Merge branch 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 sigcontext header cleanups from Ingo Molnar:
"This series reorganizes and cleans up various aspects of the main
sigcontext UAPI headers, such as unifying the data structures and
updating/adding lots of comments to explain all the ABI details and
quirks. The headers can now also be built in user-space standalone"

* 'x86-headers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/headers: Clean up too long lines
x86/headers: Remove <asm/sigcontext.h> references on the kernel side
x86/headers: Remove direct sigcontext32.h uses
x86/headers: Convert sigcontext_ia32 uses to sigcontext_32
x86/headers: Unify 'struct sigcontext_ia32' and 'struct sigcontext_32'
x86/headers: Make sigcontext pointers bit independent
x86/headers: Move the 'struct sigcontext' definitions into the UAPI header
x86/headers: Clean up the kernel's struct sigcontext types to be ABI-clean
x86/headers: Convert uses of _fpstate_ia32 to _fpstate_32
x86/headers: Unify 'struct _fpstate_ia32' and i386 struct _fpstate
x86/headers: Unify register type definitions between 32-bit compat and i386
x86/headers: Use ABI types consistently in sigcontext*.h
x86/headers: Separate out legacy user-space structure definitions
x86/headers: Clean up and better document uapi/asm/sigcontext.h
x86/headers: Clean up uapi/asm/sigcontext32.h
x86/headers: Fix (old) header file dependency bug in uapi/asm/sigcontext32.h

arch/x86/ia32/ia32_signal.c

···
 #include <asm/ptrace.h>
 #include <asm/ia32_unistd.h>
 #include <asm/user32.h>
-#include <asm/sigcontext32.h>
+#include <uapi/asm/sigcontext.h>
 #include <asm/proto.h>
 #include <asm/vdso.h>
 #include <asm/sigframe.h>
···
 }
 
 static int ia32_restore_sigcontext(struct pt_regs *regs,
-				   struct sigcontext_ia32 __user *sc)
+				   struct sigcontext_32 __user *sc)
 {
 	unsigned int tmpflags, err = 0;
 	void __user *buf;
···
  * Set up a signal frame.
  */
 
-static int ia32_setup_sigcontext(struct sigcontext_ia32 __user *sc,
+static int ia32_setup_sigcontext(struct sigcontext_32 __user *sc,
 				 void __user *fpstate,
 				 struct pt_regs *regs, unsigned int mask)
 {
···
 		unsigned long fx_aligned, math_size;
 
 		sp = fpu__alloc_mathframe(sp, 1, &fx_aligned, &math_size);
-		*fpstate = (struct _fpstate_ia32 __user *) sp;
+		*fpstate = (struct _fpstate_32 __user *) sp;
 		if (copy_fpstate_to_sigframe(*fpstate, (void __user *)fx_aligned,
 				    math_size) < 0)
 			return (void __user *) -1L;

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

···
 #define _ASM_X86_FPU_SIGNAL_H
 
 #ifdef CONFIG_X86_64
-# include <asm/sigcontext32.h>
+# include <uapi/asm/sigcontext.h>
 # include <asm/user32.h>
 struct ksignal;
 int ia32_setup_rt_frame(int sig, struct ksignal *ksig,

arch/x86/include/asm/ia32.h

···
  * 32 bit structures for IA32 support.
  */
 
-#include <asm/sigcontext32.h>
+#include <uapi/asm/sigcontext.h>
 
 /* signal.h */
 
···
 	unsigned int	  uc_flags;
 	unsigned int 	  uc_link;
 	compat_stack_t	  uc_stack;
-	struct sigcontext_ia32 uc_mcontext;
+	struct sigcontext_32 uc_mcontext;
 	compat_sigset_t	  uc_sigmask;	/* mask last for extensibility */
 };
 

arch/x86/include/asm/processor.h

···
 #include <asm/math_emu.h>
 #include <asm/segment.h>
 #include <asm/types.h>
-#include <asm/sigcontext.h>
+#include <uapi/asm/sigcontext.h>
 #include <asm/current.h>
 #include <asm/cpufeature.h>
 #include <asm/page.h>

arch/x86/include/asm/sigcontext.h

···
 #ifndef _ASM_X86_SIGCONTEXT_H
 #define _ASM_X86_SIGCONTEXT_H
 
+/* This is a legacy header - all kernel code includes <uapi/asm/sigcontext.h> directly. */
+
 #include <uapi/asm/sigcontext.h>
 
