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| 1 /* | 1 /* |
| 2 * Copyright (c) 2012 The Native Client Authors. All rights reserved. | 2 * Copyright (c) 2012 The Native Client Authors. All rights reserved. |
| 3 * Use of this source code is governed by a BSD-style license that can be | 3 * Use of this source code is governed by a BSD-style license that can be |
| 4 * found in the LICENSE file. | 4 * found in the LICENSE file. |
| 5 */ | 5 */ |
| 6 | 6 |
| 7 /* | 7 /* |
| 8 * This is the core of ia32-mode validator. Please note that this file | 8 * This is the core of ia32-mode validator. Please note that this file |
| 9 * combines ragel machine description and C language actions. Please read | 9 * combines ragel machine description and C language actions. Please read |
| 10 * validator_internals.html first to understand how the whole thing is built: | 10 * validator_internals.html first to understand how the whole thing is built: |
| 11 * it explains how the byte sequences are constructed, what constructs like | 11 * it explains how the byte sequences are constructed, what constructs like |
| 12 * "@{}" or "REX_WRX?" mean, etc. | 12 * "@{}" or "REX_WRX?" mean, etc. |
| 13 */ | 13 */ |
| 14 | 14 |
| 15 #include <assert.h> | 15 #include <assert.h> |
| 16 #include <errno.h> | 16 #include <errno.h> |
| 17 #include <stddef.h> | 17 #include <stddef.h> |
| 18 #include <stdio.h> | 18 #include <stdio.h> |
| 19 #include <stdlib.h> | 19 #include <stdlib.h> |
| 20 #include <string.h> | 20 #include <string.h> |
| 21 | 21 |
| 22 #include "native_client/src/trusted/validator_ragel/bitmap.h" | 22 #include "native_client/src/trusted/validator_ragel/bitmap.h" |
| 23 #include "native_client/src/trusted/validator_ragel/unreviewed/validator_interna
l.h" | 23 #include "native_client/src/trusted/validator_ragel/validator_internal.h" |
| 24 | 24 |
| 25 /* Ignore this information: it's not used by security model in IA32 mode. */ | 25 /* Ignore this information: it's not used by security model in IA32 mode. */ |
| 26 #undef GET_VEX_PREFIX3 | 26 #undef GET_VEX_PREFIX3 |
| 27 #define GET_VEX_PREFIX3 0 | 27 #define GET_VEX_PREFIX3 0 |
| 28 #undef SET_VEX_PREFIX3 | 28 #undef SET_VEX_PREFIX3 |
| 29 #define SET_VEX_PREFIX3(P) | 29 #define SET_VEX_PREFIX3(P) |
| 30 | 30 |
| 31 %%{ | 31 %%{ |
| 32 machine x86_32_validator; | 32 machine x86_32_validator; |
| 33 alphtype unsigned char; | 33 alphtype unsigned char; |
| (...skipping 23 matching lines...) Expand all Loading... |
| 57 include immediate_fields_parsing_ia32 | 57 include immediate_fields_parsing_ia32 |
| 58 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; | 58 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; |
| 59 include relative_fields_validator_actions | 59 include relative_fields_validator_actions |
| 60 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; | 60 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; |
| 61 include relative_fields_parsing | 61 include relative_fields_parsing |
| 62 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; | 62 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; |
| 63 include cpuid_actions | 63 include cpuid_actions |
| 64 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; | 64 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl"; |
| 65 | 65 |
| 66 # Action which marks last byte as not immediate. Most 3DNow! instructions, | 66 # Action which marks last byte as not immediate. Most 3DNow! instructions, |
