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

   1 #ifndef _UAPI_ASM_X86_SIGCONTEXT_H
   2 #define _UAPI_ASM_X86_SIGCONTEXT_H
   3
   4 /*
   5  * Linux signal context definitions. The sigcontext includes a complex hierarchy of CPU
   6  * and FPU state, available to user-space (on the stack) when a signal handler is
   7  * executed.
   8  *
   9  * As over the years this ABI grew from its very simple roots towards supporting more and
  10  * more CPU state organically, some of the details (which were rather clever hacks back
  11  * in the days) became a bit quirky by today.
  12  *
  13  * The current ABI includes flexible provisions for future extensions, so we won't have
  14  * to grow new quirks for quite some time. Promise!
  15  */
  16
  17 #include <linux/compiler.h>
  18 #include <linux/types.h>
  19
  20 #define FP_XSTATE_MAGIC1                0x46505853U
  21 #define FP_XSTATE_MAGIC2                0x46505845U
  22 #define FP_XSTATE_MAGIC2_SIZE           sizeof(FP_XSTATE_MAGIC2)
  23
  24 /*
  25  * Bytes 464..511 in the current 512-byte layout of the FXSAVE/FXRSTOR frame
  26  * are reserved for SW usage. On CPUs supporting XSAVE/XRSTOR, these bytes
  27  * are used to extend the fpstate pointer in the sigcontext, which now
  28  * includes the extended state information along with fpstate information.
  29  *
  30  * If sw_reserved.magic1 == FP_XSTATE_MAGIC1 then there's a sw_reserved.extended_size
  31  * bytes large extended context area present. (The last 32-bit word of this extended
  32  * area (at the fpstate+extended_size-FP_XSTATE_MAGIC2_SIZE address) is set to
  33  * FP_XSTATE_MAGIC2 so that you can sanity check your size calculations.)
  34  *
  35  * This extended area typically grows with newer CPUs that have larger and larger
  36  * XSAVE areas.
  37  */
  38 struct _fpx_sw_bytes {
  39         /* If set to FP_XSTATE_MAGIC1 then this is an xstate context. 0 if a legacy frame. */
  40         __u32                           magic1;
  41
  42         /*
  43          * Total size of the fpstate area:
  44          *
  45          *  - if magic1 == 0 then it's sizeof(struct _fpstate)
  46          *  - if magic1 == FP_XSTATE_MAGIC1 then it's sizeof(struct _xstate) plus extensions (if any)
  47          */
  48         __u32                           extended_size;
  49
  50         /*
  51          * Feature bit mask (including FP/SSE/extended state) that is present
  52          * in the memory layout:
  53          */
  54         __u64                           xfeatures;
  55
  56         /*
  57          * Actual XSAVE state size, based on the xfeatures saved in the layout.
  58          * 'extended_size' is greater than 'xstate_size':
  59          */
  60         __u32                           xstate_size;
  61
  62         /* For future use: */
  63         __u32                           padding[7];
  64 };
  65
  66 /*
  67  * As documented in the iBCS2 standard:
  68  *
  69  * The first part of "struct _fpstate" is just the normal i387
  70  * hardware setup, the extra "status" word is used to save the
  71  * coprocessor status word before entering the handler.
  72  *
  73  * The FPU state data structure has had to grow to accommodate the
  74  * extended FPU state required by the Streaming SIMD Extensions.
  75  * There is no documented standard to accomplish this at the moment.
  76  */
  77
  78 /* 10-byte legacy floating point register: */
  79 struct _fpreg {
  80         __u16                           significand[4];
  81         __u16                           exponent;
  82 };
  83
  84 /* 16-byte floating point register: */
  85 struct _fpxreg {
  86         __u16                           significand[4];
  87         __u16                           exponent;
  88         __u16                           padding[3];
  89 };
  90
  91 /* 16-byte XMM register: */
  92 struct _xmmreg {
  93         __u32                           element[4];
  94 };
  95
  96 #define X86_FXSR_MAGIC                  0x0000
  97
  98 /*
  99  * The 32-bit FPU frame:
 100  */
 101 struct _fpstate_32 {
 102         /* Legacy FPU environment: */
 103         __u32                           cw;
 104         __u32                           sw;
 105         __u32                           tag;
 106         __u32                           ipoff;
 107         __u32                           cssel;
 108         __u32                           dataoff;
 109         __u32                           datasel;
 110         struct _fpreg                   _st[8];
 111         __u16                           status;
 112         __u16                           magic;          /* 0xffff: regular FPU data only */
 113                                                         /* 0x0000: FXSR FPU data */
 114
 115         /* FXSR FPU environment */
 116         __u32                           _fxsr_env[6];   /* FXSR FPU env is ignored */
 117         __u32                           mxcsr;
 118         __u32                           reserved;
 119         struct _fpxreg                  _fxsr_st[8];    /* FXSR FPU reg data is ignored */
 120         struct _xmmreg                  _xmm[8];        /* First 8 XMM registers */
 121         union {
 122                 __u32                   padding1[44];   /* Second 8 XMM registers plus padding */
 123                 __u32                   padding[44];    /* Alias name for old user-space */
 124         };
 125
 126         union {
 127                 __u32                   padding2[12];
 128                 struct _fpx_sw_bytes    sw_reserved;    /* Potential extended state is encoded here */
 129         };
 130 };
 131
 132 /*
 133  * The 64-bit FPU frame. (FXSAVE format and later)
 134  *
 135  * Note1: If sw_reserved.magic1 == FP_XSTATE_MAGIC1 then the structure is
 136  *        larger: 'struct _xstate'. Note that 'struct _xstate' embedds
 137  *        'struct _fpstate' so that you can always assume the _fpstate portion
 138  *        exists so that you can check the magic value.