-#ifdef __i386__
-struct sigcontext {
-	unsigned short gs, __gsh;
-	unsigned short fs, __fsh;
-	unsigned short es, __esh;
-	unsigned short ds, __dsh;
-	unsigned long di;
-	unsigned long si;
-	unsigned long bp;
-	unsigned long sp;
-	unsigned long bx;
-	unsigned long dx;
-	unsigned long cx;
-	unsigned long ax;
-	unsigned long trapno;
-	unsigned long err;
-	unsigned long ip;
-	unsigned short cs, __csh;
-	unsigned long flags;
-	unsigned long sp_at_signal;
-	unsigned short ss, __ssh;
-
-	/*
-	 * fpstate is really (struct _fpstate *) or (struct _xstate *)
-	 * depending on the FP_XSTATE_MAGIC1 encoded in the SW reserved
-	 * bytes of (struct _fpstate) and FP_XSTATE_MAGIC2 present at the end
-	 * of extended memory layout. See comments at the definition of
-	 * (struct _fpx_sw_bytes)
-	 */
-	void __user *fpstate;		/* zero when no FPU/extended context */
-	unsigned long oldmask;
-	unsigned long cr2;
-};
-#else /* __i386__ */
-struct sigcontext {
-	unsigned long r8;
-	unsigned long r9;
-	unsigned long r10;
-	unsigned long r11;
-	unsigned long r12;
-	unsigned long r13;
-	unsigned long r14;
-	unsigned long r15;
-	unsigned long di;
-	unsigned long si;
-	unsigned long bp;
-	unsigned long bx;
-	unsigned long dx;
-	unsigned long ax;
-	unsigned long cx;
-	unsigned long sp;
-	unsigned long ip;
-	unsigned long flags;
-	unsigned short cs;
-	unsigned short gs;
-	unsigned short fs;
-	unsigned short __pad0;
-	unsigned long err;
-	unsigned long trapno;
-	unsigned long oldmask;
-	unsigned long cr2;
-
-	/*
-	 * fpstate is really (struct _fpstate *) or (struct _xstate *)
-	 * depending on the FP_XSTATE_MAGIC1 encoded in the SW reserved
-	 * bytes of (struct _fpstate) and FP_XSTATE_MAGIC2 present at the end
-	 * of extended memory layout. See comments at the definition of
-	 * (struct _fpx_sw_bytes)
-	 */
-	void __user *fpstate;		/* zero when no FPU/extended context */
-	unsigned long reserved1[8];
-};
-#endif /* !__i386__ */
 #endif /* _ASM_X86_SIGCONTEXT_H */

arch/x86/include/asm/sigframe.h

···
 #ifndef _ASM_X86_SIGFRAME_H
 #define _ASM_X86_SIGFRAME_H
 
-#include <asm/sigcontext.h>
+#include <uapi/asm/sigcontext.h>
 #include <asm/siginfo.h>
 #include <asm/ucontext.h>
 #include <linux/compat.h>
···
 #ifdef CONFIG_X86_32
 #define sigframe_ia32		sigframe
 #define rt_sigframe_ia32	rt_sigframe
-#define sigcontext_ia32		sigcontext
-#define _fpstate_ia32		_fpstate
 #define ucontext_ia32		ucontext
 #else /* !CONFIG_X86_32 */
 
···
 struct sigframe_ia32 {
 	u32 pretcode;
 	int sig;
-	struct sigcontext_ia32 sc;
+	struct sigcontext_32 sc;
 	/*
 	 * fpstate is unused. fpstate is moved/allocated after
 	 * retcode[] below. This movement allows to have the FP state and the
···
 	 * the offset of extramask[] in the sigframe and thus prevent any
 	 * legacy application accessing/modifying it.
 	 */
-	struct _fpstate_ia32 fpstate_unused;
+	struct _fpstate_32 fpstate_unused;
 #ifdef CONFIG_IA32_EMULATION
 	unsigned int extramask[_COMPAT_NSIG_WORDS-1];
 #else /* !CONFIG_IA32_EMULATION */

