[net-next-2.6.git] / arch / powerpc / kernel / signal_64.c

/*
 *  PowerPC version 
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 *
 *  Derived from "arch/i386/kernel/signal.c"
 *    Copyright (C) 1991, 1992 Linus Torvalds
 *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *
 *  This program is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License
 *  as published by the Free Software Foundation; either version
 *  2 of the License, or (at your option) any later version.
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/mm.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/unistd.h>
#include <linux/stddef.h>
#include <linux/elf.h>
#include <linux/ptrace.h>
#include <linux/module.h>

#include <asm/sigcontext.h>
#include <asm/ucontext.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>
#include <asm/vdso.h>

#define DEBUG_SIG 0

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

#define GP_REGS_SIZE	min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
#define FP_REGS_SIZE	sizeof(elf_fpregset_t)

#define TRAMP_TRACEBACK	3
#define TRAMP_SIZE	6

/*
 * When we have signals to deliver, we set up on the user stack,
 * going down from the original stack pointer:
 *	1) a rt_sigframe struct which contains the ucontext	
 *	2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
 *	   frame for the signal handler.
 */

struct rt_sigframe {
	/* sys_rt_sigreturn requires the ucontext be the first field */
	struct ucontext uc;
	unsigned long _unused[2];
	unsigned int tramp[TRAMP_SIZE];
	struct siginfo __user *pinfo;
	void __user *puc;
	struct siginfo info;
	/* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
	char abigap[288];
} __attribute__ ((aligned (16)));

long sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, unsigned long r5,
		     unsigned long r6, unsigned long r7, unsigned long r8,
		     struct pt_regs *regs)
{
	return do_sigaltstack(uss, uoss, regs->gpr[1]);
}


/*
 * Set up the sigcontext for the signal frame.
 */

static long setup_sigcontext(struct sigcontext __user *sc, struct pt_regs *regs,
		 int signr, sigset_t *set, unsigned long handler)
{
	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
	 * process never used altivec yet (MSR_VEC is zero in pt_regs of
	 * the context). This is very important because we must ensure we
	 * don't lose the VRSAVE content that may have been set prior to
	 * the process doing its first vector operation
	 * Userland shall check AT_HWCAP to know wether it can rely on the
	 * v_regs pointer or not
	 */
#ifdef CONFIG_ALTIVEC
	elf_vrreg_t __user *v_regs = (elf_vrreg_t __user *)(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
#endif
	long err = 0;

	flush_fp_to_thread(current);

#ifdef CONFIG_ALTIVEC
	err |= __put_user(v_regs, &sc->v_regs);

	/* save altivec registers */
	if (current->thread.used_vr) {
		flush_altivec_to_thread(current);
		/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
		err |= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
		/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
		 * contains valid data.
		 */
		regs->msr |= MSR_VEC;
	}
	/* We always copy to/from vrsave, it's 0 if we don't have or don't
	 * use altivec.
	 */
	err |= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
#else /* CONFIG_ALTIVEC */
	err |= __put_user(0, &sc->v_regs);
#endif /* CONFIG_ALTIVEC */
	err |= __put_user(&sc->gp_regs, &sc->regs);
	WARN_ON(!FULL_REGS(regs));
	err |= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
	err |= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
	err |= __put_user(signr, &sc->signal);
	err |= __put_user(handler, &sc->handler);
	if (set != NULL)
		err |=  __put_user(set->sig[0], &sc->oldmask);

	return err;
}

/*
 * Restore the sigcontext from the signal frame.
 */

static long restore_sigcontext(struct pt_regs *regs, sigset_t *set, int sig,
			      struct sigcontext __user *sc)
{
#ifdef CONFIG_ALTIVEC
	elf_vrreg_t __user *v_regs;
#endif
	unsigned long err = 0;
	unsigned long save_r13 = 0;
	elf_greg_t *gregs = (elf_greg_t *)regs;
#ifdef CONFIG_ALTIVEC
	unsigned long msr;
#endif
	int i;

	/* If this is not a signal return, we preserve the TLS in r13 */
	if (!sig)
		save_r13 = regs->gpr[13];

	/* copy everything before MSR */
	err |= __copy_from_user(regs, &sc->gp_regs,
				PT_MSR*sizeof(unsigned long));

	/* skip MSR and SOFTE */
	for (i = PT_MSR+1; i <= PT_RESULT; i++) {
		if (i == PT_SOFTE)
			continue;
		err |= __get_user(gregs[i], &sc->gp_regs[i]);
	}

	if (!sig)
		regs->gpr[13] = save_r13;
	if (set != NULL)
		err |=  __get_user(set->sig[0], &sc->oldmask);

	/*
	 * Do this before updating the thread state in
	 * current->thread.fpr/vr.  That way, if we get preempted
	 * and another task grabs the FPU/Altivec, it won't be
	 * tempted to save the current CPU state into the thread_struct
	 * and corrupt what we are writing there.
	 */
	discard_lazy_cpu_state();

	err |= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);

