diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
---|---|---|
committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/math-emu/get_address.c |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'arch/i386/math-emu/get_address.c')
-rw-r--r-- | arch/i386/math-emu/get_address.c | 449 |
1 files changed, 449 insertions, 0 deletions
diff --git a/arch/i386/math-emu/get_address.c b/arch/i386/math-emu/get_address.c new file mode 100644 index 000000000000..91175738e948 --- /dev/null +++ b/arch/i386/math-emu/get_address.c | |||
@@ -0,0 +1,449 @@ | |||
1 | /*---------------------------------------------------------------------------+ | ||
2 | | get_address.c | | ||
3 | | | | ||
4 | | Get the effective address from an FPU instruction. | | ||
5 | | | | ||
6 | | Copyright (C) 1992,1993,1994,1997 | | ||
7 | | W. Metzenthen, 22 Parker St, Ormond, Vic 3163, | | ||
8 | | Australia. E-mail billm@suburbia.net | | ||
9 | | | | ||
10 | | | | ||
11 | +---------------------------------------------------------------------------*/ | ||
12 | |||
13 | /*---------------------------------------------------------------------------+ | ||
14 | | Note: | | ||
15 | | The file contains code which accesses user memory. | | ||
16 | | Emulator static data may change when user memory is accessed, due to | | ||
17 | | other processes using the emulator while swapping is in progress. | | ||
18 | +---------------------------------------------------------------------------*/ | ||
19 | |||
20 | |||
21 | #include <linux/stddef.h> | ||
22 | |||
23 | #include <asm/uaccess.h> | ||
24 | #include <asm/desc.h> | ||
25 | |||
26 | #include "fpu_system.h" | ||
27 | #include "exception.h" | ||
28 | #include "fpu_emu.h" | ||
29 | |||
30 | |||
31 | #define FPU_WRITE_BIT 0x10 | ||
32 | |||
33 | static int reg_offset[] = { | ||
34 | offsetof(struct info,___eax), | ||
35 | offsetof(struct info,___ecx), | ||
36 | offsetof(struct info,___edx), | ||
37 | offsetof(struct info,___ebx), | ||
38 | offsetof(struct info,___esp), | ||
39 | offsetof(struct info,___ebp), | ||
40 | offsetof(struct info,___esi), | ||
41 | offsetof(struct info,___edi) | ||
42 | }; | ||
43 | |||
44 | #define REG_(x) (*(long *)(reg_offset[(x)]+(u_char *) FPU_info)) | ||
45 | |||
46 | static int reg_offset_vm86[] = { | ||
47 | offsetof(struct info,___cs), | ||
48 | offsetof(struct info,___vm86_ds), | ||
49 | offsetof(struct info,___vm86_es), | ||
50 | offsetof(struct info,___vm86_fs), | ||
51 | offsetof(struct info,___vm86_gs), | ||
52 | offsetof(struct info,___ss), | ||
53 | offsetof(struct info,___vm86_ds) | ||
54 | }; | ||
55 | |||
56 | #define VM86_REG_(x) (*(unsigned short *) \ | ||
57 | (reg_offset_vm86[((unsigned)x)]+(u_char *) FPU_info)) | ||
58 | |||
59 | /* These are dummy, fs and gs are not saved on the stack. */ | ||
60 | #define ___FS ___ds | ||
61 | #define ___GS ___ds | ||
62 | |||
63 | static int reg_offset_pm[] = { | ||
64 | offsetof(struct info,___cs), | ||
65 | offsetof(struct info,___ds), | ||
66 | offsetof(struct info,___es), | ||
