
	141
	142	#define INSN_MOV_R30_R16 0x47fe0410
	143	#define INSN_LDI_R0 0x201f0000
	144	#define INSN_CALLSYS 0x00000083
	145
	146	static long
b960f303	147	restore_sigcontext(struct sigcontext __user sc, struct pt_regs regs)
1da177e4 LT	148	{
1da177e4 LT	149	unsigned long usp;
b960f303	150	struct switch_stack sw = (struct switch_stack )regs - 1;
1da177e4 LT	151	long i, err = __get_user(regs->pc, &sc->sc_pc);
1da177e4 LT	152
2deba1bd AV	153	current_thread_info()->restart_block.fn = do_no_restart_syscall;
2deba1bd AV	154
1da177e4 LT	155	sw->r26 = (unsigned long) ret_from_sys_call;
	156
	157	err \|= __get_user(regs->r0, sc->sc_regs+0);
	158	err \|= __get_user(regs->r1, sc->sc_regs+1);
	159	err \|= __get_user(regs->r2, sc->sc_regs+2);
	160	err \|= __get_user(regs->r3, sc->sc_regs+3);
	161	err \|= __get_user(regs->r4, sc->sc_regs+4);
	162	err \|= __get_user(regs->r5, sc->sc_regs+5);
	163	err \|= __get_user(regs->r6, sc->sc_regs+6);
	164	err \|= __get_user(regs->r7, sc->sc_regs+7);
	165	err \|= __get_user(regs->r8, sc->sc_regs+8);
	166	err \|= __get_user(sw->r9, sc->sc_regs+9);
	167	err \|= __get_user(sw->r10, sc->sc_regs+10);
	168	err \|= __get_user(sw->r11, sc->sc_regs+11);
	169	err \|= __get_user(sw->r12, sc->sc_regs+12);
	170	err \|= __get_user(sw->r13, sc->sc_regs+13);
	171	err \|= __get_user(sw->r14, sc->sc_regs+14);
	172	err \|= __get_user(sw->r15, sc->sc_regs+15);
	173	err \|= __get_user(regs->r16, sc->sc_regs+16);
	174	err \|= __get_user(regs->r17, sc->sc_regs+17);
	175	err \|= __get_user(regs->r18, sc->sc_regs+18);
	176	err \|= __get_user(regs->r19, sc->sc_regs+19);
	177	err \|= __get_user(regs->r20, sc->sc_regs+20);
	178	err \|= __get_user(regs->r21, sc->sc_regs+21);
	179	err \|= __get_user(regs->r22, sc->sc_regs+22);
	180	err \|= __get_user(regs->r23, sc->sc_regs+23);
	181	err \|= __get_user(regs->r24, sc->sc_regs+24);
	182	err \|= __get_user(regs->r25, sc->sc_regs+25);
	183	err \|= __get_user(regs->r26, sc->sc_regs+26);
	184	err \|= __get_user(regs->r27, sc->sc_regs+27);
	185	err \|= __get_user(regs->r28, sc->sc_regs+28);
	186	err \|= __get_user(regs->gp, sc->sc_regs+29);
	187	err \|= __get_user(usp, sc->sc_regs+30);
	188	wrusp(usp);
	189
	190	for (i = 0; i < 31; i++)
	191	err \|= __get_user(sw->fp[i], sc->sc_fpregs+i);
	192	err \|= __get_user(sw->fp[31], &sc->sc_fpcr);
	193
	194	return err;
	195	}
	196
	197	/* Note that this syscall is also used by setcontext(3) to install
	198	a given sigcontext. This because it's impossible to set all
	199	registers and transfer control from userland. */
	200
	201	asmlinkage void
b960f303	202	do_sigreturn(struct sigcontext __user *sc)
1da177e4	203	{
b960f303	204	struct pt_regs *regs = current_pt_regs();
1da177e4 LT	205	sigset_t set;
	206
	207	/* Verify that it's a good sigcontext before using it */