#ifdef CONFIG_ALTIVEC
	err |= __get_user(v_regs, &sc->v_regs);
	err |= __get_user(msr, &sc->gp_regs[PT_MSR]);
	if (err)
		return err;
	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
	if (v_regs != 0 && (msr & MSR_VEC) != 0)
		err |= __copy_from_user(current->thread.vr, v_regs,
					33 * sizeof(vector128));
	else if (current->thread.used_vr)
		memset(current->thread.vr, 0, 33 * sizeof(vector128));
	/* Always get VRSAVE back */
	if (v_regs != 0)
		err |= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
	else
		current->thread.vrsave = 0;
#endif /* CONFIG_ALTIVEC */

	/* Force reload of FP/VEC */
	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1 | MSR_VEC);

	return err;
}

/*
 * Allocate space for the signal frame
 */
static inline void __user * get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,
				  size_t frame_size)
{
        unsigned long newsp;

        /* Default to using normal stack */
        newsp = regs->gpr[1];

	if ((ka->sa.sa_flags & SA_ONSTACK) && current->sas_ss_size) {
		if (! on_sig_stack(regs->gpr[1]))
			newsp = (current->sas_ss_sp + current->sas_ss_size);
	}

        return (void __user *)((newsp - frame_size) & -16ul);
}

/*
 * Setup the trampoline code on the stack
 */
static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
{
	int i;
	long err = 0;

	/* addi r1, r1, __SIGNAL_FRAMESIZE  # Pop the dummy stackframe */
	err |= __put_user(0x38210000UL | (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
	/* li r0, __NR_[rt_]sigreturn| */
	err |= __put_user(0x38000000UL | (syscall & 0xffff), &tramp[1]);
	/* sc */
	err |= __put_user(0x44000002UL, &tramp[2]);

	/* Minimal traceback info */
	for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
		err |= __put_user(0, &tramp[i]);

	if (!err)
		flush_icache_range((unsigned long) &tramp[0],
			   (unsigned long) &tramp[TRAMP_SIZE]);

	return err;
}

/*
 * Restore the user process's signal mask (also used by signal32.c)
 */
void restore_sigmask(sigset_t *set)
{
	sigdelsetmask(set, ~_BLOCKABLE);
	spin_lock_irq(&current->sighand->siglock);
	current->blocked = *set;
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);
}


/*
 * Handle {get,set,swap}_context operations
 */
int sys_swapcontext(struct ucontext __user *old_ctx,
		    struct ucontext __user *new_ctx,
		    long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
{
	unsigned char tmp;
	sigset_t set;

	/* Context size is for future use. Right now, we only make sure
	 * we are passed something we understand
	 */
	if (ctx_size < sizeof(struct ucontext))
		return -EINVAL;

	if (old_ctx != NULL) {
		if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
		    || setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
		    || __copy_to_user(&old_ctx->uc_sigmask,
				      &current->blocked, sizeof(sigset_t)))
			return -EFAULT;
	}
	if (new_ctx == NULL)
		return 0;
	if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
	    || __get_user(tmp, (u8 __user *) new_ctx)
	    || __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
		return -EFAULT;

	/*
	 * If we get a fault copying the context into the kernel's
	 * image of the user's registers, we can't just return -EFAULT
	 * because the user's registers will be corrupted.  For instance
	 * the NIP value may have been updated but not some of the
	 * other registers.  Given that we have done the access_ok
	 * and successfully read the first and last bytes of the region
	 * above, this should only happen in an out-of-memory situation
	 * or if another thread unmaps the region containing the context.
	 * We kill the task with a SIGSEGV in this situation.
	 */

	if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
		do_exit(SIGSEGV);
	restore_sigmask(&set);
	if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
		do_exit(SIGSEGV);

	/* This returns like rt_sigreturn */
	set_thread_flag(TIF_RESTOREALL);
	return 0;
}


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

int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
		     unsigned long r6, unsigned long r7, unsigned long r8,
		     struct pt_regs *regs)
{
	struct ucontext __user *uc = (struct ucontext __user *)regs->gpr[1];
	sigset_t set;

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

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

	if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
		goto badframe;
	restore_sigmask(&set);
	if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
		goto badframe;

	/* do_sigaltstack expects a __user pointer and won't modify
	 * what's in there anyway
	 */
	do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);

	set_thread_flag(TIF_RESTOREALL);
	return 0;

badframe:
#if DEBUG_SIG
	printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
	       regs, uc, &uc->uc_mcontext);
#endif
	force_sig(SIGSEGV, current);
	return 0;
}

static int setup_rt_frame(int signr, struct k_sigaction *ka, siginfo_t *info,
		sigset_t *set, struct pt_regs *regs)
{
	/* Handler is *really* a pointer to the function descriptor for
	 * the signal routine.  The first entry in the function
	 * descriptor is the entry address of signal and the second
	 * entry is the TOC value we need to use.
	 */
	func_descr_t __user *funct_desc_ptr;
	struct rt_sigframe __user *frame;
	unsigned long newsp = 0;
	long err = 0;

