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Commit ff0ebb23 authored by Roland McGrath's avatar Roland McGrath Committed by Ingo Molnar
Browse files

x86: x86 user_regset math_emu 



This converts the ptrace/signal accessors for i387 math_emu
state to the user_regset interface style, and calls these
from the old interfaces.

It also cleans up math_emulate's ptrace check to be a
single-step check, which is what it really wants.

Signed-off-by: default avatarRoland McGrath <roland@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent cc927a25

arch/x86/math-emu/fpu_entry.c

+54 −32
Original line number Diff line number Diff line
@@ -25,10 +25,11 @@ 
 +---------------------------------------------------------------------------*/



#include <linux/signal.h>

#include <linux/ptrace.h>

#include <linux/regset.h>



#include <asm/uaccess.h>

#include <asm/desc.h>

#include <asm/user.h>



#include "fpu_system.h"

#include "fpu_emu.h"
@@ -198,9 +199,7 @@ asmlinkage void math_emulate(long arg) 
			code_limit = 0xffffffff;

	}



	FPU_lookahead = 1;

	if (current->ptrace & PT_PTRACED)

		FPU_lookahead = 0;

	FPU_lookahead = !(FPU_EFLAGS & X86_EFLAGS_TF);



	if (!valid_prefix(&byte1, (u_char __user **) & FPU_EIP,

			  &addr_modes.override)) {
@@ -673,31 +672,37 @@ void math_abort(struct info *info, unsigned int signal) 
#define sstatus_word() \

  ((S387->swd & ~SW_Top & 0xffff) | ((S387->ftop << SW_Top_Shift) & SW_Top))



int restore_i387_soft(void *s387, struct _fpstate __user *buf)

int fpregs_soft_set(struct task_struct *target,

		    const struct user_regset *regset,

		    unsigned int pos, unsigned int count,

		    const void *kbuf, const void __user *ubuf)

{

	u_char __user *d = (u_char __user *) buf;

	struct i387_soft_struct *s387 = &target->thread.i387.soft;

	void *space = s387->st_space;

	int ret;

	int offset, other, i, tags, regnr, tag, newtop;



	RE_ENTRANT_CHECK_OFF;

	FPU_access_ok(VERIFY_READ, d, 7 * 4 + 8 * 10);

	if (__copy_from_user(&S387->cwd, d, 7 * 4))

		return -1;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, s387, 0,

				 offsetof(struct i387_soft_struct, st_space));

	RE_ENTRANT_CHECK_ON;



	d += 7 * 4;

	if (ret)

		return ret;



	S387->ftop = (S387->swd >> SW_Top_Shift) & 7;

	offset = (S387->ftop & 7) * 10;

	other = 80 - offset;



	RE_ENTRANT_CHECK_OFF;



	/* Copy all registers in stack order. */

	if (__copy_from_user(((u_char *) & S387->st_space) + offset, d, other))

		return -1;

	if (offset)

		if (__copy_from_user

		    ((u_char *) & S387->st_space, d + other, offset))

			return -1;

	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

				 space + offset, 0, other);

	if (!ret && offset)

		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,

					 space, 0, offset);



	RE_ENTRANT_CHECK_ON;



	/* The tags may need to be corrected now. */
@@ -716,16 +721,21 @@ int restore_i387_soft(void *s387, struct _fpstate __user *buf) 
	}

	S387->twd = tags;



	return 0;

	return ret;

}



int save_i387_soft(void *s387, struct _fpstate __user * buf)

int fpregs_soft_get(struct task_struct *target,

		    const struct user_regset *regset,

		    unsigned int pos, unsigned int count,

		    void *kbuf, void __user *ubuf)

{

	u_char __user *d = (u_char __user *) buf;

	struct i387_soft_struct *s387 = &target->thread.i387.soft;

	const void *space = s387->st_space;

	int ret;

	int offset = (S387->ftop & 7) * 10, other = 80 - offset;



	RE_ENTRANT_CHECK_OFF;

	FPU_access_ok(VERIFY_WRITE, d, 7 * 4 + 8 * 10);



#ifdef PECULIAR_486

	S387->cwd &= ~0xe080;

	/* An 80486 sets nearly all of the reserved bits to 1. */
@@ -735,21 +745,33 @@ int save_i387_soft(void *s387, struct _fpstate __user * buf) 
	S387->fcs &= ~0xf8000000;

	S387->fos |= 0xffff0000;

#endif /* PECULIAR_486 */

	if (__copy_to_user(d, &S387->cwd, 7 * 4))

		return -1;

	RE_ENTRANT_CHECK_ON;



	d += 7 * 4;

	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, s387, 0,

				  offsetof(struct i387_soft_struct, st_space));



	RE_ENTRANT_CHECK_OFF;

	/* Copy all registers in stack order. */

	if (__copy_to_user(d, ((u_char *) & S387->st_space) + offset, other))

		return -1;

	if (offset)

		if (__copy_to_user

		    (d + other, (u_char *) & S387->st_space, offset))

			return -1;

	if (!ret)

		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,

					  space + offset, 0, other);

	if (!ret)

		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,

					  space, 0, offset);



	RE_ENTRANT_CHECK_ON;



	return 1;

	return ret;

}



int save_i387_soft(void *s387, struct _fpstate __user *buf)

{

	return fpregs_soft_get(current, NULL,

			       0, sizeof(struct user_i387_struct),

			       NULL, buf) ? -1 : 1;

}



int restore_i387_soft(void *s387, struct _fpstate __user *buf)

{

	return fpregs_soft_set(current, NULL,

			       0, sizeof(struct user_i387_struct),

			       NULL, buf) ? -1 : 1;

}