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

/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1991, 1992  Linus Torvalds
 * Copyright (C) 1994 - 2000  Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 */
#include <linux/cache.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/personality.h>
#include <linux/smp.h>
#include <linux/smp_lock.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/compiler.h>

#include <asm/abi.h>
#include <asm/asm.h>
#include <linux/bitops.h>
#include <asm/cacheflush.h>
#include <asm/fpu.h>
#include <asm/sim.h>
#include <asm/uaccess.h>
#include <asm/ucontext.h>
#include <asm/cpu-features.h>
#include <asm/war.h>

#include "signal-common.h"

#define DEBUG_SIG 0

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

#if ICACHE_REFILLS_WORKAROUND_WAR == 0

struct rt_sigframe {
	u32 rs_ass[4];		/* argument save space for o32 */
	u32 rs_code[2];		/* signal trampoline */
	struct siginfo rs_info;
	struct ucontext rs_uc;
};

#else

struct rt_sigframe {
	u32 rs_ass[4];			/* argument save space for o32 */
	u32 rs_pad[2];
	struct siginfo rs_info;
	struct ucontext rs_uc;
	u32 rs_code[8] ____cacheline_aligned;	/* signal trampoline */
};

#endif

/*
 * Helper routines
 */
int setup_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
	int err = 0;
	int i;

	err |= __put_user(regs->cp0_epc, &sc->sc_pc);

	err |= __put_user(0, &sc->sc_regs[0]);
	for (i = 1; i < 32; i++)
		err |= __put_user(regs->regs[i], &sc->sc_regs[i]);

	err |= __put_user(regs->hi, &sc->sc_mdhi);
	err |= __put_user(regs->lo, &sc->sc_mdlo);
	if (cpu_has_dsp) {
		err |= __put_user(mfhi1(), &sc->sc_hi1);
		err |= __put_user(mflo1(), &sc->sc_lo1);
		err |= __put_user(mfhi2(), &sc->sc_hi2);
		err |= __put_user(mflo2(), &sc->sc_lo2);
		err |= __put_user(mfhi3(), &sc->sc_hi3);
		err |= __put_user(mflo3(), &sc->sc_lo3);
		err |= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
	}

	err |= __put_user(!!used_math(), &sc->sc_used_math);

	if (used_math()) {
		/*
		 * Save FPU state to signal context. Signal handler
		 * will "inherit" current FPU state.
		 */
		preempt_disable();

		if (!is_fpu_owner()) {
			own_fpu();
			restore_fp(current);
		}
		err |= save_fp_context(sc);

		preempt_enable();
	}
	return err;
}

int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
{
	unsigned int used_math;
	unsigned long treg;
	int err = 0;
	int i;

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

	err |= __get_user(regs->cp0_epc, &sc->sc_pc);
	err |= __get_user(regs->hi, &sc->sc_mdhi);
	err |= __get_user(regs->lo, &sc->sc_mdlo);
	if (cpu_has_dsp) {
		err |= __get_user(treg, &sc->sc_hi1); mthi1(treg);
		err |= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
		err |= __get_user(treg, &sc->sc_hi2); mthi2(treg);
		err |= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
		err |= __get_user(treg, &sc->sc_hi3); mthi3(treg);
		err |= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
		err |= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
	}

	for (i = 1; i < 32; i++)
		err |= __get_user(regs->regs[i], &sc->sc_regs[i]);

	err |= __get_user(used_math, &sc->sc_used_math);
	conditional_used_math(used_math);

	preempt_disable();

	if (used_math()) {
		/* restore fpu context if we have used it before */
		own_fpu();
		err |= restore_fp_context(sc);
	} else {
		/* signal handler may have used FPU.  Give it up. */
		lose_fpu();
	}

	preempt_enable();

	return err;
}

void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
			  size_t frame_size)
{
	unsigned long sp;

	/* Default to using normal stack */
	sp = regs->regs[29];

	/*
	 * FPU emulator may have it's own trampoline active just
	 * above the user stack, 16-bytes before the next lowest
	 * 16 byte boundary.  Try to avoid trashing it.
	 */
	sp -= 32;

	/* This is the X/Open sanctioned signal stack switching.  */
	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
		sp = current->sas_ss_sp + current->sas_ss_size;

	return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
}

int install_sigtramp(unsigned int __user *tramp, unsigned int syscall)
{
	int err;

	/*
	 * Set up the return code ...
	 *
	 *         li      v0, __NR__foo_sigreturn
	 *         syscall
	 */

	err = __put_user(0x24020000 + syscall, tramp + 0);
	err |= __put_user(0x0000000c         , tramp + 1);
	if (ICACHE_REFILLS_WORKAROUND_WAR) {
		err |= __put_user(0, tramp + 2);
		err |= __put_user(0, tramp + 3);
		err |= __put_user(0, tramp + 4);
		err |= __put_user(0, tramp + 5);
		err |= __put_user(0, tramp + 6);
		err |= __put_user(0, tramp + 7);
	}
	flush_cache_sigtramp((unsigned long) tramp);

	return err;
}

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */

#ifdef CONFIG_TRAD_SIGNALS
save_static_function(sys_sigsuspend);
__attribute_used__ noinline static int
_sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
{
	sigset_t newset;
	sigset_t __user *uset;

	uset = (sigset_t __user *) regs.regs[4];
	if (copy_from_user(&newset, uset, sizeof(sigset_t)))
		return -EFAULT;
	sigdelsetmask(&newset, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);
	current->saved_sigmask = current->blocked;
	current->blocked = newset;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_thread_flag(TIF_RESTORE_SIGMASK);
	return -ERESTARTNOHAND;
}
#endif

save_static_function(sys_rt_sigsuspend);
__attribute_used__ noinline static int
_sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
{
	sigset_t newset;
	sigset_t __user *unewset;
	size_t sigsetsize;

