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1 | /* -*- mode: C++; c-basic-offset: 4; tab-width: 4 -*- |
2 | * | |
3 | * Copyright (c) 2009 Apple Inc. All rights reserved. | |
4 | * | |
5 | * @APPLE_LICENSE_HEADER_START@ | |
6 | * | |
7 | * This file contains Original Code and/or Modifications of Original Code | |
8 | * as defined in and that are subject to the Apple Public Source License | |
9 | * Version 2.0 (the 'License'). You may not use this file except in | |
10 | * compliance with the License. Please obtain a copy of the License at | |
11 | * http://www.opensource.apple.com/apsl/ and read it before using this | |
12 | * file. | |
13 | * | |
14 | * The Original Code and all software distributed under the License are | |
15 | * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER | |
16 | * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES, | |
17 | * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY, | |
18 | * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT. | |
19 | * Please see the License for the specific language governing rights and | |
20 | * limitations under the License. | |
21 | * | |
22 | * @APPLE_LICENSE_HEADER_END@ | |
23 | */ | |
24 | ||
25 | ||
26 | #include <stdint.h> | |
27 | #include <math.h> | |
28 | #include <unistd.h> | |
29 | #include <dlfcn.h> | |
30 | ||
31 | #include <vector> | |
32 | #include <map> | |
33 | #include <ext/hash_map> | |
34 | ||
35 | #include "ld.hpp" | |
36 | #include "dtrace_dof.h" | |
37 | ||
38 | // prototype for entry point in libdtrace.dylib | |
39 | typedef uint8_t* (*createdof_func_t)(cpu_type_t, unsigned int, const char*[], unsigned int, const char*[], const char*[], uint64_t offsetsInDOF[], size_t* size); | |
40 | ||
41 | ||
42 | namespace ld { | |
43 | namespace passes { | |
44 | namespace dtrace { | |
45 | ||
46 | class File; // forward reference | |
47 | ||
48 | class Atom : public ld::Atom { | |
49 | public: | |
50 | Atom(class File& f, const char* n, const uint8_t* content, uint64_t sz); | |
51 | ||
52 | virtual ld::File* file() const { return (ld::File*)&_file; } | |
53 | virtual const char* name() const { return _name; } | |
54 | virtual uint64_t size() const { return _size; } | |
55 | virtual uint64_t objectAddress() const { return 0; } | |
56 | virtual void copyRawContent(uint8_t buffer[]) const | |
57 | { memcpy(buffer, _content, _size); } | |
58 | virtual void setScope(Scope) { } | |
59 | virtual ld::Fixup::iterator fixupsBegin() const { return &_fixups[0]; } | |
60 | virtual ld::Fixup::iterator fixupsEnd() const { return &_fixups[_fixups.size()]; } | |
61 | ||
62 | protected: | |
63 | friend class File; | |
64 | virtual ~Atom() {} | |
65 | ||
66 | class File& _file; | |
67 | const char* _name; | |
68 | const uint8_t* _content; | |
69 | uint64_t _size; | |
70 | mutable std::vector<ld::Fixup> _fixups; | |
71 | }; | |
72 | ||
73 | ||
74 | class File : public ld::File | |
75 | { | |
76 | public: | |
77 | File(const char* segmentName, const char* sectionName, const char* pth, | |
78 | const uint8_t fileContent[], uint64_t fileLength, Ordinal ord, | |
79 | const char* symbolName="dof") | |
80 | : ld::File(pth, 0, ord, Other), | |
81 | _atom(*this, symbolName, fileContent, fileLength), | |
82 | _section(segmentName, sectionName, ld::Section::typeDtraceDOF) { } | |
83 | virtual ~File() {} | |
84 | ||
85 | virtual bool forEachAtom(AtomHandler& h) const { h.doAtom(_atom); return true; } | |
86 | virtual bool justInTimeforEachAtom(const char* name, AtomHandler&) const { return false; } | |
87 | ||
88 | void reserveFixups(unsigned int count) { _atom._fixups.reserve(count); } | |
89 | void addSectionFixup(const ld::Fixup& f) { _atom._fixups.push_back(f); } | |
