signal_32.c 36.0 KB
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/*
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 * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC
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 *
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 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
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 * Copyright (C) 2001 IBM
 * Copyright (C) 1997,1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
 * Copyright (C) 1997 David S. Miller (davem@caip.rutgers.edu)
 *
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 *  Derived from "arch/i386/kernel/signal.c"
 *    Copyright (C) 1991, 1992 Linus Torvalds
 *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
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 *
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 *  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.
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 */

#include <linux/sched.h>
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#include <linux/mm.h>
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#include <linux/smp.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/errno.h>
#include <linux/elf.h>
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#include <linux/ptrace.h>
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#ifdef CONFIG_PPC64
#include <linux/syscalls.h>
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#include <linux/compat.h>
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#else
#include <linux/wait.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/tty.h>
#include <linux/binfmts.h>
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#include <linux/freezer.h>
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#endif

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#include <asm/uaccess.h>
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#include <asm/cacheflush.h>
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#include <asm/syscalls.h>
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#include <asm/sigcontext.h>
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#include <asm/vdso.h>
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#ifdef CONFIG_PPC64
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#include "ppc32.h"
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#include <asm/unistd.h>
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#else
#include <asm/ucontext.h>
#include <asm/pgtable.h>
#endif
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#include "signal.h"

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#undef DEBUG_SIG
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#ifdef CONFIG_PPC64
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#define sys_sigsuspend	compat_sys_sigsuspend
#define sys_rt_sigsuspend	compat_sys_rt_sigsuspend
#define sys_rt_sigreturn	compat_sys_rt_sigreturn
#define sys_sigaction	compat_sys_sigaction
#define sys_swapcontext	compat_sys_swapcontext
#define sys_sigreturn	compat_sys_sigreturn
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#define old_sigaction	old_sigaction32
#define sigcontext	sigcontext32
#define mcontext	mcontext32
#define ucontext	ucontext32

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/*
 * Userspace code may pass a ucontext which doesn't include VSX added
 * at the end.  We need to check for this case.
 */
#define UCONTEXTSIZEWITHOUTVSX \
		(sizeof(struct ucontext) - sizeof(elf_vsrreghalf_t32))

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/*
 * Returning 0 means we return to userspace via
 * ret_from_except and thus restore all user
 * registers from *regs.  This is what we need
 * to do when a signal has been delivered.
 */

#define GP_REGS_SIZE	min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))
#undef __SIGNAL_FRAMESIZE
#define __SIGNAL_FRAMESIZE	__SIGNAL_FRAMESIZE32
#undef ELF_NVRREG
#define ELF_NVRREG	ELF_NVRREG32

/*
 * Functions for flipping sigsets (thanks to brain dead generic
 * implementation that makes things simple for little endian only)
 */
static inline int put_sigset_t(compat_sigset_t __user *uset, sigset_t *set)
{
	compat_sigset_t	cset;

	switch (_NSIG_WORDS) {
	case 4: cset.sig[5] = set->sig[3] & 0xffffffffull;
		cset.sig[7] = set->sig[3] >> 32;
	case 3: cset.sig[4] = set->sig[2] & 0xffffffffull;
		cset.sig[5] = set->sig[2] >> 32;
	case 2: cset.sig[2] = set->sig[1] & 0xffffffffull;
		cset.sig[3] = set->sig[1] >> 32;
	case 1: cset.sig[0] = set->sig[0] & 0xffffffffull;
		cset.sig[1] = set->sig[0] >> 32;
	}
	return copy_to_user(uset, &cset, sizeof(*uset));
}

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static inline int get_sigset_t(sigset_t *set,
			       const compat_sigset_t __user *uset)
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{
	compat_sigset_t s32;

	if (copy_from_user(&s32, uset, sizeof(*uset)))
		return -EFAULT;

	/*
	 * Swap the 2 words of the 64-bit sigset_t (they are stored
	 * in the "wrong" endian in 32-bit user storage).
	 */
	switch (_NSIG_WORDS) {
	case 4: set->sig[3] = s32.sig[6] | (((long)s32.sig[7]) << 32);
	case 3: set->sig[2] = s32.sig[4] | (((long)s32.sig[5]) << 32);
	case 2: set->sig[1] = s32.sig[2] | (((long)s32.sig[3]) << 32);
	case 1: set->sig[0] = s32.sig[0] | (((long)s32.sig[1]) << 32);
	}
	return 0;
}

static inline int get_old_sigaction(struct k_sigaction *new_ka,
		struct old_sigaction __user *act)
{
	compat_old_sigset_t mask;
	compat_uptr_t handler, restorer;

	if (get_user(handler, &act->sa_handler) ||
	    __get_user(restorer, &act->sa_restorer) ||
	    __get_user(new_ka->sa.sa_flags, &act->sa_flags) ||
	    __get_user(mask, &act->sa_mask))
		return -EFAULT;
	new_ka->sa.sa_handler = compat_ptr(handler);
	new_ka->sa.sa_restorer = compat_ptr(restorer);
	siginitset(&new_ka->sa.sa_mask, mask);
	return 0;
}

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#define to_user_ptr(p)		ptr_to_compat(p)
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#define from_user_ptr(p)	compat_ptr(p)

static inline int save_general_regs(struct pt_regs *regs,
		struct mcontext __user *frame)
{
	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
	int i;

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	WARN_ON(!FULL_REGS(regs));
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	for (i = 0; i <= PT_RESULT; i ++) {
		if (i == 14 && !FULL_REGS(regs))
			i = 32;
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		if (__put_user((unsigned int)gregs[i], &frame->mc_gregs[i]))
			return -EFAULT;
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	}
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	return 0;
}

static inline int restore_general_regs(struct pt_regs *regs,
		struct mcontext __user *sr)
{
	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
	int i;

	for (i = 0; i <= PT_RESULT; i++) {
		if ((i == PT_MSR) || (i == PT_SOFTE))
			continue;
		if (__get_user(gregs[i], &sr->mc_gregs[i]))
			return -EFAULT;
	}
	return 0;
}