	/* XXX Don't preclude handling different sized sigset_t's.  */
	sigsetsize = regs.regs[5];
	if (sigsetsize != sizeof(sigset_t))
		return -EINVAL;

	unewset = (sigset_t __user *) regs.regs[4];
	if (copy_from_user(&newset, unewset, sizeof(newset)))
		return -EFAULT;
	sigdelsetmask(&newset, ~_BLOCKABLE);

	spin_lock_irq(&current->sighand->siglock);
	current->saved_sigmask = current->blocked;
	current->blocked = newset;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	current->state = TASK_INTERRUPTIBLE;
	schedule();
	set_thread_flag(TIF_RESTORE_SIGMASK);
	return -ERESTARTNOHAND;
}

#ifdef CONFIG_TRAD_SIGNALS
asmlinkage int sys_sigaction(int sig, const struct sigaction __user *act,
	struct sigaction __user *oact)
{
	struct k_sigaction new_ka, old_ka;
	int ret;
	int err = 0;

	if (act) {
		old_sigset_t mask;

		if (!access_ok(VERIFY_READ, act, sizeof(*act)))
			return -EFAULT;
		err |= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
		err |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		err |= __get_user(mask, &act->sa_mask.sig[0]);
		if (err)
			return -EFAULT;

		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)))
			return -EFAULT;
		err |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
		err |= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
		err |= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
		err |= __put_user(0, &oact->sa_mask.sig[1]);
		err |= __put_user(0, &oact->sa_mask.sig[2]);
		err |= __put_user(0, &oact->sa_mask.sig[3]);
		if (err)
			return -EFAULT;
	}

	return ret;
}
#endif

asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
{
	const stack_t __user *uss = (const stack_t __user *) regs.regs[4];
	stack_t __user *uoss = (stack_t __user *) regs.regs[5];
	unsigned long usp = regs.regs[29];

	return do_sigaltstack(uss, uoss, usp);
}

#ifdef CONFIG_TRAD_SIGNALS
save_static_function(sys_sigreturn);
__attribute_used__ noinline static void
_sys_sigreturn(nabi_no_regargs struct pt_regs regs)
{
	struct sigframe __user *frame;
	sigset_t blocked;

	frame = (struct sigframe __user *) regs.regs[29];
	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
		goto badframe;

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

	if (restore_sigcontext(&regs, &frame->sf_sc))
		goto badframe;

	/*
	 * Don't let your children do this ...
	 */
	__asm__ __volatile__(
		"move\t$29, %0\n\t"
		"j\tsyscall_exit"
		:/* no outputs */
		:"r" (&regs));
	/* Unreached */

badframe:
	force_sig(SIGSEGV, current);
}
#endif /* CONFIG_TRAD_SIGNALS */

save_static_function(sys_rt_sigreturn);
__attribute_used__ noinline static void
_sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
{
	struct rt_sigframe __user *frame;
	sigset_t set;
	stack_t st;

	frame = (struct rt_sigframe __user *) regs.regs[29];
	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
		goto badframe;
	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
		goto badframe;

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

	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
		goto badframe;

	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
		goto badframe;
	/* It is more difficult to avoid calling this function than to
	   call it and ignore errors.  */
	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);

	/*
	 * Don't let your children do this ...
	 */
	__asm__ __volatile__(
		"move\t$29, %0\n\t"
		"j\tsyscall_exit"
		:/* no outputs */
		:"r" (&regs));
	/* Unreached */

badframe:
	force_sig(SIGSEGV, current);
}

#ifdef CONFIG_TRAD_SIGNALS
int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
	int signr, sigset_t *set)
{
	struct sigframe __user *frame;
	int err = 0;

	frame = get_sigframe(ka, regs, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
		goto give_sigsegv;

	err |= install_sigtramp(frame->sf_code, __NR_sigreturn);

	err |= setup_sigcontext(regs, &frame->sf_sc);
	err |= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
	if (err)
		goto give_sigsegv;

	/*
	 * Arguments to signal handler:
	 *
	 *   a0 = signal number
	 *   a1 = 0 (should be cause)
	 *   a2 = pointer to struct sigcontext
	 *
	 * $25 and c0_epc point to the signal handler, $29 points to the
	 * struct sigframe.
	 */
	regs->regs[ 4] = signr;
	regs->regs[ 5] = 0;
	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
	regs->regs[29] = (unsigned long) frame;
	regs->regs[31] = (unsigned long) frame->sf_code;
	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
	       current->comm, current->pid,
	       frame, regs->cp0_epc, frame->regs[31]);
#endif
	return 0;

give_sigsegv:
	force_sigsegv(signr, current);
	return -EFAULT;
}
#endif

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

	frame = get_sigframe(ka, regs, sizeof(*frame));
	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
		goto give_sigsegv;

	err |= install_sigtramp(frame->rs_code, __NR_rt_sigreturn);