arch/x86/include/asm/signal.h

···
 
 #define __ARCH_HAS_SA_RESTORER
 
-#include <asm/sigcontext.h>
+#include <uapi/asm/sigcontext.h>
 
 #ifdef __i386__
 

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

···
 #ifndef _UAPI_ASM_X86_SIGCONTEXT_H
 #define _UAPI_ASM_X86_SIGCONTEXT_H
 
+/*
+ * Linux signal context definitions. The sigcontext includes a complex
+ * hierarchy of CPU and FPU state, available to user-space (on the stack) when
+ * a signal handler is executed.
+ *
+ * As over the years this ABI grew from its very simple roots towards
+ * supporting more and more CPU state organically, some of the details (which
+ * were rather clever hacks back in the days) became a bit quirky by today.
+ *
+ * The current ABI includes flexible provisions for future extensions, so we
+ * won't have to grow new quirks for quite some time. Promise!
+ */
+
 #include <linux/compiler.h>
 #include <linux/types.h>
 
-#define FP_XSTATE_MAGIC1	0x46505853U
-#define FP_XSTATE_MAGIC2	0x46505845U
-#define FP_XSTATE_MAGIC2_SIZE	sizeof(FP_XSTATE_MAGIC2)
+#define FP_XSTATE_MAGIC1		0x46505853U
+#define FP_XSTATE_MAGIC2		0x46505845U
+#define FP_XSTATE_MAGIC2_SIZE		sizeof(FP_XSTATE_MAGIC2)
 
