signal_32.c 35.8 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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#include <linux/ratelimit.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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#include <asm/switch_to.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) {
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	case 4: cset.sig[6] = set->sig[3] & 0xffffffffull;
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		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) ||
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			__get_user(new_ka->sa.sa_restorer, &act->sa_restorer) ||
			__get_user(new_ka->sa.sa_flags, &act->sa_flags) ||
			__get_user(mask, &act->sa_mask))
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		return -EFAULT;
	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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{
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	sigset_t blocked;
	siginitset(&blocked, mask);
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	return sigsuspend(&blocked);
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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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	regs->trap = 0;
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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;
}

592
#ifdef CONFIG_PPC64
593
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);
608
		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) {
616
		ret = put_user(to_user_ptr(old_ka.sa.sa_handler), &oact->sa_handler);
617
		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.
 */
630
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) {
639 640
		if (get_sigset_t(&s, set))
			return -EFAULT;
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	}
642

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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,
647
				 sigsetsize);
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	set_fs(old_fs);
	if (ret)
		return ret;
	if (oset) {
652
		if (put_sigset_t(oset, &s))
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			return -EFAULT;
	}
	return 0;
}

658
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) {
669
		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;
}

731 732
#define copy_siginfo_to_user	copy_siginfo_to_user32

733 734 735 736 737 738 739 740 741 742 743 744
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.
 */
752
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();
757

758 759 760 761
	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
772
 *       sigaltatck               compat_sys_sigaltstack
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 */

775
int compat_sys_sigaltstack(u32 __new, u32 __old, int r5,
L
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		      int r6, int r7, int r8, struct pt_regs *regs)
{
778 779
	stack_32_t __user * newstack = compat_ptr(__new);
	stack_32_t __user * oldstack = compat_ptr(__old);
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780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810
	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  &&
811
		(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;
}
817
#endif /* CONFIG_PPC64 */
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/*
 * Set up a signal frame for a "real-time" signal handler
 * (one which gets siginfo).
 */
823
int handle_rt_signal32(unsigned long sig, struct k_sigaction *ka,
824
		siginfo_t *info, sigset_t *oldset,
825
		struct pt_regs *regs)
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{
827 828
	struct rt_sigframe __user *rt_sf;
	struct mcontext __user *frame;
829
	void __user *addr;
830
	unsigned long newsp = 0;
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	/* Set up Signal Frame */
	/* Put a Real Time Context onto stack */
834
	rt_sf = get_sigframe(ka, regs, sizeof(*rt_sf), 1);
835
	addr = rt_sf;
836
	if (unlikely(rt_sf == NULL))
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		goto badframe;

	/* Put the siginfo & fill in most of the ucontext */
840
	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)
847 848 849
	    || __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;
854
	addr = frame;
855
	if (vdso32_rt_sigtramp && current->mm->context.vdso_base) {
856
		if (save_user_regs(regs, frame, 0, 1))
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			goto badframe;
858
		regs->link = current->mm->context.vdso_base + vdso32_rt_sigtramp;
859
	} else {
860
		if (save_user_regs(regs, frame, __NR_rt_sigreturn, 1))
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			goto badframe;
		regs->link = (unsigned long) frame->tramp;
	}
864 865 866

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

867 868
	/* create a stack frame for the caller of the handler */
	newsp = ((unsigned long)rt_sf) - (__SIGNAL_FRAMESIZE + 16);
869
	addr = (void __user *)regs->gpr[1];
870
	if (put_user(regs->gpr[1], (u32 __user *)newsp))
871
		goto badframe;
872 873

	/* Fill registers for signal handler */
874
	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;
880 881
	/* enter the signal handler in big-endian mode */
	regs->msr &= ~MSR_LE;
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	return 1;

badframe:
885
#ifdef DEBUG_SIG
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	printk("badframe in handle_rt_signal, regs=%p frame=%p newsp=%lx\n",
	       regs, frame, newsp);
#endif
889 890 891 892 893 894
	if (show_unhandled_signals)
		printk_ratelimited(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);
895

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	force_sigsegv(sig, current);
	return 0;
}

900
static int do_setcontext(struct ucontext __user *ucp, struct pt_regs *regs, int sig)
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{
	sigset_t set;
903 904 905 906 907 908 909
	struct mcontext __user *mcp;

	if (get_sigset_t(&set, &ucp->uc_sigmask))
		return -EFAULT;
#ifdef CONFIG_PPC64
	{
		u32 cmcp;
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911 912 913
		if (__get_user(cmcp, &ucp->uc_regs))
			return -EFAULT;
		mcp = (struct mcontext __user *)(u64)cmcp;
914
		/* no need to check access_ok(mcp), since mcp < 4GB */
915 916 917
	}
#else
	if (__get_user(mcp, &ucp->uc_regs))
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		return -EFAULT;
919 920
	if (!access_ok(VERIFY_READ, mcp, sizeof(*mcp)))
		return -EFAULT;
921
#endif
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	restore_sigmask(&set);
923
	if (restore_user_regs(regs, mcp, sig))
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		return -EFAULT;

	return 0;
}

929
long sys_swapcontext(struct ucontext __user *old_ctx,
930 931
		     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;
934
	int ctx_has_vsx_region = 0;
L
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936 937 938
#ifdef CONFIG_PPC64
	unsigned long new_msr = 0;

