1 /* 2 * Copyright (C) 2008 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 /* 18 * Dalvik bytecode verifier. 19 */ 20 #ifndef _DALVIK_CODEVERIFY 21 #define _DALVIK_CODEVERIFY 22 23 #include "analysis/VerifySubs.h" 24 25 26 /* 27 * Enumeration for register type values. The "hi" piece of a 64-bit value 28 * MUST immediately follow the "lo" piece in the enumeration, so we can check 29 * that hi==lo+1. 30 * 31 * Assignment of constants: 32 * [-MAXINT,-32768) : integer 33 * [-32768,-128) : short 34 * [-128,0) : byte 35 * 0 : zero 36 * 1 : one 37 * [2,128) : posbyte 38 * [128,32768) : posshort 39 * [32768,65536) : char 40 * [65536,MAXINT] : integer 41 * 42 * Allowed "implicit" widening conversions: 43 * zero -> boolean, posbyte, byte, posshort, short, char, integer, ref (null) 44 * one -> boolean, posbyte, byte, posshort, short, char, integer 45 * boolean -> posbyte, byte, posshort, short, char, integer 46 * posbyte -> posshort, short, integer, char 47 * byte -> short, integer 48 * posshort -> integer, char 49 * short -> integer 50 * char -> integer 51 * 52 * In addition, all of the above can convert to "float". 53 * 54 * We're more careful with integer values than the spec requires. The 55 * motivation is to restrict byte/char/short to the correct range of values. 56 * For example, if a method takes a byte argument, we don't want to allow 57 * the code to load the constant "1024" and pass it in. 58 */ 59 enum { 60 kRegTypeUnknown = 0, /* initial state; use value=0 so calloc works */ 61 kRegTypeUninit = 1, /* MUST be odd to distinguish from pointer */ 62 kRegTypeConflict, /* merge clash makes this reg's type unknowable */ 63 64 /* 65 * Category-1nr types. The order of these is chiseled into a couple 66 * of tables, so don't add, remove, or reorder if you can avoid it. 67 */ 68 #define kRegType1nrSTART kRegTypeFloat 69 kRegTypeFloat, 70 kRegTypeZero, /* 32-bit 0, could be Boolean, Int, Float, or Ref */ 71 kRegTypeOne, /* 32-bit 1, could be Boolean, Int, Float */ 72 kRegTypeBoolean, /* must be 0 or 1 */ 73 kRegTypePosByte, /* byte, known positive (can become char) */ 74 kRegTypeByte, 75 kRegTypePosShort, /* short, known positive (can become char) */ 76 kRegTypeShort, 77 kRegTypeChar, 78 kRegTypeInteger, 79 #define kRegType1nrEND kRegTypeInteger 80 81 kRegTypeLongLo, /* lower-numbered register; endian-independent */ 82 kRegTypeLongHi, 83 kRegTypeDoubleLo, 84 kRegTypeDoubleHi, 85 86 /* 87 * Enumeration max; this is used with "full" (32-bit) RegType values. 88 * 89 * Anything larger than this is a ClassObject or uninit ref. Mask off 90 * all but the low 8 bits; if you're left with kRegTypeUninit, pull 91 * the uninit index out of the high 24. Because kRegTypeUninit has an 92 * odd value, there is no risk of a particular ClassObject pointer bit 93 * pattern being confused for it (assuming our class object allocator 94 * uses word alignment). 95 */ 96 kRegTypeMAX 97 }; 98 #define kRegTypeUninitMask 0xff 99 #define kRegTypeUninitShift 8 100 101 /* 102 * RegType holds information about the type of data held in a register. 103 * For most types it's a simple enum. For reference types it holds a 104 * pointer to the ClassObject, and for uninitialized references it holds 105 * an index into the UninitInstanceMap. 106 */ 107 typedef u4 RegType; 108 109 /* 110 * Table that maps uninitialized instances to classes, based on the 111 * address of the new-instance instruction. 112 */ 113 typedef struct UninitInstanceMap { 114 int numEntries; 115 struct { 116 int addr; /* code offset, or -1 for method arg ("this") */ 117 ClassObject* clazz; /* class created at this address */ 118 } map[1]; 119 } UninitInstanceMap; 120 #define kUninitThisArgAddr (-1) 121 #define kUninitThisArgSlot 0 122 123 /* 124 * Various bits of data generated by the verifier, wrapped up in a package 125 * for ease of use by the register map generator. 126 */ 127 typedef struct VerifierData { 128 /* 129 * The method we're working on. 130 */ 131 const Method* method; 132 133 /* 134 * Number of code units of instructions in the method. A cache of the 135 * value calculated by dvmGetMethodInsnsSize(). 136 */ 137 u4 insnsSize; 138 139 /* 140 * Number of registers we track for each instruction. This is equal 141 * to the method's declared "registersSize". (Does not include the 142 * pending return value.) 143 */ 144 u4 insnRegCount; 145 146 /* 147 * Instruction widths and flags, one entry per code unit. 148 */ 149 InsnFlags* insnFlags; 150 151 /* 152 * Uninitialized instance map, used for tracking the movement of 153 * objects that have been allocated but not initialized. 