path: root/arch/powerpc/kernel/signal_32.c

// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Signal handling for 32bit PPC and 32bit tasks on 64bit PPC
 *
 *  PowerPC version
 *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
 * 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)
 *
 *  Derived from "arch/i386/kernel/signal.c"
 *    Copyright (C) 1991, 1992 Linus Torvalds
 *    1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 */

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

#include <linux/uaccess.h>
#include <asm/cacheflush.h>
#include <asm/syscalls.h>
#include <asm/sigcontext.h>
#include <asm/vdso.h>
#include <asm/switch_to.h>
#include <asm/tm.h>
#include <asm/asm-prototypes.h>
#ifdef CONFIG_PPC64
#include <asm/syscalls_32.h>
#include <asm/unistd.h>
#else
#include <asm/ucontext.h>
#endif

#include "signal.h"


#ifdef CONFIG_PPC64
#define old_sigaction	old_sigaction32
#define sigcontext	sigcontext32
#define mcontext	mcontext32
#define ucontext	ucontext32

/*
 * 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))

/*
 * 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)
 */
#define unsafe_put_sigset_t	unsafe_put_compat_sigset
#define unsafe_get_sigset_t	unsafe_get_compat_sigset

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

static __always_inline int
__unsafe_save_general_regs(struct pt_regs *regs, struct mcontext __user *frame)
{
	elf_greg_t64 *gregs = (elf_greg_t64 *)regs;
	int val, i;

	for (i = 0; i <= PT_RESULT; i ++) {
		/* Force usr to alway see softe as 1 (interrupts enabled) */
		if (i == PT_SOFTE)
			val = 1;
		else
			val = gregs[i];

		unsafe_put_user(val, &frame->mc_gregs[i], failed);
	}
	return 0;

failed:
	return 1;
}

static __always_inline int
__unsafe_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;
		unsafe_get_user(