	208	if (!access_ok(VERIFY_READ, sc, sizeof(*sc)))
	209	goto give_sigsegv;
	210	if (__get_user(set.sig[0], &sc->sc_mask))
	211	goto give_sigsegv;
	212
2561b069	213	set_current_blocked(&set);
1da177e4	214
b960f303	215	if (restore_sigcontext(sc, regs))
1da177e4 LT	216	goto give_sigsegv;
	217
	218	/* Send SIGTRAP if we're single-stepping: */
	219	if (ptrace_cancel_bpt (current)) {
	220	siginfo_t info;
	221
	222	info.si_signo = SIGTRAP;
	223	info.si_errno = 0;
	224	info.si_code = TRAP_BRKPT;
	225	info.si_addr = (void __user *) regs->pc;
	226	info.si_trapno = 0;
	227	send_sig_info(SIGTRAP, &info, current);
	228	}
	229	return;
	230
	231	give_sigsegv:
	232	force_sig(SIGSEGV, current);
	233	}
	234
	235	asmlinkage void
b960f303	236	do_rt_sigreturn(struct rt_sigframe __user *frame)
1da177e4	237	{
b960f303	238	struct pt_regs *regs = current_pt_regs();
1da177e4 LT	239	sigset_t set;
	240
	241	/* Verify that it's a good ucontext_t before using it */
	242	if (!access_ok(VERIFY_READ, &frame->uc, sizeof(frame->uc)))
	243	goto give_sigsegv;
	244	if (__copy_from_user(&set, &frame->uc.uc_sigmask, sizeof(set)))
	245	goto give_sigsegv;
	246
2561b069	247	set_current_blocked(&set);
1da177e4	248
b960f303	249	if (restore_sigcontext(&frame->uc.uc_mcontext, regs))
1da177e4 LT	250	goto give_sigsegv;
	251
	252	/* Send SIGTRAP if we're single-stepping: */
	253	if (ptrace_cancel_bpt (current)) {
	254	siginfo_t info;
	255
	256	info.si_signo = SIGTRAP;
	257	info.si_errno = 0;
	258	info.si_code = TRAP_BRKPT;
	259	info.si_addr = (void __user *) regs->pc;
	260	info.si_trapno = 0;
	261	send_sig_info(SIGTRAP, &info, current);
	262	}
	263	return;
	264
	265	give_sigsegv:
	266	force_sig(SIGSEGV, current);
	267	}
	268
	269
	270	/*
	271	* Set up a signal frame.
	272	*/
	273
	274	static inline void __user *
cfd60c07	275	get_sigframe(struct ksignal *ksig, unsigned long sp, size_t frame_size)
1da177e4	276	{
cfd60c07	277	return (void __user *)((sigsp(sp, ksig) - frame_size) & -32ul);
1da177e4 LT	278	}
	279
	280	static long
	281	setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
d9d0738a	282	unsigned long mask, unsigned long sp)
1da177e4	283	{
d9d0738a	284	struct switch_stack sw = (struct switch_stack )regs - 1;
1da177e4 LT	285	long i, err = 0;
	286
	287	err \|= __put_user(on_sig_stack((unsigned long)sc), &sc->sc_onstack);
	288	err \|= __put_user(mask, &sc->sc_mask);
	289	err \|= __put_user(regs->pc, &sc->sc_pc);
	290	err \|= __put_user(8, &sc->sc_ps);
	291
	292	err \|= __put_user(regs->r0 , sc->sc_regs+0);
	293	err \|= __put_user(regs->r1 , sc->sc_regs+1);
	294	err \|= __put_user(regs->r2 , sc->sc_regs+2);
	295	err \|= __put_user(regs->r3 , sc->sc_regs+3);
	296	err \|= __put_user(regs->r4 , sc->sc_regs+4);
	297	err \|= __put_user(regs->r5 , sc->sc_regs+5);