67 | offsetof(struct info,___FS), | ||
68 | offsetof(struct info,___GS), | ||
69 | offsetof(struct info,___ss), | ||
70 | offsetof(struct info,___ds) | ||
71 | }; | ||
72 | |||
73 | #define PM_REG_(x) (*(unsigned short *) \ | ||
74 | (reg_offset_pm[((unsigned)x)]+(u_char *) FPU_info)) | ||
75 | |||
76 | |||
77 | /* Decode the SIB byte. This function assumes mod != 0 */ | ||
78 | static int sib(int mod, unsigned long *fpu_eip) | ||
79 | { | ||
80 | u_char ss,index,base; | ||
81 | long offset; | ||
82 | |||
83 | RE_ENTRANT_CHECK_OFF; | ||
84 | FPU_code_access_ok(1); | ||
85 | FPU_get_user(base, (u_char __user *) (*fpu_eip)); /* The SIB byte */ | ||
86 | RE_ENTRANT_CHECK_ON; | ||
87 | (*fpu_eip)++; | ||
88 | ss = base >> 6; | ||
89 | index = (base >> 3) & 7; | ||
90 | base &= 7; | ||
91 | |||
92 | if ((mod == 0) && (base == 5)) | ||
93 | offset = 0; /* No base register */ | ||
94 | else | ||
95 | offset = REG_(base); | ||
96 | |||
97 | if (index == 4) | ||
98 | { | ||
99 | /* No index register */ | ||
100 | /* A non-zero ss is illegal */ | ||
101 | if ( ss ) | ||
102 | EXCEPTION(EX_Invalid); | ||
103 | } | ||
104 | else | ||
105 | { | ||
106 | offset += (REG_(index)) << ss; | ||
107 | } | ||
108 | |||
109 | if (mod == 1) | ||
110 | { | ||
111 | /* 8 bit signed displacement */ | ||
112 | long displacement; | ||
113 | RE_ENTRANT_CHECK_OFF; | ||
114 | FPU_code_access_ok(1); | ||
115 | FPU_get_user(displacement, (signed char __user *) (*fpu_eip)); | ||
116 | offset += displacement; | ||
117 | RE_ENTRANT_CHECK_ON; | ||
118 | (*fpu_eip)++; | ||
119 | } | ||
120 | else if (mod == 2 || base == 5) /* The second condition also has mod==0 */ | ||
121 | { | ||
122 | /* 32 bit displacement */ | ||
123 | long displacement; | ||
124 | RE_ENTRANT_CHECK_OFF; | ||
125 | FPU_code_access_ok(4); | ||
126 | FPU_get_user(displacement, (long __user *) (*fpu_eip)); | ||
127 | offset += displacement; | ||
128 | RE_ENTRANT_CHECK_ON; | ||
129 | (*fpu_eip) += 4; | ||
130 | } | ||
131 | |||
132 | return offset; | ||
133 | } | ||
134 | |||
135 | |||
136 | static unsigned long vm86_segment(u_char segment, | ||
137 | struct address *addr) | ||
138 | { | ||
139 | segment--; | ||
140 | #ifdef PARANOID | ||
141 | if ( segment > PREFIX_SS_ ) | ||
142 | { | ||
143 | EXCEPTION(EX_INTERNAL|0x130); | ||
144 | math_abort(FPU_info,SIGSEGV); | ||
145 | } | ||
146 | #endif /* PARANOID */ | ||
147 | addr->selector = VM86_REG_(segment); | ||
148 | return (unsigned long)VM86_REG_(segment) << 4; | ||
149 | } | ||
150 | |||
151 | |||
152 | /* This should work for 16 and 32 bit protected mode. */ | ||
153 | static long pm_address(u_char FPU_modrm, u_char segment, | ||
154 | struct address *addr, long offset) | ||
155 | { | ||
156 | struct desc_struct descriptor; | ||
157 | unsigned long base_address, limit, address, seg_top; | ||
158 | unsigned short selector; | ||
159 | |||
160 | segment--; | ||
161 | |||
162 | #ifdef PARANOID | ||
163 | /* segment is unsigned, so this also detects if segment was 0: */ | ||