	/* Create siginfo.  */
	err |= copy_siginfo_to_user(&frame->rs_info, info);

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->rs_uc.uc_flags);
	err |= __put_user(NULL, &frame->rs_uc.uc_link);
	err |= __put_user((void __user *)current->sas_ss_sp,
	                  &frame->rs_uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->regs[29]),
	                  &frame->rs_uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size,
	                  &frame->rs_uc.uc_stack.ss_size);
	err |= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
	err |= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));

	if (err)
		goto give_sigsegv;

	/*
	 * Arguments to signal handler:
	 *
	 *   a0 = signal number
	 *   a1 = 0 (should be cause)
	 *   a2 = pointer to ucontext
	 *
	 * $25 and c0_epc point to the signal handler, $29 points to
	 * the struct rt_sigframe.
	 */
	regs->regs[ 4] = signr;
	regs->regs[ 5] = (unsigned long) &frame->rs_info;
	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
	regs->regs[29] = (unsigned long) frame;
	regs->regs[31] = (unsigned long) frame->rs_code;
	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;

#if DEBUG_SIG
	printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
	       current->comm, current->pid,
	       frame, regs->cp0_epc, regs->regs[31]);
#endif
	return 0;

give_sigsegv:
	force_sigsegv(signr, current);
	return -EFAULT;
}

static inline int handle_signal(unsigned long sig, siginfo_t *info,
	struct k_sigaction *ka, sigset_t *oldset, struct pt_regs *regs)
{
	int ret;

	switch(regs->regs[0]) {
	case ERESTART_RESTARTBLOCK:
	case ERESTARTNOHAND:
		regs->regs[2] = EINTR;
		break;
	case ERESTARTSYS:
		if (!(ka->sa.sa_flags & SA_RESTART)) {
			regs->regs[2] = EINTR;
			break;
		}
	/* fallthrough */
	case ERESTARTNOINTR:		/* Userland will reload $v0.  */
		regs->regs[7] = regs->regs[26];
		regs->cp0_epc -= 8;
	}

	regs->regs[0] = 0;		/* Don't deal with this again.  */

	if (sig_uses_siginfo(ka))
		ret = current->thread.abi->setup_rt_frame(ka, regs, sig, oldset, info);
	else
		ret = current->thread.abi->setup_frame(ka, regs, sig, oldset);

	spin_lock_irq(&current->sighand->siglock);
	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	if (!(ka->sa.sa_flags & SA_NODEFER))
		sigaddset(&current->blocked,sig);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

	return ret;
}

void do_signal(struct pt_regs *regs)
{
	struct k_sigaction ka;
	sigset_t *oldset;
	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;

	if (test_thread_flag(TIF_RESTORE_SIGMASK))
		oldset = &current->saved_sigmask;
	else
		oldset = &current->blocked;

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		/* Whee!  Actually deliver the signal.  */
		if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
			/*
			 * A signal was successfully delivered; the saved
			 * sigmask will have been stored in the signal frame,
			 * and will be restored by sigreturn, so we can simply
			 * clear the TIF_RESTORE_SIGMASK flag.
			 */
			if (test_thread_flag(TIF_RESTORE_SIGMASK))
				clear_thread_flag(TIF_RESTORE_SIGMASK);
		}

		return;
	}

	/*
	 * Who's code doesn't conform to the restartable syscall convention
	 * dies here!!!  The li instruction, a single machine instruction,
	 * must directly be followed by the syscall instruction.
	 */
	if (regs->regs[0]) {
		if (regs->regs[2] == ERESTARTNOHAND ||
		    regs->regs[2] == ERESTARTSYS ||
		    regs->regs[2] == ERESTARTNOINTR) {
			regs->regs[7] = regs->regs[26];
			regs->cp0_epc -= 8;
		}
		if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
			regs->regs[2] = __NR_restart_syscall;
			regs->regs[7] = regs->regs[26];
			regs->cp0_epc -= 4;
		}
		regs->regs[0] = 0;	/* Don't deal with this again.  */
	}

	/*
	 * If there's no signal to deliver, we just put the saved sigmask
	 * back
	 */
	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
		clear_thread_flag(TIF_RESTORE_SIGMASK);
		sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	}
}