	298	err \|= __put_user(regs->r6 , sc->sc_regs+6);
	299	err \|= __put_user(regs->r7 , sc->sc_regs+7);
	300	err \|= __put_user(regs->r8 , sc->sc_regs+8);
	301	err \|= __put_user(sw->r9 , sc->sc_regs+9);
	302	err \|= __put_user(sw->r10 , sc->sc_regs+10);
	303	err \|= __put_user(sw->r11 , sc->sc_regs+11);
	304	err \|= __put_user(sw->r12 , sc->sc_regs+12);
	305	err \|= __put_user(sw->r13 , sc->sc_regs+13);
	306	err \|= __put_user(sw->r14 , sc->sc_regs+14);
	307	err \|= __put_user(sw->r15 , sc->sc_regs+15);
	308	err \|= __put_user(regs->r16, sc->sc_regs+16);
	309	err \|= __put_user(regs->r17, sc->sc_regs+17);
	310	err \|= __put_user(regs->r18, sc->sc_regs+18);
	311	err \|= __put_user(regs->r19, sc->sc_regs+19);
	312	err \|= __put_user(regs->r20, sc->sc_regs+20);
	313	err \|= __put_user(regs->r21, sc->sc_regs+21);
	314	err \|= __put_user(regs->r22, sc->sc_regs+22);
	315	err \|= __put_user(regs->r23, sc->sc_regs+23);
	316	err \|= __put_user(regs->r24, sc->sc_regs+24);
	317	err \|= __put_user(regs->r25, sc->sc_regs+25);
	318	err \|= __put_user(regs->r26, sc->sc_regs+26);
	319	err \|= __put_user(regs->r27, sc->sc_regs+27);
	320	err \|= __put_user(regs->r28, sc->sc_regs+28);
	321	err \|= __put_user(regs->gp , sc->sc_regs+29);
	322	err \|= __put_user(sp, sc->sc_regs+30);
	323	err \|= __put_user(0, sc->sc_regs+31);
	324
	325	for (i = 0; i < 31; i++)
	326	err \|= __put_user(sw->fp[i], sc->sc_fpregs+i);
	327	err \|= __put_user(0, sc->sc_fpregs+31);
	328	err \|= __put_user(sw->fp[31], &sc->sc_fpcr);
	329
	330	err \|= __put_user(regs->trap_a0, &sc->sc_traparg_a0);
	331	err \|= __put_user(regs->trap_a1, &sc->sc_traparg_a1);
	332	err \|= __put_user(regs->trap_a2, &sc->sc_traparg_a2);
	333
	334	return err;
	335	}
	336
b927b3e2	337	static int
cfd60c07	338	setup_frame(struct ksignal ksig, sigset_t set, struct pt_regs *regs)
1da177e4 LT	339	{
	340	unsigned long oldsp, r26, err = 0;
	341	struct sigframe __user *frame;
	342
	343	oldsp = rdusp();
cfd60c07	344	frame = get_sigframe(ksig, oldsp, sizeof(*frame));
1da177e4	345	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
cbdfb9ff	346	return -EFAULT;
1da177e4	347
d9d0738a	348	err \|= setup_sigcontext(&frame->sc, regs, set->sig[0], oldsp);
1da177e4	349	if (err)
cbdfb9ff	350	return -EFAULT;
1da177e4 LT	351
	352	/* Set up to return from userspace. If provided, use a stub
	353	already in userspace. */
cfd60c07 AV	354	r26 = (unsigned long) ksig->ka.ka_restorer;
cfd60c07 AV	355	if (!r26) {
1da177e4 LT	356	err \|= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
	357	err \|= __put_user(INSN_LDI_R0+__NR_sigreturn, frame->retcode+1);
	358	err \|= __put_user(INSN_CALLSYS, frame->retcode+2);
	359	imb();
	360	r26 = (unsigned long) frame->retcode;
	361	}
	362
	363	/* Check that everything was written properly. */
