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Side by Side Diff: src/trusted/validator_ragel/unreviewed/validator_x86_32.rl

Issue 11000033: Move validator_x86_XX.rl out of unreviewed. (Closed) Base URL: svn://svn.chromium.org/native_client/trunk/src/native_client/
Patch Set: Created 7 years, 9 months ago
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1 /*
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
4 * found in the LICENSE file.
5 */
6
7 /*
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
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
12 * "@{}" or "REX_WRX?" mean, etc.
13 */
14
15 #include <assert.h>
16 #include <errno.h>
17 #include <stddef.h>
18 #include <stdio.h>
19 #include <stdlib.h>
20 #include <string.h>
21
22 #include "native_client/src/trusted/validator_ragel/bitmap.h"
23 #include "native_client/src/trusted/validator_ragel/unreviewed/validator_interna l.h"
24
25 /* Ignore this information: it's not used by security model in IA32 mode. */
26 #undef GET_VEX_PREFIX3
27 #define GET_VEX_PREFIX3 0
28 #undef SET_VEX_PREFIX3
29 #define SET_VEX_PREFIX3(P)
30
31 %%{
32 machine x86_32_validator;
33 alphtype unsigned char;
34 variable p current_position;
35 variable pe end_of_bundle;
36 variable eof end_of_bundle;
37 variable cs current_state;
38
39 include byte_machine "byte_machines.rl";
40
41 include prefixes_parsing_validator
42 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
43 include vex_actions_ia32
44 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
45 include vex_parsing_ia32
46 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
47 include displacement_fields_actions
48 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
49 include displacement_fields_parsing
50 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
51 include modrm_parsing_ia32_validator
52 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
53 include immediate_fields_actions
54 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
55 include immediate_fields_parsing_ia32
56 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
57 include relative_fields_validator_actions
58 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
59 include relative_fields_parsing
60 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
61 include cpuid_actions
62 "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
63
64 # Action which marks last byte as not immediate. Most 3DNow! instructions,
65 # some AVX and XOP instructions have this property. It's referenced by
66 # decode_x86_32 machine in [autogenerated] "validator_x86_32_instruction.rl"
67 # file.
68 action last_byte_is_not_immediate {
69 instruction_info_collected |= LAST_BYTE_IS_NOT_IMMEDIATE;
70 }
71
72 include decode_x86_32 "validator_x86_32_instruction.rl";
73
74 special_instruction =
75 # and $~0x1f, %eXX call %eXX
76 # vvvvvvvvvv
77 (0x83 0xe0 0xe0 0xff (0xd0|0xe0) | # naclcall/jmp %eax
78 0x83 0xe1 0xe0 0xff (0xd1|0xe1) | # naclcall/jmp %ecx
79 0x83 0xe2 0xe0 0xff (0xd2|0xe2) | # naclcall/jmp %edx
80 0x83 0xe3 0xe0 0xff (0xd3|0xe3) | # naclcall/jmp %ebx
81 0x83 0xe4 0xe0 0xff (0xd4|0xe4) | # naclcall/jmp %esp
82 0x83 0xe5 0xe0 0xff (0xd5|0xe5) | # naclcall/jmp %ebp
83 0x83 0xe6 0xe0 0xff (0xd6|0xe6) | # naclcall/jmp %esi
84 0x83 0xe7 0xe0 0xff (0xd7|0xe7)) # naclcall/jmp %edi
85 # ^^^^ ^^^^
86 # and $~0x1f, %eXX jmp %eXX
87 @{
88 UnmarkValidJumpTarget((current_position - data) - 1, valid_targets);
89 instruction_begin -= 3;
90 instruction_info_collected |= SPECIAL_INSTRUCTION;
91 } |
92 (0x65 0xa1 (0x00|0x04) 0x00 0x00 0x00 | # mov %gs:0x0/0x4,%eax
93 0x65 0x8b (0x05|0x0d|0x015|0x1d|0x25|0x2d|0x35|0x3d)
94 (0x00|0x04) 0x00 0x00 0x00); # mov %gs:0x0/0x4,%reg
95
96 # Check if call is properly aligned
97 #
98 # For direct call we explicitly encode all variations. For indirect call
99 # we accept all the special instructions which ends with register-addressed
100 # indirect call.
101 call_alignment =
102 ((one_instruction &
103 # Direct call
104 ((data16 0xe8 rel16) |
105 (0xe8 rel32))) |
106 (special_instruction &
107 # Indirect call
108 (any* data16? 0xff ((opcode_2 | opcode_3) any* &
109 modrm_registers))))
110 # Call instruction must aligned to the end of bundle. Previously this was
111 # strict requirement, today it's just warning to aid with debugging.
112 @{
113 if (((current_position - data) & kBundleMask) != kBundleMask)
114 instruction_info_collected |= BAD_CALL_ALIGNMENT;
115 };
116
117 # This action calls user's callback (if needed) and cleans up validator's
118 # internal state.
119 #
120 # We call the user callback if there are validation errors or if the
121 # CALL_USER_CALLBACK_ON_EACH_INSTRUCTION option is used.