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

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

	err |= __put_user(&frame->info, &frame->pinfo);
	err |= __put_user(&frame->uc, &frame->puc);
	err |= copy_siginfo_to_user(&frame->info, info);
	if (err)
		goto badframe;

	/* Create the ucontext.  */
	err |= __put_user(0, &frame->uc.uc_flags);
	err |= __put_user(0, &frame->uc.uc_link);
	err |= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	err |= __put_user(sas_ss_flags(regs->gpr[1]),
			  &frame->uc.uc_stack.ss_flags);
	err |= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	err |= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
				(unsigned long)ka->sa.sa_handler);
	err |= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	if (err)
		goto badframe;

	/* Make sure signal handler doesn't get spurious FP exceptions */
	current->thread.fpscr.val = 0;

	/* Set up to return from userspace. */
	if (vdso64_rt_sigtramp && current->thread.vdso_base) {
		regs->link = current->thread.vdso_base + vdso64_rt_sigtramp;
	} else {
		err |= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
		if (err)
			goto badframe;
		regs->link = (unsigned long) &frame->tramp[0];
	}
	funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;

	/* Allocate a dummy caller frame for the signal handler. */
	newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE;
	err |= put_user(regs->gpr[1], (unsigned long __user *)newsp);

	/* Set up "regs" so we "return" to the signal handler. */
	err |= get_user(regs->nip, &funct_desc_ptr->entry);
	regs->gpr[1] = newsp;
	err |= get_user(regs->gpr[2], &funct_desc_ptr->toc);
	regs->gpr[3] = signr;
	regs->result = 0;
	if (ka->sa.sa_flags & SA_SIGINFO) {
		err |= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
		err |= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
		regs->gpr[6] = (unsigned long) frame;
	} else {
		regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
	}
	if (err)
		goto badframe;

	return 1;

badframe:
#if DEBUG_SIG
	printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
	       regs, frame, newsp);
#endif
	force_sigsegv(signr, current);
	return 0;
}


/*
 * OK, we're invoking a handler
 */
static int handle_signal(unsigned long sig, struct k_sigaction *ka,
			 siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
{
	int ret;

	/* Set up Signal Frame */
	ret = setup_rt_frame(sig, ka, info, oldset, regs);

	if (ret) {
		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;
}

static inline void syscall_restart(struct pt_regs *regs, struct k_sigaction *ka)
{
	switch ((int)regs->result) {
	case -ERESTART_RESTARTBLOCK:
	case -ERESTARTNOHAND:
		/* ERESTARTNOHAND means that the syscall should only be
		 * restarted if there was no handler for the signal, and since
		 * we only get here if there is a handler, we dont restart.
		 */
		regs->result = -EINTR;
		regs->gpr[3] = EINTR;
		regs->ccr |= 0x10000000;
		break;
	case -ERESTARTSYS:
		/* ERESTARTSYS means to restart the syscall if there is no
		 * handler or the handler was registered with SA_RESTART
		 */
		if (!(ka->sa.sa_flags & SA_RESTART)) {
			regs->result = -EINTR;
			regs->gpr[3] = EINTR;
			regs->ccr |= 0x10000000;
			break;
		}
		/* fallthrough */
	case -ERESTARTNOINTR:
		/* ERESTARTNOINTR means that the syscall should be
		 * called again after the signal handler returns.
		 */
		regs->gpr[3] = regs->orig_gpr3;
		regs->nip -= 4;
		regs->result = 0;
		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.
 */
int do_signal(sigset_t *oldset, struct pt_regs *regs)
{
	siginfo_t info;
	int signr;
	struct k_sigaction ka;

	/*
	 * If the current thread is 32 bit - invoke the
	 * 32 bit signal handling code
	 */
	if (test_thread_flag(TIF_32BIT))
		return do_signal32(oldset, regs);

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

	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	if (signr > 0) {
		int ret;

		/* Whee!  Actually deliver the signal.  */
		if (TRAP(regs) == 0x0C00)
			syscall_restart(regs, &ka);

		/*
		 * Reenable the DABR before delivering the signal to
		 * user space. The DABR will have been cleared if it
		 * triggered inside the kernel.
		 */
		if (current->thread.dabr)
			set_dabr(current->thread.dabr);

		ret = handle_signal(signr, &ka, &info, oldset, regs);

		/* If a signal was successfully delivered, the saved sigmask is in
		   its frame, and we can clear the TIF_RESTORE_SIGMASK flag */
		if (ret && test_thread_flag(TIF_RESTORE_SIGMASK))
			clear_thread_flag(TIF_RESTORE_SIGMASK);

		return ret;
	}

	if (TRAP(regs) == 0x0C00) {	/* System Call! */
		if ((int)regs->result == -ERESTARTNOHAND ||
		    (int)regs->result == -ERESTARTSYS ||
		    (int)regs->result == -ERESTARTNOINTR) {
			regs->gpr[3] = regs->orig_gpr3;
			regs->nip -= 4; /* Back up & retry system call */
			regs->result = 0;
		} else if ((int)regs->result == -ERESTART_RESTARTBLOCK) {
			regs->gpr[0] = __NR_restart_syscall;
			regs->nip -= 4;
			regs->result = 0;
		}
	}
	/* No signal to deliver -- 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);
	}