	364	if (err)
cbdfb9ff	365	return err;
1da177e4 LT	366
	367	/* "Return" to the handler */
	368	regs->r26 = r26;
cfd60c07 AV	369	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
cfd60c07 AV	370	regs->r16 = ksig->sig; /* a0: signal number */
1da177e4 LT	371	regs->r17 = 0; /* a1: exception code */
	372	regs->r18 = (unsigned long) &frame->sc; /* a2: sigcontext pointer */
	373	wrusp((unsigned long) frame);
	374
	375	#if DEBUG_SIG
	376	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
	377	current->comm, current->pid, frame, regs->pc, regs->r26);
	378	#endif
b927b3e2	379	return 0;
1da177e4 LT	380	}
1da177e4 LT	381
b927b3e2	382	static int
cfd60c07	383	setup_rt_frame(struct ksignal ksig, sigset_t set, struct pt_regs *regs)
1da177e4 LT	384	{
	385	unsigned long oldsp, r26, err = 0;
	386	struct rt_sigframe __user *frame;
	387
	388	oldsp = rdusp();
cfd60c07	389	frame = get_sigframe(ksig, oldsp, sizeof(*frame));
1da177e4	390	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
cbdfb9ff	391	return -EFAULT;
1da177e4	392
cfd60c07	393	err \|= copy_siginfo_to_user(&frame->info, &ksig->info);
1da177e4 LT	394
	395	/* Create the ucontext. */
	396	err \|= __put_user(0, &frame->uc.uc_flags);
	397	err \|= __put_user(0, &frame->uc.uc_link);
	398	err \|= __put_user(set->sig[0], &frame->uc.uc_osf_sigmask);
50ececcf	399	err \|= __save_altstack(&frame->uc.uc_stack, oldsp);
d9d0738a	400	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs,
1da177e4 LT	401	set->sig[0], oldsp);
	402	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	403	if (err)
cbdfb9ff	404	return -EFAULT;
1da177e4 LT	405
	406	/* Set up to return from userspace. If provided, use a stub
	407	already in userspace. */
cfd60c07 AV	408	r26 = (unsigned long) ksig->ka.ka_restorer;
cfd60c07 AV	409	if (!r26) {
1da177e4 LT	410	err \|= __put_user(INSN_MOV_R30_R16, frame->retcode+0);
	411	err \|= __put_user(INSN_LDI_R0+__NR_rt_sigreturn,
	412	frame->retcode+1);
	413	err \|= __put_user(INSN_CALLSYS, frame->retcode+2);
	414	imb();
	415	r26 = (unsigned long) frame->retcode;
	416	}
	417
	418	if (err)
cbdfb9ff	419	return -EFAULT;
1da177e4 LT	420
	421	/* "Return" to the handler */
	422	regs->r26 = r26;
cfd60c07 AV	423	regs->r27 = regs->pc = (unsigned long) ksig->ka.sa.sa_handler;
cfd60c07 AV	424	regs->r16 = ksig->sig; /* a0: signal number */
1da177e4 LT	425	regs->r17 = (unsigned long) &frame->info; /* a1: siginfo pointer */
	426	regs->r18 = (unsigned long) &frame->uc; /* a2: ucontext pointer */
	427	wrusp((unsigned long) frame);
	428
	429	#if DEBUG_SIG
	430	printk("SIG deliver (%s:%d): sp=%p pc=%p ra=%p\n",
	431	current->comm, current->pid, frame, regs->pc, regs->r26);
	432	#endif
	433
b927b3e2	434	return 0;
1da177e4 LT	435	}
	436
	437
	438	/*
	439	* OK, we're invoking a handler.