90 | ld::Atom& atom() { return _atom; } | |
91 | private: | |
92 | friend class Atom; | |
93 | ||
94 | Atom _atom; | |
95 | ld::Section _section; | |
96 | }; | |
97 | ||
98 | Atom::Atom(File& f, const char* n, const uint8_t* content, uint64_t sz) | |
99 | : ld::Atom(f._section, ld::Atom::definitionRegular, ld::Atom::combineNever, | |
100 | ld::Atom::scopeTranslationUnit, ld::Atom::typeUnclassified, | |
101 | symbolTableNotIn, false, false, false, ld::Atom::Alignment(0)), | |
102 | _file(f), _name(strdup(n)), _content(content), _size(sz) {} | |
103 | ||
104 | ||
105 | ||
106 | class CStringEquals | |
107 | { | |
108 | public: | |
109 | bool operator()(const char* left, const char* right) const { return (strcmp(left, right) == 0); } | |
110 | }; | |
111 | ||
112 | struct DTraceProbeInfo { | |
113 | DTraceProbeInfo(const ld::Atom* a, uint32_t o, const char* n) : atom(a), offset(o), probeName(n) {} | |
114 | const ld::Atom* atom; | |
115 | uint32_t offset; | |
116 | const char* probeName; | |
117 | }; | |
118 | typedef __gnu_cxx::hash_map<const char*, std::vector<DTraceProbeInfo>, __gnu_cxx::hash<const char*>, CStringEquals> ProviderToProbes; | |
119 | typedef __gnu_cxx::hash_set<const char*, __gnu_cxx::hash<const char*>, CStringEquals> CStringSet; | |
120 | ||
121 | ||
122 | ||
123 | void doPass(const Options& opts, ld::Internal& internal) | |
124 | { | |
125 | static bool log = false; | |
126 | ||
127 | // only make __dof section in final linked images | |
128 | if ( opts.outputKind() == Options::kObjectFile ) | |
129 | return; | |
130 | ||
131 | // scan all atoms looking for dtrace probes | |
132 | std::vector<DTraceProbeInfo> probeSites; | |
133 | std::vector<DTraceProbeInfo> isEnabledSites; | |
134 | std::map<const ld::Atom*,CStringSet> atomToDtraceTypes; | |
135 | for (std::vector<ld::Internal::FinalSection*>::iterator sit=internal.sections.begin(); sit != internal.sections.end(); ++sit) { | |
136 | ld::Internal::FinalSection* sect = *sit; | |
137 | if ( sect->type() != ld::Section::typeCode ) | |
138 | continue; | |
139 | for (std::vector<const ld::Atom*>::iterator ait=sect->atoms.begin(); ait != sect->atoms.end(); ++ait) { | |
140 | const ld::Atom* atom = *ait; | |
141 | for (ld::Fixup::iterator fit = atom->fixupsBegin(), end=atom->fixupsEnd(); fit != end; ++fit) { | |
142 | switch ( fit->kind ) { | |
143 | case ld::Fixup::kindStoreX86DtraceCallSiteNop: | |
144 | case ld::Fixup::kindStoreARMDtraceCallSiteNop: | |
145 | case ld::Fixup::kindStoreThumbDtraceCallSiteNop: | |
146 | probeSites.push_back(DTraceProbeInfo(atom, fit->offsetInAtom, fit->u.name)); | |
147 | break; | |
148 | case ld::Fixup::kindStoreX86DtraceIsEnableSiteClear: | |
149 | case ld::Fixup::kindStoreARMDtraceIsEnableSiteClear: | |
150 | case ld::Fixup::kindStoreThumbDtraceIsEnableSiteClear: | |
151 | isEnabledSites.push_back(DTraceProbeInfo(atom, fit->offsetInAtom, fit->u.name)); | |
152 | break; | |
153 | case ld::Fixup::kindDtraceExtra: | |
154 | atomToDtraceTypes[atom].insert(fit->u.name); | |
155 | break; | |
156 | default: | |
157 | break; | |
158 | } | |
159 | } | |
160 | } | |
161 | } | |
162 | ||
163 | // if no probes, we're done | |
164 | if ( (probeSites.size() == 0) && (isEnabledSites.size() == 0) ) | |
165 | return; | |
166 | ||
167 | ld::Fixup::Kind storeKind = ld::Fixup::kindNone; | |
168 | switch ( opts.architecture() ) { | |
169 | case CPU_TYPE_I386: | |
170 | case CPU_TYPE_X86_64: | |
171 | case CPU_TYPE_ARM: | |
172 | storeKind = ld::Fixup::kindStoreLittleEndian32; | |
173 | break; | |
174 | default: | |
175 | throw "unsupported arch for DOF"; | |
176 | } | |
177 | ||
178 | // partition probes by provider name | |
179 | // The symbol names looks like: | |