/*
 * notification of userspace execution resumption
 * - triggered by the TIF_WORK_MASK flags
 */
asmlinkage void do_notify_resume(struct pt_regs *regs, void *unused,
	__u32 thread_info_flags)
{
	/* deal with pending signal delivery */
	if (thread_info_flags & (_TIF_SIGPENDING | _TIF_RESTORE_SIGMASK))
		current->thread.abi->do_signal(regs);
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* This file is subject to the terms and conditions of the GNU General Public
	3	* License. See the file "COPYING" in the main directory of this archive
	4	* for more details.
	5	*
	6	* Copyright (C) 1991, 1992 Linus Torvalds
	7	* Copyright (C) 1994 - 2000 Ralf Baechle
	8	* Copyright (C) 1999, 2000 Silicon Graphics, Inc.
	9	*/
02416dcf	10	#include <linux/cache.h>
1da177e4 LT	11	#include <linux/sched.h>
	12	#include <linux/mm.h>
	13	#include <linux/personality.h>
	14	#include <linux/smp.h>
	15	#include <linux/smp_lock.h>
	16	#include <linux/kernel.h>
	17	#include <linux/signal.h>
	18	#include <linux/errno.h>
	19	#include <linux/wait.h>
	20	#include <linux/ptrace.h>
	21	#include <linux/unistd.h>
	22	#include <linux/compiler.h>
	23
e50c0a8f	24	#include <asm/abi.h>
1da177e4 LT	25	#include <asm/asm.h>
	26	#include <linux/bitops.h>
	27	#include <asm/cacheflush.h>
	28	#include <asm/fpu.h>
	29	#include <asm/sim.h>
	30	#include <asm/uaccess.h>
	31	#include <asm/ucontext.h>
	32	#include <asm/cpu-features.h>
02416dcf	33	#include <asm/war.h>
1da177e4 LT	34
	35	#include "signal-common.h"
	36
	37	#define DEBUG_SIG 0
	38
	39	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	40
c0b9bae9 FBH	41	#if ICACHE_REFILLS_WORKAROUND_WAR == 0
	42
	43	struct rt_sigframe {
	44	u32 rs_ass[4]; /* argument save space for o32 */
	45	u32 rs_code[2]; /* signal trampoline */
	46	struct siginfo rs_info;
	47	struct ucontext rs_uc;
	48	};
	49
	50	#else
	51
	52	struct rt_sigframe {
	53	u32 rs_ass[4]; /* argument save space for o32 */
	54	u32 rs_pad[2];
	55	struct siginfo rs_info;
	56	struct ucontext rs_uc;
	57	u32 rs_code[8] ____cacheline_aligned; /* signal trampoline */
	58	};
	59
	60	#endif
	61
c3fc4ab3 FBH	62	/*
	63	* Helper routines
	64	*/
	65	int setup_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	66	{
	67	int err = 0;
	68	int i;
	69
	70	err \|= __put_user(regs->cp0_epc, &sc->sc_pc);
	71
	72	err \|= __put_user(0, &sc->sc_regs[0]);
	73	for (i = 1; i < 32; i++)
	74	err \|= __put_user(regs->regs[i], &sc->sc_regs[i]);
	75
	76	err \|= __put_user(regs->hi, &sc->sc_mdhi);
	77	err \|= __put_user(regs->lo, &sc->sc_mdlo);
	78	if (cpu_has_dsp) {
	79	err \|= __put_user(mfhi1(), &sc->sc_hi1);
	80	err \|= __put_user(mflo1(), &sc->sc_lo1);
	81	err \|= __put_user(mfhi2(), &sc->sc_hi2);
	82	err \|= __put_user(mflo2(), &sc->sc_lo2);
	83	err \|= __put_user(mfhi3(), &sc->sc_hi3);
	84	err \|= __put_user(mflo3(), &sc->sc_lo3);
	85	err \|= __put_user(rddsp(DSP_MASK), &sc->sc_dsp);
	86	}
	87
	88	err \|= __put_user(!!used_math(), &sc->sc_used_math);
	89
	90	if (used_math()) {
	91	/*
	92	* Save FPU state to signal context. Signal handler
	93	* will "inherit" current FPU state.
	94	*/
	95	preempt_disable();
	96
	97	if (!is_fpu_owner()) {
	98	own_fpu();
	99	restore_fp(current);
	100	}
	101	err \|= save_fp_context(sc);
	102
	103	preempt_enable();
	104	}
	105	return err;
	106	}
	107
	108	int restore_sigcontext(struct pt_regs regs, struct sigcontext __user sc)
	109	{
	110	unsigned int used_math;
	111	unsigned long treg;
	112	int err = 0;
	113	int i;
	114
	115	/* Always make any pending restarted system calls return -EINTR */
	116	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	117
	118	err \|= __get_user(regs->cp0_epc, &sc->sc_pc);
	119	err \|= __get_user(regs->hi, &sc->sc_mdhi);
	120	err \|= __get_user(regs->lo, &sc->sc_mdlo);
	121	if (cpu_has_dsp) {
	122	err \|= __get_user(treg, &sc->sc_hi1); mthi1(treg);
	123	err \|= __get_user(treg, &sc->sc_lo1); mtlo1(treg);
	124	err \|= __get_user(treg, &sc->sc_hi2); mthi2(treg);