#else /* CONFIG_PPC64 */

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

static inline int put_sigset_t(sigset_t __user *uset, sigset_t *set)
{
	return copy_to_user(uset, set, sizeof(*uset));
}

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static inline int get_sigset_t(sigset_t *set, const sigset_t __user *uset)
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{
	return copy_from_user(set, uset, sizeof(*uset));
}

static inline int get_old_sigaction(struct k_sigaction *new_ka,
		struct old_sigaction __user *act)
{
	old_sigset_t mask;

	if (!access_ok(VERIFY_READ, act, sizeof(*act)) ||
			__get_user(new_ka->sa.sa_handler, &act->sa_handler) ||
			__get_user(new_ka->sa.sa_restorer, &act->sa_restorer))
		return -EFAULT;
	__get_user(new_ka->sa.sa_flags, &act->sa_flags);
	__get_user(mask, &act->sa_mask);
	siginitset(&new_ka->sa.sa_mask, mask);
	return 0;
}

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#define to_user_ptr(p)		((unsigned long)(p))
#define from_user_ptr(p)	((void __user *)(p))
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static inline int save_general_regs(struct pt_regs *regs,
		struct mcontext __user *frame)
{
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	WARN_ON(!FULL_REGS(regs));
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	return __copy_to_user(&frame->mc_gregs, regs, GP_REGS_SIZE);
}

static inline int restore_general_regs(struct pt_regs *regs,
		struct mcontext __user *sr)
{
	/* copy up to but not including MSR */
	if (__copy_from_user(regs, &sr->mc_gregs,
				PT_MSR * sizeof(elf_greg_t)))
		return -EFAULT;
	/* copy from orig_r3 (the word after the MSR) up to the end */
	if (__copy_from_user(&regs->orig_gpr3, &sr->mc_gregs[PT_ORIG_R3],
				GP_REGS_SIZE - PT_ORIG_R3 * sizeof(elf_greg_t)))
		return -EFAULT;
	return 0;
}

#endif /* CONFIG_PPC64 */

/*
 * Atomically swap in the new signal mask, and wait for a signal.
 */
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long sys_sigsuspend(old_sigset_t mask)
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{
	mask &= _BLOCKABLE;
	spin_lock_irq(&current->sighand->siglock);
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	current->saved_sigmask = current->blocked;
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	siginitset(&current->blocked, mask);
	recalc_sigpending();
	spin_unlock_irq(&current->sighand->siglock);

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

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

#ifdef CONFIG_PPC64
	if (sig < 0)
		sig = -sig;
#endif

	if (act) {
		if (get_old_sigaction(&new_ka, act))
			return -EFAULT;
	}

	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(to_user_ptr(old_ka.sa.sa_handler),
			    &oact->sa_handler) ||
		    __put_user(to_user_ptr(old_ka.sa.sa_restorer),
			    &oact->sa_restorer) ||
		    __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;
}
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/*
 * When we have signals to deliver, we set up on the
 * user stack, going down from the original stack pointer:
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 *	an ABI gap of 56 words
 *	an mcontext struct
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 *	a sigcontext struct
 *	a gap of __SIGNAL_FRAMESIZE bytes
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 *
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 * Each of these things must be a multiple of 16 bytes in size. The following
 * structure represent all of this except the __SIGNAL_FRAMESIZE gap
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 *
 */
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struct sigframe {
	struct sigcontext sctx;		/* the sigcontext */
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	struct mcontext	mctx;		/* all the register values */
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	/*
	 * Programs using the rs6000/xcoff abi can save up to 19 gp
	 * regs and 18 fp regs below sp before decrementing it.
	 */
	int			abigap[56];
};

/* We use the mc_pad field for the signal return trampoline. */
#define tramp	mc_pad

/*
 *  When we have rt signals to deliver, we set up on the
 *  user stack, going down from the original stack pointer:
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 *	one rt_sigframe struct (siginfo + ucontext + ABI gap)
 *	a gap of __SIGNAL_FRAMESIZE+16 bytes
 *  (the +16 is to get the siginfo and ucontext in the same
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 *  positions as in older kernels).
 *
 *  Each of these things must be a multiple of 16 bytes in size.
 *
 */
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struct rt_sigframe {
#ifdef CONFIG_PPC64
	compat_siginfo_t info;
#else
	struct siginfo info;
#endif
	struct ucontext	uc;
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	/*
	 * Programs using the rs6000/xcoff abi can save up to 19 gp
	 * regs and 18 fp regs below sp before decrementing it.
	 */
	int			abigap[56];
};

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#ifdef CONFIG_VSX
unsigned long copy_fpr_to_user(void __user *to,
			       struct task_struct *task)
{
	double buf[ELF_NFPREG];
	int i;

	/* save FPR copy to local buffer then write to the thread_struct */
	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
		buf[i] = task->thread.TS_FPR(i);
	memcpy(&buf[i], &task->thread.fpscr, sizeof(double));
	return __copy_to_user(to, buf, ELF_NFPREG * sizeof(double));
}

unsigned long copy_fpr_from_user(struct task_struct *task,
				 void __user *from)
{
	double buf[ELF_NFPREG];
	int i;

	if (__copy_from_user(buf, from, ELF_NFPREG * sizeof(double)))
		return 1;
	for (i = 0; i < (ELF_NFPREG - 1) ; i++)
		task->thread.TS_FPR(i) = buf[i];
	memcpy(&task->thread.fpscr, &buf[i], sizeof(double));

	return 0;
}

unsigned long copy_vsx_to_user(void __user *to,
			       struct task_struct *task)
{
	double buf[ELF_NVSRHALFREG];
	int i;