 /*
- * bytes 464..511 in the current 512byte layout of fxsave/fxrstor frame
- * are reserved for SW usage. On cpu's supporting xsave/xrstor, these bytes
- * are used to extended the fpstate pointer in the sigcontext, which now
- * includes the extended state information along with fpstate information.
+ * Bytes 464..511 in the current 512-byte layout of the FXSAVE/FXRSTOR frame
+ * are reserved for SW usage. On CPUs supporting XSAVE/XRSTOR, these bytes are
+ * used to extend the fpstate pointer in the sigcontext, which now includes the
+ * extended state information along with fpstate information.
  *
- * Presence of FP_XSTATE_MAGIC1 at the beginning of this SW reserved
- * area and FP_XSTATE_MAGIC2 at the end of memory layout
- * (extended_size - FP_XSTATE_MAGIC2_SIZE) indicates the presence of the
- * extended state information in the memory layout pointed by the fpstate
- * pointer in sigcontext.
+ * If sw_reserved.magic1 == FP_XSTATE_MAGIC1 then there's a
+ * sw_reserved.extended_size bytes large extended context area present. (The
+ * last 32-bit word of this extended area (at the
+ * fpstate+extended_size-FP_XSTATE_MAGIC2_SIZE address) is set to
+ * FP_XSTATE_MAGIC2 so that you can sanity check your size calculations.)
+ *
+ * This extended area typically grows with newer CPUs that have larger and
+ * larger XSAVE areas.
  */
 struct _fpx_sw_bytes {
-	__u32 magic1;		/* FP_XSTATE_MAGIC1 */
-	__u32 extended_size;	/* total size of the layout referred by
-				 * fpstate pointer in the sigcontext.
-				 */
-	__u64 xfeatures;
-				/* feature bit mask (including fp/sse/extended
-				 * state) that is present in the memory
-				 * layout.
-				 */
-	__u32 xstate_size;	/* actual xsave state size, based on the
-				 * features saved in the layout.
-				 * 'extended_size' will be greater than
-				 * 'xstate_size'.
-				 */
-	__u32 padding[7];	/*  for future use. */
+	/*
+	 * If set to FP_XSTATE_MAGIC1 then this is an xstate context.
+	 * 0 if a legacy frame.
+	 */
+	__u32				magic1;
+
+	/*
+	 * Total size of the fpstate area:
+	 *
+	 *  - if magic1 == 0 then it's sizeof(struct _fpstate)
+	 *  - if magic1 == FP_XSTATE_MAGIC1 then it's sizeof(struct _xstate)
+	 *    plus extensions (if any)
+	 */
+	__u32				extended_size;
+
+	/*
+	 * Feature bit mask (including FP/SSE/extended state) that is present
+	 * in the memory layout:
+	 */
+	__u64				xfeatures;
+
+	/*
+	 * Actual XSAVE state size, based on the xfeatures saved in the layout.
+	 * 'extended_size' is greater than 'xstate_size':
+	 */
+	__u32				xstate_size;
+
+	/* For future use: */
+	__u32				padding[7];
+};
+
+/*
+ * As documented in the iBCS2 standard:
+ *
+ * The first part of "struct _fpstate" is just the normal i387 hardware setup,
+ * the extra "status" word is used to save the coprocessor status word before
+ * entering the handler.
+ *
+ * The FPU state data structure has had to grow to accommodate the extended FPU
+ * state required by the Streaming SIMD Extensions.  There is no documented
+ * standard to accomplish this at the moment.
+ */
+
+/* 10-byte legacy floating point register: */
+struct _fpreg {
+	__u16				significand[4];
+	__u16				exponent;
+};
+
+/* 16-byte floating point register: */
+struct _fpxreg {
+	__u16				significand[4];
+	__u16				exponent;
+	__u16				padding[3];
+};
+
+/* 16-byte XMM register: */
+struct _xmmreg {
+	__u32				element[4];
+};
+
+#define X86_FXSR_MAGIC			0x0000
+
+/*
+ * The 32-bit FPU frame:
+ */
+struct _fpstate_32 {
+	/* Legacy FPU environment: */
+	__u32				cw;
+	__u32				sw;
+	__u32				tag;
+	__u32				ipoff;
+	__u32				cssel;
+	__u32				dataoff;
+	__u32				datasel;
+	struct _fpreg			_st[8];
+	__u16				status;
+	__u16				magic;		/* 0xffff: regular FPU data only */
+							/* 0x0000: FXSR FPU data */
+
+	/* FXSR FPU environment */
+	__u32				_fxsr_env[6];	/* FXSR FPU env is ignored */
+	__u32				mxcsr;
+	__u32				reserved;
+	struct _fpxreg			_fxsr_st[8];	/* FXSR FPU reg data is ignored */
+	struct _xmmreg			_xmm[8];	/* First 8 XMM registers */
+	union {
+		__u32			padding1[44];	/* Second 8 XMM registers plus padding */
+		__u32			padding[44];	/* Alias name for old user-space */
+	};
+
+	union {
+		__u32			padding2[12];
+		struct _fpx_sw_bytes	sw_reserved;	/* Potential extended state is encoded here */
+	};
+};
+
+/*
+ * The 64-bit FPU frame. (FXSAVE format and later)
+ *
+ * Note1: If sw_reserved.magic1 == FP_XSTATE_MAGIC1 then the structure is
+ *        larger: 'struct _xstate'. Note that 'struct _xstate' embedds
+ *        'struct _fpstate' so that you can always assume the _fpstate portion
+ *        exists so that you can check the magic value.
+ *
+ * Note2: Reserved fields may someday contain valuable data. Always
+ *	  save/restore them when you change signal frames.
+ */
+struct _fpstate_64 {
+	__u16				cwd;
+	__u16				swd;
+	/* Note this is not the same as the 32-bit/x87/FSAVE twd: */
+	__u16				twd;
+	__u16				fop;
+	__u64				rip;
+	__u64				rdp;
+	__u32				mxcsr;
+	__u32				mxcsr_mask;
+	__u32				st_space[32];	/*  8x  FP registers, 16 bytes each */
+	__u32				xmm_space[64];	/* 16x XMM registers, 16 bytes each */
+	__u32				reserved2[12];
+	union {
+		__u32			reserved3[12];
+		struct _fpx_sw_bytes	sw_reserved;	/* Potential extended state is encoded here */
+	};
 };
 
