Move validator_x86_XX.rl out of unreviewed.

src/trusted/validator_ragel/validator_x86_32.rl

 /*
  * Copyright (c) 2012 The Native Client Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /*
  * This is the core of ia32-mode validator.  Please note that this file
  * combines ragel machine description and C language actions.  Please read
  * validator_internals.html first to understand how the whole thing is built:
  * it explains how the byte sequences are constructed, what constructs like
  * "@{}" or "REX_WRX?" mean, etc.
  */
 
 #include <assert.h>
 #include <errno.h>
 #include <stddef.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 
 #include "native_client/src/trusted/validator_ragel/bitmap.h"
-#include "native_client/src/trusted/validator_ragel/unreviewed/validator_internal.h"
+#include "native_client/src/trusted/validator_ragel/validator_internal.h"
 
 /* Ignore this information: it's not used by security model in IA32 mode.  */
+/* TODO(khim): change gen_dfa to remove needs for these lines.  */
 #undef GET_VEX_PREFIX3
 #define GET_VEX_PREFIX3 0
 #undef SET_VEX_PREFIX3
 #define SET_VEX_PREFIX3(P)
 
 %%{
   machine x86_32_validator;
   alphtype unsigned char;
   variable p current_position;
   variable pe end_of_bundle;
@@ skipping 18 matching lines @@
     "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
   include immediate_fields_parsing_ia32
     "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
   include relative_fields_validator_actions
     "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
   include relative_fields_parsing
     "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
   include cpuid_actions
     "native_client/src/trusted/validator_ragel/unreviewed/parse_instruction.rl";
 
-  # Action which marks last byte as not immediate.  Most 3DNow! instructions,
-  # some AVX and XOP instructions have this property.   It's referenced by
-  # decode_x86_32 machine in [autogenerated] "validator_x86_32_instruction.rl"
-  # file.
-  action last_byte_is_not_immediate {
-    instruction_info_collected |= LAST_BYTE_IS_NOT_IMMEDIATE;
-  }
-
   include decode_x86_32 "validator_x86_32_instruction.rl";
 
   special_instruction =
    # and $~0x1f, %eXX  call  %eXX
    #                   vvvvvvvvvv
     (0x83 0xe0 0xe0    0xff (0xd0|0xe0)  | # naclcall/jmp %eax
      0x83 0xe1 0xe0    0xff (0xd1|0xe1)  | # naclcall/jmp %ecx
      0x83 0xe2 0xe0    0xff (0xd2|0xe2)  | # naclcall/jmp %edx
      0x83 0xe3 0xe0    0xff (0xd3|0xe3)  | # naclcall/jmp %ebx
      0x83 0xe4 0xe0    0xff (0xd4|0xe4)  | # naclcall/jmp %esp
      0x83 0xe5 0xe0    0xff (0xd5|0xe5)  | # naclcall/jmp %ebp
      0x83 0xe6 0xe0    0xff (0xd6|0xe6)  | # naclcall/jmp %esi
      0x83 0xe7 0xe0    0xff (0xd7|0xe7))   # naclcall/jmp %edi
    #                   ^^^^       ^^^^
    # and $~0x1f, %eXX     jmp %eXX
     @{
       UnmarkValidJumpTarget((current_position - data) - 1, valid_targets);
       instruction_begin -= 3;
       instruction_info_collected |= SPECIAL_INSTRUCTION;
     } |
     (0x65 0xa1 (0x00|0x04) 0x00 0x00 0x00      | # mov %gs:0x0/0x4,%eax
      0x65 0x8b (0x05|0x0d|0x015|0x1d|0x25|0x2d|0x35|0x3d)
           (0x00|0x04) 0x00 0x00 0x00);           # mov %gs:0x0/0x4,%reg
 
-  # Check if call is properly aligned
-  #
-  # For direct call we explicitly encode all variations.  For indirect call
-  # we accept all the special instructions which ends with register-addressed
-  # indirect call.
+  # For direct call we explicitly encode all variations.
+  direct_call = (data16 0xe8 rel16) | (0xe8 rel32);
+
+  # For indirect call we accept only near register-addressed indirect call.
+  indirect_call_register = data16? 0xff (opcode_2 & modrm_registers);
+
+  # Ragel machine that accepts one call instruction or call superinstruction and
+  # checks if call is properly aligned.
   call_alignment =
-    ((one_instruction &
-      # Direct call
-      ((data16 0xe8 rel16) |
-       (0xe8 rel32))) |
-     (special_instruction &
-      # Indirect call
-      (any* data16? 0xff ((opcode_2 | opcode_3) any* &
-                          modrm_registers))))
+    ((one_instruction & direct_call)
+     # For indirect calls we accept all the special instructions which ends with
+     # register-addressed indirect call.
+     (special_instruction & (any* indirect_call_register)))
     # Call instruction must aligned to the end of bundle.  Previously this was
     # strict requirement, today it's just warning to aid with debugging.
     @{
       if (((current_position - data) & kBundleMask) != kBundleMask)
         instruction_info_collected |= BAD_CALL_ALIGNMENT;
     };
 
-  # This action calls user's callback (if needed) and cleans up validator's
+  # This action calls users callback (if needed) and cleans up validators

[halyavin, 2013/03/19 15:03:54]

user, not users

[khim, 2013/03/21 14:38:17]

Done.