	/* save FPR copy to local buffer then write to the thread_struct */
	for (i = 0; i < ELF_NVSRHALFREG; i++)
		buf[i] = task->thread.fpr[i][TS_VSRLOWOFFSET];
	return __copy_to_user(to, buf, ELF_NVSRHALFREG * sizeof(double));
}

unsigned long copy_vsx_from_user(struct task_struct *task,
				 void __user *from)
{
	double buf[ELF_NVSRHALFREG];
	int i;

	if (__copy_from_user(buf, from, ELF_NVSRHALFREG * sizeof(double)))
		return 1;
	for (i = 0; i < ELF_NVSRHALFREG ; i++)
		task->thread.fpr[i][TS_VSRLOWOFFSET] = buf[i];
	return 0;
}
#else
inline unsigned long copy_fpr_to_user(void __user *to,
				      struct task_struct *task)
{
	return __copy_to_user(to, task->thread.fpr,
			      ELF_NFPREG * sizeof(double));
}

inline unsigned long copy_fpr_from_user(struct task_struct *task,
					void __user *from)
{
	return __copy_from_user(task->thread.fpr, from,
			      ELF_NFPREG * sizeof(double));
}
#endif

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/*
 * Save the current user registers on the user stack.
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 * We only save the altivec/spe registers if the process has used
 * altivec/spe instructions at some point.
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 */
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static int save_user_regs(struct pt_regs *regs, struct mcontext __user *frame,
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		int sigret, int ctx_has_vsx_region)
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{
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	unsigned long msr = regs->msr;

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	/* Make sure floating point registers are stored in regs */
	flush_fp_to_thread(current);

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	/* save general registers */
	if (save_general_regs(regs, frame))
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		return 1;

#ifdef CONFIG_ALTIVEC
	/* save altivec registers */
	if (current->thread.used_vr) {
		flush_altivec_to_thread(current);
		if (__copy_to_user(&frame->mc_vregs, current->thread.vr,
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				   ELF_NVRREG * sizeof(vector128)))
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			return 1;
		/* set MSR_VEC in the saved MSR value to indicate that
		   frame->mc_vregs contains valid data */
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		msr |= MSR_VEC;
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	}
	/* else assert((regs->msr & MSR_VEC) == 0) */

	/* We always copy to/from vrsave, it's 0 if we don't have or don't
	 * use altivec. Since VSCR only contains 32 bits saved in the least
	 * significant bits of a vector, we "cheat" and stuff VRSAVE in the
	 * most significant bits of that same vector. --BenH
	 */
	if (__put_user(current->thread.vrsave, (u32 __user *)&frame->mc_vregs[32]))
		return 1;
#endif /* CONFIG_ALTIVEC */
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	if (copy_fpr_to_user(&frame->mc_fregs, current))
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		return 1;
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#ifdef CONFIG_VSX
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	/*
	 * Copy VSR 0-31 upper half from thread_struct to local
	 * buffer, then write that to userspace.  Also set MSR_VSX in
	 * the saved MSR value to indicate that frame->mc_vregs
	 * contains valid data
	 */
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	if (current->thread.used_vsr && ctx_has_vsx_region) {
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		__giveup_vsx(current);
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		if (copy_vsx_to_user(&frame->mc_vsregs, current))
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			return 1;
		msr |= MSR_VSX;
	}
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#endif /* CONFIG_VSX */
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#ifdef CONFIG_SPE
	/* save spe registers */
	if (current->thread.used_spe) {
		flush_spe_to_thread(current);
		if (__copy_to_user(&frame->mc_vregs, current->thread.evr,
				   ELF_NEVRREG * sizeof(u32)))
			return 1;
		/* set MSR_SPE in the saved MSR value to indicate that
		   frame->mc_vregs contains valid data */
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		msr |= MSR_SPE;
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	}
	/* else assert((regs->msr & MSR_SPE) == 0) */

	/* We always copy to/from spefscr */
	if (__put_user(current->thread.spefscr, (u32 __user *)&frame->mc_vregs + ELF_NEVRREG))
		return 1;
#endif /* CONFIG_SPE */

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	if (__put_user(msr, &frame->mc_gregs[PT_MSR]))
		return 1;
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	if (sigret) {
		/* Set up the sigreturn trampoline: li r0,sigret; sc */
		if (__put_user(0x38000000UL + sigret, &frame->tramp[0])
		    || __put_user(0x44000002UL, &frame->tramp[1]))
			return 1;
		flush_icache_range((unsigned long) &frame->tramp[0],
				   (unsigned long) &frame->tramp[2]);
	}

	return 0;
}

/*
 * Restore the current user register values from the user stack,
 * (except for MSR).
 */
static long restore_user_regs(struct pt_regs *regs,
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			      struct mcontext __user *sr, int sig)
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{
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	long err;
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	unsigned int save_r2 = 0;
	unsigned long msr;
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#ifdef CONFIG_VSX
	int i;
#endif
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	/*
	 * restore general registers but not including MSR or SOFTE. Also
	 * take care of keeping r2 (TLS) intact if not a signal
	 */
	if (!sig)
		save_r2 = (unsigned int)regs->gpr[2];
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	err = restore_general_regs(regs, sr);
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	err |= __get_user(msr, &sr->mc_gregs[PT_MSR]);
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	if (!sig)
		regs->gpr[2] = (unsigned long) save_r2;
	if (err)
		return 1;

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	/* if doing signal return, restore the previous little-endian mode */
	if (sig)
		regs->msr = (regs->msr & ~MSR_LE) | (msr & MSR_LE);

