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 verification subroutines.
19 */
20 #include "Dalvik.h"
21 #include "analysis/CodeVerify.h"
22 #include "libdex/InstrUtils.h"
23
24
25 /*
26 * This is used when debugging to apply a magnifying glass to the
27 * verification of a particular method.
28 */
dvmWantVerboseVerification(const Method * meth)29 bool dvmWantVerboseVerification(const Method* meth)
30 {
31 return false; /* COMMENT OUT to enable verbose debugging */
32
33 const char* cd = "Lcom/android/server/am/ActivityManagerService;";
34 const char* mn = "trimApplications";
35 const char* sg = "()V";
36 return (strcmp(meth->clazz->descriptor, cd) == 0 &&
37 dvmCompareNameDescriptorAndMethod(mn, sg, meth) == 0);
38 }
39
40 /*
41 * Output a code verifier warning message. For the pre-verifier it's not
42 * a big deal if something fails (and it may even be expected), but if
43 * we're doing just-in-time verification it's significant.
44 */
dvmLogVerifyFailure(const Method * meth,const char * format,...)45 void dvmLogVerifyFailure(const Method* meth, const char* format, ...)
46 {
47 va_list ap;
48 int logLevel;
49
50 if (gDvm.optimizing) {
51 return;
52 //logLevel = ANDROID_LOG_DEBUG;
53 } else {
54 logLevel = ANDROID_LOG_WARN;
55 }
56
57 va_start(ap, format);
58 LOG_PRI_VA(logLevel, LOG_TAG, format, ap);
59 if (meth != NULL) {
60 char* desc = dexProtoCopyMethodDescriptor(&meth->prototype);
61 LOG_PRI(logLevel, LOG_TAG, "VFY: rejected %s.%s %s",
62 meth->clazz->descriptor, meth->name, desc);
63 free(desc);
64 }
65 }
66
67 /*
68 * Show a relatively human-readable message describing the failure to
69 * resolve a class.
70 *
71 * TODO: this is somewhat misleading when resolution fails because of
72 * illegal access rather than nonexistent class.
73 */
dvmLogUnableToResolveClass(const char * missingClassDescr,const Method * meth)74 void dvmLogUnableToResolveClass(const char* missingClassDescr,
75 const Method* meth)
76 {
77 if (gDvm.optimizing) {
78 return;
79 }
80
81 std::string dotMissingClass = dvmHumanReadableDescriptor(missingClassDescr);
82 std::string dotFromClass = dvmHumanReadableDescriptor(meth->clazz->descriptor);
83 LOGE("Could not find class '%s', referenced from method %s.%s",
84 dotMissingClass.c_str(), dotFromClass.c_str(), meth->name);
85 }
86
87 /*
88 * Extract the relative offset from a branch instruction.
89 *
90 * Returns "false" on failure (e.g. this isn't a branch instruction).
91 */
dvmGetBranchOffset(const Method * meth,const InsnFlags * insnFlags,int curOffset,s4 * pOffset,bool * pConditional)92 bool dvmGetBranchOffset(const Method* meth, const InsnFlags* insnFlags,
93 int curOffset, s4* pOffset, bool* pConditional)
94 {
95 const u2* insns = meth->insns + curOffset;
96
97 switch (*insns & 0xff) {
98 case OP_GOTO:
99 *pOffset = ((s2) *insns) >> 8;
100 *pConditional = false;
101 break;
102 case OP_GOTO_32:
103 *pOffset = insns[1] | (((u4) insns[2]) << 16);
104 *pConditional = false;
105 break;
106 case OP_GOTO_16:
107 *pOffset = (s2) insns[1];
108 *pConditional = false;
109 break;
110 case OP_IF_EQ:
111 case OP_IF_NE:
112 case OP_IF_LT:
113 case OP_IF_GE:
114 case OP_IF_GT:
115 case OP_IF_LE:
116 case OP_IF_EQZ:
117 case OP_IF_NEZ:
118 case OP_IF_LTZ:
119 case OP_IF_GEZ:
120 case OP_IF_GTZ:
121 case OP_IF_LEZ:
122 *pOffset = (s2) insns[1];
123 *pConditional = true;
124 break;
125 default:
126 return false;
127 break;
128 }
129
130 return true;
131 }
132