 #ifdef __i386__
-/*
- * As documented in the iBCS2 standard..
- *
- * The first part of "struct _fpstate" is just the normal i387
- * hardware setup, the extra "status" word is used to save the
- * coprocessor status word before entering the handler.
- *
- * Pentium III FXSR, SSE support
- *	Gareth Hughes <[e-mail]>, May 2000
- *
- * The FPU state data structure has had to grow to accommodate the
- * extended FPU state required by the Streaming SIMD Extensions.
- * There is no documented standard to accomplish this at the moment.
- */
-struct _fpreg {
-	unsigned short significand[4];
-	unsigned short exponent;
-};
-
-struct _fpxreg {
-	unsigned short significand[4];
-	unsigned short exponent;
-	unsigned short padding[3];
-};
-
-struct _xmmreg {
-	unsigned long element[4];
-};
-
-struct _fpstate {
-	/* Regular FPU environment */
-	unsigned long	cw;
-	unsigned long	sw;
-	unsigned long	tag;
-	unsigned long	ipoff;
-	unsigned long	cssel;
-	unsigned long	dataoff;
-	unsigned long	datasel;
-	struct _fpreg	_st[8];
-	unsigned short	status;
-	unsigned short	magic;		/* 0xffff = regular FPU data only */
-
-	/* FXSR FPU environment */
-	unsigned long	_fxsr_env[6];	/* FXSR FPU env is ignored */
-	unsigned long	mxcsr;
-	unsigned long	reserved;
-	struct _fpxreg	_fxsr_st[8];	/* FXSR FPU reg data is ignored */
-	struct _xmmreg	_xmm[8];
-	unsigned long	padding1[44];
-
-	union {
-		unsigned long	padding2[12];
-		struct _fpx_sw_bytes sw_reserved; /* represents the extended
-						   * state info */
-	};
-};
-
-#define X86_FXSR_MAGIC		0x0000
-
-#ifndef __KERNEL__
-/*
- * User-space might still rely on the old definition:
- */
-struct sigcontext {
-	unsigned short gs, __gsh;
-	unsigned short fs, __fsh;
-	unsigned short es, __esh;
-	unsigned short ds, __dsh;
-	unsigned long edi;
-	unsigned long esi;
-	unsigned long ebp;
-	unsigned long esp;
-	unsigned long ebx;
-	unsigned long edx;
-	unsigned long ecx;
-	unsigned long eax;
-	unsigned long trapno;
-	unsigned long err;
-	unsigned long eip;
-	unsigned short cs, __csh;
-	unsigned long eflags;
-	unsigned long esp_at_signal;
-	unsigned short ss, __ssh;
-	struct _fpstate __user *fpstate;
-	unsigned long oldmask;
-	unsigned long cr2;
-};
-#endif /* !__KERNEL__ */
-
-#else /* __i386__ */
-
-/* FXSAVE frame */
-/* Note: reserved1/2 may someday contain valuable data. Always save/restore
-   them when you change signal frames. */
-struct _fpstate {
-	__u16	cwd;
-	__u16	swd;
-	__u16	twd;		/* Note this is not the same as the
-				   32bit/x87/FSAVE twd */
-	__u16	fop;
-	__u64	rip;
-	__u64	rdp;
-	__u32	mxcsr;
-	__u32	mxcsr_mask;
-	__u32	st_space[32];	/* 8*16 bytes for each FP-reg */
-	__u32	xmm_space[64];	/* 16*16 bytes for each XMM-reg  */
-	__u32	reserved2[12];
-	union {
-		__u32	reserved3[12];
-		struct _fpx_sw_bytes sw_reserved; /* represents the extended
-						   * state information */
-	};
-};
-
-#ifndef __KERNEL__
-/*
- * User-space might still rely on the old definition:
- */
-struct sigcontext {
-	__u64 r8;
-	__u64 r9;
-	__u64 r10;
-	__u64 r11;
-	__u64 r12;
-	__u64 r13;
-	__u64 r14;
-	__u64 r15;
-	__u64 rdi;
-	__u64 rsi;
-	__u64 rbp;
-	__u64 rbx;
-	__u64 rdx;
-	__u64 rax;
-	__u64 rcx;
-	__u64 rsp;
-	__u64 rip;
-	__u64 eflags;		/* RFLAGS */
-	__u16 cs;
-	__u16 gs;
-	__u16 fs;
-	__u16 __pad0;
-	__u64 err;
-	__u64 trapno;
-	__u64 oldmask;
-	__u64 cr2;
-	struct _fpstate __user *fpstate;	/* zero when no FPU context */
-#ifdef __ILP32__
-	__u32 __fpstate_pad;
+# define _fpstate _fpstate_32
+#else
+# define _fpstate _fpstate_64
 #endif
-	__u64 reserved1[8];
-};
-#endif /* !__KERNEL__ */
-
-#endif /* !__i386__ */
 
 struct _header {
-	__u64 xfeatures;
-	__u64 reserved1[2];
-	__u64 reserved2[5];
+	__u64				xfeatures;
+	__u64				reserved1[2];
+	__u64				reserved2[5];
 };
 
 struct _ymmh_state {
-	/* 16 * 16 bytes for each YMMH-reg */
-	__u32 ymmh_space[64];
+	/* 16x YMM registers, 16 bytes each: */
+	__u32				ymmh_space[64];
 };
 