	return 0;
}
EXPORT_SYMBOL(do_signal);
Commit	Line	Data
1da177e4	1	/*
1da177e4 LT	2	* PowerPC version
	3	* Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
	4	*
	5	* Derived from "arch/i386/kernel/signal.c"
	6	* Copyright (C) 1991, 1992 Linus Torvalds
	7	* 1997-11-28 Modified for POSIX.1b signals by Richard Henderson
	8	*
	9	* This program is free software; you can redistribute it and/or
	10	* modify it under the terms of the GNU General Public License
	11	* as published by the Free Software Foundation; either version
	12	* 2 of the License, or (at your option) any later version.
	13	*/
	14
	15	#include <linux/config.h>
	16	#include <linux/sched.h>
	17	#include <linux/mm.h>
	18	#include <linux/smp.h>
	19	#include <linux/smp_lock.h>
	20	#include <linux/kernel.h>
	21	#include <linux/signal.h>
	22	#include <linux/errno.h>
	23	#include <linux/wait.h>
	24	#include <linux/unistd.h>
	25	#include <linux/stddef.h>
	26	#include <linux/elf.h>
	27	#include <linux/ptrace.h>
	28	#include <linux/module.h>
	29
	30	#include <asm/sigcontext.h>
	31	#include <asm/ucontext.h>
	32	#include <asm/uaccess.h>
	33	#include <asm/pgtable.h>
1da177e4 LT	34	#include <asm/unistd.h>
1da177e4 LT	35	#include <asm/cacheflush.h>
a7f31841	36	#include <asm/syscalls.h>
1da177e4 LT	37	#include <asm/vdso.h>
	38
	39	#define DEBUG_SIG 0
	40
	41	#define _BLOCKABLE (~(sigmask(SIGKILL) \| sigmask(SIGSTOP)))
	42
6741f3a7	43	#define GP_REGS_SIZE min(sizeof(elf_gregset_t), sizeof(struct pt_regs))
1da177e4 LT	44	#define FP_REGS_SIZE sizeof(elf_fpregset_t)
	45
	46	#define TRAMP_TRACEBACK 3
	47	#define TRAMP_SIZE 6
	48
	49	/*
	50	* When we have signals to deliver, we set up on the user stack,
	51	* going down from the original stack pointer:
	52	* 1) a rt_sigframe struct which contains the ucontext
	53	* 2) a gap of __SIGNAL_FRAMESIZE bytes which acts as a dummy caller
	54	* frame for the signal handler.
	55	*/
	56
	57	struct rt_sigframe {
	58	/* sys_rt_sigreturn requires the ucontext be the first field */
	59	struct ucontext uc;
	60	unsigned long _unused[2];
	61	unsigned int tramp[TRAMP_SIZE];
29e646df AV	62	struct siginfo __user *pinfo;
29e646df AV	63	void __user *puc;
1da177e4 LT	64	struct siginfo info;
	65	/* 64 bit ABI allows for 288 bytes below sp before decrementing it. */
	66	char abigap[288];
	67	} __attribute__ ((aligned (16)));
	68
1da177e4 LT	69	long sys_sigaltstack(const stack_t __user uss, stack_t __user uoss, unsigned long r5,
	70	unsigned long r6, unsigned long r7, unsigned long r8,
	71	struct pt_regs *regs)
	72	{
	73	return do_sigaltstack(uss, uoss, regs->gpr[1]);
	74	}
	75
	76
	77	/*
	78	* Set up the sigcontext for the signal frame.
	79	*/
	80
	81	static long setup_sigcontext(struct sigcontext __user sc, struct pt_regs regs,
	82	int signr, sigset_t *set, unsigned long handler)
	83	{
	84	/* When CONFIG_ALTIVEC is set, we _always_ setup v_regs even if the
	85	* process never used altivec yet (MSR_VEC is zero in pt_regs of
	86	* the context). This is very important because we must ensure we
	87	* don't lose the VRSAVE content that may have been set prior to
	88	* the process doing its first vector operation
	89	* Userland shall check AT_HWCAP to know wether it can rely on the
	90	* v_regs pointer or not
	91	*/
	92	#ifdef CONFIG_ALTIVEC
	93	elf_vrreg_t __user v_regs = (elf_vrreg_t __user )(((unsigned long)sc->vmx_reserve + 15) & ~0xful);
	94	#endif
	95	long err = 0;
	96
	97	flush_fp_to_thread(current);
	98
1da177e4 LT	99	#ifdef CONFIG_ALTIVEC
	100	err \|= __put_user(v_regs, &sc->v_regs);
	101
	102	/* save altivec registers */
	103	if (current->thread.used_vr) {
	104	flush_altivec_to_thread(current);
	105	/* Copy 33 vec registers (vr0..31 and vscr) to the stack */
	106	err \|= __copy_to_user(v_regs, current->thread.vr, 33 * sizeof(vector128));