180 | // "___dtrace_probe$" provider-name "$" probe-name [ "$"... ] | |
181 | // "___dtrace_isenabled$" provider-name "$" probe-name [ "$"... ] | |
182 | ProviderToProbes providerToProbes; | |
183 | std::vector<DTraceProbeInfo> emptyList; | |
184 | for(std::vector<DTraceProbeInfo>::iterator it = probeSites.begin(); it != probeSites.end(); ++it) { | |
185 | // ignore probes in functions that were coalesed away rdar://problem/5628149 | |
186 | if ( it->atom->coalescedAway() ) | |
187 | continue; | |
188 | const char* providerStart = &it->probeName[16]; | |
189 | const char* providerEnd = strchr(providerStart, '$'); | |
190 | if ( providerEnd != NULL ) { | |
191 | char providerName[providerEnd-providerStart+1]; | |
192 | strlcpy(providerName, providerStart, providerEnd-providerStart+1); | |
193 | ProviderToProbes::iterator pos = providerToProbes.find(providerName); | |
194 | if ( pos == providerToProbes.end() ) { | |
195 | const char* dup = strdup(providerName); | |
196 | providerToProbes[dup] = emptyList; | |
197 | } | |
198 | providerToProbes[providerName].push_back(*it); | |
199 | } | |
200 | } | |
201 | for(std::vector<DTraceProbeInfo>::iterator it = isEnabledSites.begin(); it != isEnabledSites.end(); ++it) { | |
202 | // ignore probes in functions that were coalesed away rdar://problem/5628149 | |
203 | if ( it->atom->coalescedAway() ) | |
204 | continue; | |
205 | const char* providerStart = &it->probeName[20]; | |
206 | const char* providerEnd = strchr(providerStart, '$'); | |
207 | if ( providerEnd != NULL ) { | |
208 | char providerName[providerEnd-providerStart+1]; | |
209 | strlcpy(providerName, providerStart, providerEnd-providerStart+1); | |
210 | ProviderToProbes::iterator pos = providerToProbes.find(providerName); | |
211 | if ( pos == providerToProbes.end() ) { | |
212 | const char* dup = strdup(providerName); | |
213 | providerToProbes[dup] = emptyList; | |
214 | } | |
215 | providerToProbes[providerName].push_back(*it); | |
216 | } | |
217 | } | |
218 | ||
219 | // create a DOF section for each provider | |
220 | int dofIndex=1; | |
221 | CStringSet sectionNamesUsed; | |
222 | for(ProviderToProbes::iterator pit = providerToProbes.begin(); pit != providerToProbes.end(); ++pit, ++dofIndex) { | |
223 | const char* providerName = pit->first; | |
224 | const std::vector<DTraceProbeInfo>& probes = pit->second; | |
225 | ||
226 | // open library and find dtrace_create_dof() | |
227 | void* handle = dlopen("/usr/lib/libdtrace.dylib", RTLD_LAZY); | |
228 | if ( handle == NULL ) | |
229 | throwf("couldn't dlopen() /usr/lib/libdtrace.dylib: %s", dlerror()); | |
230 | createdof_func_t pCreateDOF = (createdof_func_t)dlsym(handle, "dtrace_ld_create_dof"); | |
231 | if ( pCreateDOF == NULL ) | |
232 | throwf("couldn't find \"dtrace_ld_create_dof\" in /usr/lib/libdtrace.dylib: %s", dlerror()); | |
233 | // build list of typedefs/stability infos for this provider | |
234 | CStringSet types; | |
235 | for(std::vector<DTraceProbeInfo>::const_iterator it = probes.begin(); it != probes.end(); ++it) { | |
236 | std::map<const ld::Atom*,CStringSet>::iterator pos = atomToDtraceTypes.find(it->atom); | |
237 | if ( pos != atomToDtraceTypes.end() ) { | |
238 | for(CStringSet::iterator sit = pos->second.begin(); sit != pos->second.end(); ++sit) { | |
239 | const char* providerStart = strchr(*sit, '$')+1; | |
240 | const char* providerEnd = strchr(providerStart, '$'); | |
241 | if ( providerEnd != NULL ) { | |
242 | char aProviderName[providerEnd-providerStart+1]; | |
243 | strlcpy(aProviderName, providerStart, providerEnd-providerStart+1); | |
244 | if ( strcmp(aProviderName, providerName) == 0 ) | |
245 | types.insert(*sit); | |
246 | } | |
