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
   6  * hierarchy of CPU and FPU state, available to user-space (on the stack) when
   7  * a signal handler is executed.
   8  *
   9  * As over the years this ABI grew from its very simple roots towards
  10  * supporting more and more CPU state organically, some of the details (which
  11  * were rather clever hacks back in the days) became a bit quirky by today.
  12  *
  13  * The current ABI includes flexible provisions for future extensions, so we
  14  * won't have 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 are
  27  * used to extend the fpstate pointer in the sigcontext, which now includes the
  28  * extended state information along with fpstate information.
  29  *
  30  * If sw_reserved.magic1 == FP_XSTATE_MAGIC1 then there's a
  31  * sw_reserved.extended_size bytes large extended context area present. (The
  32  * last 32-bit word of this extended area (at the
  33  * fpstate+extended_size-FP_XSTATE_MAGIC2_SIZE address) is set to
  34  * FP_XSTATE_MAGIC2 so that you can sanity check your size calculations.)
  35  *
  36  * This extended area typically grows with newer CPUs that have larger and
  37  * larger XSAVE areas.
  38  */
  39 struct _fpx_sw_bytes {
  40         /*
  41          * If set to FP_XSTATE_MAGIC1 then this is an xstate context.
  42          * 0 if a legacy frame.
  43          */
  44         __u32                           magic1;
  45
  46         /*
  47          * Total size of the fpstate area:
  48          *
  49          *  - if magic1 == 0 then it's sizeof(struct _fpstate)
  50          *  - if magic1 == FP_XSTATE_MAGIC1 then it's sizeof(struct _xstate)
  51          *    plus extensions (if any)
  52          */
  53         __u32                           extended_size;
  54
  55         /*
  56          * Feature bit mask (including FP/SSE/extended state) that is present
  57          * in the memory layout:
  58          */
  59         __u64                           xfeatures;
  60
  61         /*
  62          * Actual XSAVE state size, based on the xfeatures saved in the layout.
  63          * 'extended_size' is greater than 'xstate_size':
  64          */
  65         __u32                           xstate_size;
  66
  67         /* For future use: */
  68         __u32                           padding[7];
  69 };
  70
  71 /*
  72  * As documented in the iBCS2 standard:
  73  *
  74  * The first part of "struct _fpstate" is just the normal i387 hardware setup,
  75  * the extra "status" word is used to save the coprocessor status word before
  76  * entering the handler.
  77  *
  78  * The FPU state data structure has had to grow to accommodate the extended FPU
  79  * state required by the Streaming SIMD Extensions.  There is no documented
  80  * standard to accomplish this at the moment.
  81  */
  82
  83 /* 10-byte legacy floating point register: */
  84 struct _fpreg {
  85         __u16                           significand[4];
  86         __u16                           exponent;
  87 };
  88
  89 /* 16-byte floating point register: */
  90 struct _fpxreg {
  91         __u16                           significand[4];
  92         __u16                           exponent;
  93         __u16                           padding[3];
  94 };
  95
  96 /* 16-byte XMM register: */
  97 struct _xmmreg {
  98         __u32                           element[4];
  99 };
 100
 101 #define X86_FXSR_MAGIC                  0x0000
 102
 103 /*
 104  * The 32-bit FPU frame:
 105  */
 106 struct _fpstate_32 {
 107         /* Legacy FPU environment: */
 108         __u32                           cw;
 109         __u32                           sw;
 110         __u32                           tag;
 111         __u32                           ipoff;
 112         __u32                           cssel;
 113         __u32                           dataoff;
 114         __u32                           datasel;
 115         struct _fpreg                   _st[8];
 116         __u16                           status;
 117         __u16                           magic;          /* 0xffff: regular FPU data only */
 118                                                         /* 0x0000: FXSR FPU data */
 119
 120         /* FXSR FPU environment */
 121         __u32                           _fxsr_env[6];   /* FXSR FPU env is ignored */
 122         __u32                           mxcsr;
 123         __u32                           reserved;
 124         struct _fpxreg                  _fxsr_st[8];    /* FXSR FPU reg data is ignored */
 125         struct _xmmreg                  _xmm[8];        /* First 8 XMM registers */
 126         union {
 127                 __u32                   padding1[44];   /* Second 8 XMM registers plus padding */
 128                 __u32                   padding[44];    /* Alias name for old user-space */
 129         };
 130
 131         union {
 132                 __u32                   padding2[12];
 133                 struct _fpx_sw_bytes    sw_reserved;    /* Potential extended state is encoded here */
 134         };
 135 };
 136
 137 /*
 138  * The 64-bit FPU frame. (FXSAVE format and later)
 139  *
 140  * Note1: If sw_reserved.magic1 == FP_XSTATE_MAGIC1 then the structure is
 141  *        larger: 'struct _xstate'. Note that 'struct _xstate' embedds
 142  *        'struct _fpstate' so that you can always assume the _fpstate portion
 143  *        exists so that you can check the magic value.