 139  *
 140  * Note2: Reserved fields may someday contain valuable data. Always save/restore
 141  *        them when you change signal frames.
 142  */
 143 struct _fpstate_64 {
 144         __u16                           cwd;
 145         __u16                           swd;
 146         /* Note this is not the same as the 32-bit/x87/FSAVE twd: */
 147         __u16                           twd;
 148         __u16                           fop;
 149         __u64                           rip;
 150         __u64                           rdp;
 151         __u32                           mxcsr;
 152         __u32                           mxcsr_mask;
 153         __u32                           st_space[32];   /*  8x  FP registers, 16 bytes each */
 154         __u32                           xmm_space[64];  /* 16x XMM registers, 16 bytes each */
 155         __u32                           reserved2[12];
 156         union {
 157                 __u32                   reserved3[12];
 158                 struct _fpx_sw_bytes    sw_reserved;    /* Potential extended state is encoded here */
 159         };
 160 };
 161
 162 #ifdef __i386__
 163 # define _fpstate _fpstate_32
 164 #else
 165 # define _fpstate _fpstate_64
 166 #endif
 167
 168 #define _fpstate_ia32 _fpstate_32
 169
 170 struct _header {
 171         __u64                           xfeatures;
 172         __u64                           reserved1[2];
 173         __u64                           reserved2[5];
 174 };
 175
 176 struct _ymmh_state {
 177         /* 16x YMM registers, 16 bytes each: */
 178         __u32                           ymmh_space[64];
 179 };
 180
 181 /*
 182  * Extended state pointed to by sigcontext::fpstate.
 183  *
 184  * In addition to the fpstate, information encoded in _xstate::xstate_hdr
 185  * indicates the presence of other extended state information supported
 186  * by the CPU and kernel:
 187  */
 188 struct _xstate {
 189         struct _fpstate                 fpstate;
 190         struct _header                  xstate_hdr;
 191         struct _ymmh_state              ymmh;
 192         /* New processor state extensions go here: */
 193 };
 194
 195 /*
 196  * The old user-space sigcontext definition, just in case user-space still
 197  * relies on it. The kernel definition (in asm/sigcontext.h) has unified
 198  * field names but otherwise the same layout.
 199  */
 200 #ifndef __KERNEL__
 201 # ifdef __i386__
 202 struct sigcontext {
 203         __u16                           gs, __gsh;
 204         __u16                           fs, __fsh;
 205         __u16                           es, __esh;
 206         __u16                           ds, __dsh;
 207         __u32                           edi;
 208         __u32                           esi;
 209         __u32                           ebp;
 210         __u32                           esp;
 211         __u32                           ebx;
 212         __u32                           edx;
 213         __u32                           ecx;
 214         __u32                           eax;
 215         __u32                           trapno;
 216         __u32                           err;
 217         __u32                           eip;
 218         __u16                           cs, __csh;
 219         __u32                           eflags;
 220         __u32                           esp_at_signal;
 221         __u16                           ss, __ssh;
 222         struct _fpstate __user          *fpstate;
 223         __u32                           oldmask;
 224         __u32                           cr2;
 225 };
 226 # else /* __x86_64__: */
 227 struct sigcontext {
 228         __u64                           r8;
 229         __u64                           r9;
 230         __u64                           r10;
 231         __u64                           r11;
 232         __u64                           r12;
 233         __u64                           r13;
 234         __u64                           r14;
 235         __u64                           r15;
 236         __u64                           rdi;
 237         __u64                           rsi;
 238         __u64                           rbp;
 239         __u64                           rbx;
 240         __u64                           rdx;
 241         __u64                           rax;
 242         __u64                           rcx;
 243         __u64                           rsp;
 244         __u64                           rip;
 245         __u64                           eflags;         /* RFLAGS */
 246         __u16                           cs;
 247         __u16                           gs;
 248         __u16                           fs;
 249         __u16                           __pad0;
 250         __u64                           err;
 251         __u64                           trapno;
 252         __u64                           oldmask;
 253         __u64                           cr2;
 254         struct _fpstate __user          *fpstate;       /* Zero when no FPU context */
 255 #  ifdef __ILP32__
 256         __u32                           __fpstate_pad;
 257 #  endif
 258         __u64                           reserved1[8];
 259 };
 260 # endif /* __x86_64__ */
 261 #endif /* !__KERNEL__ */
 262
 263 #endif /* _UAPI_ASM_X86_SIGCONTEXT_H */