path: root/arch/x86/kernel/signal.c

/*
 *  Copyright (C) 1991, 1992  Linus Torvalds
 *  Copyright (C) 2000, 2001, 2002 Andi Kleen SuSE Labs
 *
 *  1997-11-28  Modified for POSIX.1b signals by Richard Henderson
 *  2000-06-20  Pentium III FXSR, SSE support by Gareth Hughes
 *  2000-2002   x86-64 support by Andi Kleen
 */

#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/wait.h>
#include <linux/ptrace.h>
#include <linux/tracehook.h>
#include <linux/unistd.h>
#include <linux/stddef.h>
#include <linux/personality.h>
#include <linux/uaccess.h>

#include <asm/processor.h>
#include <asm/ucontext.h>
#include <asm/i387.h>
#include <asm/vdso.h>

#ifdef CONFIG_X86_64
#include <asm/proto.h>
#include <asm/ia32_unistd.h>
#include <asm/mce.h>
#endif /* CONFIG_X86_64 */

#include <asm/syscall.h>
#include <asm/syscalls.h>

#include <asm/sigframe.h>

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

#define __FIX_EFLAGS	(X86_EFLAGS_AC | X86_EFLAGS_OF | \
			 X86_EFLAGS_DF | X86_EFLAGS_TF | X86_EFLAGS_SF | \
			 X86_EFLAGS_ZF | X86_EFLAGS_AF | X86_EFLAGS_PF | \
			 X86_EFLAGS_CF)

#ifdef CONFIG_X86_32
# define FIX_EFLAGS	(__FIX_EFLAGS | X86_EFLAGS_RF)
#else
# define FIX_EFLAGS	__FIX_EFLAGS
#endif

#define COPY(x)			{		\
	err |= __get_user(regs->x, &sc->x);	\
}

#define COPY_SEG(seg)		{			\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		regs->seg = tmp;			\
}

#define COPY_SEG_CPL3(seg)	{			\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		regs->seg = tmp | 3;			\
}

#define GET_SEG(seg)		{			\
		unsigned short tmp;			\
		err |= __get_user(tmp, &sc->seg);	\
		loadsegment(seg, tmp);			\
}

static int
restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc,
		   unsigned long *pax)
{
	void __user *buf;
	unsigned int tmpflags;
	unsigned int err = 0;

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

#ifdef CONFIG_X86_32
	GET_SEG(gs);
	COPY_SEG(fs);
	COPY_SEG(es);
	COPY_SEG(ds);
#endif /* CONFIG_X86_32 */

	COPY(di); COPY(si); COPY(bp); COPY(sp); COPY(bx);
	COPY(dx); COPY(cx); COPY(ip);

#ifdef CONFIG_X86_64
	COPY(r8);
	COPY(r9);
	COPY(r10);
	COPY(r11);
	COPY(r12);
	COPY(r13);
	COPY(r14);
	COPY(r15);
#endif /* CONFIG_X86_64 */

#ifdef CONFIG_X86_32
	COPY_SEG_CPL3(cs);
	COPY_SEG_CPL3(ss);
#else /* !CONFIG_X86_32 */
	/* Kernel saves and restores only the CS segment register on signals,
	 * which is the bare minimum needed to allow mixed 32/64-bit code.
	 * App's signal handler can save/restore other segments if needed. */
	COPY_SEG_CPL3(cs);
#endif /* CONFIG_X86_32 */

	err |= __get_user(tmpflags, &sc->flags);
	regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
	regs->orig_ax = -1;		/* disable syscall checks */

	err |= __get_user(buf, &sc->fpstate);
	err |= restore_i387_xstate(buf);

	err |= __get_user(*pax, &sc->ax);
	return err;
}

static int
setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,
		 struct pt_regs *regs, unsigned long mask)
{
	int err = 0;

#ifdef CONFIG_X86_32
	{
		unsigned int tmp;

		savesegment(gs, tmp);
		err |= __put_user(tmp, (unsigned int __user *)&sc->gs);
	}
	err |= __put_user(regs->fs, (unsigned int __user *)&sc->fs);
	err |= __put_user(regs->es, (unsigned int __user *)&sc->es);
	err |= __put_user(regs->ds, (unsigned int __user *)&sc->ds);
#endif /* CONFIG_X86_32 */

	err |= __put_user(regs->di, &sc->di);
	err |= __put_user(regs->si, &sc->si);
	err |= __put_user(regs->bp, &sc->bp);
	err |= __put_user(regs->sp, &sc->sp);
	err |= __put_user(regs->bx, &sc->bx);
	err |= __put_user(regs->dx, &sc->dx);
	err |= __put_user(regs->cx, &sc->cx);
	err |= __put_user(regs->ax, &sc->ax);
#ifdef CONFIG_X86_64
	err |= __put_user(regs->r8, &sc->r8);
	err |= __put_user(regs->r9, &sc->r9);
	err |= __put_user(regs->r10, &sc->r10);
	err |= __put_user(regs->r11, &sc->r11);
	err |= __put_user(regs->r12, &sc->r12);
	err |= __put_user(regs->r13, &sc->r13);
	err |= __put_user(regs->r14, &sc->r14);
	err |= __put_user(regs->r15, &sc->r15);
#endif /* CONFIG_X86_64 */

	err |= __put_user(current->thread.trap_no, &sc->trapno);
	err |= __put_user(current->thread.error_code, &sc->err);
	err |= __put_user(regs->ip, &sc->ip);
#ifdef CONFIG_X86_32
	err |=<