 /*
- * Extended state pointed by the fpstate pointer in the sigcontext.
- * In addition to the fpstate, information encoded in the xstate_hdr
- * indicates the presence of other extended state information
- * supported by the processor and OS.
+ * Extended state pointed to by sigcontext::fpstate.
+ *
+ * In addition to the fpstate, information encoded in _xstate::xstate_hdr
+ * indicates the presence of other extended state information supported
+ * by the CPU and kernel:
  */
 struct _xstate {
-	struct _fpstate fpstate;
-	struct _header xstate_hdr;
-	struct _ymmh_state ymmh;
-	/* new processor state extensions go here */
+	struct _fpstate			fpstate;
+	struct _header			xstate_hdr;
+	struct _ymmh_state		ymmh;
+	/* New processor state extensions go here: */
 };
+
+/*
+ * The 32-bit signal frame:
+ */
+struct sigcontext_32 {
+	__u16				gs, __gsh;
+	__u16				fs, __fsh;
+	__u16				es, __esh;
+	__u16				ds, __dsh;
+	__u32				di;
+	__u32				si;
+	__u32				bp;
+	__u32				sp;
+	__u32				bx;
+	__u32				dx;
+	__u32				cx;
+	__u32				ax;
+	__u32				trapno;
+	__u32				err;
+	__u32				ip;
+	__u16				cs, __csh;
+	__u32				flags;
+	__u32				sp_at_signal;
+	__u16				ss, __ssh;
+
+	/*
+	 * fpstate is really (struct _fpstate *) or (struct _xstate *)
+	 * depending on the FP_XSTATE_MAGIC1 encoded in the SW reserved
+	 * bytes of (struct _fpstate) and FP_XSTATE_MAGIC2 present at the end
+	 * of extended memory layout. See comments at the definition of
+	 * (struct _fpx_sw_bytes)
+	 */
+	__u32				fpstate; /* Zero when no FPU/extended context */
+	__u32				oldmask;
+	__u32				cr2;
+};
+
+/*
+ * The 64-bit signal frame:
+ */
+struct sigcontext_64 {
+	__u64				r8;
+	__u64				r9;
+	__u64				r10;
+	__u64				r11;
+	__u64				r12;
+	__u64				r13;
+	__u64				r14;
+	__u64				r15;
+	__u64				di;
+	__u64				si;
+	__u64				bp;
+	__u64				bx;
+	__u64				dx;
+	__u64				ax;
+	__u64				cx;
+	__u64				sp;
+	__u64				ip;
+	__u64				flags;
+	__u16				cs;
+	__u16				gs;
+	__u16				fs;
+	__u16				__pad0;
+	__u64				err;
+	__u64				trapno;
+	__u64				oldmask;
+	__u64				cr2;
+
+	/*
+	 * fpstate is really (struct _fpstate *) or (struct _xstate *)
+	 * depending on the FP_XSTATE_MAGIC1 encoded in the SW reserved
+	 * bytes of (struct _fpstate) and FP_XSTATE_MAGIC2 present at the end
+	 * of extended memory layout. See comments at the definition of
+	 * (struct _fpx_sw_bytes)
+	 */
+	__u64				fpstate; /* Zero when no FPU/extended context */
+	__u64				reserved1[8];
+};
+
+/*
+ * Create the real 'struct sigcontext' type:
+ */
+#ifdef __KERNEL__
+# ifdef __i386__
+#  define sigcontext sigcontext_32
+# else
+#  define sigcontext sigcontext_64
+# endif
+#endif
+
+/*
+ * The old user-space sigcontext definition, just in case user-space still
+ * relies on it. The kernel definition (in asm/sigcontext.h) has unified
+ * field names but otherwise the same layout.
+ */
+#ifndef __KERNEL__
+
+#define _fpstate_ia32			_fpstate_32
+#define sigcontext_ia32			sigcontext_32
+
+
+# ifdef __i386__
+struct sigcontext {
+	__u16				gs, __gsh;
+	__u16				fs, __fsh;
+	__u16				es, __esh;
+	__u16				ds, __dsh;
+	__u32				edi;
+	__u32				esi;
+	__u32				ebp;
+	__u32				esp;
+	__u32				ebx;
+	__u32				edx;
+	__u32				ecx;
+	__u32				eax;
+	__u32				trapno;
+	__u32				err;
+	__u32				eip;
+	__u16				cs, __csh;
+	__u32				eflags;
+	__u32				esp_at_signal;
+	__u16				ss, __ssh;
+	struct _fpstate __user		*fpstate;
+	__u32				oldmask;
+	__u32				cr2;
+};
+# else /* __x86_64__: */
+struct sigcontext {
+	__u64				r8;
+	__u64				r9;
+	__u64				r10;
+	__u64				r11;
+	__u64				r12;
+	__u64				r13;
+	__u64				r14;
+	__u64				r15;
+	__u64				rdi;
+	__u64				rsi;
+	__u64				rbp;
+	__u64				rbx;
+	__u64				rdx;
+	__u64				rax;
+	__u64				rcx;
+	__u64				rsp;
+	__u64				rip;
+	__u64				eflags;		/* RFLAGS */
+	__u16				cs;
+	__u16				gs;
+	__u16				fs;
+	__u16				__pad0;
+	__u64				err;
+	__u64				trapno;
+	__u64				oldmask;
+	__u64				cr2;
+	struct _fpstate __user		*fpstate;	/* Zero when no FPU context */
+#  ifdef __ILP32__
+	__u32				__fpstate_pad;
+#  endif
+	__u64				reserved1[8];
+};
+# endif /* __x86_64__ */
+#endif /* !__KERNEL__ */
 