 144  *
 145  * Note2: Reserved fields may someday contain valuable data. Always
 146  *        save/restore them when you change signal frames.
 147  */
 148 struct _fpstate_64 {
 149         __u16                           cwd;
 150         __u16                           swd;
 151         /* Note this is not the same as the 32-bit/x87/FSAVE twd: */
 152         __u16                           twd;
 153         __u16                           fop;
 154         __u64                           rip;
 155         __u64                           rdp;
 156         __u32                           mxcsr;
 157         __u32                           mxcsr_mask;
 158         __u32                           st_space[32];   /*  8x  FP registers, 16 bytes each */
 159         __u32                           xmm_space[64];  /* 16x XMM registers, 16 bytes each */
 160         __u32                           reserved2[12];
 161         union {
 162                 __u32                   reserved3[12];
 163                 struct _fpx_sw_bytes    sw_reserved;    /* Potential extended state is encoded here */
 164         };
 165 };
 166
 167 #ifdef __i386__
 168 # define _fpstate _fpstate_32
 169 #else
 170 # define _fpstate _fpstate_64
 171 #endif
 172
 173 struct _header {
 174         __u64                           xfeatures;
 175         __u64                           reserved1[2];
 176         __u64                           reserved2[5];
 177 };
 178
 179 struct _ymmh_state {
 180         /* 16x YMM registers, 16 bytes each: */
 181         __u32                           ymmh_space[64];
 182 };
 183
 184 /*
 185  * Extended state pointed to by sigcontext::fpstate.
 186  *
 187  * In addition to the fpstate, information encoded in _xstate::xstate_hdr
 188  * indicates the presence of other extended state information supported
 189  * by the CPU and kernel:
 190  */
 191 struct _xstate {
 192         struct _fpstate                 fpstate;
 193         struct _header                  xstate_hdr;
 194         struct _ymmh_state              ymmh;
 195         /* New processor state extensions go here: */
 196 };
 197
 198 /*
 199  * The 32-bit signal frame:
 200  */
 201 struct sigcontext_32 {
 202         __u16                           gs, __gsh;
 203         __u16                           fs, __fsh;
 204         __u16                           es, __esh;
 205         __u16                           ds, __dsh;
 206         __u32                           di;
 207         __u32                           si;
 208         __u32                           bp;
 209         __u32                           sp;
 210         __u32                           bx;
 211         __u32                           dx;
 212         __u32                           cx;
 213         __u32                           ax;
 214         __u32                           trapno;
 215         __u32                           err;
 216         __u32                           ip;
 217         __u16                           cs, __csh;
 218         __u32                           flags;
 219         __u32                           sp_at_signal;
 220         __u16                           ss, __ssh;
 221
 222         /*
 223          * fpstate is really (struct _fpstate *) or (struct _xstate *)
 224          * depending on the FP_XSTATE_MAGIC1 encoded in the SW reserved
 225          * bytes of (struct _fpstate) and FP_XSTATE_MAGIC2 present at the end
 226          * of extended memory layout. See comments at the definition of
 227          * (struct _fpx_sw_bytes)
 228          */
 229         __u32                           fpstate; /* Zero when no FPU/extended context */
 230         __u32                           oldmask;
 231         __u32                           cr2;
 232 };
 233
 234 /*
 235  * The 64-bit signal frame:
 236  */
 237 struct sigcontext_64 {
 238         __u64                           r8;
 239         __u64                           r9;
 240         __u64                           r10;
 241         __u64                           r11;
 242         __u64                           r12;
 243         __u64                           r13;
 244         __u64                           r14;
 245         __u64                           r15;
 246         __u64                           di;
 247         __u64                           si;
 248         __u64                           bp;
 249         __u64                           bx;
 250         __u64                           dx;
 251         __u64                           ax;
 252         __u64                           cx;
 253         __u64                           sp;