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	/*
	 * Do this before updating the thread state in
	 * current->thread.fpr/vr/evr.  That way, if we get preempted
	 * and another task grabs the FPU/Altivec/SPE, 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();

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#ifdef CONFIG_ALTIVEC
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	/*
	 * Force the process to reload the altivec registers from
	 * current->thread when it next does altivec instructions
	 */
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	regs->msr &= ~MSR_VEC;
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	if (msr & MSR_VEC) {
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		/* restore altivec registers from the stack */
		if (__copy_from_user(current->thread.vr, &sr->mc_vregs,
				     sizeof(sr->mc_vregs)))
			return 1;
	} else if (current->thread.used_vr)
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		memset(current->thread.vr, 0, ELF_NVRREG * sizeof(vector128));
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	/* Always get VRSAVE back */
	if (__get_user(current->thread.vrsave, (u32 __user *)&sr->mc_vregs[32]))
		return 1;
#endif /* CONFIG_ALTIVEC */
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	if (copy_fpr_from_user(current, &sr->mc_fregs))
		return 1;
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#ifdef CONFIG_VSX
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	/*
	 * Force the process to reload the VSX registers from
	 * current->thread when it next does VSX instruction.
	 */
	regs->msr &= ~MSR_VSX;
	if (msr & MSR_VSX) {
		/*
		 * Restore altivec registers from the stack to a local
		 * buffer, then write this out to the thread_struct
		 */
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		if (copy_vsx_from_user(current, &sr->mc_vsregs))
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			return 1;
	} else if (current->thread.used_vsr)
		for (i = 0; i < 32 ; i++)
			current->thread.fpr[i][TS_VSRLOWOFFSET] = 0;
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#endif /* CONFIG_VSX */
	/*
	 * force the process to reload the FP registers from
	 * current->thread when it next does FP instructions
	 */
	regs->msr &= ~(MSR_FP | MSR_FE0 | MSR_FE1);

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#ifdef CONFIG_SPE
	/* force the process to reload the spe registers from
	   current->thread when it next does spe instructions */
	regs->msr &= ~MSR_SPE;
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	if (msr & MSR_SPE) {
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		/* restore spe registers from the stack */
		if (__copy_from_user(current->thread.evr, &sr->mc_vregs,
				     ELF_NEVRREG * sizeof(u32)))
			return 1;
	} else if (current->thread.used_spe)
		memset(current->thread.evr, 0, ELF_NEVRREG * sizeof(u32));

	/* Always get SPEFSCR back */
	if (__get_user(current->thread.spefscr, (u32 __user *)&sr->mc_vregs + ELF_NEVRREG))
		return 1;
#endif /* CONFIG_SPE */

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	return 0;
}

597
#ifdef CONFIG_PPC64
598
long compat_sys_rt_sigaction(int sig, const struct sigaction32 __user *act,
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		struct sigaction32 __user *oact, size_t sigsetsize)
{
	struct k_sigaction new_ka, old_ka;
	int ret;

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

	if (act) {
		compat_uptr_t handler;

		ret = get_user(handler, &act->sa_handler);
		new_ka.sa.sa_handler = compat_ptr(handler);
613
		ret |= get_sigset_t(&new_ka.sa.sa_mask, &act->sa_mask);
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		ret |= __get_user(new_ka.sa.sa_flags, &act->sa_flags);
		if (ret)
			return -EFAULT;
	}

	ret = do_sigaction(sig, act ? &new_ka : NULL, oact ? &old_ka : NULL);
	if (!ret && oact) {
621
		ret = put_user(to_user_ptr(old_ka.sa.sa_handler), &oact->sa_handler);
622
		ret |= put_sigset_t(&oact->sa_mask, &old_ka.sa.sa_mask);
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		ret |= __put_user(old_ka.sa.sa_flags, &oact->sa_flags);
	}
	return ret;
}

/*
 * Note: it is necessary to treat how as an unsigned int, with the
 * corresponding cast to a signed int to insure that the proper
 * conversion (sign extension) between the register representation
 * of a signed int (msr in 32-bit mode) and the register representation
 * of a signed int (msr in 64-bit mode) is performed.
 */
635
long compat_sys_rt_sigprocmask(u32 how, compat_sigset_t __user *set,
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		compat_sigset_t __user *oset, size_t sigsetsize)
{
	sigset_t s;
	sigset_t __user *up;
	int ret;
	mm_segment_t old_fs = get_fs();

	if (set) {
644 645
		if (get_sigset_t(&s, set))
			return -EFAULT;
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	}
647

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	set_fs(KERNEL_DS);
	/* This is valid because of the set_fs() */
	up = (sigset_t __user *) &s;
	ret = sys_rt_sigprocmask((int)how, set ? up : NULL, oset ? up : NULL,
652
				 sigsetsize);
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	set_fs(old_fs);
	if (ret)
		return ret;
	if (oset) {
657
		if (put_sigset_t(oset, &s))
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			return -EFAULT;
	}
	return 0;
}

663
long compat_sys_rt_sigpending(compat_sigset_t __user *set, compat_size_t sigsetsize)
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{
	sigset_t s;
	int ret;
	mm_segment_t old_fs = get_fs();

	set_fs(KERNEL_DS);
	/* The __user pointer cast is valid because of the set_fs() */
	ret = sys_rt_sigpending((sigset_t __user *) &s, sigsetsize);
	set_fs(old_fs);
	if (!ret) {
674
		if (put_sigset_t(set, &s))
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			return -EFAULT;
	}
	return ret;
}


int copy_siginfo_to_user32(struct compat_siginfo __user *d, siginfo_t *s)
{
	int err;

	if (!access_ok (VERIFY_WRITE, d, sizeof(*d)))
		return -EFAULT;

