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Commit ab513701 authored by Suresh Siddha's avatar Suresh Siddha Committed by Ingo Molnar
Browse files

x86, xsave: reorganization of signal save/restore fpstate code layout 



move 64bit routines that saves/restores fpstate in/from user stack from
signal_64.c to xsave.c

restore_i387_xstate() now handles the condition when user passes
NULL fpstate.

Other misc changes for prepartion of xsave/xrstor sigcontext support.

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent 3c1c7f10

arch/x86/ia32/ia32_signal.c

+7 −21
Original line number Diff line number Diff line
@@ -216,7 +216,7 @@ static int ia32_restore_sigcontext(struct pt_regs *regs, 
				   unsigned int *peax)

{

	unsigned int tmpflags, gs, oldgs, err = 0;

	struct _fpstate_ia32 __user *buf;

	void __user *buf;

	u32 tmp;



	/* Always make any pending restarted system calls return -EINTR */
@@ -260,26 +260,12 @@ static int ia32_restore_sigcontext(struct pt_regs *regs, 


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

	buf = compat_ptr(tmp);

	if (buf) {

		if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))

			goto badframe;

		err |= restore_i387_ia32(buf);

	} else {

		struct task_struct *me = current;



		if (used_math()) {

			clear_fpu(me);

			clear_used_math();

		}

	}

	err |= restore_i387_xstate_ia32(buf);



	err |= __get_user(tmp, &sc->ax);

	*peax = tmp;



	return err;



badframe:

	return 1;

}



asmlinkage long sys32_sigreturn(struct pt_regs *regs)
@@ -351,7 +337,7 @@ asmlinkage long sys32_rt_sigreturn(struct pt_regs *regs) 
 */



static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,

				 struct _fpstate_ia32 __user *fpstate,

				 void __user *fpstate,

				 struct pt_regs *regs, unsigned int mask)

{

	int tmp, err = 0;
@@ -382,7 +368,7 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, 
	err |= __put_user((u32)regs->flags, &sc->flags);

	err |= __put_user((u32)regs->sp, &sc->sp_at_signal);



	tmp = save_i387_ia32(fpstate);

	tmp = save_i387_xstate_ia32(fpstate);

	if (tmp < 0)

		err = -EFAULT;

	else {
@@ -404,7 +390,7 @@ static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc, 
 */

static void __user *get_sigframe(struct k_sigaction *ka, struct pt_regs *regs,

				 size_t frame_size,

				 struct _fpstate_ia32 **fpstate)

				 void **fpstate)

{

	unsigned long sp;
@@ -441,7 +427,7 @@ int ia32_setup_frame(int sig, struct k_sigaction *ka, 
	struct sigframe __user *frame;

	void __user *restorer;

	int err = 0;

	struct _fpstate_ia32 __user *fpstate = NULL;

	void __user *fpstate = NULL;



	/* copy_to_user optimizes that into a single 8 byte store */

	static const struct {
@@ -529,7 +515,7 @@ int ia32_setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	struct rt_sigframe __user *frame;

	void __user *restorer;

	int err = 0;

	struct _fpstate_ia32 __user *fpstate = NULL;

	void __user *fpstate = NULL;



	/* __copy_to_user optimizes that into a single 8 byte store */

	static const struct {

arch/x86/kernel/i387.c

+31 −13
Original line number Diff line number Diff line
@@ -21,9 +21,10 @@ 
# include <asm/sigcontext32.h>

# include <asm/user32.h>

#else

# define save_i387_ia32		save_i387

# define restore_i387_ia32	restore_i387

# define save_i387_xstate_ia32		save_i387_xstate

# define restore_i387_xstate_ia32	restore_i387_xstate

# define _fpstate_ia32		_fpstate

# define _xstate_ia32		_xstate

# define sig_xstate_ia32_size   sig_xstate_size

# define user_i387_ia32_struct	user_i387_struct

# define user32_fxsr_struct	user_fxsr_struct
@@ -424,7 +425,6 @@ static inline int save_i387_fsave(struct _fpstate_ia32 __user *buf) 
	struct task_struct *tsk = current;

	struct i387_fsave_struct *fp = &tsk->thread.xstate->fsave;



	unlazy_fpu(tsk);

	fp->status = fp->swd;

	if (__copy_to_user(buf, fp, sizeof(struct i387_fsave_struct)))

		return -1;
@@ -438,8 +438,6 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) 
	struct user_i387_ia32_struct env;

	int err = 0;



	unlazy_fpu(tsk);



	convert_from_fxsr(&env, tsk);

	if (__copy_to_user(buf, &env, sizeof(env)))

		return -1;
@@ -455,10 +453,16 @@ static int save_i387_fxsave(struct _fpstate_ia32 __user *buf) 
	return 1;

}



int save_i387_ia32(struct _fpstate_ia32 __user *buf)

int save_i387_xstate_ia32(void __user *buf)

{

	struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;

	struct task_struct *tsk = current;



	if (!used_math())

		return 0;



	if (!access_ok(VERIFY_WRITE, buf, sig_xstate_ia32_size))

		return -EACCES;

