mozglue/baseprofiler/lul/platform-linux-lul.cpp

   1 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 #include <stdio.h>
   7 #include <signal.h>
   8 #include <string.h>
   9 #include <stdlib.h>
  10 #include <time.h>
  11
  12 #include "AutoObjectMapper.h"
  13 #include "BaseProfiler.h"
  14 #include "SharedLibraries.h"
  15 #include "platform.h"
  16 #include "PlatformMacros.h"
  17 #include "LulMain.h"
  18
  19 // Contains miscellaneous helpers that are used to connect the Gecko Profiler
  20 // and LUL.
  21
  22 // Find out, in a platform-dependent way, where the code modules got
  23 // mapped in the process' virtual address space, and get |aLUL| to
  24 // load unwind info for them.
  25 void read_procmaps(lul::LUL* aLUL) {
  26   MOZ_ASSERT(aLUL->CountMappings() == 0);
  27
  28 #if defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
  29   SharedLibraryInfo info = SharedLibraryInfo::GetInfoForSelf();
  30
  31   for (size_t i = 0; i < info.GetSize(); i++) {
  32     const SharedLibrary& lib = info.GetEntry(i);
  33
  34     std::string nativePath = lib.GetDebugPath();
  35
  36     // We can use the standard POSIX-based mapper.
  37     AutoObjectMapperPOSIX mapper(aLUL->mLog);
  38
  39     // Ask |mapper| to map the object.  Then hand its mapped address
  40     // to NotifyAfterMap().
  41     void* image = nullptr;
  42     size_t size = 0;
  43     bool ok = mapper.Map(&image, &size, nativePath);
  44     if (ok && image && size > 0) {
  45       aLUL->NotifyAfterMap(lib.GetStart(), lib.GetEnd() - lib.GetStart(),
  46                            nativePath.c_str(), image);
  47     } else if (!ok && lib.GetDebugName().empty()) {
  48       // The object has no name and (as a consequence) the mapper failed to map
  49       // it.  This happens on Linux, where GetInfoForSelf() produces such a
  50       // mapping for the VDSO.  This is a problem on x86-{linux,android} because
  51       // lack of knowledge about the mapped area inhibits LUL's special
  52       // __kernel_syscall handling.  Hence notify |aLUL| at least of the
  53       // mapping, even though it can't read any unwind information for the area.
  54       aLUL->NotifyExecutableArea(lib.GetStart(), lib.GetEnd() - lib.GetStart());
  55     }
  56
  57     // |mapper| goes out of scope at this point and so its destructor
  58     // unmaps the object.
  59   }
  60
  61 #else
  62 #  error "Unknown platform"
  63 #endif
  64 }
  65
  66 // LUL needs a callback for its logging sink.
  67 void logging_sink_for_LUL(const char* str) {
  68   // These are only printed when Verbose logging is enabled (e.g. with
  69   // MOZ_BASE_PROFILER_VERBOSE_LOGGING=1). This is because LUL's logging is much
  70   // more verbose than the rest of the profiler's logging, which occurs at the
  71   // Info (3) and Debug (4) levels.
  72   // FIXME: This causes a build failure in memory/replace/dmd/test/SmokeDMD (!)
  73   // and other places, because it doesn't link the implementation in
  74   // platform.cpp.
  75   // VERBOSE_LOG("[%d] %s", profiler_current_process_id(), str);
  76 }