| 67 # some AVX and XOP instructions have this property. It's referenced by | 67 # some AVX and XOP instructions have this property. |
| 68 # decode_x86_32 machine in [autogenerated] "validator_x86_32_instruction.rl" | 68 # |
| 69 # file. | 69 # This action is referenced by decode_x86_32 ragel machine in [autogenerated] |
| 70 # "validator_x86_32_instruction.rl" file. |
| 70 action last_byte_is_not_immediate { | 71 action last_byte_is_not_immediate { |
| 71 instruction_info_collected |= LAST_BYTE_IS_NOT_IMMEDIATE; | 72 instruction_info_collected |= LAST_BYTE_IS_NOT_IMMEDIATE; |
| 72 } | 73 } |
| 73 | 74 |
| 74 include decode_x86_32 "validator_x86_32_instruction.rl"; | 75 include decode_x86_32 "validator_x86_32_instruction.rl"; |
| 75 | 76 |
| 76 special_instruction = | 77 special_instruction = |
| 77 # and $~0x1f, %eXX call %eXX | 78 # and $~0x1f, %eXX call %eXX |
| 78 # vvvvvvvvvv | 79 # vvvvvvvvvv |
| 79 (0x83 0xe0 0xe0 0xff (0xd0|0xe0) | # naclcall/jmp %eax | 80 (0x83 0xe0 0xe0 0xff (0xd0|0xe0) | # naclcall/jmp %eax |
| 80 0x83 0xe1 0xe0 0xff (0xd1|0xe1) | # naclcall/jmp %ecx | 81 0x83 0xe1 0xe0 0xff (0xd1|0xe1) | # naclcall/jmp %ecx |
| 81 0x83 0xe2 0xe0 0xff (0xd2|0xe2) | # naclcall/jmp %edx | 82 0x83 0xe2 0xe0 0xff (0xd2|0xe2) | # naclcall/jmp %edx |
| 82 0x83 0xe3 0xe0 0xff (0xd3|0xe3) | # naclcall/jmp %ebx | 83 0x83 0xe3 0xe0 0xff (0xd3|0xe3) | # naclcall/jmp %ebx |
| 83 0x83 0xe4 0xe0 0xff (0xd4|0xe4) | # naclcall/jmp %esp | 84 0x83 0xe4 0xe0 0xff (0xd4|0xe4) | # naclcall/jmp %esp |
| 84 0x83 0xe5 0xe0 0xff (0xd5|0xe5) | # naclcall/jmp %ebp | 85 0x83 0xe5 0xe0 0xff (0xd5|0xe5) | # naclcall/jmp %ebp |
| 85 0x83 0xe6 0xe0 0xff (0xd6|0xe6) | # naclcall/jmp %esi | 86 0x83 0xe6 0xe0 0xff (0xd6|0xe6) | # naclcall/jmp %esi |
| 86 0x83 0xe7 0xe0 0xff (0xd7|0xe7)) # naclcall/jmp %edi | 87 0x83 0xe7 0xe0 0xff (0xd7|0xe7)) # naclcall/jmp %edi |
| 87 # ^^^^ ^^^^ | 88 # ^^^^ ^^^^ |
| 88 # and $~0x1f, %eXX jmp %eXX | 89 # and $~0x1f, %eXX jmp %eXX |
| 89 @{ | 90 @{ |
| 90 UnmarkValidJumpTarget((current_position - data) - 1, valid_targets); | 91 UnmarkValidJumpTarget((current_position - data) - 1, valid_targets); |
| 91 instruction_begin -= 3; | 92 instruction_begin -= 3; |
| 92 instruction_info_collected |= SPECIAL_INSTRUCTION; | 93 instruction_info_collected |= SPECIAL_INSTRUCTION; |
| 93 } | | 94 } | |
| 94 (0x65 0xa1 (0x00|0x04) 0x00 0x00 0x00 | # mov %gs:0x0/0x4,%eax | 95 (0x65 0xa1 (0x00|0x04) 0x00 0x00 0x00 | # mov %gs:0x0/0x4,%eax |
| 95 0x65 0x8b (0x05|0x0d|0x015|0x1d|0x25|0x2d|0x35|0x3d) | 96 0x65 0x8b (0x05|0x0d|0x015|0x1d|0x25|0x2d|0x35|0x3d) |
| 96 (0x00|0x04) 0x00 0x00 0x00); # mov %gs:0x0/0x4,%reg | 97 (0x00|0x04) 0x00 0x00 0x00); # mov %gs:0x0/0x4,%reg |
| 97 | 98 |
| 98 # Check if call is properly aligned | 99 # Ragel machine which checks if call is properly aligned. |
| 99 # | 100 # |
| 100 # For direct call we explicitly encode all variations. For indirect call | 101 # For direct call we explicitly encode all variations. For indirect call |
| 101 # we accept all the special instructions which ends with indirect call. | 102 # we accept all the special instructions which ends with indirect call. |
| 102 call_alignment = | 103 call_alignment = |
| 103 ((one_instruction & | 104 ((one_instruction & |
| 104 # Direct call | 105 # Direct call |
| 105 ((data16 0xe8 rel16) | | 106 ((data16 0xe8 rel16) | |
| 106 (0xe8 rel32))) | | 107 (0xe8 rel32))) | |
| 107 (special_instruction & | 108 (special_instruction & |
| 108 # Indirect call | 109 # Indirect call |
