path: root/arch/ppc64/kernel/signal32.c

/*
 * signal32.c: Support 32bit signal syscalls.
 *
 * 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)
 *
 * These routines maintain argument size conversion between 32bit and 64bit
 * environment.
 *
 *      This program is free software; you can redistribute it and/or
 *      modify it under the terms of the GNU General Public License
 *      as published by the Free Software Foundation; either version
 *      2 of the License, or (at your option) any later version.
 */

#include <linux/config.h>
#include <linux/sched.h>
#include <linux/mm.h> 
#include <linux/smp.h>
#include <linux/smp_lock.h>
#include <linux/kernel.h>
#include <linux/signal.h>
#include <linux/syscalls.h>
#include <linux/errno.h>
#include <linux/elf.h>
#include <linux/compat.h>
#include <linux/ptrace.h>
#include <asm/ppc32.h>
#include <asm/uaccess.h>
#include <asm/ppcdebug.h>
#include <asm/unistd.h>
#include <asm/cacheflush.h>
#include <asm/vdso.h>

#define DEBUG_SIG 0

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

#define GP_REGS_SIZE32	min(sizeof(elf_gregset_t32), sizeof(struct pt_regs32))

/*
 * When we have signals to deliver, we set up on the
 * user stack, going down from the original stack pointer:
 *	a sigregs32 struct
 *	a sigcontext32 struct
 *	a gap of __SIGNAL_FRAMESIZE32 bytes
 *
 * Each of these things must be a multiple of 16 bytes in size.
 *
 */
struct sigregs32 {
	struct mcontext32	mctx;		/* all the register values */
	/*
	 * 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:
 *	one rt_sigframe32 struct (siginfo + ucontext + ABI gap)
 *	a gap of __SIGNAL_FRAMESIZE32+16 bytes
 *  (the +16 is to get the siginfo and ucontext32 in the same
 *  positions as in older kernels).
 *
 *  Each of these things must be a multiple of 16 bytes in size.
 *
 */
struct rt_sigframe32 {
	compat_siginfo_t	info;
	struct ucontext32	uc;
	/*
	 * 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];
};


/*
 * Common utility functions used by signal and context support
 *
 */

/*
 * Restore the user process's signal mask
 * (implemented in signal.c)
 */
extern void restore_sigmask(sigset_t *set);

/*
 * Functions for flipping sigsets (thanks to brain dead generic
 * implementation that makes things simple for little endian only
 */
static inline void compat_from_sigset(compat_sigset_t *compat, sigset_t *set)
{
	switch (_NSIG_WORDS) {
	case 4: compat->sig[5] = set->sig[3] & 0xffffffffull ;
		compat->sig[7] = set->sig[3] >> 32; 
	case 3: compat->sig[4] = set->sig[2] & 0xffffffffull ;
		compat->sig[5] = set->sig[2] >> 32; 
	case 2: compat->sig[2] = set->sig[1] & 0xffffffffull ;
		compat->sig[3] = set->sig[1] >> 32; 
	case 1: compat->sig[0] = set->sig[0] & 0xffffffffull ;
		compat->sig[1] = set->sig[0] >> 32; 
	}
}

static inline void sigset_from_compat(sigset_t *set, compat_sigset_t *compat)
{
	switch (_NSIG_WORDS) {
	case 4: set->sig[3] = compat->sig[6] | (((long)compat->sig[7]) << 32);
	case 3: set->sig[2] = compat->sig[4] | (((long)compat->sig[5]) << 32);
	case 2: set->sig[1] = compat->sig[2] | (((long)compat->sig[3]) << 32);
	case 1: set->sig[0] = compat->sig[0] | (((long)compat->sig[1]) << 32);
	}
}


/*
 * Save the current user registers on the user stack.
 * We only save the altivec registers if the process has used
 * altivec instructions at some point.
 */
static int save_user_regs(struct pt_regs *regs, struct mcontext32 __user *frame, int sigret)
{
	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
	int i, err = 0;

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

	/* save general and floating-point registers */
	for (i = 0; i <= PT_RESULT; i ++)
		err |= __put_user((unsigned int)gregs[i], &frame->mc_gregs[i]);
	err |= __copy_to_user(&frame->mc_fregs, current->thread.fpr,
			      ELF_NFPREG * sizeof(double));
	if (err)
		return 1;

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

#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,
				   ELF_NVRREG32 * sizeof