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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 ss; | |
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 | ||
345 | /* | |
346 | * Prior to 2.5.64 ("[PATCH] x86-64 updates for 2.5.64-bk3"), | |
347 | * Linux saved and restored fs and gs in these slots. This | |
348 | * was counterproductive, as fsbase and gsbase were never | |
349 | * saved, so arch_prctl was presumably unreliable. | |
350 | * | |
351 | * These slots should never be reused without extreme caution: | |
352 | * | |
353 | * - Some DOSEMU versions stash fs and gs in these slots manually, | |
354 | * thus overwriting anything the kernel expects to be preserved | |
355 | * in these slots. | |
356 | * | |
357 | * - If these slots are ever needed for any other purpose, | |
358 | * there is some risk that very old 64-bit binaries could get | |
359 | * confused. I doubt that many such binaries still work, | |
360 | * though, since the same patch in 2.5.64 also removed the | |
361 | * 64-bit set_thread_area syscall, so it appears that there | |
362 | * is no TLS API beyond modify_ldt that works in both pre- | |
363 | * and post-2.5.64 kernels. | |
364 | * | |
365 | * If the kernel ever adds explicit fs, gs, fsbase, and gsbase | |
366 | * save/restore, it will most likely need to be opt-in and use | |
367 | * different context slots. | |
368 | */ | |
369 | __u16 gs; | |
370 | __u16 fs; | |
371 | union { | |
372 | __u16 ss; /* If UC_SIGCONTEXT_SS */ | |
373 | __u16 __pad0; /* Alias name for old (!UC_SIGCONTEXT_SS) user-space */ | |
374 | }; | |
375 | __u64 err; | |
376 | __u64 trapno; | |
377 | __u64 oldmask; | |
378 | __u64 cr2; | |
379 | struct _fpstate __user *fpstate; /* Zero when no FPU context */ | |
380 | # ifdef __ILP32__ | |
381 | __u32 __fpstate_pad; | |
382 | # endif | |
383 | __u64 reserved1[8]; | |
384 | }; | |
385 | # endif /* __x86_64__ */ | |
386 | #endif /* !__KERNEL__ */ | |
387 | ||
388 | #endif /* _UAPI_ASM_X86_SIGCONTEXT_H */ |