	125	err \|= __get_user(treg, &sc->sc_lo2); mtlo2(treg);
126	err \|= __get_user(treg, &sc->sc_hi3); mthi3(treg);
127	err \|= __get_user(treg, &sc->sc_lo3); mtlo3(treg);
128	err \|= __get_user(treg, &sc->sc_dsp); wrdsp(treg, DSP_MASK);
129	}
130
131	for (i = 1; i < 32; i++)
132	err \|= __get_user(regs->regs[i], &sc->sc_regs[i]);
133
134	err \|= __get_user(used_math, &sc->sc_used_math);
135	conditional_used_math(used_math);
136
137	preempt_disable();
138
139	if (used_math()) {
140	/* restore fpu context if we have used it before */
141	own_fpu();
142	err \|= restore_fp_context(sc);
143	} else {
144	/* signal handler may have used FPU. Give it up. */
145	lose_fpu();
146	}
147
148	preempt_enable();
149
150	return err;
151	}
152
153	void __user get_sigframe(struct k_sigaction ka, struct pt_regs *regs,
154	size_t frame_size)
155	{
156	unsigned long sp;
157
158	/* Default to using normal stack */
159	sp = regs->regs[29];
160
161	/*
162	* FPU emulator may have it's own trampoline active just
163	* above the user stack, 16-bytes before the next lowest
164	* 16 byte boundary. Try to avoid trashing it.
165	*/
166	sp -= 32;
167
168	/* This is the X/Open sanctioned signal stack switching. */
169	if ((ka->sa.sa_flags & SA_ONSTACK) && (sas_ss_flags (sp) == 0))
170	sp = current->sas_ss_sp + current->sas_ss_size;
171
172	return (void __user *)((sp - frame_size) & (ICACHE_REFILLS_WORKAROUND_WAR ? ~(cpu_icache_line_size()-1) : ALMASK));
173	}
174
175	int install_sigtramp(unsigned int __user *tramp, unsigned int syscall)
176	{
177	int err;
178
179	/*
180	* Set up the return code ...
181	*
182	* li v0, __NR__foo_sigreturn
183	* syscall
184	*/
185
186	err = __put_user(0x24020000 + syscall, tramp + 0);
601dde45	187	err \|= __put_user(0x0000000c , tramp + 1);
c3fc4ab3 FBH	188	if (ICACHE_REFILLS_WORKAROUND_WAR) {
	189	err \|= __put_user(0, tramp + 2);
	190	err \|= __put_user(0, tramp + 3);
	191	err \|= __put_user(0, tramp + 4);
	192	err \|= __put_user(0, tramp + 5);
	193	err \|= __put_user(0, tramp + 6);
	194	err \|= __put_user(0, tramp + 7);
	195	}
	196	flush_cache_sigtramp((unsigned long) tramp);
	197
	198	return err;
	199	}
	200
1da177e4 LT	201	/*
	202	* Atomically swap in the new signal mask, and wait for a signal.
	203	*/
	204
	205	#ifdef CONFIG_TRAD_SIGNALS
	206	save_static_function(sys_sigsuspend);
	207	__attribute_used__ noinline static int
	208	_sys_sigsuspend(nabi_no_regargs struct pt_regs regs)
	209	{
7b3e2fc8	210	sigset_t newset;
fe00f943	211	sigset_t __user *uset;
1da177e4	212
fe00f943	213	uset = (sigset_t __user *) regs.regs[4];
1da177e4 LT	214	if (copy_from_user(&newset, uset, sizeof(sigset_t)))
	215	return -EFAULT;
	216	sigdelsetmask(&newset, ~_BLOCKABLE);
	217
	218	spin_lock_irq(&current->sighand->siglock);
7b3e2fc8	219	current->saved_sigmask = current->blocked;
1da177e4 LT	220	current->blocked = newset;
	221	recalc_sigpending();
	222	spin_unlock_irq(&current->sighand->siglock);
	223
7b3e2fc8 RB	224	current->state = TASK_INTERRUPTIBLE;
	225	schedule();
	226	set_thread_flag(TIF_RESTORE_SIGMASK);
	227	return -ERESTARTNOHAND;
1da177e4 LT	228	}
	229	#endif
	230
	231	save_static_function(sys_rt_sigsuspend);
	232	__attribute_used__ noinline static int
	233	_sys_rt_sigsuspend(nabi_no_regargs struct pt_regs regs)
	234	{
7b3e2fc8	235	sigset_t newset;
fe00f943	236	sigset_t __user *unewset;
1da177e4 LT	237	size_t sigsetsize;
	238
	239	/* XXX Don't preclude handling different sized sigset_t's. */
	240	sigsetsize = regs.regs[5];
	241	if (sigsetsize != sizeof(sigset_t))
	242	return -EINVAL;
	243
fe00f943	244	unewset = (sigset_t __user *) regs.regs[4];
1da177e4 LT	245	if (copy_from_user(&newset, unewset, sizeof(newset)))
	246	return -EFAULT;
	247	sigdelsetmask(&newset, ~_BLOCKABLE);
	248
	249	spin_lock_irq(&current->sighand->siglock);
7b3e2fc8	250	current->saved_sigmask = current->blocked;
1da177e4	251	current->blocked = newset;
e0daad44	252	recalc_sigpending();
1da177e4 LT	253	spin_unlock_irq(&current->sighand->siglock);