	107	/* set MSR_VEC in the MSR value in the frame to indicate that sc->v_reg)
	108	* contains valid data.
	109	*/
	110	regs->msr \|= MSR_VEC;
	111	}
	112	/* We always copy to/from vrsave, it's 0 if we don't have or don't
	113	* use altivec.
	114	*/
	115	err \|= __put_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
	116	#else /* CONFIG_ALTIVEC */
	117	err \|= __put_user(0, &sc->v_regs);
	118	#endif /* CONFIG_ALTIVEC */
	119	err \|= __put_user(&sc->gp_regs, &sc->regs);
1bd79336	120	WARN_ON(!FULL_REGS(regs));
1da177e4 LT	121	err \|= __copy_to_user(&sc->gp_regs, regs, GP_REGS_SIZE);
	122	err \|= __copy_to_user(&sc->fp_regs, &current->thread.fpr, FP_REGS_SIZE);
	123	err \|= __put_user(signr, &sc->signal);
	124	err \|= __put_user(handler, &sc->handler);
	125	if (set != NULL)
	126	err \|= __put_user(set->sig[0], &sc->oldmask);
	127
	128	return err;
	129	}
	130
	131	/*
	132	* Restore the sigcontext from the signal frame.
	133	*/
	134
	135	static long restore_sigcontext(struct pt_regs regs, sigset_t set, int sig,
	136	struct sigcontext __user *sc)
	137	{
	138	#ifdef CONFIG_ALTIVEC
	139	elf_vrreg_t __user *v_regs;
	140	#endif
	141	unsigned long err = 0;
	142	unsigned long save_r13 = 0;
	143	elf_greg_t gregs = (elf_greg_t )regs;
	144	#ifdef CONFIG_ALTIVEC
	145	unsigned long msr;
	146	#endif
	147	int i;
	148
	149	/* If this is not a signal return, we preserve the TLS in r13 */
	150	if (!sig)
	151	save_r13 = regs->gpr[13];
	152
	153	/* copy everything before MSR */
	154	err \|= __copy_from_user(regs, &sc->gp_regs,
	155	PT_MSR*sizeof(unsigned long));
	156
	157	/* skip MSR and SOFTE */
	158	for (i = PT_MSR+1; i <= PT_RESULT; i++) {
	159	if (i == PT_SOFTE)
	160	continue;
	161	err \|= __get_user(gregs[i], &sc->gp_regs[i]);
	162	}
	163
	164	if (!sig)
	165	regs->gpr[13] = save_r13;
1da177e4 LT	166	if (set != NULL)
	167	err \|= __get_user(set->sig[0], &sc->oldmask);
	168
5388fb10 PM	169	/*
	170	* Do this before updating the thread state in
	171	* current->thread.fpr/vr. That way, if we get preempted
	172	* and another task grabs the FPU/Altivec, it won't be
	173	* tempted to save the current CPU state into the thread_struct
	174	* and corrupt what we are writing there.
	175	*/
	176	discard_lazy_cpu_state();
	177
	178	err \|= __copy_from_user(&current->thread.fpr, &sc->fp_regs, FP_REGS_SIZE);
	179
1da177e4 LT	180	#ifdef CONFIG_ALTIVEC
	181	err \|= __get_user(v_regs, &sc->v_regs);
	182	err \|= __get_user(msr, &sc->gp_regs[PT_MSR]);
	183	if (err)
	184	return err;
	185	/* Copy 33 vec registers (vr0..31 and vscr) from the stack */
	186	if (v_regs != 0 && (msr & MSR_VEC) != 0)
	187	err \|= __copy_from_user(current->thread.vr, v_regs,
	188	33 * sizeof(vector128));
	189	else if (current->thread.used_vr)
	190	memset(current->thread.vr, 0, 33 * sizeof(vector128));
	191	/* Always get VRSAVE back */
	192	if (v_regs != 0)
	193	err \|= __get_user(current->thread.vrsave, (u32 __user *)&v_regs[33]);
	194	else
	195	current->thread.vrsave = 0;
	196	#endif /* CONFIG_ALTIVEC */
	197
1da177e4 LT	198	/* Force reload of FP/VEC */
	199	regs->msr &= ~(MSR_FP \| MSR_FE0 \| MSR_FE1 \| MSR_VEC);
	200
	201	return err;
	202	}
	203
	204	/*
	205	* Allocate space for the signal frame
	206	*/
	207	static inline void __user * get_sigframe(struct k_sigaction ka, struct pt_regs regs,
	208	size_t frame_size)
	209	{
	210	unsigned long newsp;
	211
	212	/* Default to using normal stack */
	213	newsp = regs->gpr[1];
	214
11089f08	215	if ((ka->sa.sa_flags & SA_ONSTACK) && current->sas_ss_size) {
1da177e4 LT	216	if (! on_sig_stack(regs->gpr[1]))
	217	newsp = (current->sas_ss_sp + current->sas_ss_size);
	218	}
	219
	220	return (void __user *)((newsp - frame_size) & -16ul);
	221	}
	222
	223	/*
	224	* Setup the trampoline code on the stack
	225	*/
