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-rw-r--r--arch/x86/include/uapi/asm/sigcontext.h475
1 files changed, 307 insertions, 168 deletions
diff --git a/arch/x86/include/uapi/asm/sigcontext.h b/arch/x86/include/uapi/asm/sigcontext.h
index 40836a9a7250..d485232f1e9f 100644
--- a/arch/x86/include/uapi/asm/sigcontext.h
+++ b/arch/x86/include/uapi/asm/sigcontext.h
@@ -1,221 +1,360 @@
#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.
+ *
+ * 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.)
*
- * 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.
+ * 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];
};
-#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.
+ * As documented in the iBCS2 standard:
*
- * Pentium III FXSR, SSE support
- * Gareth Hughes <gareth@valinux.com>, May 2000
+ * 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.
+ * 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 {
- unsigned short significand[4];
- unsigned short exponent;
+ __u16 significand[4];
+ __u16 exponent;
};
+/* 16-byte floating point register: */
struct _fpxreg {
- unsigned short significand[4];
- unsigned short exponent;
- unsigned short padding[3];
+ __u16 significand[4];
+ __u16 exponent;
+ __u16 padding[3];
};
+/* 16-byte XMM register: */
struct _xmmreg {
- unsigned long element[4];
+ __u32 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 */
+#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 */
- 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];
+ __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 {
- unsigned long padding2[12];
- struct _fpx_sw_bytes sw_reserved; /* represents the extended
- * state info */
+ __u32 padding2[12];
+ struct _fpx_sw_bytes sw_reserved; /* Potential extended state is encoded here */
};
};
-#define X86_FXSR_MAGIC 0x0000
-
-#ifndef __KERNEL__
/*
- * User-space might still rely on the old definition:
+ * 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 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];
+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; /* represents the extended
- * state information */
+ __u32 reserved3[12];
+ struct _fpx_sw_bytes sw_reserved; /* Potential extended state is encoded here */
};
};
-#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;
+#ifdef __i386__
+# 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 */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.