1da177e4 LT	254
7b3e2fc8 RB	255	current->state = TASK_INTERRUPTIBLE;
	256	schedule();
	257	set_thread_flag(TIF_RESTORE_SIGMASK);
	258	return -ERESTARTNOHAND;
1da177e4 LT	259	}
	260
	261	#ifdef CONFIG_TRAD_SIGNALS
9c6031cc AN	262	asmlinkage int sys_sigaction(int sig, const struct sigaction __user *act,
9c6031cc AN	263	struct sigaction __user *oact)
1da177e4 LT	264	{
	265	struct k_sigaction new_ka, old_ka;
	266	int ret;
	267	int err = 0;
	268
	269	if (act) {
	270	old_sigset_t mask;
	271
	272	if (!access_ok(VERIFY_READ, act, sizeof(*act)))
	273	return -EFAULT;
	274	err \|= __get_user(new_ka.sa.sa_handler, &act->sa_handler);
	275	err \|= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
	276	err \|= __get_user(mask, &act->sa_mask.sig[0]);
	277	if (err)
	278	return -EFAULT;
	279
	280	siginitset(&new_ka.sa.sa_mask, mask);
	281	}
	282
	283	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	284
	285	if (!ret && oact) {
	286	if (!access_ok(VERIFY_WRITE, oact, sizeof(*oact)))
e0daad44	287	return -EFAULT;
1da177e4 LT	288	err \|= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	289	err \|= __put_user(old_ka.sa.sa_handler, &oact->sa_handler);
	290	err \|= __put_user(old_ka.sa.sa_mask.sig[0], oact->sa_mask.sig);
	291	err \|= __put_user(0, &oact->sa_mask.sig[1]);
	292	err \|= __put_user(0, &oact->sa_mask.sig[2]);
	293	err \|= __put_user(0, &oact->sa_mask.sig[3]);
	294	if (err)
	295	return -EFAULT;
	296	}
	297
	298	return ret;
	299	}
	300	#endif
	301
	302	asmlinkage int sys_sigaltstack(nabi_no_regargs struct pt_regs regs)
	303	{
fe00f943 RB	304	const stack_t __user uss = (const stack_t __user ) regs.regs[4];
fe00f943 RB	305	stack_t __user uoss = (stack_t __user ) regs.regs[5];
1da177e4 LT	306	unsigned long usp = regs.regs[29];
	307
	308	return do_sigaltstack(uss, uoss, usp);
	309	}
	310
1da177e4 LT	311	#ifdef CONFIG_TRAD_SIGNALS
	312	save_static_function(sys_sigreturn);
	313	__attribute_used__ noinline static void
	314	_sys_sigreturn(nabi_no_regargs struct pt_regs regs)
	315	{
9bbf28a3	316	struct sigframe __user *frame;
1da177e4 LT	317	sigset_t blocked;
1da177e4 LT	318
9bbf28a3	319	frame = (struct sigframe __user *) regs.regs[29];
1da177e4 LT	320	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	321	goto badframe;
	322	if (__copy_from_user(&blocked, &frame->sf_mask, sizeof(blocked)))
	323	goto badframe;
	324
	325	sigdelsetmask(&blocked, ~_BLOCKABLE);
	326	spin_lock_irq(&current->sighand->siglock);
	327	current->blocked = blocked;
	328	recalc_sigpending();
	329	spin_unlock_irq(&current->sighand->siglock);
	330
	331	if (restore_sigcontext(&regs, &frame->sf_sc))
	332	goto badframe;
	333
	334	/*
	335	* Don't let your children do this ...
	336	*/
1da177e4 LT	337	__asm__ __volatile__(
	338	"move\t$29, %0\n\t"
	339	"j\tsyscall_exit"
	340	:/* no outputs */
	341	:"r" (&regs));
	342	/* Unreached */
	343
	344	badframe:
	345	force_sig(SIGSEGV, current);
	346	}
e50c0a8f	347	#endif /* CONFIG_TRAD_SIGNALS */
1da177e4 LT	348
	349	save_static_function(sys_rt_sigreturn);
	350	__attribute_used__ noinline static void
	351	_sys_rt_sigreturn(nabi_no_regargs struct pt_regs regs)
	352	{
9bbf28a3	353	struct rt_sigframe __user *frame;
1da177e4 LT	354	sigset_t set;
	355	stack_t st;
	356
9bbf28a3	357	frame = (struct rt_sigframe __user *) regs.regs[29];
1da177e4 LT	358	if (!access_ok(VERIFY_READ, frame, sizeof(*frame)))
	359	goto badframe;
	360	if (__copy_from_user(&set, &frame->rs_uc.uc_sigmask, sizeof(set)))
	361	goto badframe;
	362
	363	sigdelsetmask(&set, ~_BLOCKABLE);
	364	spin_lock_irq(&current->sighand->siglock);
	365	current->blocked = set;
	366	recalc_sigpending();
	367	spin_unlock_irq(&current->sighand->siglock);
	368
	369	if (restore_sigcontext(&regs, &frame->rs_uc.uc_mcontext))
	370	goto badframe;
	371
	372	if (__copy_from_user(&st, &frame->rs_uc.uc_stack, sizeof(st)))
	373	goto badframe;
	374	/* It is more difficult to avoid calling this function than to
	375	call it and ignore errors. */