 #endif /* _UAPI_ASM_X86_SIGCONTEXT_H */

arch/x86/include/uapi/asm/sigcontext32.h

···
 #ifndef _ASM_X86_SIGCONTEXT32_H
 #define _ASM_X86_SIGCONTEXT32_H
 
-#include <linux/types.h>
+/* This is a legacy file - all the type definitions are in sigcontext.h: */
 
-/* signal context for 32bit programs. */
-
-#define X86_FXSR_MAGIC		0x0000
-
-struct _fpreg {
-	unsigned short significand[4];
-	unsigned short exponent;
-};
-
-struct _fpxreg {
-	unsigned short significand[4];
-	unsigned short exponent;
-	unsigned short padding[3];
-};
-
-struct _xmmreg {
-	__u32	element[4];
-};
-
-/* FSAVE frame with extensions */
-struct _fpstate_ia32 {
-	/* Regular FPU environment */
-	__u32 	cw;
-	__u32	sw;
-	__u32	tag;	/* not compatible to 64bit twd */
-	__u32	ipoff;
-	__u32	cssel;
-	__u32	dataoff;
-	__u32	datasel;
-	struct _fpreg	_st[8];
-	unsigned short	status;
-	unsigned short	magic;		/* 0xffff = regular FPU data only */
-
-	/* FXSR FPU environment */
-	__u32	_fxsr_env[6];
-	__u32	mxcsr;
-	__u32	reserved;
-	struct _fpxreg	_fxsr_st[8];
-	struct _xmmreg	_xmm[8];	/* It's actually 16 */
-	__u32	padding[44];
-	union {
-		__u32 padding2[12];
-		struct _fpx_sw_bytes sw_reserved;
-	};
-};
-
-struct sigcontext_ia32 {
-       unsigned short gs, __gsh;
-       unsigned short fs, __fsh;
-       unsigned short es, __esh;
-       unsigned short ds, __dsh;
-       unsigned int di;
-       unsigned int si;
-       unsigned int bp;
-       unsigned int sp;
-       unsigned int bx;
-       unsigned int dx;
-       unsigned int cx;
-       unsigned int ax;
-       unsigned int trapno;
-       unsigned int err;
-       unsigned int ip;
-       unsigned short cs, __csh;
-       unsigned int flags;
-       unsigned int sp_at_signal;
-       unsigned short ss, __ssh;
-       unsigned int fpstate;		/* really (struct _fpstate_ia32 *) */
-       unsigned int oldmask;
-       unsigned int cr2;
-};
+#include <asm/sigcontext.h>
 
