Commit 49e4eb41 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov
Browse files

x86/fpu/xstate: Use fpstate for copy_uabi_to_xstate() 



Prepare for dynamically enabled states per task. The function needs to
retrieve the features and sizes which are valid in a fpstate
context. Retrieve them from fpstate.

Move the function declarations to the core header as they are not
required anywhere else.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20211013145323.233529986@linutronix.de
parent 3ac8d757

arch/x86/include/asm/fpu/xstate.h

+0 −12
Original line number Diff line number Diff line
@@ -129,20 +129,8 @@ extern void __init update_regset_xstate_info(unsigned int size, 
					     u64 xstate_mask);



int xfeature_size(int xfeature_nr);

int copy_uabi_from_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf);

int copy_sigframe_from_user_to_xstate(struct xregs_state *xsave, const void __user *ubuf);



void xsaves(struct xregs_state *xsave, u64 mask);

void xrstors(struct xregs_state *xsave, u64 mask);



enum xstate_copy_mode {

	XSTATE_COPY_FP,

	XSTATE_COPY_FX,

	XSTATE_COPY_XSAVE,

};



struct membuf;

void copy_xstate_to_uabi_buf(struct membuf to, struct task_struct *tsk,

			     enum xstate_copy_mode mode);



#endif

arch/x86/kernel/fpu/core.c

+1 −1
Original line number Diff line number Diff line
@@ -222,7 +222,7 @@ int fpu_copy_kvm_uabi_to_fpstate(struct fpu *fpu, const void *buf, u64 xcr0, 
	if (ustate->xsave.header.xfeatures & ~xcr0)

		return -EINVAL;



	ret = copy_uabi_from_kernel_to_xstate(&kstate->regs.xsave, ustate);

	ret = copy_uabi_from_kernel_to_xstate(kstate, ustate);

	if (ret)

		return ret;

arch/x86/kernel/fpu/regset.c

+2 −3
Original line number Diff line number Diff line
@@ -8,11 +8,11 @@ 
#include <asm/fpu/api.h>

#include <asm/fpu/signal.h>

#include <asm/fpu/regset.h>

#include <asm/fpu/xstate.h>



#include "context.h"

#include "internal.h"

#include "legacy.h"

#include "xstate.h"



/*

 * The xstateregs_active() routine is the same as the regset_fpregs_active() routine,
@@ -168,8 +168,7 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset, 
	}



	fpu_force_restore(fpu);

	ret = copy_uabi_from_kernel_to_xstate(&fpu->fpstate->regs.xsave,

					      kbuf ?: tmpbuf);

	ret = copy_uabi_from_kernel_to_xstate(fpu->fpstate, kbuf ?: tmpbuf);



out:

	vfree(tmpbuf);

arch/x86/kernel/fpu/signal.c

+1 −1
Original line number Diff line number Diff line
@@ -375,7 +375,7 @@ static bool __fpu_restore_sig(void __user *buf, void __user *buf_fx, 


	fpregs = &fpu->fpstate->regs;

	if (use_xsave() && !fx_only) {

		if (copy_sigframe_from_user_to_xstate(&fpregs->xsave, buf_fx))

		if (copy_sigframe_from_user_to_xstate(fpu->fpstate, buf_fx))

			return false;

	} else {

		if (__copy_from_user(&fpregs->fxsave, buf_fx,

arch/x86/kernel/fpu/xstate.c

+10 −8
Original line number Diff line number Diff line
@@ -463,10 +463,11 @@ int xfeature_size(int xfeature_nr) 
}



/* Validate an xstate header supplied by userspace (ptrace or sigreturn) */

static int validate_user_xstate_header(const struct xstate_header *hdr)

static int validate_user_xstate_header(const struct xstate_header *hdr,

				       struct fpstate *fpstate)

{

	/* No unknown or supervisor features may be set */

	if (hdr->xfeatures & ~xfeatures_mask_uabi())

	if (hdr->xfeatures & ~fpstate->user_xfeatures)

		return -EINVAL;



	/* Userspace must use the uncompacted format */
@@ -1115,9 +1116,10 @@ static int copy_from_buffer(void *dst, unsigned int offset, unsigned int size, 
}





static int copy_uabi_to_xstate(struct xregs_state *xsave, const void *kbuf,

static int copy_uabi_to_xstate(struct fpstate *fpstate, const void *kbuf,

			       const void __user *ubuf)

{

	struct xregs_state *xsave = &fpstate->regs.xsave;

	unsigned int offset, size;

	struct xstate_header hdr;

	u64 mask;
@@ -1127,7 +1129,7 @@ static int copy_uabi_to_xstate(struct xregs_state *xsave, const void *kbuf, 
	if (copy_from_buffer(&hdr, offset, sizeof(hdr), kbuf, ubuf))

		return -EFAULT;



	if (validate_user_xstate_header(&hdr))

	if (validate_user_xstate_header(&hdr, fpstate))

		return -EINVAL;



	/* Validate MXCSR when any of the related features is in use */
@@ -1182,9 +1184,9 @@ static int copy_uabi_to_xstate(struct xregs_state *xsave, const void *kbuf, 
 * Convert from a ptrace standard-format kernel buffer to kernel XSAVE[S]

 * format and copy to the target thread. Used by ptrace and KVM.

 */

int copy_uabi_from_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf)

int copy_uabi_from_kernel_to_xstate(struct fpstate *fpstate, const void *kbuf)

{

	return copy_uabi_to_xstate(xsave, kbuf, NULL);

	return copy_uabi_to_xstate(fpstate, kbuf, NULL);

}



/*
@@ -1192,10 +1194,10 @@ int copy_uabi_from_kernel_to_xstate(struct xregs_state *xsave, const void *kbuf) 
 * XSAVE[S] format and copy to the target thread. This is called from the

 * sigreturn() and rt_sigreturn() system calls.

 */

int copy_sigframe_from_user_to_xstate(struct xregs_state *xsave,

int copy_sigframe_from_user_to_xstate(struct fpstate *fpstate,

				      const void __user *ubuf)

{

	return copy_uabi_to_xstate(xsave, NULL, ubuf);

	return copy_uabi_to_xstate(fpstate, NULL, ubuf);

}



static bool validate_independent_components(u64 mask)