	226	static long setup_trampoline(unsigned int syscall, unsigned int __user *tramp)
	227	{
	228	int i;
	229	long err = 0;
	230
	231	/* addi r1, r1, __SIGNAL_FRAMESIZE # Pop the dummy stackframe */
	232	err \|= __put_user(0x38210000UL \| (__SIGNAL_FRAMESIZE & 0xffff), &tramp[0]);
	233	/* li r0, __NR_[rt_]sigreturn\| */
	234	err \|= __put_user(0x38000000UL \| (syscall & 0xffff), &tramp[1]);
	235	/* sc */
	236	err \|= __put_user(0x44000002UL, &tramp[2]);
	237
	238	/* Minimal traceback info */
	239	for (i=TRAMP_TRACEBACK; i < TRAMP_SIZE ;i++)
	240	err \|= __put_user(0, &tramp[i]);
	241
	242	if (!err)
	243	flush_icache_range((unsigned long) &tramp[0],
	244	(unsigned long) &tramp[TRAMP_SIZE]);
	245
	246	return err;
	247	}
	248
	249	/*
	250	* Restore the user process's signal mask (also used by signal32.c)
	251	*/
	252	void restore_sigmask(sigset_t *set)
	253	{
	254	sigdelsetmask(set, ~_BLOCKABLE);
	255	spin_lock_irq(&current->sighand->siglock);
	256	current->blocked = *set;
	257	recalc_sigpending();
	258	spin_unlock_irq(&current->sighand->siglock);
	259	}
	260
	261
	262	/*
	263	* Handle {get,set,swap}_context operations
	264	*/
	265	int sys_swapcontext(struct ucontext __user *old_ctx,
	266	struct ucontext __user *new_ctx,
	267	long ctx_size, long r6, long r7, long r8, struct pt_regs *regs)
	268	{
	269	unsigned char tmp;
	270	sigset_t set;
	271
	272	/* Context size is for future use. Right now, we only make sure
	273	* we are passed something we understand
	274	*/
	275	if (ctx_size < sizeof(struct ucontext))
	276	return -EINVAL;
	277
	278	if (old_ctx != NULL) {
	279	if (!access_ok(VERIFY_WRITE, old_ctx, sizeof(*old_ctx))
280	\|\| setup_sigcontext(&old_ctx->uc_mcontext, regs, 0, NULL, 0)
281	\|\| __copy_to_user(&old_ctx->uc_sigmask,
282	&current->blocked, sizeof(sigset_t)))
283	return -EFAULT;
284	}
285	if (new_ctx == NULL)
286	return 0;
287	if (!access_ok(VERIFY_READ, new_ctx, sizeof(*new_ctx))
288	\|\| __get_user(tmp, (u8 __user *) new_ctx)
289	\|\| __get_user(tmp, (u8 __user *) (new_ctx + 1) - 1))
290	return -EFAULT;
291
292	/*
293	* If we get a fault copying the context into the kernel's
294	* image of the user's registers, we can't just return -EFAULT
295	* because the user's registers will be corrupted. For instance
296	* the NIP value may have been updated but not some of the
297	* other registers. Given that we have done the access_ok
298	* and successfully read the first and last bytes of the region
299	* above, this should only happen in an out-of-memory situation
300	* or if another thread unmaps the region containing the context.
301	* We kill the task with a SIGSEGV in this situation.
302	*/
303
304	if (__copy_from_user(&set, &new_ctx->uc_sigmask, sizeof(set)))
305	do_exit(SIGSEGV);
306	restore_sigmask(&set);
307	if (restore_sigcontext(regs, NULL, 0, &new_ctx->uc_mcontext))
308	do_exit(SIGSEGV);
309
310	/* This returns like rt_sigreturn */
401d1f02	311	set_thread_flag(TIF_RESTOREALL);
1da177e4 LT	312	return 0;
	313	}
	314
	315
	316	/*
	317	* Do a signal return; undo the signal stack.
	318	*/
	319
	320	int sys_rt_sigreturn(unsigned long r3, unsigned long r4, unsigned long r5,
	321	unsigned long r6, unsigned long r7, unsigned long r8,
	322	struct pt_regs *regs)
	323	{
	324	struct ucontext __user uc = (struct ucontext __user )regs->gpr[1];
	325	sigset_t set;
	326
	327	/* Always make any pending restarted system calls return -EINTR */
	328	current_thread_info()->restart_block.fn = do_no_restart_syscall;
	329
	330	if (!access_ok(VERIFY_READ, uc, sizeof(*uc)))
	331	goto badframe;
	332
	333	if (__copy_from_user(&set, &uc->uc_sigmask, sizeof(set)))
	334	goto badframe;
	335	restore_sigmask(&set);
	336	if (restore_sigcontext(regs, NULL, 1, &uc->uc_mcontext))
	337	goto badframe;
	338
	339	/* do_sigaltstack expects a __user pointer and won't modify