   # internal state.
   #
-  # We call the user callback if there are validation errors or if the
-  # CALL_USER_CALLBACK_ON_EACH_INSTRUCTION option is used.
+  # We call the user callback either on validation errors or on every
+  # instruction, depending on CALL_USER_CALLBACK_ON_EACH_INSTRUTION option.
   #
   # After that we move instruction_begin and clean all the variables which
-  # only used in the processing of a single instruction (prefixes, operand
-  # states and instruction_info_collected).
+  # are only used in the processing of a single instruction (here it's just
+  # instruction_info_collected, there are more state in x86-64 case).
   action end_of_instruction_cleanup {
     /* Mark start of this instruction as a valid target for jump.  */
     MarkValidJumpTarget(instruction_begin - data, valid_targets);
 
     /* Call user-supplied callback.  */
     instruction_end = current_position + 1;
     if ((instruction_info_collected & VALIDATION_ERRORS_MASK) ||
         (options & CALL_USER_CALLBACK_ON_EACH_INSTRUCTION)) {
       result &= user_callback(instruction_begin, instruction_end,
                               instruction_info_collected, callback_data);
     }
 
-    /* On successful match the instruction_begin must point to the next byte
-     * to be able to report the new offset as the start of instruction
-     * causing error.  */
+    /*
+     * We may set instruction_begin at the first byte of the instruction instead
+     * of here but in the case of incorrect one byte instructions user callback
+     * may be called before instruction_begin is set.
+     */
     instruction_begin = instruction_end;
 
     /* Clear variables (well, one variable currently).  */
     instruction_info_collected = 0;
   }
 
   # This action reports fatal error detected by DFA.
   action report_fatal_error {
     result &= user_callback(instruction_begin, current_position,
                             UNRECOGNIZED_INSTRUCTION, callback_data);
     /*
      * Process the next bundle: "continue" here is for the "for" cycle in
      * the ValidateChunkIA32 function.
      *
      * It does not affect the case which we really care about (when code
      * is validatable), but makes it possible to detect more errors in one
      * run in tools like ncval.
      */
     continue;
   }
 
   # This is main ragel machine: it does 99% of validation work. There are only
-  # one thing to do if this machine accepts the bundles - check that direct
-  # jumps are correct. This is done in the following way:
+  # one thing to do if this ragel machine accepts the bundles - check that
+  # direct jumps are correct. This is done in the following way:
   #  * DFA fills two arrays: valid_targets and jump_dests.
   #  * ProcessInvalidJumpTargets checks that "jump_dests & !valid_targets == 0".
   # All other checks are done here.
   main := ((call_alignment | one_instruction | special_instruction)
      @end_of_instruction_cleanup)*
     $!report_fatal_error;
 
 }%%
 
+/*
+ * The "write data" statement causes Ragel to emit the constant static data
+ * needed by the ragel machine.
+ */
 %% write data;
 
-
 Bool ValidateChunkIA32(const uint8_t *data, size_t size,
                        uint32_t options,
                        const NaClCPUFeaturesX86 *cpu_features,
                        ValidationCallbackFunc user_callback,
                        void *callback_data) {
   bitmap_word valid_targets_small;
   bitmap_word jump_dests_small;
   bitmap_word *valid_targets;
   bitmap_word *jump_dests;
   const uint8_t *current_position;
@@ skipping 16 matching lines @@
       free(jump_dests);
       free(valid_targets);
       errno = ENOMEM;
       return FALSE;
     }
   }
 
   /*
    * This option is usually used in tests: we will process the whole chunk
    * in one pass. Usually each bundle is processed separately which means
-   * instructions (and super-instructions) can not cross borders of the bundle.
+   * instructions (and "superinstructions") can not cross borders of the bundle.
    */
   if (options & PROCESS_CHUNK_AS_A_CONTIGUOUS_STREAM)
     end_of_bundle = data + size;
   else
     end_of_bundle = data + kBundleSize;
 
   /*
    * Main loop.  Here we process the data array bundle-after-bundle.
    * Ragel-produced DFA does all the checks with one exception: direct jumps.
    * It collects the two arrays: valid_targets and jump_dests which are used
    * to test direct jumps later.
    */
   for (current_position = data;
        current_position < data + size;
        current_position = end_of_bundle,
        end_of_bundle = current_position + kBundleSize) {
     /* Start of the instruction being processed.  */
     const uint8_t *instruction_begin = current_position;
     /* Only used locally in the end_of_instruction_cleanup action.  */
     const uint8_t *instruction_end;
     uint32_t instruction_info_collected = 0;
     int current_state;
 
+    /*
+     * The "write init" statement causes Ragel to emit initialization code.
+     * This should be executed once before the ragel machine is started.
+     */
     %% write init;
+    /*
+     * The "write exec" statement causes Ragel to emit the ragel machine's
+     * execution code.
+     */
     %% write exec;
   }
 
   /*
    * Check the direct jumps.  All the targets from jump_dests must be in
    * valid_targets.
    */
   result &= ProcessInvalidJumpTargets(data, size, valid_targets, jump_dests,
                                       user_callback, callback_data);
 
   /* We only use malloc for a large code sequences  */
   if (jump_dests != &jump_dests_small) free(jump_dests);
   if (valid_targets != &valid_targets_small) free(valid_targets);
   if (!result) errno = EINVAL;
   return result;
 }