939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
	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;
	}
954 955 956 957 958 959 960 961 962 963 964 965 966
	/*
	 * 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;
967 968 969
	/* Does the context have enough room to store VSX data? */
	if (ctx_size >= sizeof(struct ucontext))
		ctx_has_vsx_region = 1;
970
#else
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	/* Context size is for future use. Right now, we only make sure
	 * we are passed something we understand
	 */
974
	if (ctx_size < sizeof(struct ucontext))
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		return -EINVAL;
976
#endif
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	if (old_ctx != NULL) {
978 979 980 981 982 983 984 985 986 987 988
		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);
989 990
		if (!access_ok(VERIFY_WRITE, old_ctx, ctx_size)
		    || save_user_regs(regs, mctx, 0, ctx_has_vsx_region)
991
		    || put_sigset_t(&old_ctx->uc_sigmask, &current->blocked)
992
		    || __put_user(to_user_ptr(mctx), &old_ctx->uc_regs))
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			return -EFAULT;
	}
	if (new_ctx == NULL)
		return 0;
997
	if (!access_ok(VERIFY_READ, new_ctx, ctx_size)
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	    || __get_user(tmp, (u8 __user *) new_ctx)
999
	    || __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.
	 */
1013
	if (do_setcontext(new_ctx, regs, 0))
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		do_exit(SIGSEGV);
1015 1016

	set_thread_flag(TIF_RESTOREALL);
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	return 0;
}

1020
long sys_rt_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
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		     struct pt_regs *regs)
{
1023
	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;

1028 1029
	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;
1032
	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
1041 1042 1043
	 */
#ifdef CONFIG_PPC64
	/*
1044
	 * 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...
	 */
1048
	compat_sys_sigaltstack((u32)(u64)&rt_sf->uc.uc_stack, 0, 0, 0, 0, 0, regs);
1049 1050 1051
#else
	do_sigaltstack(&rt_sf->uc.uc_stack, NULL, regs->gpr[1]);
#endif
1052 1053
	set_thread_flag(TIF_RESTOREALL);
	return 0;
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 bad:
1056 1057 1058 1059 1060 1061
	if (show_unhandled_signals)
		printk_ratelimited(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);
1062

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	force_sig(SIGSEGV, current);
	return 0;
}

1067 1068 1069 1070 1071 1072 1073 1074
#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;
1075
	unsigned char tmp;
1076
	unsigned long new_msr = regs->msr;
1077
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1078 1079 1080 1081
	unsigned long new_dbcr0 = current->thread.dbcr0;
#endif

	for (i=0; i<ndbg; i++) {
1082
		if (copy_from_user(&op, dbg + i, sizeof(op)))
1083 1084 1085
			return -EFAULT;
		switch (op.dbg_type) {
		case SIG_DBG_SINGLE_STEPPING:
1086
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1087 1088 1089 1090
			if (op.dbg_value) {
				new_msr |= MSR_DE;
				new_dbcr0 |= (DBCR0_IDM | DBCR0_IC);
			} else {
1091 1092 1093 1094 1095 1096
				new_dbcr0 &= ~DBCR0_IC;
				if (!DBCR_ACTIVE_EVENTS(new_dbcr0,
						current->thread.dbcr1)) {
					new_msr &= ~MSR_DE;
					new_dbcr0 &= ~DBCR0_IDM;
				}
1097 1098 1099 1100 1101 1102 1103 1104 1105
			}
#else
			if (op.dbg_value)
				new_msr |= MSR_SE;
			else
				new_msr &= ~MSR_SE;
#endif
			break;
		case SIG_DBG_BRANCH_TRACING:
1106
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126
			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;
1127
#ifdef CONFIG_PPC_ADV_DEBUG_REGS
1128 1129 1130
	current->thread.dbcr0 = new_dbcr0;
#endif

1131 1132 1133 1134 1135
	if (!access_ok(VERIFY_READ, ctx, sizeof(*ctx))
	    || __get_user(tmp, (u8 __user *) ctx)
	    || __get_user(tmp, (u8 __user *) (ctx + 1) - 1))
		return -EFAULT;

1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147
	/*
	 * 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)) {
1148 1149 1150 1151 1152 1153
		if (show_unhandled_signals)
			printk_ratelimited(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);
1154

1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167
		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]);

1168
	set_thread_flag(TIF_RESTOREALL);
1169 1170 1171 1172
 out:
	return 0;
}
#endif
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1173 1174 1175 1176

/*
 * OK, we're invoking a handler
 */
1177
int handle_signal32(unsigned long sig, struct k_sigaction *ka,
1178
		    siginfo_t *info, sigset_t *oldset, struct pt_regs *regs)
L
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1179
{
1180
	struct sigcontext __user *sc;
1181 1182
	struct sigframe __user *frame;
	unsigned long newsp = 0;
L
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1183 1184