 254         __u64                           ip;
 255         __u64                           flags;
 256         __u16                           cs;
 257         __u16                           gs;
 258         __u16                           fs;
 259         __u16                           __pad0;
 260         __u64                           err;
 261         __u64                           trapno;
 262         __u64                           oldmask;
 263         __u64                           cr2;
 264
 265         /*
 266          * fpstate is really (struct _fpstate *) or (struct _xstate *)
 267          * depending on the FP_XSTATE_MAGIC1 encoded in the SW reserved
 268          * bytes of (struct _fpstate) and FP_XSTATE_MAGIC2 present at the end
 269          * of extended memory layout. See comments at the definition of
 270          * (struct _fpx_sw_bytes)
 271          */
 272         __u64                           fpstate; /* Zero when no FPU/extended context */
 273         __u64                           reserved1[8];
 274 };
 275
 276 /*
 277  * Create the real 'struct sigcontext' type:
 278  */
 279 #ifdef __KERNEL__
 280 # ifdef __i386__
 281 #  define sigcontext sigcontext_32
 282 # else
 283 #  define sigcontext sigcontext_64
 284 # endif
 285 #endif
 286
 287 /*
 288  * The old user-space sigcontext definition, just in case user-space still
 289  * relies on it. The kernel definition (in asm/sigcontext.h) has unified
 290  * field names but otherwise the same layout.
 291  */
 292 #ifndef __KERNEL__
 293
 294 #define _fpstate_ia32                   _fpstate_32
 295 #define sigcontext_ia32                 sigcontext_32
 296
 297
 298 # ifdef __i386__
 299 struct sigcontext {
 300         __u16                           gs, __gsh;
 301         __u16                           fs, __fsh;
 302         __u16                           es, __esh;
 303         __u16                           ds, __dsh;
 304         __u32                           edi;
 305         __u32                           esi;
 306         __u32                           ebp;
 307         __u32                           esp;
 308         __u32                           ebx;
 309         __u32                           edx;
 310         __u32                           ecx;
 311         __u32                           eax;
 312         __u32                           trapno;
 313         __u32                           err;
 314         __u32                           eip;
 315         __u16                           cs, __csh;
 316         __u32                           eflags;
 317         __u32                           esp_at_signal;
 318         __u16                           ss, __ssh;
 319         struct _fpstate __user          *fpstate;
 320         __u32                           oldmask;
 321         __u32                           cr2;
 322 };
 323 # else /* __x86_64__: */
 324 struct sigcontext {
 325         __u64                           r8;
 326         __u64                           r9;
 327         __u64                           r10;
 328         __u64                           r11;
 329         __u64                           r12;
 330         __u64                           r13;
 331         __u64                           r14;
 332         __u64                           r15;
 333         __u64                           rdi;
 334         __u64                           rsi;
 335         __u64                           rbp;
 336         __u64                           rbx;
 337         __u64                           rdx;
 338         __u64                           rax;
 339         __u64                           rcx;
 340         __u64                           rsp;
 341         __u64                           rip;
 342         __u64                           eflags;         /* RFLAGS */
 343         __u16                           cs;
 344         __u16                           gs;
 345         __u16                           fs;
 346         __u16                           __pad0;
 347         __u64                           err;
 348         __u64                           trapno;
 349         __u64                           oldmask;
 350         __u64                           cr2;
 351         struct _fpstate __user          *fpstate;       /* Zero when no FPU context */
 352 #  ifdef __ILP32__
 353         __u32                           __fpstate_pad;
 354 #  endif
 355         __u64                           reserved1[8];
 356 };
 357 # endif /* __x86_64__ */
 358 #endif /* !__KERNEL__ */
 359
 360 #endif /* _UAPI_ASM_X86_SIGCONTEXT_H */