	/* If you change siginfo_t structure, please be sure
	 * this code is fixed accordingly.
	 * It should never copy any pad contained in the structure
	 * to avoid security leaks, but must copy the generic
	 * 3 ints plus the relevant union member.
	 * This routine must convert siginfo from 64bit to 32bit as well
	 * at the same time.
	 */
	err = __put_user(s->si_signo, &d->si_signo);
	err |= __put_user(s->si_errno, &d->si_errno);
	err |= __put_user((short)s->si_code, &d->si_code);
	if (s->si_code < 0)
		err |= __copy_to_user(&d->_sifields._pad, &s->_sifields._pad,
				      SI_PAD_SIZE32);
	else switch(s->si_code >> 16) {
	case __SI_CHLD >> 16:
		err |= __put_user(s->si_pid, &d->si_pid);
		err |= __put_user(s->si_uid, &d->si_uid);
		err |= __put_user(s->si_utime, &d->si_utime);
		err |= __put_user(s->si_stime, &d->si_stime);
		err |= __put_user(s->si_status, &d->si_status);
		break;
	case __SI_FAULT >> 16:
		err |= __put_user((unsigned int)(unsigned long)s->si_addr,
				  &d->si_addr);
		break;
	case __SI_POLL >> 16:
		err |= __put_user(s->si_band, &d->si_band);
		err |= __put_user(s->si_fd, &d->si_fd);
		break;
	case __SI_TIMER >> 16:
		err |= __put_user(s->si_tid, &d->si_tid);
		err |= __put_user(s->si_overrun, &d->si_overrun);
		err |= __put_user(s->si_int, &d->si_int);
		break;
	case __SI_RT >> 16: /* This is not generated by the kernel as of now.  */
	case __SI_MESGQ >> 16:
		err |= __put_user(s->si_int, &d->si_int);
		/* fallthrough */
	case __SI_KILL >> 16:
	default:
		err |= __put_user(s->si_pid, &d->si_pid);
		err |= __put_user(s->si_uid, &d->si_uid);
		break;
	}
	return err;
}

736 737
#define copy_siginfo_to_user	copy_siginfo_to_user32

738 739 740 741 742 743 744 745 746 747 748 749
int copy_siginfo_from_user32(siginfo_t *to, struct compat_siginfo __user *from)
{
	memset(to, 0, sizeof *to);

	if (copy_from_user(to, from, 3*sizeof(int)) ||
	    copy_from_user(to->_sifields._pad,
			   from->_sifields._pad, SI_PAD_SIZE32))
		return -EFAULT;

	return 0;
}

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/*
 * Note: it is necessary to treat pid and sig as unsigned ints, with the
 * corresponding cast to a signed int to insure that the proper conversion
 * (sign extension) between the register representation of a signed int
 * (msr in 32-bit mode) and the register representation of a signed int
 * (msr in 64-bit mode) is performed.
 */
757
long compat_sys_rt_sigqueueinfo(u32 pid, u32 sig, compat_siginfo_t __user *uinfo)
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{
	siginfo_t info;
	int ret;
	mm_segment_t old_fs = get_fs();
762

763 764 765 766
	ret = copy_siginfo_from_user32(&info, uinfo);
	if (unlikely(ret))
		return ret;

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	set_fs (KERNEL_DS);
	/* The __user pointer cast is valid becasuse of the set_fs() */
	ret = sys_rt_sigqueueinfo((int)pid, (int)sig, (siginfo_t __user *) &info);
	set_fs (old_fs);
	return ret;
}
/*
 *  Start Alternate signal stack support
 *
 *  System Calls
777
 *       sigaltatck               compat_sys_sigaltstack
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 */

780
int compat_sys_sigaltstack(u32 __new, u32 __old, int r5,
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		      int r6, int r7, int r8, struct pt_regs *regs)
{
783 784
	stack_32_t __user * newstack = compat_ptr(__new);
	stack_32_t __user * oldstack = compat_ptr(__old);
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	stack_t uss, uoss;
	int ret;
	mm_segment_t old_fs;
	unsigned long sp;
	compat_uptr_t ss_sp;

	/*
	 * set sp to the user stack on entry to the system call
	 * the system call router sets R9 to the saved registers
	 */
	sp = regs->gpr[1];

	/* Put new stack info in local 64 bit stack struct */
	if (newstack) {
		if (get_user(ss_sp, &newstack->ss_sp) ||
		    __get_user(uss.ss_flags, &newstack->ss_flags) ||
		    __get_user(uss.ss_size, &newstack->ss_size))
			return -EFAULT;
		uss.ss_sp = compat_ptr(ss_sp);
	}

	old_fs = get_fs();
	set_fs(KERNEL_DS);
	/* The __user pointer casts are valid because of the set_fs() */
	ret = do_sigaltstack(
		newstack ? (stack_t __user *) &uss : NULL,
		oldstack ? (stack_t __user *) &uoss : NULL,
		sp);
	set_fs(old_fs);
	/* Copy the stack information to the user output buffer */
	if (!ret && oldstack  &&
816
		(put_user(ptr_to_compat(uoss.ss_sp), &oldstack->ss_sp) ||
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		 __put_user(uoss.ss_flags, &oldstack->ss_flags) ||
		 __put_user(uoss.ss_size, &oldstack->ss_size)))
		return -EFAULT;
	return ret;
}
822
#endif /* CONFIG_PPC64 */
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/*
 * Set up a signal frame for a "real-time" signal handler
 * (one which gets siginfo).
 */
828
int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
829
		siginfo_t *info, sigset_t *oldset,
830
		struct pt_regs *regs)
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{
832 833
	struct rt_sigframe __user *rt_sf;
	struct mcontext __user *frame;
834
	void __user *addr;
835
	unsigned long newsp = 0;
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	/* Set up Signal Frame */
	/* Put a Real Time Context onto stack */
839
	rt_sf = get_sigframe(ka, regs, sizeof(*rt_sf), 1);
840
	addr = rt_sf;
841
	if (unlikely(rt_sf == NULL))
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		goto badframe;