164 | if ( segment > PREFIX_SS_ ) | ||
165 | { | ||
166 | EXCEPTION(EX_INTERNAL|0x132); | ||
167 | math_abort(FPU_info,SIGSEGV); | ||
168 | } | ||
169 | #endif /* PARANOID */ | ||
170 | |||
171 | switch ( segment ) | ||
172 | { | ||
173 | /* fs and gs aren't used by the kernel, so they still have their | ||
174 | user-space values. */ | ||
175 | case PREFIX_FS_-1: | ||
176 | /* The cast is needed here to get gcc 2.8.0 to use a 16 bit register | ||
177 | in the assembler statement. */ | ||
178 | |||
179 | __asm__("mov %%fs,%0":"=r" (selector)); | ||
180 | addr->selector = selector; | ||
181 | break; | ||
182 | case PREFIX_GS_-1: | ||
183 | /* The cast is needed here to get gcc 2.8.0 to use a 16 bit register | ||
184 | in the assembler statement. */ | ||
185 | __asm__("mov %%gs,%0":"=r" (selector)); | ||
186 | addr->selector = selector; | ||
187 | break; | ||
188 | default: | ||
189 | addr->selector = PM_REG_(segment); | ||
190 | } | ||
191 | |||
192 | descriptor = LDT_DESCRIPTOR(PM_REG_(segment)); | ||
193 | base_address = SEG_BASE_ADDR(descriptor); | ||
194 | address = base_address + offset; | ||
195 | limit = base_address | ||
196 | + (SEG_LIMIT(descriptor)+1) * SEG_GRANULARITY(descriptor) - 1; | ||
197 | if ( limit < base_address ) limit = 0xffffffff; | ||
198 | |||
199 | if ( SEG_EXPAND_DOWN(descriptor) ) | ||
200 | { | ||
201 | if ( SEG_G_BIT(descriptor) ) | ||
202 | seg_top = 0xffffffff; | ||
203 | else | ||
204 | { | ||
205 | seg_top = base_address + (1 << 20); | ||
206 | if ( seg_top < base_address ) seg_top = 0xffffffff; | ||
207 | } | ||
208 | access_limit = | ||
209 | (address <= limit) || (address >= seg_top) ? 0 : | ||
210 | ((seg_top-address) >= 255 ? 255 : seg_top-address); | ||
211 | } | ||
212 | else | ||
213 | { | ||
214 | access_limit = | ||
215 | (address > limit) || (address < base_address) ? 0 : | ||
216 | ((limit-address) >= 254 ? 255 : limit-address+1); | ||
217 | } | ||
218 | if ( SEG_EXECUTE_ONLY(descriptor) || | ||
219 | (!SEG_WRITE_PERM(descriptor) && (FPU_modrm & FPU_WRITE_BIT)) ) | ||
220 | { | ||
221 | access_limit = 0; | ||
222 | } | ||
223 | return address; | ||
224 | } | ||
225 | |||
226 | |||
227 | /* | ||
228 | MOD R/M byte: MOD == 3 has a special use for the FPU | ||
229 | SIB byte used iff R/M = 100b | ||
230 | |||
231 | 7 6 5 4 3 2 1 0 | ||
232 | ..... ......... ......... | ||
233 | MOD OPCODE(2) R/M | ||
234 | |||
235 | |||
236 | SIB byte | ||
237 | |||
238 | 7 6 5 4 3 2 1 0 | ||
239 | ..... ......... ......... | ||
240 | SS INDEX BASE | ||
241 | |||
242 | */ | ||
243 | |||
244 | void __user *FPU_get_address(u_char FPU_modrm, unsigned long *fpu_eip, | ||
245 | struct address *addr, | ||
246 | fpu_addr_modes addr_modes) | ||
247 | { | ||
248 | u_char mod; | ||
249 | unsigned rm = FPU_modrm & 7; | ||
250 | long *cpu_reg_ptr; | ||
251 | int address = 0; /* Initialized just to stop compiler warnings. */ | ||
252 | |||
253 | /* Memory accessed via the cs selector is write protected | ||