| (...skipping 45 matching lines...) Expand 10 before | Expand all | Expand 10 after Loading... |
| 154 * the ValidateChunkIA32 function. | 155 * the ValidateChunkIA32 function. |
| 155 * | 156 * |
| 156 * It does not affect the case which we really care about (when code | 157 * It does not affect the case which we really care about (when code |
| 157 * is validatable), but makes it possible to detect more errors in one | 158 * is validatable), but makes it possible to detect more errors in one |
| 158 * run in tools like ncval. | 159 * run in tools like ncval. |
| 159 */ | 160 */ |
| 160 continue; | 161 continue; |
| 161 } | 162 } |
| 162 | 163 |
| 163 # This is main ragel machine: it does 99% of validation work. There are only | 164 # This is main ragel machine: it does 99% of validation work. There are only |
| 164 # one thing to do if this machine accepts the bundles - check that direct | 165 # one thing to do if this ragel machine accepts the bundles - check that |
| 165 # jumps are correct. This is done in the following way: | 166 # direct jumps are correct. This is done in the following way: |
| 166 # * DFA fills two arrays: valid_targets and jump_dests. | 167 # * DFA fills two arrays: valid_targets and jump_dests. |
| 167 # * ProcessInvalidJumpTargets checks that "jump_dests & !valid_targets == 0". | 168 # * ProcessInvalidJumpTargets checks that "jump_dests & !valid_targets == 0". |
| 168 # All other checks are done here. | 169 # All other checks are done here. |
| 169 main := ((call_alignment | one_instruction | special_instruction) | 170 main := ((call_alignment | one_instruction | special_instruction) |
| 170 @end_of_instruction_cleanup)* | 171 @end_of_instruction_cleanup)* |
| 171 $!report_fatal_error; | 172 $!report_fatal_error; |
| 172 | 173 |
| 173 }%% | 174 }%% |
| 174 | 175 |
| 176 /* |
| 177 * The "write data" statement causes Ragel to emit the constant static data |
| 178 * needed by the ragel machine. |
| 179 */ |
| 175 %% write data; | 180 %% write data; |
| 176 | 181 |
| 177 | |
| 178 Bool ValidateChunkIA32(const uint8_t *data, size_t size, | 182 Bool ValidateChunkIA32(const uint8_t *data, size_t size, |
| 179 uint32_t options, | 183 uint32_t options, |
| 180 const NaClCPUFeaturesX86 *cpu_features, | 184 const NaClCPUFeaturesX86 *cpu_features, |
| 181 ValidationCallbackFunc user_callback, | 185 ValidationCallbackFunc user_callback, |
| 182 void *callback_data) { | 186 void *callback_data) { |
| 183 bitmap_word valid_targets_small; | 187 bitmap_word valid_targets_small; |
| 184 bitmap_word jump_dests_small; | 188 bitmap_word jump_dests_small; |
| 185 bitmap_word *valid_targets; | 189 bitmap_word *valid_targets; |
| 186 bitmap_word *jump_dests; | 190 bitmap_word *jump_dests; |
| 187 const uint8_t *current_position; | 191 const uint8_t *current_position; |
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| 204 free(jump_dests); | 208 free(jump_dests); |
| 205 free(valid_targets); | 209 free(valid_targets); |
| 206 errno = ENOMEM; | 210 errno = ENOMEM; |
| 207 return FALSE; | 211 return FALSE; |
| 208 } | 212 } |
| 209 } | 213 } |
| 210 | 214 |
| 211 /* | 215 /* |
| 212 * This option is usually used in tests: we will process the whole chunk | 216 * This option is usually used in tests: we will process the whole chunk |
| 213 * in one pass. Usually each bundle is processed separately which means | 217 * in one pass. Usually each bundle is processed separately which means |