	/* Set up Signal Frame */
1185
	frame = get_sigframe(ka, regs, sizeof(*frame), 1);
1186
	if (unlikely(frame == NULL))
L
Linus Torvalds 已提交
1187
		goto badframe;
1188
	sc = (struct sigcontext __user *) &frame->sctx;
L
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1189 1190

#if _NSIG != 64
1191
#error "Please adjust handle_signal()"
L
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1192
#endif
1193
	if (__put_user(to_user_ptr(ka->sa.sa_handler), &sc->handler)
L
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1194
	    || __put_user(oldset->sig[0], &sc->oldmask)
1195
#ifdef CONFIG_PPC64
L
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1196
	    || __put_user((oldset->sig[0] >> 32), &sc->_unused[3])
1197 1198 1199
#else
	    || __put_user(oldset->sig[1], &sc->_unused[3])
#endif
1200
	    || __put_user(to_user_ptr(&frame->mctx), &sc->regs)
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1201 1202 1203
	    || __put_user(sig, &sc->signal))
		goto badframe;

1204
	if (vdso32_sigtramp && current->mm->context.vdso_base) {
1205
		if (save_user_regs(regs, &frame->mctx, 0, 1))
L
Linus Torvalds 已提交
1206
			goto badframe;
1207
		regs->link = current->mm->context.vdso_base + vdso32_sigtramp;
1208
	} else {
1209
		if (save_user_regs(regs, &frame->mctx, __NR_sigreturn, 1))
L
Linus Torvalds 已提交
1210 1211 1212 1213
			goto badframe;
		regs->link = (unsigned long) frame->mctx.tramp;
	}

1214 1215
	current->thread.fpscr.val = 0;	/* turn off all fp exceptions */

1216 1217
	/* create a stack frame for the caller of the handler */
	newsp = ((unsigned long)frame) - __SIGNAL_FRAMESIZE;
1218
	if (put_user(regs->gpr[1], (u32 __user *)newsp))
L
Linus Torvalds 已提交
1219
		goto badframe;
1220

1221
	regs->gpr[1] = newsp;
L
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1222 1223 1224
	regs->gpr[3] = sig;
	regs->gpr[4] = (unsigned long) sc;
	regs->nip = (unsigned long) ka->sa.sa_handler;
1225 1226
	/* enter the signal handler in big-endian mode */
	regs->msr &= ~MSR_LE;
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1227 1228 1229 1230

	return 1;

badframe:
1231 1232 1233
#ifdef DEBUG_SIG
	printk("badframe in handle_signal, regs=%p frame=%p newsp=%lx\n",
	       regs, frame, newsp);
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1234
#endif
1235 1236 1237 1238 1239 1240
	if (show_unhandled_signals)
		printk_ratelimited(KERN_INFO
				   "%s[%d]: bad frame in handle_signal32: "
				   "%p nip %08lx lr %08lx\n",
				   current->comm, current->pid,
				   frame, regs->nip, regs->link);
1241

L
Linus Torvalds 已提交
1242 1243 1244 1245 1246 1247 1248
	force_sigsegv(sig, current);
	return 0;
}

/*
 * Do a signal return; undo the signal stack.
 */
1249
long sys_sigreturn(int r3, int r4, int r5, int r6, int r7, int r8,
L
Linus Torvalds 已提交
1250 1251
		       struct pt_regs *regs)
{
1252 1253 1254
	struct sigcontext __user *sc;
	struct sigcontext sigctx;
	struct mcontext __user *sr;
1255
	void __user *addr;
L
Linus Torvalds 已提交
1256 1257 1258 1259 1260
	sigset_t set;

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

1261
	sc = (struct sigcontext __user *)(regs->gpr[1] + __SIGNAL_FRAMESIZE);
1262
	addr = sc;
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1263 1264 1265
	if (copy_from_user(&sigctx, sc, sizeof(sigctx)))
		goto badframe;

1266
#ifdef CONFIG_PPC64
L
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1267 1268 1269 1270 1271
	/*
	 * 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);
1272 1273 1274 1275
#else
	set.sig[0] = sigctx.oldmask;
	set.sig[1] = sigctx._unused[3];
#endif
L
Linus Torvalds 已提交
1276 1277
	restore_sigmask(&set);

1278
	sr = (struct mcontext __user *)from_user_ptr(sigctx.regs);
1279
	addr = sr;
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Linus Torvalds 已提交
1280 1281 1282 1283
	if (!access_ok(VERIFY_READ, sr, sizeof(*sr))
	    || restore_user_regs(regs, sr, 1))
		goto badframe;

1284
	set_thread_flag(TIF_RESTOREALL);
1285
	return 0;
L
Linus Torvalds 已提交
1286 1287

badframe:
1288 1289 1290 1291 1292 1293
	if (show_unhandled_signals)
		printk_ratelimited(KERN_INFO
				   "%s[%d]: bad frame in sys_sigreturn: "
				   "%p nip %08lx lr %08lx\n",
				   current->comm, current->pid,
				   addr, regs->nip, regs->link);
1294

L
Linus Torvalds 已提交
1295 1296 1297
	force_sig(SIGSEGV, current);
	return 0;
}