	340	* what's in there anyway
	341	*/
	342	do_sigaltstack(&uc->uc_stack, NULL, regs->gpr[1]);
	343
401d1f02 DW	344	set_thread_flag(TIF_RESTOREALL);
401d1f02 DW	345	return 0;
1da177e4 LT	346
	347	badframe:
	348	#if DEBUG_SIG
	349	printk("badframe in sys_rt_sigreturn, regs=%p uc=%p &uc->uc_mcontext=%p\n",
	350	regs, uc, &uc->uc_mcontext);
	351	#endif
	352	force_sig(SIGSEGV, current);
	353	return 0;
	354	}
	355
	356	static int setup_rt_frame(int signr, struct k_sigaction ka, siginfo_t info,
	357	sigset_t set, struct pt_regs regs)
	358	{
	359	/* Handler is really a pointer to the function descriptor for
	360	* the signal routine. The first entry in the function
	361	* descriptor is the entry address of signal and the second
	362	* entry is the TOC value we need to use.
	363	*/
	364	func_descr_t __user *funct_desc_ptr;
	365	struct rt_sigframe __user *frame;
	366	unsigned long newsp = 0;
	367	long err = 0;
	368
	369	frame = get_sigframe(ka, regs, sizeof(*frame));
	370
	371	if (!access_ok(VERIFY_WRITE, frame, sizeof(*frame)))
	372	goto badframe;
	373
	374	err \|= __put_user(&frame->info, &frame->pinfo);
	375	err \|= __put_user(&frame->uc, &frame->puc);
	376	err \|= copy_siginfo_to_user(&frame->info, info);
	377	if (err)
	378	goto badframe;
	379
	380	/* Create the ucontext. */
	381	err \|= __put_user(0, &frame->uc.uc_flags);
	382	err \|= __put_user(0, &frame->uc.uc_link);
	383	err \|= __put_user(current->sas_ss_sp, &frame->uc.uc_stack.ss_sp);
	384	err \|= __put_user(sas_ss_flags(regs->gpr[1]),
	385	&frame->uc.uc_stack.ss_flags);
	386	err \|= __put_user(current->sas_ss_size, &frame->uc.uc_stack.ss_size);
	387	err \|= setup_sigcontext(&frame->uc.uc_mcontext, regs, signr, NULL,
	388	(unsigned long)ka->sa.sa_handler);
	389	err \|= __copy_to_user(&frame->uc.uc_sigmask, set, sizeof(*set));
	390	if (err)
	391	goto badframe;
	392
cc657f53 PM	393	/* Make sure signal handler doesn't get spurious FP exceptions */
	394	current->thread.fpscr.val = 0;
	395
1da177e4 LT	396	/* Set up to return from userspace. */
	397	if (vdso64_rt_sigtramp && current->thread.vdso_base) {
	398	regs->link = current->thread.vdso_base + vdso64_rt_sigtramp;
	399	} else {
	400	err \|= setup_trampoline(__NR_rt_sigreturn, &frame->tramp[0]);
	401	if (err)
	402	goto badframe;
	403	regs->link = (unsigned long) &frame->tramp[0];
	404	}
	405	funct_desc_ptr = (func_descr_t __user *) ka->sa.sa_handler;
	406
	407	/* Allocate a dummy caller frame for the signal handler. */
	408	newsp = (unsigned long)frame - __SIGNAL_FRAMESIZE;
	409	err \|= put_user(regs->gpr[1], (unsigned long __user *)newsp);
	410
	411	/* Set up "regs" so we "return" to the signal handler. */
	412	err \|= get_user(regs->nip, &funct_desc_ptr->entry);
	413	regs->gpr[1] = newsp;
	414	err \|= get_user(regs->gpr[2], &funct_desc_ptr->toc);
	415	regs->gpr[3] = signr;
	416	regs->result = 0;
	417	if (ka->sa.sa_flags & SA_SIGINFO) {
	418	err \|= get_user(regs->gpr[4], (unsigned long __user *)&frame->pinfo);
	419	err \|= get_user(regs->gpr[5], (unsigned long __user *)&frame->puc);
	420	regs->gpr[6] = (unsigned long) frame;
	421	} else {
	422	regs->gpr[4] = (unsigned long)&frame->uc.uc_mcontext;
	423	}
	424	if (err)
	425	goto badframe;
	426
1da177e4 LT	427	return 1;
	428
	429	badframe:
	430	#if DEBUG_SIG
	431	printk("badframe in setup_rt_frame, regs=%p frame=%p newsp=%lx\n",
	432	regs, frame, newsp);
	433	#endif
	434	force_sigsegv(signr, current);
	435	return 0;
	436	}
	437
	438
	439	/*
	440	* OK, we're invoking a handler
	441	*/
	442	static int handle_signal(unsigned long sig, struct k_sigaction *ka,
	443	siginfo_t info, sigset_t oldset, struct pt_regs *regs)
	444	{
	445	int ret;
	446
	447	/* Set up Signal Frame */
	448	ret = setup_rt_frame(sig, ka, info, oldset, regs);
	449
69be8f18	450	if (ret) {
1da177e4 LT	451	spin_lock_irq(&current->sighand->siglock);