154 */ 155 UninitInstanceMap* uninitMap; 156 157 /* 158 * Array of SRegType arrays, one entry per code unit. We only need 159 * entries for code units that hold the start of an "interesting" 160 * instruction. For register map generation, we're only interested 161 * in GC points. 162 */ 163 RegType** addrRegs; 164 } VerifierData; 165 166 167 /* table with static merge logic for primitive types */ 168 extern const char gDvmMergeTab[kRegTypeMAX][kRegTypeMAX]; 169 170 171 /* 172 * Returns "true" if the flags indicate that this address holds the start 173 * of an instruction. 174 */ 175 INLINE bool dvmInsnIsOpcode(const InsnFlags* insnFlags, int addr) { 176 return (insnFlags[addr] & kInsnFlagWidthMask) != 0; 177 } 178 179 /* 180 * Extract the unsigned 16-bit instruction width from "flags". 181 */ 182 INLINE int dvmInsnGetWidth(const InsnFlags* insnFlags, int addr) { 183 return insnFlags[addr] & kInsnFlagWidthMask; 184 } 185 186 /* 187 * Changed? 188 */ 189 INLINE bool dvmInsnIsChanged(const InsnFlags* insnFlags, int addr) { 190 return (insnFlags[addr] & kInsnFlagChanged) != 0; 191 } 192 INLINE void dvmInsnSetChanged(InsnFlags* insnFlags, int addr, bool changed) 193 { 194 if (changed) 195 insnFlags[addr] |= kInsnFlagChanged; 196 else 197 insnFlags[addr] &= ~kInsnFlagChanged; 198 } 199 200 /* 201 * Visited? 202 */ 203 INLINE bool dvmInsnIsVisited(const InsnFlags* insnFlags, int addr) { 204 return (insnFlags[addr] & kInsnFlagVisited) != 0; 205 } 206 INLINE void dvmInsnSetVisited(InsnFlags* insnFlags, int addr, bool changed) 207 { 208 if (changed) 209 insnFlags[addr] |= kInsnFlagVisited; 210 else 211 insnFlags[addr] &= ~kInsnFlagVisited; 212 } 213 214 /* 215 * Visited or changed? 216 */ 217 INLINE bool dvmInsnIsVisitedOrChanged(const InsnFlags* insnFlags, int addr) { 218 return (insnFlags[addr] & (kInsnFlagVisited|kInsnFlagChanged)) != 0; 219 } 220 221 /* 222 * In a "try" block? 223 */ 224 INLINE bool dvmInsnIsInTry(const InsnFlags* insnFlags, int addr) { 225 return (insnFlags[addr] & kInsnFlagInTry) != 0; 226 } 227 INLINE void dvmInsnSetInTry(InsnFlags* insnFlags, int addr, bool inTry) 228 { 229 assert(inTry); 230 //if (inTry) 231 insnFlags[addr] |= kInsnFlagInTry; 232 //else 233 // insnFlags[addr] &= ~kInsnFlagInTry; 234 } 235 236 /* 237 * Instruction is a branch target or exception handler? 238 */ 239 INLINE bool dvmInsnIsBranchTarget(const InsnFlags* insnFlags, int addr) { 240 return (insnFlags[addr] & kInsnFlagBranchTarget) != 0; 241 } 242 INLINE void dvmInsnSetBranchTarget(InsnFlags* insnFlags, int addr, 243 bool isBranch) 244 { 245 assert(isBranch); 246 //if (isBranch) 247 insnFlags[addr] |= kInsnFlagBranchTarget; 248 //else 249 // insnFlags[addr] &= ~kInsnFlagBranchTarget; 250 } 251 252 /* 253 * Instruction is a GC point? 254 */ 255 INLINE bool dvmInsnIsGcPoint(const InsnFlags* insnFlags, int addr) { 256 return (insnFlags[addr] & kInsnFlagGcPoint) != 0; 257 } 258 INLINE void dvmInsnSetGcPoint(InsnFlags* insnFlags, int addr, 259 bool isGcPoint) 260 { 261 assert(isGcPoint); 262 //if (isGcPoint) 263 insnFlags[addr] |= kInsnFlagGcPoint; 264 //else 265 // insnFlags[addr] &= ~kInsnFlagGcPoint; 266 } 267 268 269 /* 270 * Create a new UninitInstanceMap. 271 */ 272 UninitInstanceMap* dvmCreateUninitInstanceMap(const Method* meth, 273 const InsnFlags* insnFlags, int newInstanceCount); 274 275 /* 276 * Release the storage associated with an UninitInstanceMap. 277 */ 278 void dvmFreeUninitInstanceMap(UninitInstanceMap* uninitMap); 279 280 /* 281 * Associate a class with an address. Returns the map slot index, or -1 282 * if the address isn't listed in the map (shouldn't happen) or if a 283 * different class is already associated with the address (shouldn't 284 * happen either). 285 */ 286 //int dvmSetUninitInstance(UninitInstanceMap* uninitMap, int addr, 287 // ClassObject* clazz); 288 289 /* 290 * Return the class associated with an uninitialized reference. Pass in 291 * the map index. 292 */ 293 //ClassObject* dvmGetUninitInstance(const UninitInstanceMap* uninitMap, int idx); 294 295 /* 296 * Clear the class associated with an uninitialized reference. Pass in 297 * the map index. 298 */ 299 //void dvmClearUninitInstance(UninitInstanceMap* uninitMap, int idx); 300 301 302 /* 303 * Verify bytecode in "meth". "insnFlags" should be populated with 304 * instruction widths and "in try" flags. 305 */ 306 bool dvmVerifyCodeFlow(VerifierData* vdata); 307 308 #endif /*_DALVIK_CODEVERIFY*/ 309