254 | in `non-segmented' 32 bit protected mode. */ | ||
255 | if ( !addr_modes.default_mode && (FPU_modrm & FPU_WRITE_BIT) | ||
256 | && (addr_modes.override.segment == PREFIX_CS_) ) | ||
257 | { | ||
258 | math_abort(FPU_info,SIGSEGV); | ||
259 | } | ||
260 | |||
261 | addr->selector = FPU_DS; /* Default, for 32 bit non-segmented mode. */ | ||
262 | |||
263 | mod = (FPU_modrm >> 6) & 3; | ||
264 | |||
265 | if (rm == 4 && mod != 3) | ||
266 | { | ||
267 | address = sib(mod, fpu_eip); | ||
268 | } | ||
269 | else | ||
270 | { | ||
271 | cpu_reg_ptr = & REG_(rm); | ||
272 | switch (mod) | ||
273 | { | ||
274 | case 0: | ||
275 | if (rm == 5) | ||
276 | { | ||
277 | /* Special case: disp32 */ | ||
278 | RE_ENTRANT_CHECK_OFF; | ||
279 | FPU_code_access_ok(4); | ||
280 | FPU_get_user(address, (unsigned long __user *) (*fpu_eip)); | ||
281 | (*fpu_eip) += 4; | ||
282 | RE_ENTRANT_CHECK_ON; | ||
283 | addr->offset = address; | ||
284 | return (void __user *) address; | ||
285 | } | ||
286 | else | ||
287 | { | ||
288 | address = *cpu_reg_ptr; /* Just return the contents | ||
289 | of the cpu register */ | ||
290 | addr->offset = address; | ||
291 | return (void __user *) address; | ||
292 | } | ||
293 | case 1: | ||
294 | /* 8 bit signed displacement */ | ||
295 | RE_ENTRANT_CHECK_OFF; | ||
296 | FPU_code_access_ok(1); | ||
297 | FPU_get_user(address, (signed char __user *) (*fpu_eip)); | ||
298 | RE_ENTRANT_CHECK_ON; | ||
299 | (*fpu_eip)++; | ||
300 | break; | ||
301 | case 2: | ||
302 | /* 32 bit displacement */ | ||
303 | RE_ENTRANT_CHECK_OFF; | ||
304 | FPU_code_access_ok(4); | ||
305 | FPU_get_user(address, (long __user *) (*fpu_eip)); | ||
306 | (*fpu_eip) += 4; | ||
307 | RE_ENTRANT_CHECK_ON; | ||
308 | break; | ||
309 | case 3: | ||
310 | /* Not legal for the FPU */ | ||
311 | EXCEPTION(EX_Invalid); | ||
312 | } | ||
313 | address += *cpu_reg_ptr; | ||
314 | } | ||
315 | |||
316 | addr->offset = address; | ||
317 | |||
318 | switch ( addr_modes.default_mode ) | ||
319 | { | ||
320 | case 0: | ||
321 | break; | ||
322 | case VM86: | ||
323 | address += vm86_segment(addr_modes.override.segment, addr); | ||
324 | break; | ||
325 | case PM16: | ||
326 | case SEG32: | ||
327 | address = pm_address(FPU_modrm, addr_modes.override.segment, | ||
328 | addr, address); | ||
329 | break; | ||
330 | default: | ||
331 | EXCEPTION(EX_INTERNAL|0x133); | ||
332 | } | ||
333 | |||
334 | return (void __user *)address; | ||
335 | } | ||
336 | |||
337 | |||
338 | void __user *FPU_get_address_16(u_char FPU_modrm, unsigned long *fpu_eip, | ||
339 | struct address *addr, | ||
340 | fpu_addr_modes addr_modes) | ||
341 | { | ||
342 | u_char mod; | ||
343 | unsigned rm = FPU_modrm & 7; | ||
344 | int address = 0; /* Default used for mod == 0 */ | ||
345 | |||
346 | /* Memory accessed via the cs selector is write protected | ||
347 | in `non-segmented' 32 bit protected mode. */ | ||
348 | if ( !addr_modes.default_mode && (FPU_modrm & FPU_WRITE_BIT) | ||
349 | && (addr_modes.override.segment == PREFIX_CS_) ) | ||