1da177e4 LT	452	sigorsets(&current->blocked, &current->blocked, &ka->sa.sa_mask);
69be8f18 SR	453	if (!(ka->sa.sa_flags & SA_NODEFER))
69be8f18 SR	454	sigaddset(&current->blocked,sig);
1da177e4 LT	455	recalc_sigpending();
	456	spin_unlock_irq(&current->sighand->siglock);
	457	}
	458
	459	return ret;
	460	}
	461
	462	static inline void syscall_restart(struct pt_regs regs, struct k_sigaction ka)
	463	{
	464	switch ((int)regs->result) {
	465	case -ERESTART_RESTARTBLOCK:
	466	case -ERESTARTNOHAND:
	467	/* ERESTARTNOHAND means that the syscall should only be
	468	* restarted if there was no handler for the signal, and since
	469	* we only get here if there is a handler, we dont restart.
	470	*/
	471	regs->result = -EINTR;
401d1f02 DW	472	regs->gpr[3] = EINTR;
401d1f02 DW	473	regs->ccr \|= 0x10000000;
1da177e4 LT	474	break;
	475	case -ERESTARTSYS:
	476	/* ERESTARTSYS means to restart the syscall if there is no
	477	* handler or the handler was registered with SA_RESTART
	478	*/
	479	if (!(ka->sa.sa_flags & SA_RESTART)) {
	480	regs->result = -EINTR;
401d1f02 DW	481	regs->gpr[3] = EINTR;
401d1f02 DW	482	regs->ccr \|= 0x10000000;
1da177e4 LT	483	break;
	484	}
	485	/* fallthrough */
	486	case -ERESTARTNOINTR:
	487	/* ERESTARTNOINTR means that the syscall should be
	488	* called again after the signal handler returns.
	489	*/
	490	regs->gpr[3] = regs->orig_gpr3;
	491	regs->nip -= 4;
	492	regs->result = 0;
	493	break;
	494	}
	495	}
	496
	497	/*
	498	* Note that 'init' is a special process: it doesn't get signals it doesn't
	499	* want to handle. Thus you cannot kill init even with a SIGKILL even by
	500	* mistake.
	501	*/
	502	int do_signal(sigset_t oldset, struct pt_regs regs)
	503	{
	504	siginfo_t info;
	505	int signr;
	506	struct k_sigaction ka;
	507
	508	/*
	509	* If the current thread is 32 bit - invoke the
	510	* 32 bit signal handling code
	511	*/
	512	if (test_thread_flag(TIF_32BIT))
	513	return do_signal32(oldset, regs);
	514
f27201da DW	515	if (test_thread_flag(TIF_RESTORE_SIGMASK))
	516	oldset = &current->saved_sigmask;
	517	else if (!oldset)
1da177e4 LT	518	oldset = &current->blocked;
	519
	520	signr = get_signal_to_deliver(&info, &ka, regs, NULL);
	521	if (signr > 0) {
f27201da DW	522	int ret;
f27201da DW	523
1da177e4 LT	524	/* Whee! Actually deliver the signal. */
	525	if (TRAP(regs) == 0x0C00)
	526	syscall_restart(regs, &ka);
fd9648df AB	527
	528	/*
	529	* Reenable the DABR before delivering the signal to
	530	* user space. The DABR will have been cleared if it
	531	* triggered inside the kernel.
	532	*/
	533	if (current->thread.dabr)
	534	set_dabr(current->thread.dabr);
	535
f27201da DW	536	ret = handle_signal(signr, &ka, &info, oldset, regs);
	537
	538	/* If a signal was successfully delivered, the saved sigmask is in
	539	its frame, and we can clear the TIF_RESTORE_SIGMASK flag */
	540	if (ret && test_thread_flag(TIF_RESTORE_SIGMASK))
	541	clear_thread_flag(TIF_RESTORE_SIGMASK);
	542
	543	return ret;
1da177e4 LT	544	}
	545
	546	if (TRAP(regs) == 0x0C00) { /* System Call! */
	547	if ((int)regs->result == -ERESTARTNOHAND \|\|
	548	(int)regs->result == -ERESTARTSYS \|\|
	549	(int)regs->result == -ERESTARTNOINTR) {
	550	regs->gpr[3] = regs->orig_gpr3;
	551	regs->nip -= 4; /* Back up & retry system call */
	552	regs->result = 0;
	553	} else if ((int)regs->result == -ERESTART_RESTARTBLOCK) {
	554	regs->gpr[0] = __NR_restart_syscall;
	555	regs->nip -= 4;
	556	regs->result = 0;
	557	}
	558	}
f27201da DW	559	/* No signal to deliver -- put the saved sigmask back */
	560	if (test_thread_flag(TIF_RESTORE_SIGMASK)) {
	561	clear_thread_flag(TIF_RESTORE_SIGMASK);
	562	sigprocmask(SIG_SETMASK, &current->saved_sigmask, NULL);
	563	}
1da177e4 LT	564
	565	return 0;
	566	}
	567	EXPORT_SYMBOL(do_signal);