9bbf28a3	376	do_sigaltstack((stack_t __user *)&st, NULL, regs.regs[29]);
1da177e4 LT	377
	378	/*
	379	* Don't let your children do this ...
	380	*/
	381	__asm__ __volatile__(
	382	"move\t$29, %0\n\t"
	383	"j\tsyscall_exit"
	384	:/* no outputs */
	385	:"r" (&regs));
	386	/* Unreached */
	387
	388	badframe:
	389	force_sig(SIGSEGV, current);
	390	}
	391
	392	#ifdef CONFIG_TRAD_SIGNALS
129bc8f7	393	int setup_frame(struct k_sigaction * ka, struct pt_regs *regs,
1da177e4 LT	394	int signr, sigset_t *set)
1da177e4 LT	395	{
9bbf28a3	396	struct sigframe __user *frame;
1da177e4 LT	397	int err = 0;
	398
	399	frame = get_sigframe(ka, regs, sizeof(*frame));
	400	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
	401	goto give_sigsegv;
	402
601dde45	403	err \|= install_sigtramp(frame->sf_code, __NR_sigreturn);
1da177e4 LT	404
	405	err \|= setup_sigcontext(regs, &frame->sf_sc);
	406	err \|= __copy_to_user(&frame->sf_mask, set, sizeof(*set));
	407	if (err)
	408	goto give_sigsegv;
	409
	410	/*
	411	* Arguments to signal handler:
	412	*
	413	* a0 = signal number
	414	* a1 = 0 (should be cause)
	415	* a2 = pointer to struct sigcontext
	416	*
	417	* $25 and c0_epc point to the signal handler, $29 points to the
	418	* struct sigframe.
	419	*/
	420	regs->regs[ 4] = signr;
	421	regs->regs[ 5] = 0;
	422	regs->regs[ 6] = (unsigned long) &frame->sf_sc;
	423	regs->regs[29] = (unsigned long) frame;
	424	regs->regs[31] = (unsigned long) frame->sf_code;
	425	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
	426
	427	#if DEBUG_SIG
	428	printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
	429	current->comm, current->pid,
	430	frame, regs->cp0_epc, frame->regs[31]);
	431	#endif
e0daad44	432	return 0;
1da177e4 LT	433
	434	give_sigsegv:
	435	force_sigsegv(signr, current);
7b3e2fc8	436	return -EFAULT;
1da177e4 LT	437	}
	438	#endif
	439
129bc8f7	440	int setup_rt_frame(struct k_sigaction * ka, struct pt_regs *regs,
1da177e4 LT	441	int signr, sigset_t set, siginfo_t info)
1da177e4 LT	442	{
9bbf28a3	443	struct rt_sigframe __user *frame;
1da177e4 LT	444	int err = 0;
	445
	446	frame = get_sigframe(ka, regs, sizeof(*frame));
	447	if (!access_ok(VERIFY_WRITE, frame, sizeof (*frame)))
	448	goto give_sigsegv;
	449
601dde45	450	err \|= install_sigtramp(frame->rs_code, __NR_rt_sigreturn);
1da177e4 LT	451
	452	/* Create siginfo. */
	453	err \|= copy_siginfo_to_user(&frame->rs_info, info);
	454
	455	/* Create the ucontext. */
	456	err \|= __put_user(0, &frame->rs_uc.uc_flags);
5665a0ac	457	err \|= __put_user(NULL, &frame->rs_uc.uc_link);
9c6031cc	458	err \|= __put_user((void __user *)current->sas_ss_sp,
1da177e4 LT	459	&frame->rs_uc.uc_stack.ss_sp);
	460	err \|= __put_user(sas_ss_flags(regs->regs[29]),
	461	&frame->rs_uc.uc_stack.ss_flags);
	462	err \|= __put_user(current->sas_ss_size,
	463	&frame->rs_uc.uc_stack.ss_size);
	464	err \|= setup_sigcontext(regs, &frame->rs_uc.uc_mcontext);
	465	err \|= __copy_to_user(&frame->rs_uc.uc_sigmask, set, sizeof(*set));
	466
	467	if (err)
	468	goto give_sigsegv;
	469
	470	/*
	471	* Arguments to signal handler:
	472	*
	473	* a0 = signal number
	474	* a1 = 0 (should be cause)
	475	* a2 = pointer to ucontext
	476	*
	477	* $25 and c0_epc point to the signal handler, $29 points to
	478	* the struct rt_sigframe.
	479	*/
	480	regs->regs[ 4] = signr;
	481	regs->regs[ 5] = (unsigned long) &frame->rs_info;
	482	regs->regs[ 6] = (unsigned long) &frame->rs_uc;
	483	regs->regs[29] = (unsigned long) frame;
	484	regs->regs[31] = (unsigned long) frame->rs_code;
	485	regs->cp0_epc = regs->regs[25] = (unsigned long) ka->sa.sa_handler;
	486
	487	#if DEBUG_SIG
	488	printk("SIG deliver (%s:%d): sp=0x%p pc=0x%lx ra=0x%p\n",
	489	current->comm, current->pid,
	490	frame, regs->cp0_epc, regs->regs[31]);
	491	#endif
7b3e2fc8	492	return 0;
1da177e4 LT	493
	494	give_sigsegv:
	495	force_sigsegv(signr, current);
7b3e2fc8	496	return -EFAULT;
1da177e4 LT	497	}
1da177e4 LT	498
129bc8f7	499	static inline int handle_signal(unsigned long sig, siginfo_t *info,