247 | } | |
248 | } | |
249 | } | |
250 | int typeCount = types.size(); | |
251 | const char* typeNames[typeCount]; | |
252 | //fprintf(stderr, "types for %s:\n", providerName); | |
253 | uint32_t index = 0; | |
254 | for(CStringSet::iterator it = types.begin(); it != types.end(); ++it) { | |
255 | typeNames[index] = *it; | |
256 | //fprintf(stderr, "\t%s\n", *it); | |
257 | ++index; | |
258 | } | |
259 | ||
260 | // build list of probe/isenabled sites | |
261 | const uint32_t probeCount = probes.size(); | |
262 | const char* probeNames[probeCount]; | |
263 | const char* funtionNames[probeCount]; | |
264 | uint64_t offsetsInDOF[probeCount]; | |
265 | index = 0; | |
266 | for(std::vector<DTraceProbeInfo>::const_iterator it = probes.begin(); it != probes.end(); ++it) { | |
267 | probeNames[index] = it->probeName; | |
268 | funtionNames[index] = it->atom->name(); | |
269 | offsetsInDOF[index] = 0; | |
270 | ++index; | |
271 | } | |
272 | if ( log ) { | |
273 | fprintf(stderr, "calling libtrace to create DOF:\n"); | |
274 | fprintf(stderr, " types::\n"); | |
275 | for(int i=0; i < typeCount; ++i) | |
276 | fprintf(stderr, " [%u]\t %s\n", i, typeNames[i]); | |
277 | fprintf(stderr, " probes::\n"); | |
278 | for(uint32_t i=0; i < probeCount; ++i) | |
279 | fprintf(stderr, " [%u]\t %s in %s\n", i, probeNames[i], funtionNames[i]); | |
280 | } | |
281 | ||
282 | // call dtrace library to create DOF section | |
283 | size_t dofSectionSize; | |
284 | uint8_t* p = (*pCreateDOF)(opts.architecture(), typeCount, typeNames, probeCount, probeNames, funtionNames, offsetsInDOF, &dofSectionSize); | |
285 | if ( p != NULL ) { | |
286 | char* sectionName = new char[18]; // alloc new string, pass ownership to File() | |
287 | strcpy(sectionName, "__dof_"); | |
288 | strlcpy(§ionName[6], providerName, 10); | |
289 | // create unique section name so each DOF is in its own section | |
290 | if ( sectionNamesUsed.count(sectionName) != 0 ) { | |
291 | sectionName[15] = '0'; | |
292 | sectionName[16] = '\0'; | |
293 | while ( sectionNamesUsed.count(sectionName) != 0 ) { | |
294 | ++sectionName[15]; | |
295 | } | |
296 | } | |
297 | sectionNamesUsed.insert(sectionName); | |
298 | char symbolName[strlen(providerName)+64]; | |
299 | sprintf(symbolName, "__dtrace_dof_for_provider_%s", providerName); | |
300 | File* f = new File("__TEXT", sectionName, "dtrace", p, dofSectionSize, ld::File::Ordinal::NullOrdinal(), symbolName); | |
301 | if ( log ) { | |
302 | fprintf(stderr, "libdtrace created DOF of size %ld\n", dofSectionSize); | |
303 | } | |
304 | // add references | |
305 | f->reserveFixups(3*probeCount); | |
306 | for (uint32_t i=0; i < probeCount; ++i) { | |
307 | uint64_t offset = offsetsInDOF[i]; | |
308 | //fprintf(stderr, "%s offset[%d]=0x%08llX\n", providerName, i, offset); | |
309 | if ( offset > dofSectionSize ) | |
310 | throwf("offsetsInDOF[%d]=%0llX > dofSectionSize=%0lX\n", i, offset, dofSectionSize); | |
311 | f->addSectionFixup(ld::Fixup(offset, ld::Fixup::k1of4, ld::Fixup::kindSetTargetAddress, probes[i].atom)); | |
312 | f->addSectionFixup(ld::Fixup(offset, ld::Fixup::k2of4, ld::Fixup::kindAddAddend, probes[i].offset)); | |
313 | f->addSectionFixup(ld::Fixup(offset, ld::Fixup::k3of4, ld::Fixup::kindSubtractTargetAddress, &f->atom())); | |
314 | f->addSectionFixup(ld::Fixup(offset, ld::Fixup::k4of4, storeKind)); | |
315 | } | |
316 | // insert new section | |
317 | internal.addAtom(f->atom()); | |
318 | } | |
319 | else { | |
320 | throw "error creating dtrace DOF section"; | |
321 | } | |
322 | } | |
323 | ||
324 | ||
325 | ||
326 | } | |
327 | ||
328 | ||
329 | } // namespace dtrace | |
330 | } // namespace passes | |
331 | } // namespace ld |