	440	*/
cbdfb9ff	441	static inline void
cfd60c07	442	handle_signal(struct ksignal ksig, struct pt_regs regs)
1da177e4	443	{
b7f9a11a	444	sigset_t *oldset = sigmask_to_save();
b927b3e2 RH	445	int ret;
b927b3e2 RH	446
cfd60c07 AV	447	if (ksig->ka.sa.sa_flags & SA_SIGINFO)
cfd60c07 AV	448	ret = setup_rt_frame(ksig, oldset, regs);
1da177e4	449	else
cfd60c07	450	ret = setup_frame(ksig, oldset, regs);
1da177e4	451
cfd60c07	452	signal_setup_done(ret, ksig, 0);
1da177e4 LT	453	}
	454
	455	static inline void
	456	syscall_restart(unsigned long r0, unsigned long r19,
	457	struct pt_regs regs, struct k_sigaction ka)
	458	{
	459	switch (regs->r0) {
	460	case ERESTARTSYS:
	461	if (!(ka->sa.sa_flags & SA_RESTART)) {
	462	case ERESTARTNOHAND:
	463	regs->r0 = EINTR;
	464	break;
	465	}
	466	/* fallthrough */
	467	case ERESTARTNOINTR:
	468	regs->r0 = r0; /* reset v0 and a3 and replay syscall */
	469	regs->r19 = r19;
	470	regs->pc -= 4;
	471	break;
	472	case ERESTART_RESTARTBLOCK:
1da177e4 LT	473	regs->r0 = EINTR;
	474	break;
	475	}
	476	}
	477
	478
	479	/*
	480	* Note that 'init' is a special process: it doesn't get signals it doesn't
	481	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	482	* mistake.
	483	*
	484	* Note that we go through the signals twice: once to check the signals that
	485	* the kernel can handle, and then we build all the user-level signal handling
	486	* stack-frames in one go after that.
	487	*
	488	* "r0" and "r19" are the registers we need to restore for system call
	489	* restart. "r0" is also used as an indicator whether we can restart at
	490	* all (if we get here from anything but a syscall return, it will be 0)
	491	*/
b927b3e2	492	static void
d9d0738a	493	do_signal(struct pt_regs *regs, unsigned long r0, unsigned long r19)
1da177e4	494	{
1da177e4	495	unsigned long single_stepping = ptrace_cancel_bpt(current);
cfd60c07	496	struct ksignal ksig;
1da177e4 LT	497
1da177e4 LT	498	/* This lets the debugger run, ... */
cfd60c07 AV	499	if (get_signal(&ksig)) {
	500	/* ... so re-check the single stepping. */
	501	single_stepping \|= ptrace_cancel_bpt(current);
1da177e4	502	/* Whee! Actually deliver the signal. */
b927b3e2	503	if (r0)
cfd60c07 AV	504	syscall_restart(r0, r19, regs, &ksig.ka);
	505	handle_signal(&ksig, regs);
	506	} else {
	507	single_stepping \|= ptrace_cancel_bpt(current);
	508	if (r0) {
	509	switch (regs->r0) {
	510	case ERESTARTNOHAND:
	511	case ERESTARTSYS:
	512	case ERESTARTNOINTR:
	513	/* Reset v0 and a3 and replay syscall. */
	514	regs->r0 = r0;
	515	regs->r19 = r19;
	516	regs->pc -= 4;
	517	break;
	518	case ERESTART_RESTARTBLOCK:
	519	/* Set v0 to the restart_syscall and replay */
	520	regs->r0 = __NR_restart_syscall;
	521	regs->pc -= 4;
	522	break;
	523	}
1da177e4	524	}
cfd60c07	525	restore_saved_sigmask();
1da177e4 LT	526	}
	527	if (single_stepping)
	528	ptrace_set_bpt(current); /* re-set breakpoint */
1da177e4 LT	529	}
	530
	531	void
cb450766	532	do_work_pending(struct pt_regs *regs, unsigned long thread_flags,
b927b3e2	533	unsigned long r0, unsigned long r19)
1da177e4	534	{
6972d6f2 AV	535	do {
	536	if (thread_flags & _TIF_NEED_RESCHED) {
	537	schedule();
	538	} else {
	539	local_irq_enable();
	540	if (thread_flags & _TIF_SIGPENDING) {
d9d0738a	541	do_signal(regs, r0, r19);
6972d6f2 AV	542	r0 = 0;
	543	} else {
	544	clear_thread_flag(TIF_NOTIFY_RESUME);
	545	tracehook_notify_resume(regs);
	546	}
	547	}
	548	local_irq_disable();
	549	thread_flags = current_thread_info()->flags;
	550	} while (thread_flags & _TIF_WORK_MASK);
1da177e4	551	}