350 | { | ||
351 | math_abort(FPU_info,SIGSEGV); | ||
352 | } | ||
353 | |||
354 | addr->selector = FPU_DS; /* Default, for 32 bit non-segmented mode. */ | ||
355 | |||
356 | mod = (FPU_modrm >> 6) & 3; | ||
357 | |||
358 | switch (mod) | ||
359 | { | ||
360 | case 0: | ||
361 | if (rm == 6) | ||
362 | { | ||
363 | /* Special case: disp16 */ | ||
364 | RE_ENTRANT_CHECK_OFF; | ||
365 | FPU_code_access_ok(2); | ||
366 | FPU_get_user(address, (unsigned short __user *) (*fpu_eip)); | ||
367 | (*fpu_eip) += 2; | ||
368 | RE_ENTRANT_CHECK_ON; | ||
369 | goto add_segment; | ||
370 | } | ||
371 | break; | ||
372 | case 1: | ||
373 | /* 8 bit signed displacement */ | ||
374 | RE_ENTRANT_CHECK_OFF; | ||
375 | FPU_code_access_ok(1); | ||
376 | FPU_get_user(address, (signed char __user *) (*fpu_eip)); | ||
377 | RE_ENTRANT_CHECK_ON; | ||
378 | (*fpu_eip)++; | ||
379 | break; | ||
380 | case 2: | ||
381 | /* 16 bit displacement */ | ||
382 | RE_ENTRANT_CHECK_OFF; | ||
383 | FPU_code_access_ok(2); | ||
384 | FPU_get_user(address, (unsigned short __user *) (*fpu_eip)); | ||
385 | (*fpu_eip) += 2; | ||
386 | RE_ENTRANT_CHECK_ON; | ||
387 | break; | ||
388 | case 3: | ||
389 | /* Not legal for the FPU */ | ||
390 | EXCEPTION(EX_Invalid); | ||
391 | break; | ||
392 | } | ||
393 | switch ( rm ) | ||
394 | { | ||
395 | case 0: | ||
396 | address += FPU_info->___ebx + FPU_info->___esi; | ||
397 | break; | ||
398 | case 1: | ||
399 | address += FPU_info->___ebx + FPU_info->___edi; | ||
400 | break; | ||
401 | case 2: | ||
402 | address += FPU_info->___ebp + FPU_info->___esi; | ||
403 | if ( addr_modes.override.segment == PREFIX_DEFAULT ) | ||
404 | addr_modes.override.segment = PREFIX_SS_; | ||
405 | break; | ||
406 | case 3: | ||
407 | address += FPU_info->___ebp + FPU_info->___edi; | ||
408 | if ( addr_modes.override.segment == PREFIX_DEFAULT ) | ||
409 | addr_modes.override.segment = PREFIX_SS_; | ||
410 | break; | ||
411 | case 4: | ||
412 | address += FPU_info->___esi; | ||
413 | break; | ||
414 | case 5: | ||
415 | address += FPU_info->___edi; | ||
416 | break; | ||
417 | case 6: | ||
418 | address += FPU_info->___ebp; | ||
419 | if ( addr_modes.override.segment == PREFIX_DEFAULT ) | ||
420 | addr_modes.override.segment = PREFIX_SS_; | ||
421 | break; | ||
422 | case 7: | ||
423 | address += FPU_info->___ebx; | ||
424 | break; | ||
425 | } | ||
426 | |||
427 | add_segment: | ||
428 | address &= 0xffff; | ||
429 | |||
430 | addr->offset = address; | ||
431 | |||
432 | switch ( addr_modes.default_mode ) | ||
433 | { | ||
434 | case 0: | ||
435 | break; | ||
436 | case VM86: | ||
437 | address += vm86_segment(addr_modes.override.segment, addr); | ||
438 | break; | ||
439 | case PM16: | ||
440 | case SEG32: | ||
441 | address = pm_address(FPU_modrm, addr_modes.override.segment, | ||
442 | addr, address); | ||
443 | break; | ||
444 | default: | ||
445 | EXCEPTION(EX_INTERNAL|0x131); | ||
446 | } | ||
447 | |||
448 | return (void __user *)address ; | ||
449 | } | ||