122 #
123 # After that we move instruction_begin and clean all the variables which
124 # only used in the processing of a single instruction (prefixes, operand
125 # states and instruction_info_collected).
126 action end_of_instruction_cleanup {
127 /* Mark start of this instruction as a valid target for jump. */
128 MarkValidJumpTarget(instruction_begin - data, valid_targets);
129
130 /* Call user-supplied callback. */
131 instruction_end = current_position + 1;
132 if ((instruction_info_collected & VALIDATION_ERRORS_MASK) ||
133 (options & CALL_USER_CALLBACK_ON_EACH_INSTRUCTION)) {
134 result &= user_callback(instruction_begin, instruction_end,
135 instruction_info_collected, callback_data);
136 }
137
138 /* On successful match the instruction_begin must point to the next byte
139 * to be able to report the new offset as the start of instruction
140 * causing error. */
141 instruction_begin = instruction_end;
142
143 /* Clear variables (well, one variable currently). */
144 instruction_info_collected = 0;
145 }
146
147 # This action reports fatal error detected by DFA.
148 action report_fatal_error {
149 result &= user_callback(instruction_begin, current_position,
150 UNRECOGNIZED_INSTRUCTION, callback_data);
151 /*
152 * Process the next bundle: "continue" here is for the "for" cycle in
153 * the ValidateChunkIA32 function.
154 *
155 * It does not affect the case which we really care about (when code
156 * is validatable), but makes it possible to detect more errors in one
157 * run in tools like ncval.
158 */
159 continue;
160 }
161
162 # This is main ragel machine: it does 99% of validation work. There are only
163 # one thing to do if this machine accepts the bundles - check that direct
164 # jumps are correct. This is done in the following way:
165 # * DFA fills two arrays: valid_targets and jump_dests.
166 # * ProcessInvalidJumpTargets checks that "jump_dests & !valid_targets == 0".
167 # All other checks are done here.
168 main := ((call_alignment | one_instruction | special_instruction)
169 @end_of_instruction_cleanup)*
170 $!report_fatal_error;
171
172 }%%
173
174 %% write data;
175
176
177 Bool ValidateChunkIA32(const uint8_t *data, size_t size,
178 uint32_t options,
179 const NaClCPUFeaturesX86 *cpu_features,
180 ValidationCallbackFunc user_callback,
181 void *callback_data) {
182 bitmap_word valid_targets_small;
183 bitmap_word jump_dests_small;
184 bitmap_word *valid_targets;
185 bitmap_word *jump_dests;
186 const uint8_t *current_position;
187 const uint8_t *end_of_bundle;
188 int result = TRUE;
189
190 CHECK(sizeof valid_targets_small == sizeof jump_dests_small);
191 CHECK(size % kBundleSize == 0);
192
193 /* For a very small sequences (one bundle) malloc is too expensive. */
194 if (size <= (sizeof valid_targets_small * 8)) {
195 valid_targets_small = 0;
196 valid_targets = &valid_targets_small;
197 jump_dests_small = 0;
198 jump_dests = &jump_dests_small;
199 } else {
200 valid_targets = BitmapAllocate(size);
201 jump_dests = BitmapAllocate(size);
202 if (!valid_targets || !jump_dests) {
203 free(jump_dests);
204 free(valid_targets);
205 errno = ENOMEM;
206 return FALSE;
207 }
208 }
209
210 /*
211 * This option is usually used in tests: we will process the whole chunk
212 * in one pass. Usually each bundle is processed separately which means
213 * instructions (and super-instructions) can not cross borders of the bundle.
214 */
215 if (options & PROCESS_CHUNK_AS_A_CONTIGUOUS_STREAM)
216 end_of_bundle = data + size;
217 else
218 end_of_bundle = data + kBundleSize;
219
220 /*
221 * Main loop. Here we process the data array bundle-after-bundle.
222 * Ragel-produced DFA does all the checks with one exception: direct jumps.
223 * It collects the two arrays: valid_targets and jump_dests which are used
224 * to test direct jumps later.
225 */
226 for (current_position = data;
227 current_position < data + size;
228 current_position = end_of_bundle,
229 end_of_bundle = current_position + kBundleSize) {
230 /* Start of the instruction being processed. */
231 const uint8_t *instruction_begin = current_position;
232 /* Only used locally in the end_of_instruction_cleanup action. */
233 const uint8_t *instruction_end;
234 uint32_t instruction_info_collected = 0;
235 int current_state;
236
237 %% write init;
238 %% write exec;
239 }
240
241 /*
242 * Check the direct jumps. All the targets from jump_dests must be in
243 * valid_targets.
244 */
245 result &= ProcessInvalidJumpTargets(data, size, valid_targets, jump_dests,
246 user_callback, callback_data);
247
248 /* We only use malloc for a large code sequences */
249 if (jump_dests != &jump_dests_small) free(jump_dests);
250 if (valid_targets != &valid_targets_small) free(valid_targets);
251 if (!result) errno = EINVAL;
252 return result;
253 }
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