Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 389 insertions, 0 deletions

diff --git a/arch/x86/include/uapi/asm/sigcontext.h b/arch/x86/include/uapi/asm/sigcontext.h
new file mode 100644
index 000000000..844d60eb1
--- /dev/null
+++ b/arch/x86/include/uapi/asm/sigcontext.h
@@ -0,0 +1,389 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+#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)
+
+/*
+ * 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.
+ *
+ * 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 {
+	/*
+	 * 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__
+# define _fpstate _fpstate_32
+#else
+# define _fpstate _fpstate_64
+#endif
+
+struct _header {
+	__u64				xfeatures;
+	__u64				reserved1[2];
+	__u64				reserved2[5];
+};
+
+struct _ymmh_state {
+	/* 16x YMM registers, 16 bytes each: */
+	__u32				ymmh_space[64];
+};
+
+/*
+ * 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: */
+};
+
+/*
+ * 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				ss;
+	__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;
+
+	/*
+	 * Prior to 2.5.64 ("[PATCH] x86-64 updates for 2.5.64-bk3"),
+	 * Linux saved and restored fs and gs in these slots.  This
+	 * was counterproductive, as fsbase and gsbase were never
+	 * saved, so arch_prctl was presumably unreliable.
+	 *
+	 * These slots should never be reused without extreme caution:
+	 *
+	 *  - Some DOSEMU versions stash fs and gs in these slots manually,
+	 *    thus overwriting anything the kernel expects to be preserved
+	 *    in these slots.
+	 *
+	 *  - If these slots are ever needed for any other purpose,
+	 *    there is some risk that very old 64-bit binaries could get
+	 *    confused.  I doubt that many such binaries still work,
+	 *    though, since the same patch in 2.5.64 also removed the
+	 *    64-bit set_thread_area syscall, so it appears that there
+	 *    is no TLS API beyond modify_ldt that works in both pre-
+	 *    and post-2.5.64 kernels.
+	 *
+	 * If the kernel ever adds explicit fs, gs, fsbase, and gsbase
+	 * save/restore, it will most likely need to be opt-in and use
+	 * different context slots.
+	 */
+	__u16				gs;
+	__u16				fs;
+	union {
+		__u16			ss;	/* If UC_SIGCONTEXT_SS */
+		__u16			__pad0;	/* Alias name for old (!UC_SIGCONTEXT_SS) user-space */
+	};
+	__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 */