x86/fpu: Rename 'xsave_hdr' to 'header'

Code like:

           fpu->state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;

is an eyesore, because not only is the words 'xsave' and 'state'
are repeated twice times (!), but also because of the 'hdr' and 'bv'
abbreviations that are pretty meaningless at a first glance.

Start cleaning this up by renaming 'xsave_hdr' to 'header'.
Reviewed-by: NBorislav Petkov <bp@alien8.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

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

@@ -261,7 +261,7 @@ static inline int fpu_save_init(struct fpu *fpu)
 		/*
 		 * xsave header may indicate the init state of the FP.
 		 */
-		if (!(fpu->state->xsave.xsave_hdr.xstate_bv & XSTATE_FP))
+		if (!(fpu->state->xsave.header.xstate_bv & XSTATE_FP))
 			return 1;
 	} else if (use_fxsr()) {
 		fpu_fxsave(fpu);

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

@@ -99,7 +99,7 @@ struct bndcsr {
 	u64				bndstatus;
 } __packed;
 
-struct xsave_hdr_struct {
+struct xstate_header {
 	u64				xstate_bv;
 	u64				xcomp_bv;
 	u64				reserved[6];
@@ -107,7 +107,7 @@ struct xsave_hdr_struct {
 
 struct xsave_struct {
 	struct i387_fxsave_struct	i387;
-	struct xsave_hdr_struct		xsave_hdr;
+	struct xstate_header		header;
 	struct ymmh_struct		ymmh;
 	struct lwp_struct		lwp;
 	struct bndreg			bndreg[4];

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

@@ -212,7 +212,7 @@ static inline int xsave_user(struct xsave_struct __user *buf)
 	 * Clear the xsave header first, so that reserved fields are
 	 * initialized to zero.
 	 */
-	err = __clear_user(&buf->xsave_hdr, sizeof(buf->xsave_hdr));
+	err = __clear_user(&buf->header, sizeof(buf->header));
 	if (unlikely(err))
 		return -EFAULT;
 

arch/x86/include/asm/user.h

@@ -14,7 +14,7 @@ struct user_ymmh_regs {
 	__u32 ymmh_space[64];
 };
 
-struct user_xsave_hdr {
+struct user_xstate_header {
 	__u64 xstate_bv;
 	__u64 reserved1[2];
 	__u64 reserved2[5];
@@ -41,11 +41,11 @@ struct user_xsave_hdr {
  * particular process/thread.
  *
  * Also when the user modifies certain state FP/SSE/etc through the
- * ptrace interface, they must ensure that the xsave_hdr.xstate_bv
+ * ptrace interface, they must ensure that the header.xstate_bv
  * bytes[512..519] of the memory layout are updated correspondingly.
  * i.e., for example when FP state is modified to a non-init state,
- * xsave_hdr.xstate_bv's bit 0 must be set to '1', when SSE is modified to
- * non-init state, xsave_hdr.xstate_bv's bit 1 must to be set to '1', etc.
+ * header.xstate_bv's bit 0 must be set to '1', when SSE is modified to
+ * non-init state, header.xstate_bv's bit 1 must to be set to '1', etc.
  */
 #define USER_XSTATE_FX_SW_WORDS 6
 #define USER_XSTATE_XCR0_WORD	0
@@ -55,7 +55,7 @@ struct user_xstateregs {
 		__u64 fpx_space[58];
 		__u64 xstate_fx_sw[USER_XSTATE_FX_SW_WORDS];
 	} i387;
-	struct user_xsave_hdr xsave_hdr;
+	struct user_xstate_header header;
 	struct user_ymmh_regs ymmh;
 	/* further processor state extensions go here */
 };

arch/x86/include/uapi/asm/sigcontext.h

@@ -209,7 +209,7 @@ struct sigcontext {
 
 #endif /* !__i386__ */
 
-struct _xsave_hdr {
+struct _header {
 	__u64 xstate_bv;
 	__u64 reserved1[2];
 	__u64 reserved2[5];
@@ -228,7 +228,7 @@ struct _ymmh_state {
  */
 struct _xstate {
 	struct _fpstate fpstate;
-	struct _xsave_hdr xstate_hdr;
+	struct _header xstate_hdr;
 	struct _ymmh_state ymmh;
 	/* new processor state extensions go here */
 };

arch/x86/kernel/fpu/core.c

@@ -470,7 +470,7 @@ int xfpregs_set(struct task_struct *target, const struct user_regset *regset,
 	 * presence of FP and SSE state.
 	 */
 	if (cpu_has_xsave)
-		fpu->state->xsave.xsave_hdr.xstate_bv |= XSTATE_FPSSE;
+		fpu->state->xsave.header.xstate_bv |= XSTATE_FPSSE;
 
 	return ret;
 }
@@ -528,11 +528,11 @@ int xstateregs_set(struct task_struct *target, const struct user_regset *regset,
 	 * mxcsr reserved bits must be masked to zero for security reasons.
 	 */
 	xsave->i387.mxcsr &= mxcsr_feature_mask;
-	xsave->xsave_hdr.xstate_bv &= xfeatures_mask;
+	xsave->header.xstate_bv &= xfeatures_mask;
 	/*
 	 * These bits must be zero.
 	 */
-	memset(&xsave->xsave_hdr.reserved, 0, 48);
+	memset(&xsave->header.reserved, 0, 48);
 
 	return ret;
 }
@@ -740,7 +740,7 @@ int fpregs_set(struct task_struct *target, const struct user_regset *regset,
 	 * presence of FP.
 	 */
 	if (cpu_has_xsave)
-		fpu->state->xsave.xsave_hdr.xstate_bv |= XSTATE_FP;
+		fpu->state->xsave.header.xstate_bv |= XSTATE_FP;
 	return ret;
 }
 

arch/x86/kernel/fpu/xsave.c

@@ -32,7 +32,7 @@ static unsigned int xfeatures_nr;
 /*
  * If a processor implementation discern that a processor state component is
  * in its initialized state it may modify the corresponding bit in the
- * xsave_hdr.xstate_bv as '0', with out modifying the corresponding memory
+ * header.xstate_bv as '0', with out modifying the corresponding memory
  * layout in the case of xsaveopt. While presenting the xstate information to
  * the user, we always ensure that the memory layout of a feature will be in
  * the init state if the corresponding header bit is zero. This is to ensure
@@ -48,7 +48,7 @@ void __sanitize_i387_state(struct task_struct *tsk)
 	if (!fx)
 		return;
 