	/* Put the siginfo & fill in most of the ucontext */
845
	if (copy_siginfo_to_user(&rt_sf->info, info)
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	    || __put_user(0, &rt_sf->uc.uc_flags)
	    || __put_user(0, &rt_sf->uc.uc_link)
	    || __put_user(current->sas_ss_sp, &rt_sf->uc.uc_stack.ss_sp)
	    || __put_user(sas_ss_flags(regs->gpr[1]),
			  &rt_sf->uc.uc_stack.ss_flags)
	    || __put_user(current->sas_ss_size, &rt_sf->uc.uc_stack.ss_size)
852 853 854
	    || __put_user(to_user_ptr(&rt_sf->uc.uc_mcontext),
		    &rt_sf->uc.uc_regs)
	    || put_sigset_t(&rt_sf->uc.uc_sigmask, oldset))
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		goto badframe;

	/* Save user registers on the stack */
	frame = &rt_sf->uc.uc_mcontext;
859
	addr = frame;
860
	if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
861
		if (save_user_regs(regs, frame, 0, 1))
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			goto badframe;
863
		regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp;
864
	} else {
865
		if (save_user_regs(regs, frame, __NR_rt_sigreturn, 1))
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			goto badframe;
		regs->link = (unsigned long) frame->tramp;
	}
869 870 871

	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */

872 873
	/* create a stack frame for the caller of the handler */
	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
874
	addr = (void __user *)regs->gpr[1];
875
	if (put_user(regs->gpr[1], (u32 __user *)newsp))
876
		goto badframe;
877 878

	/* Fill registers for signal handler */
879
	regs->gpr[1] = newsp;
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	regs->gpr[3] = sig;
	regs->gpr[4] = (unsigned long) &rt_sf->info;
	regs->gpr[5] = (unsigned long) &rt_sf->uc;
	regs->gpr[6] = (unsigned long) rt_sf;
	regs->nip = (unsigned long) ka->sa.sa_handler;
885 886
	/* enter the signal handler in big-endian mode */
	regs->msr &= ~MSR_LE;
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	regs->trap = 0;
	return 1;

badframe:
891
#ifdef DEBUG_SIG
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	printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
	       regs, frame, newsp);
#endif
895 896 897 898 899 900
	if (show_unhandled_signals && printk_ratelimit())
		printk(KERN_INFO "%s[%d]: bad frame in handle_rt_signal32: "
			"%p nip %08lx lr %08lx\n",
			current->comm, current->pid,
			addr, regs->nip, regs->link);

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	force_sigsegv(sig, current);
	return 0;
}

905
static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
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{
	sigset_t set;
908 909 910 911 912 913 914
	struct mcontext __user *mcp;

	if (get_sigset_t(&set, &ucp->uc_sigmask))
		return -EFAULT;
#ifdef CONFIG_PPC64
	{
		u32 cmcp;
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916 917 918
		if (__get_user(cmcp, &ucp->uc_regs))
			return -EFAULT;
		mcp = (struct mcontext __user *)(u64)cmcp;
919
		/* no need to check access_ok(mcp), since mcp < 4GB */
920 921 922
	}
#else
	if (__get_user(mcp, &ucp->uc_regs))
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		return -EFAULT;
924 925
	if (!access_ok(VERIFY_READ, mcp, sizeof(*mcp)))
		return -EFAULT;
926
#endif
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	restore_sigmask(&set);
928
	if (restore_user_regs(regs, mcp, sig))
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		return -EFAULT;

	return 0;
}

934
long sys_swapcontext(struct ucontext __user *old_ctx,
935 936
		     struct ucontext __user *new_ctx,
		     int ctx_size, int r6, int r7, int r8, struct pt_regs *regs)
L
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{
	unsigned char tmp;
939
	int ctx_has_vsx_region = 0;
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941 942 943
#ifdef CONFIG_PPC64
	unsigned long new_msr = 0;

944 945 946 947 948 949 950 951 952 953 954 955 956 957 958
	if (new_ctx) {
		struct mcontext __user *mcp;
		u32 cmcp;

		/*
		 * Get pointer to the real mcontext.  No need for
		 * access_ok since we are dealing with compat
		 * pointers.
		 */
		if (__get_user(cmcp, &new_ctx->uc_regs))
			return -EFAULT;
		mcp = (struct mcontext __user *)(u64)cmcp;
		if (__get_user(new_msr, &mcp->mc_gregs[PT_MSR]))
			return -EFAULT;
	}
959 960 961 962 963 964 965 966 967 968 969 970 971
	/*
	 * Check that the context is not smaller than the original
	 * size (with VMX but without VSX)
	 */
	if (ctx_size < UCONTEXTSIZEWITHOUTVSX)
		return -EINVAL;
	/*
	 * If the new context state sets the MSR VSX bits but
	 * it doesn't provide VSX state.
	 */
	if ((ctx_size < sizeof(struct ucontext)) &&
	    (new_msr & MSR_VSX))
		return -EINVAL;
972 973 974
	/* Does the context have enough room to store VSX data? */
	if (ctx_size >= sizeof(struct ucontext))
		ctx_has_vsx_region = 1;
975
#else
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	/* Context size is for future use. Right now, we only make sure
	 * we are passed something we understand
	 */
979
	if (ctx_size < sizeof(struct ucontext))
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		return -EINVAL;
981
#endif
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	if (old_ctx != NULL) {
983 984 985 986 987 988 989 990 991 992 993
		struct mcontext __user *mctx;