| 214 * instructions (and super-instructions) can not cross borders of the bundle. | 218 * instructions (and "superinstructions") can not cross borders of the bundle. |
| 215 */ | 219 */ |
| 216 if (options & PROCESS_CHUNK_AS_A_CONTIGUOUS_STREAM) | 220 if (options & PROCESS_CHUNK_AS_A_CONTIGUOUS_STREAM) |
| 217 end_of_bundle = data + size; | 221 end_of_bundle = data + size; |
| 218 else | 222 else |
| 219 end_of_bundle = data + kBundleSize; | 223 end_of_bundle = data + kBundleSize; |
| 220 | 224 |
| 221 /* | 225 /* |
| 222 * Main loop. Here we process the data array bundle-after-bundle. | 226 * Main loop. Here we process the data array bundle-after-bundle. |
| 223 * Ragel-produced DFA does all the checks with one exception: direct jumps. | 227 * Ragel-produced DFA does all the checks with one exception: direct jumps. |
| 224 * It collects the two arrays: valid_targets and jump_dests which are used | 228 * It collects the two arrays: valid_targets and jump_dests which are used |
| 225 * to test direct jumps later. | 229 * to test direct jumps later. |
| 226 */ | 230 */ |
| 227 for (current_position = data; | 231 for (current_position = data; |
| 228 current_position < data + size; | 232 current_position < data + size; |
| 229 current_position = end_of_bundle, | 233 current_position = end_of_bundle, |
| 230 end_of_bundle = current_position + kBundleSize) { | 234 end_of_bundle = current_position + kBundleSize) { |
| 231 /* Start of the instruction being processed. */ | 235 /* Start of the instruction being processed. */ |
| 232 const uint8_t *instruction_begin = current_position; | 236 const uint8_t *instruction_begin = current_position; |
| 233 /* Only used locally in the end_of_instruction_cleanup action. */ | 237 /* Only used locally in the end_of_instruction_cleanup action. */ |
| 234 const uint8_t *instruction_end; | 238 const uint8_t *instruction_end; |
| 235 uint32_t instruction_info_collected = 0; | 239 uint32_t instruction_info_collected = 0; |
| 236 int current_state; | 240 int current_state; |
| 237 | 241 |
| 242 /* |
| 243 * The "write init" statement causes Ragel to emit initialization code. |
| 244 * This should be executed once before the ragel machine is started. |
| 245 */ |
| 238 %% write init; | 246 %% write init; |
| 247 /* |
| 248 * The "write exec" statement causes Ragel to emit the ragel machine's |
| 249 * execution code. |
| 250 */ |
| 239 %% write exec; | 251 %% write exec; |
| 240 } | 252 } |
| 241 | 253 |
| 242 /* | 254 /* |
| 243 * Check the direct jumps. All the targets from jump_dests must be in | 255 * Check the direct jumps. All the targets from jump_dests must be in |
| 244 * valid_targets. | 256 * valid_targets. |
| 245 */ | 257 */ |
| 246 result &= ProcessInvalidJumpTargets(data, size, valid_targets, jump_dests, | 258 result &= ProcessInvalidJumpTargets(data, size, valid_targets, jump_dests, |
| 247 user_callback, callback_data); | 259 user_callback, callback_data); |
| 248 | 260 |
| 249 /* We only use malloc for a large code sequences */ | 261 /* We only use malloc for a large code sequences */ |
| 250 if (jump_dests != &jump_dests_small) free(jump_dests); | 262 if (jump_dests != &jump_dests_small) free(jump_dests); |
| 251 if (valid_targets != &valid_targets_small) free(valid_targets); | 263 if (valid_targets != &valid_targets_small) free(valid_targets); |
| 252 if (!result) errno = EINVAL; | 264 if (!result) errno = EINVAL; |
| 253 return result; | 265 return result; |
| 254 } | 266 } |
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