-	xstate_bv = tsk->thread.fpu.state->xsave.xsave_hdr.xstate_bv;
+	xstate_bv = tsk->thread.fpu.state->xsave.header.xstate_bv;
 
 	/*
 	 * None of the feature bits are in init state. So nothing else
@@ -106,7 +106,7 @@ static inline int check_for_xstate(struct i387_fxsave_struct __user *buf,
 				   struct _fpx_sw_bytes *fx_sw)
 {
 	int min_xstate_size = sizeof(struct i387_fxsave_struct) +
-			      sizeof(struct xsave_hdr_struct);
+			      sizeof(struct xstate_header);
 	unsigned int magic2;
 
 	if (__copy_from_user(fx_sw, &buf->sw_reserved[0], sizeof(*fx_sw)))
@@ -178,7 +178,7 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame)
 	 * Read the xstate_bv which we copied (directly from the cpu or
 	 * from the state in task struct) to the user buffers.
 	 */
-	err |= __get_user(xstate_bv, (__u32 *)&x->xsave_hdr.xstate_bv);
+	err |= __get_user(xstate_bv, (__u32 *)&x->header.xstate_bv);
 
 	/*
 	 * For legacy compatible, we always set FP/SSE bits in the bit
@@ -193,7 +193,7 @@ static inline int save_xstate_epilog(void __user *buf, int ia32_frame)
 	 */
 	xstate_bv |= XSTATE_FPSSE;
 
-	err |= __put_user(xstate_bv, (__u32 *)&x->xsave_hdr.xstate_bv);
+	err |= __put_user(xstate_bv, (__u32 *)&x->header.xstate_bv);
 
 	return err;
 }
@@ -280,20 +280,20 @@ sanitize_restored_xstate(struct task_struct *tsk,
 			 u64 xstate_bv, int fx_only)
 {
 	struct xsave_struct *xsave = &tsk->thread.fpu.state->xsave;
-	struct xsave_hdr_struct *xsave_hdr = &xsave->xsave_hdr;
+	struct xstate_header *header = &xsave->header;
 
 	if (use_xsave()) {
 		/* These bits must be zero. */
-		memset(xsave_hdr->reserved, 0, 48);
+		memset(header->reserved, 0, 48);
 
 		/*
 		 * Init the state that is not present in the memory
 		 * layout and not enabled by the OS.
 		 */
 		if (fx_only)
-			xsave_hdr->xstate_bv = XSTATE_FPSSE;
+			header->xstate_bv = XSTATE_FPSSE;
 		else
-			xsave_hdr->xstate_bv &= (xfeatures_mask & xstate_bv);
+			header->xstate_bv &= (xfeatures_mask & xstate_bv);
 	}
 
 	if (use_fxsr()) {
@@ -574,9 +574,9 @@ static void __init setup_init_fpu_buf(void)
 	print_xstate_features();
 
 	if (cpu_has_xsaves) {
-		init_xstate_buf->xsave_hdr.xcomp_bv =
+		init_xstate_buf->header.xcomp_bv =
 						(u64)1 << 63 | xfeatures_mask;
-		init_xstate_buf->xsave_hdr.xstate_bv = xfeatures_mask;
+		init_xstate_buf->header.xstate_bv = xfeatures_mask;
 	}
 
 	/*

arch/x86/kvm/x86.c

@@ -3197,7 +3197,7 @@ static int kvm_vcpu_ioctl_x86_set_debugregs(struct kvm_vcpu *vcpu,
 static void fill_xsave(u8 *dest, struct kvm_vcpu *vcpu)
 {
 	struct xsave_struct *xsave = &vcpu->arch.guest_fpu.state->xsave;
-	u64 xstate_bv = xsave->xsave_hdr.xstate_bv;
+	u64 xstate_bv = xsave->header.xstate_bv;
 	u64 valid;
 
 	/*
@@ -3243,9 +3243,9 @@ static void load_xsave(struct kvm_vcpu *vcpu, u8 *src)
 	memcpy(xsave, src, XSAVE_HDR_OFFSET);
 
 	/* Set XSTATE_BV and possibly XCOMP_BV.  */
-	xsave->xsave_hdr.xstate_bv = xstate_bv;
+	xsave->header.xstate_bv = xstate_bv;
 	if (cpu_has_xsaves)
-		xsave->xsave_hdr.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED;
+		xsave->header.xcomp_bv = host_xcr0 | XSTATE_COMPACTION_ENABLED;
 
 	/*
 	 * Copy each region from the non-compacted offset to the
@@ -7014,7 +7014,7 @@ int fx_init(struct kvm_vcpu *vcpu)
 
 	fpstate_init(&vcpu->arch.guest_fpu);
 	if (cpu_has_xsaves)
-		vcpu->arch.guest_fpu.state->xsave.xsave_hdr.xcomp_bv =
+		vcpu->arch.guest_fpu.state->xsave.header.xcomp_bv =
 			host_xcr0 | XSTATE_COMPACTION_ENABLED;
 
 	/*