		/*
		 * old_ctx might not be 16-byte aligned, in which
		 * case old_ctx->uc_mcontext won't be either.
		 * Because we have the old_ctx->uc_pad2 field
		 * before old_ctx->uc_mcontext, we need to round down
		 * from &old_ctx->uc_mcontext to a 16-byte boundary.
		 */
		mctx = (struct mcontext __user *)
			((unsigned long) &old_ctx->uc_mcontext & ~0xfUL);
994 995
		if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
		    || save_user_regs(regs, mctx, 0, ctx_has_vsx_region)
996
		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
997
		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
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			return -EFAULT;
	}
	if (new_ctx == NULL)
		return 0;
1002
	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
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	    || __get_user(tmp, (u8 __user *) new_ctx)
1004
	    || __get_user(tmp, (u8 __user *) new_ctx + ctx_size - 1))
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		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.
	 */
1018
	if (do_setcontext(new_ctx, regs, 0))
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		do_exit(SIGSEGV);
1020 1021

	set_thread_flag(TIF_RESTOREALL);
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	return 0;
}

1025
long sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
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		     struct pt_regs *regs)
{
1028
	struct rt_sigframe __user *rt_sf;
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	/* Always make any pending restarted system calls return -EINTR */
	current_thread_info()->restart_block.fn = do_no_restart_syscall;

1033 1034
	rt_sf = (struct rt_sigframe __user *)
		(regs->gpr[1] + __SIGNAL_FRAMESIZE + 16);
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	if (!access_ok(VERIFY_READ, rt_sf, sizeof(*rt_sf)))
		goto bad;
1037
	if (do_setcontext(&rt_sf->uc, regs, 1))
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		goto bad;

	/*
	 * It's not clear whether or why it is desirable to save the
	 * sigaltstack setting on signal delivery and restore it on
	 * signal return.  But other architectures do this and we have
	 * always done it up until now so it is probably better not to
	 * change it.  -- paulus
1046 1047 1048
	 */
#ifdef CONFIG_PPC64
	/*
1049
	 * We use the compat_sys_ version that does the 32/64 bits conversion
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	 * and takes userland pointer directly. What about error checking ?
	 * nobody does any...
	 */
1053
	compat_sys_sigaltstack((u32)(u64)&rt_sf->uc.uc_stack, 0, 0, 0, 0, 0, regs);
1054 1055 1056
#else
	do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]);
#endif
1057 1058
	set_thread_flag(TIF_RESTOREALL);
	return 0;
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 bad:
1061 1062 1063 1064 1065 1066
	if (show_unhandled_signals && printk_ratelimit())
		printk(KERN_INFO "%s[%d]: bad frame in sys_rt_sigreturn: "
			"%p nip %08lx lr %08lx\n",
			current->comm, current->pid,
			rt_sf, regs->nip, regs->link);

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	force_sig(SIGSEGV, current);
	return 0;
}

1071 1072 1073 1074 1075 1076 1077 1078
#ifdef CONFIG_PPC32
int sys_debug_setcontext(struct ucontext __user *ctx,
			 int ndbg, struct sig_dbg_op __user *dbg,
			 int r6, int r7, int r8,
			 struct pt_regs *regs)
{
	struct sig_dbg_op op;
	int i;
1079
	unsigned char tmp;
1080
	unsigned long new_msr = regs->msr;
1081
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1082 1083 1084 1085
	unsigned long new_dbcr0 = current->thread.dbcr0;
#endif

	for (i=0; i<ndbg; i++) {
1086
		if (copy_from_user(&op, dbg + i, sizeof(op)))
1087 1088 1089
			return -EFAULT;
		switch (op.dbg_type) {
		case SIG_DBG_SINGLE_STEPPING:
1090
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1091 1092 1093 1094
			if (op.dbg_value) {
				new_msr |= MSR_DE;
				new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
			} else {
1095 1096 1097 1098 1099 1100
				new_dbcr0 &= ~DBCR0_IC;
				if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
						current->thread.dbcr1)) {
					new_msr &= ~MSR_DE;
					new_dbcr0 &= ~DBCR0_IDM;
				}
1101 1102 1103 1104 1105 1106 1107 1108 1109
			}
#else
			if (op.dbg_value)
				new_msr |= MSR_SE;
			else
				new_msr &= ~MSR_SE;
#endif
			break;
		case SIG_DBG_BRANCH_TRACING:
1110
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130
			return -EINVAL;
#else
			if (op.dbg_value)
				new_msr |= MSR_BE;
			else
				new_msr &= ~MSR_BE;
#endif
			break;

		default:
			return -EINVAL;
		}
	}

	/* We wait until here to actually install the values in the
	   registers so if we fail in the above loop, it will not
	   affect the contents of these registers.  After this point,
	   failure is a problem, anyway, and it's very unlikely unless
	   the user is really doing something wrong. */
	regs->msr = new_msr;
1131
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1132 1133 1134
	current->thread.dbcr0 = new_dbcr0;
#endif

1135 1136 1137 1138 1139
	if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx))
	    || __get_user(tmp, (u8 __user *) ctx)
	    || __get_user(tmp, (u8 __user *) (ctx + 1) - 1))
		return -EFAULT;

1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151
	/*
	 * 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 (do_setcontext(ctx, regs, 1)) {
1152 1153 1154 1155 1156 1157 1158
		if (show_unhandled_signals && printk_ratelimit())
			printk(KERN_INFO "%s[%d]: bad frame in "
				"sys_debug_setcontext: %p nip %08lx "
				"lr %08lx\n",
				current->comm, current->pid,
				ctx, regs->nip, regs->link);

1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171
		force_sig(SIGSEGV, current);
		goto out;
	}