1da177e4 LT	500	struct k_sigaction ka, sigset_t oldset, struct pt_regs *regs)
1da177e4 LT	501	{
129bc8f7 RB	502	int ret;
129bc8f7 RB	503
1da177e4 LT	504	switch(regs->regs[0]) {
	505	case ERESTART_RESTARTBLOCK:
	506	case ERESTARTNOHAND:
	507	regs->regs[2] = EINTR;
	508	break;
	509	case ERESTARTSYS:
7b3e2fc8	510	if (!(ka->sa.sa_flags & SA_RESTART)) {
1da177e4 LT	511	regs->regs[2] = EINTR;
	512	break;
	513	}
	514	/* fallthrough */
	515	case ERESTARTNOINTR: /* Userland will reload $v0. */
	516	regs->regs[7] = regs->regs[26];
	517	regs->cp0_epc -= 8;
	518	}
	519
	520	regs->regs[0] = 0; /* Don't deal with this again. */
	521
e50c0a8f	522	if (sig_uses_siginfo(ka))
129bc8f7	523	ret = current->thread.abi->setup_rt_frame(ka, regs, sig, oldset, info);
1da177e4	524	else
129bc8f7	525	ret = current->thread.abi->setup_frame(ka, regs, sig, oldset);
1da177e4	526
69be8f18 SR	527	spin_lock_irq(&current->sighand->siglock);
	528	sigorsets(&current->blocked,&current->blocked,&ka->sa.sa_mask);
	529	if (!(ka->sa.sa_flags & SA_NODEFER))
1da177e4	530	sigaddset(&current->blocked,sig);
69be8f18 SR	531	recalc_sigpending();
69be8f18 SR	532	spin_unlock_irq(&current->sighand->siglock);
129bc8f7 RB	533
129bc8f7 RB	534	return ret;
1da177e4 LT	535	}
1da177e4 LT	536
40ac5d47	537	void do_signal(struct pt_regs *regs)
1da177e4 LT	538	{
1da177e4 LT	539	struct k_sigaction ka;
7b3e2fc8	540	sigset_t *oldset;
1da177e4 LT	541	siginfo_t info;
	542	int signr;
	543
1da177e4 LT	544	/*
	545	* We want the common case to go fast, which is why we may in certain
	546	* cases get here from kernel mode. Just return without doing anything
	547	* if so.
	548	*/
	549	if (!user_mode(regs))
40ac5d47	550	return;
1da177e4	551
7b3e2fc8 RB	552	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	553	oldset = &current->saved_sigmask;
	554	else
1da177e4 LT	555	oldset = &current->blocked;
	556
	557	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
7b3e2fc8 RB	558	if (signr > 0) {
	559	/* Whee! Actually deliver the signal. */
	560	if (handle_signal(signr, &info, &ka, oldset, regs) == 0) {
	561	/*
	562	* A signal was successfully delivered; the saved
	563	* sigmask will have been stored in the signal frame,
	564	* and will be restored by sigreturn, so we can simply
	565	* clear the TIF_RESTORE_SIGMASK flag.
	566	*/
	567	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	568	clear_thread_flag(TIF_RESTORE_SIGMASK);
	569	}
45887e12 RB	570
45887e12 RB	571	return;
7b3e2fc8	572	}
1da177e4	573
1da177e4 LT	574	/*
	575	* Who's code doesn't conform to the restartable syscall convention
	576	* dies here!!! The li instruction, a single machine instruction,
	577	* must directly be followed by the syscall instruction.
	578	*/
	579	if (regs->regs[0]) {
	580	if (regs->regs[2] == ERESTARTNOHAND \|\|
	581	regs->regs[2] == ERESTARTSYS \|\|
	582	regs->regs[2] == ERESTARTNOINTR) {
	583	regs->regs[7] = regs->regs[26];
	584	regs->cp0_epc -= 8;
	585	}
	586	if (regs->regs[2] == ERESTART_RESTARTBLOCK) {
	587	regs->regs[2] = __NR_restart_syscall;
	588	regs->regs[7] = regs->regs[26];
	589	regs->cp0_epc -= 4;
	590	}
13fdd31a	591	regs->regs[0] = 0; /* Don't deal with this again. */
1da177e4	592	}
7b3e2fc8 RB	593
	594	/*
	595	* If there's no signal to deliver, we just put the saved sigmask
	596	* back
	597	*/
	598	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	599	clear_thread_flag(TIF_RESTORE_SIGMASK);
	600	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	601	}
1da177e4 LT	602	}
	603
	604	/*
	605	* notification of userspace execution resumption
7b3e2fc8	606	* - triggered by the TIF_WORK_MASK flags
1da177e4	607	*/
7b3e2fc8	608	asmlinkage void do_notify_resume(struct pt_regs regs, void unused,
1da177e4 LT	609	__u32 thread_info_flags)
	610	{
	611	/* deal with pending signal delivery */
7b3e2fc8 RB	612	if (thread_info_flags & (_TIF_SIGPENDING \| _TIF_RESTORE_SIGMASK))
7b3e2fc8 RB	613	current->thread.abi->do_signal(regs);
1da177e4	614	}