	/*

	 * This will cause a "finit" to be triggered by the next

	 * attempted FPU operation by the 'current' process.
@@ -468,13 +472,15 @@ int save_i387_ia32(struct _fpstate_ia32 __user *buf) 
	if (!HAVE_HWFP) {

		return fpregs_soft_get(current, NULL,

				       0, sizeof(struct user_i387_ia32_struct),

				       NULL, buf) ? -1 : 1;

				       NULL, fp) ? -1 : 1;

	}



	unlazy_fpu(tsk);



	if (cpu_has_fxsr)

		return save_i387_fxsave(buf);

		return save_i387_fxsave(fp);

	else

		return save_i387_fsave(buf);

		return save_i387_fsave(fp);

}



static inline int restore_i387_fsave(struct _fpstate_ia32 __user *buf)
@@ -502,14 +508,26 @@ static int restore_i387_fxsave(struct _fpstate_ia32 __user *buf) 
	return 0;

}



int restore_i387_ia32(struct _fpstate_ia32 __user *buf)

int restore_i387_xstate_ia32(void __user *buf)

{

	int err;

	struct task_struct *tsk = current;

	struct _fpstate_ia32 __user *fp = (struct _fpstate_ia32 __user *) buf;



	if (HAVE_HWFP)

		clear_fpu(tsk);



	if (!buf) {

		if (used_math()) {

			clear_fpu(tsk);

			clear_used_math();

		}



		return 0;

	} else

		if (!access_ok(VERIFY_READ, buf, sig_xstate_ia32_size))

			return -EACCES;



	if (!used_math()) {

		err = init_fpu(tsk);

		if (err)
@@ -518,13 +536,13 @@ int restore_i387_ia32(struct _fpstate_ia32 __user *buf) 


	if (HAVE_HWFP) {

		if (cpu_has_fxsr)

			err = restore_i387_fxsave(buf);

			err = restore_i387_fxsave(fp);

		else

			err = restore_i387_fsave(buf);

			err = restore_i387_fsave(fp);

	} else {

		err = fpregs_soft_set(current, NULL,

				      0, sizeof(struct user_i387_ia32_struct),

				      NULL, buf) != 0;

				      NULL, fp) != 0;

	}

	set_used_math();

arch/x86/kernel/signal_32.c

+7 −21
Original line number Diff line number Diff line
@@ -159,28 +159,14 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, 
	}



	{

		struct _fpstate __user *buf;

		void __user *buf;



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

		if (buf) {

			if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))

				goto badframe;

			err |= restore_i387(buf);

		} else {

			struct task_struct *me = current;



			if (used_math()) {

				clear_fpu(me);

				clear_used_math();

			}

		}

		err |= restore_i387_xstate(buf);

	}



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

	return err;



badframe:

	return 1;

}



asmlinkage unsigned long sys_sigreturn(unsigned long __unused)
@@ -262,7 +248,7 @@ asmlinkage int sys_rt_sigreturn(unsigned long __unused) 
 * Set up a signal frame.

 */

static int

setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate,

setup_sigcontext(struct sigcontext __user *sc, void __user *fpstate,

		 struct pt_regs *regs, unsigned long mask)

{

	int tmp, err = 0;
@@ -289,7 +275,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, 
	err |= __put_user(regs->sp, &sc->sp_at_signal);

	err |= __put_user(regs->ss, (unsigned int __user *)&sc->ss);



	tmp = save_i387(fpstate);

	tmp = save_i387_xstate(fpstate);

	if (tmp < 0)

		err = 1;

	else
@@ -307,7 +293,7 @@ setup_sigcontext(struct sigcontext __user *sc, struct _fpstate __user *fpstate, 
 */

static inline void __user *

get_sigframe(struct k_sigaction *ka, struct pt_regs *regs, size_t frame_size,

	     struct _fpstate **fpstate)

	     void **fpstate)

{

	unsigned long sp;
@@ -356,7 +342,7 @@ setup_frame(int sig, struct k_sigaction *ka, sigset_t *set, 
	void __user *restorer;

	int err = 0;

	int usig;

	struct _fpstate __user *fpstate = NULL;

	void __user *fpstate = NULL;



	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);
@@ -434,7 +420,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
	void __user *restorer;

	int err = 0;

	int usig;

	struct _fpstate __user *fpstate = NULL;

	void __user *fpstate = NULL;



	frame = get_sigframe(ka, regs, sizeof(*frame), &fpstate);

arch/x86/kernel/signal_64.c

+3 −80
Original line number Diff line number Diff line
@@ -53,69 +53,6 @@ sys_sigaltstack(const stack_t __user *uss, stack_t __user *uoss, 
	return do_sigaltstack(uss, uoss, regs->sp);

}



/*

 * Signal frame handlers.