	/*
	 * It's not clear whether or why it is desirable to save the
	 * sigaltstack setting on signal delivery and restore it on
	 * signal return.  But other architectures do this and we have
	 * always done it up until now so it is probably better not to
	 * change it.  -- paulus
	 */
	do_sigaltstack(&ctx->uc_stack, NULL, regs->gpr[1]);

1172
	set_thread_flag(TIF_RESTOREALL);
1173 1174 1175 1176
 out:
	return 0;
}
#endif
L
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1177 1178 1179 1180

/*
 * OK, we're invoking a handler
 */
1181
int handle_signal32(unsigned long sig, struct k_sigaction *ka,
1182
		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
L
Linus Torvalds 已提交
1183
{
1184
	struct sigcontext __user *sc;
1185 1186
	struct sigframe __user *frame;
	unsigned long newsp = 0;
L
Linus Torvalds 已提交
1187 1188

	/* Set up Signal Frame */
1189
	frame = get_sigframe(ka, regs, sizeof(*frame), 1);
1190
	if (unlikely(frame == NULL))
L
Linus Torvalds 已提交
1191
		goto badframe;
1192
	sc = (struct sigcontext __user *) &frame->sctx;
L
Linus Torvalds 已提交
1193 1194

#if _NSIG != 64
1195
#error "Please adjust handle_signal()"
L
Linus Torvalds 已提交
1196
#endif
1197
	if (__put_user(to_user_ptr(ka->sa.sa_handler), &sc->handler)
L
Linus Torvalds 已提交
1198
	    || __put_user(oldset->sig[0], &sc->oldmask)
1199
#ifdef CONFIG_PPC64
L
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1200
	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
1201 1202 1203
#else
	    || __put_user(oldset->sig[1], &sc->_unused[3])
#endif
1204
	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
L
Linus Torvalds 已提交
1205 1206 1207
	    || __put_user(sig, &sc->signal))
		goto badframe;

1208
	if (vdso32_sigtramp && current->mm->context.vdso_base) {
1209
		if (save_user_regs(regs, &frame->mctx, 0, 1))
L
Linus Torvalds 已提交
1210
			goto badframe;
1211
		regs->link = current->mm->context.vdso_base + vdso32_sigtramp;
1212
	} else {
1213
		if (save_user_regs(regs, &frame->mctx, __NR_sigreturn, 1))
L
Linus Torvalds 已提交
1214 1215 1216 1217
			goto badframe;
		regs->link = (unsigned long) frame->mctx.tramp;
	}

1218 1219
	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */

1220 1221
	/* create a stack frame for the caller of the handler */
	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1222
	if (put_user(regs->gpr[1], (u32 __user *)newsp))
L
Linus Torvalds 已提交
1223
		goto badframe;
1224

1225
	regs->gpr[1] = newsp;
L
Linus Torvalds 已提交
1226 1227 1228
	regs->gpr[3] = sig;
	regs->gpr[4] = (unsigned long) sc;
	regs->nip = (unsigned long) ka->sa.sa_handler;
1229 1230
	/* enter the signal handler in big-endian mode */
	regs->msr &= ~MSR_LE;
L
Linus Torvalds 已提交
1231 1232 1233 1234 1235
	regs->trap = 0;

	return 1;

badframe:
1236 1237 1238
#ifdef DEBUG_SIG
	printk("badframe in handle_signal, regs=%p frame=%p newsp=%lx\n",
	       regs, frame, newsp);
L
Linus Torvalds 已提交
1239
#endif
1240 1241 1242 1243 1244 1245
	if (show_unhandled_signals && printk_ratelimit())
		printk(KERN_INFO "%s[%d]: bad frame in handle_signal32: "
			"%p nip %08lx lr %08lx\n",
			current->comm, current->pid,
			frame, regs->nip, regs->link);

L
Linus Torvalds 已提交
1246 1247 1248 1249 1250 1251 1252
	force_sigsegv(sig, current);
	return 0;
}

/*
 * Do a signal return; undo the signal stack.
 */
1253
long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
L
Linus Torvalds 已提交
1254 1255
		       struct pt_regs *regs)
{
1256 1257 1258
	struct sigcontext __user *sc;
	struct sigcontext sigctx;
	struct mcontext __user *sr;
1259
	void __user *addr;
L
Linus Torvalds 已提交
1260 1261 1262 1263 1264
	sigset_t set;

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

1265
	sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1266
	addr = sc;
L
Linus Torvalds 已提交
1267 1268 1269
	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
		goto badframe;

1270
#ifdef CONFIG_PPC64
L
Linus Torvalds 已提交
1271 1272 1273 1274 1275
	/*
	 * Note that PPC32 puts the upper 32 bits of the sigmask in the
	 * unused part of the signal stackframe
	 */
	set.sig[0] = sigctx.oldmask + ((long)(sigctx._unused[3]) << 32);
1276 1277 1278 1279
#else
	set.sig[0] = sigctx.oldmask;
	set.sig[1] = sigctx._unused[3];
#endif
L
Linus Torvalds 已提交
1280 1281
	restore_sigmask(&set);

1282
	sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1283
	addr = sr;
L
Linus Torvalds 已提交
1284 1285 1286 1287
	if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
	    || restore_user_regs(regs, sr, 1))
		goto badframe;

1288
	set_thread_flag(TIF_RESTOREALL);
1289
	return 0;
L
Linus Torvalds 已提交
1290 1291

badframe:
1292 1293 1294 1295 1296 1297
	if (show_unhandled_signals && printk_ratelimit())
		printk(KERN_INFO "%s[%d]: bad frame in sys_sigreturn: "
			"%p nip %08lx lr %08lx\n",
			current->comm, current->pid,
			addr, regs->nip, regs->link);

L
Linus Torvalds 已提交
1298 1299 1300
	force_sig(SIGSEGV, current);
	return 0;
}