 #endif /* _ASM_X86_SIGCONTEXT32_H */

arch/x86/kernel/asm-offsets.c

···
 
 #if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
 	BLANK();
-	OFFSET(IA32_SIGCONTEXT_ax, sigcontext_ia32, ax);
-	OFFSET(IA32_SIGCONTEXT_bx, sigcontext_ia32, bx);
-	OFFSET(IA32_SIGCONTEXT_cx, sigcontext_ia32, cx);
-	OFFSET(IA32_SIGCONTEXT_dx, sigcontext_ia32, dx);
-	OFFSET(IA32_SIGCONTEXT_si, sigcontext_ia32, si);
-	OFFSET(IA32_SIGCONTEXT_di, sigcontext_ia32, di);
-	OFFSET(IA32_SIGCONTEXT_bp, sigcontext_ia32, bp);
-	OFFSET(IA32_SIGCONTEXT_sp, sigcontext_ia32, sp);
-	OFFSET(IA32_SIGCONTEXT_ip, sigcontext_ia32, ip);
+	OFFSET(IA32_SIGCONTEXT_ax, sigcontext_32, ax);
+	OFFSET(IA32_SIGCONTEXT_bx, sigcontext_32, bx);
+	OFFSET(IA32_SIGCONTEXT_cx, sigcontext_32, cx);
+	OFFSET(IA32_SIGCONTEXT_dx, sigcontext_32, dx);
+	OFFSET(IA32_SIGCONTEXT_si, sigcontext_32, si);
+	OFFSET(IA32_SIGCONTEXT_di, sigcontext_32, di);
+	OFFSET(IA32_SIGCONTEXT_bp, sigcontext_32, bp);
+	OFFSET(IA32_SIGCONTEXT_sp, sigcontext_32, sp);
+	OFFSET(IA32_SIGCONTEXT_ip, sigcontext_32, ip);
 
 	BLANK();
 	OFFSET(IA32_RT_SIGFRAME_sigcontext, rt_sigframe_ia32, uc.uc_mcontext);

arch/x86/kernel/fpu/signal.c

···
 	if (use_fxsr()) {
 		struct xregs_state *xsave = &tsk->thread.fpu.state.xsave;
 		struct user_i387_ia32_struct env;
-		struct _fpstate_ia32 __user *fp = buf;
+		struct _fpstate_32 __user *fp = buf;
 
 		convert_from_fxsr(&env, tsk);
 
···
 	if (!static_cpu_has(X86_FEATURE_FPU))
 		return fpregs_soft_get(current, NULL, 0,
 			sizeof(struct user_i387_ia32_struct), NULL,
-			(struct _fpstate_ia32 __user *) buf) ? -1 : 1;
+			(struct _fpstate_32 __user *) buf) ? -1 : 1;
 
 	if (fpregs_active()) {
 		/* Save the live register state to the user directly. */

arch/x86/kernel/signal.c

···
 
 int restore_sigcontext(struct pt_regs *regs, struct sigcontext __user *sc)
 {
+	unsigned long buf_val;
 	void __user *buf;
 	unsigned int tmpflags;
 	unsigned int err = 0;
···
 		regs->flags = (regs->flags & ~FIX_EFLAGS) | (tmpflags & FIX_EFLAGS);
 		regs->orig_ax = -1;		/* disable syscall checks */
 
-		get_user_ex(buf, &sc->fpstate);
+		get_user_ex(buf_val, &sc->fpstate);
+		buf = (void __user *)buf_val;
 	} get_user_catch(err);
 
 	err |= fpu__restore_sig(buf, config_enabled(CONFIG_X86_32));

arch/x86/math-emu/fpu_emu.h

···
 
 #include "fpu_system.h"
 
-#include <asm/sigcontext.h>	/* for struct _fpstate */
+#include <uapi/asm/sigcontext.h>	/* for struct _fpstate */
 #include <asm/math_emu.h>
 #include <linux/linkage.h>