 */



static inline int save_i387(struct _fpstate __user *buf)

{

	struct task_struct *tsk = current;

	int err = 0;



	BUILD_BUG_ON(sizeof(struct user_i387_struct) !=

			sizeof(tsk->thread.xstate->fxsave));



	if ((unsigned long)buf % 16)

		printk("save_i387: bad fpstate %p\n", buf);



	if (!used_math())

		return 0;

	clear_used_math(); /* trigger finit */

	if (task_thread_info(tsk)->status & TS_USEDFPU) {

		err = save_i387_checking((struct i387_fxsave_struct __user *)

					 buf);

		if (err)

			return err;

		task_thread_info(tsk)->status &= ~TS_USEDFPU;

		stts();

	} else {

		if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,

				   sizeof(struct i387_fxsave_struct)))

			return -1;

	}

	return 1;

}



/*

 * This restores directly out of user space. Exceptions are handled.

 */

static inline int restore_i387(struct _fpstate __user *buf)

{

	struct task_struct *tsk = current;

	int err;



	if (!used_math()) {

		err = init_fpu(tsk);

		if (err)

			return err;

	}



	if (!(task_thread_info(current)->status & TS_USEDFPU)) {

		clts();

		task_thread_info(current)->status |= TS_USEDFPU;

	}

	err = restore_fpu_checking((__force struct i387_fxsave_struct *)buf);

	if (unlikely(err)) {

		/*

		 * Encountered an error while doing the restore from the

		 * user buffer, clear the fpu state.

		 */

		clear_fpu(tsk);

		clear_used_math();

	}

	return err;

}



/*

 * Do a signal return; undo the signal stack.

 */
@@ -160,25 +97,11 @@ restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc, 
	{

		struct _fpstate __user * buf;

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



		if (buf) {

			if (!access_ok(VERIFY_READ, buf, sizeof(*buf)))

				goto badframe;

			err |= restore_i387(buf);

		} else {

			struct task_struct *me = current;

			if (used_math()) {

				clear_fpu(me);

				clear_used_math();

			}

		}

		err |= restore_i387_xstate(buf);

	}



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

	return err;



badframe:

	return 1;

}



asmlinkage long sys_rt_sigreturn(struct pt_regs *regs)
@@ -276,7 +199,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
			   sigset_t *set, struct pt_regs * regs)

{

	struct rt_sigframe __user *frame;

	struct _fpstate __user *fp = NULL; 

	void __user *fp = NULL;

	int err = 0;

	struct task_struct *me = current;
@@ -288,7 +211,7 @@ static int setup_rt_frame(int sig, struct k_sigaction *ka, siginfo_t *info, 
		if (!access_ok(VERIFY_WRITE, fp, sizeof(struct _fpstate)))

			goto give_sigsegv;



		if (save_i387(fp) < 0) 

		if (save_i387_xstate(fp) < 0)

			err |= -1; 

	} else

		frame = get_stack(ka, regs, sizeof(struct rt_sigframe)) - 8;

arch/x86/kernel/xsave.c

+79 −0
Original line number Diff line number Diff line
@@ -12,6 +12,85 @@ 
 */

unsigned int pcntxt_hmask, pcntxt_lmask;



#ifdef CONFIG_X86_64

/*

 * Signal frame handlers.

 */



int save_i387_xstate(void __user *buf)

{

	struct task_struct *tsk = current;

	int err = 0;



	if (!access_ok(VERIFY_WRITE, buf, sig_xstate_size))

		return -EACCES;



	BUILD_BUG_ON(sizeof(struct user_i387_struct) !=

			sizeof(tsk->thread.xstate->fxsave));



	if ((unsigned long)buf % 16)

		printk("save_i387_xstate: bad fpstate %p\n", buf);



	if (!used_math())

		return 0;

	clear_used_math(); /* trigger finit */

	if (task_thread_info(tsk)->status & TS_USEDFPU) {

		err = save_i387_checking((struct i387_fxsave_struct __user *)

					 buf);

		if (err)

			return err;

		task_thread_info(tsk)->status &= ~TS_USEDFPU;

		stts();

	} else {

		if (__copy_to_user(buf, &tsk->thread.xstate->fxsave,

				   xstate_size))

			return -1;

	}

	return 1;

}



/*

 * This restores directly out of user space. Exceptions are handled.

 */

int restore_i387_xstate(void __user *buf)

{

	struct task_struct *tsk = current;

	int err;



	if (!buf) {

		if (used_math()) {

			clear_fpu(tsk);

			clear_used_math();

		}



		return 0;

	} else

		if (!access_ok(VERIFY_READ, buf, sig_xstate_size))

			return -EACCES;



	if (!used_math()) {

		err = init_fpu(tsk);

		if (err)

			return err;

	}



	if (!(task_thread_info(current)->status & TS_USEDFPU)) {

		clts();

		task_thread_info(current)->status |= TS_USEDFPU;

	}

	err = fxrstor_checking((__force struct i387_fxsave_struct *)buf);

	if (unlikely(err)) {

		/*

		 * Encountered an error while doing the restore from the

		 * user buffer, clear the fpu state.

		 */

		clear_fpu(tsk);

		clear_used_math();

	}

	return err;

}

#endif



/*

 * Represents init state for the supported extended state.

 */