Commit 0b0dd831 authored by Gabriele Svelto's avatar Gabriele Svelto
Browse files

Bug 1752703 - Move the pthread_thread_create() interposer under mozglue and... 

Bug 1752703 - Move the pthread_thread_create() interposer under mozglue and prepare for having a single place where we place interposer functions r=glandium

Differential Revision: https://phabricator.services.mozilla.com/D164470
parent b0f78a8a

browser/app/moz.build

+0 −5
Original line number Diff line number Diff line
@@ -53,11 +53,6 @@ LOCAL_INCLUDES += [ 
    "/xpcom/build",

]



# The pthred_create() interposer needs to be linked as early as possible so

# that it will appear before libpthread when resolving symbols.

if CONFIG["OS_ARCH"] == "Linux" and CONFIG["MOZ_CRASHREPORTER"]:

    USE_LIBS += ["pthread_create_interposer"]



if CONFIG["LIBFUZZER"]:

    USE_LIBS += ["fuzzer"]

    LOCAL_INCLUDES += [

ipc/app/moz.build

+0 −5
Original line number Diff line number Diff line
@@ -16,11 +16,6 @@ else: 
        "MozillaRuntimeMain.cpp",

    ]



# The pthred_create() interposer needs to be linked as early as possible so

# that it will appear before libpthread when resolving symbols.

if CONFIG["OS_ARCH"] == "Linux" and CONFIG["MOZ_CRASHREPORTER"]:

    USE_LIBS += ["pthread_create_interposer"]



include("/ipc/chromium/chromium-config.mozbuild")



LOCAL_INCLUDES += [

js/src/make-source-package.py

+1 −0
Original line number Diff line number Diff line
@@ -155,6 +155,7 @@ rsync_filter_list = """ 


+ /mozglue/baseprofiler/**

+ /mozglue/build/**

+ /mozglue/interposers/**

+ /mozglue/misc/**

+ /mozglue/moz.build

+ /mozglue/static/**

js/xpconnect/shell/moz.build

+0 −5
Original line number Diff line number Diff line
@@ -10,11 +10,6 @@ SOURCES += [ 
    "xpcshell.cpp",

]



# The pthred_create() interposer needs to be linked as early as possible so

# that it will appear before libpthread when resolving symbols.

if CONFIG["OS_ARCH"] == "Linux" and CONFIG["MOZ_CRASHREPORTER"]:

    USE_LIBS += ["pthread_create_interposer"]



if CONFIG["LIBFUZZER"]:

    USE_LIBS += ["fuzzer"]

mozglue/interposers/InterposerHelper.h

0 → 100644
+66 −0
Original line number Diff line number Diff line 
/* This Source Code Form is subject to the terms of the Mozilla Public

 * License, v. 2.0. If a copy of the MPL was not distributed with this

 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */



#ifndef InterposerHelper_h

#define InterposerHelper_h



#include <type_traits>



#ifdef MOZ_LINKER

#  include "Linker.h"

#else

#  include <dlfcn.h>

#endif



#include "mozilla/Assertions.h"



template <typename T>

static inline T dlsym_wrapper(void* aHandle, const char* aName) {

#ifdef MOZ_LINKER

  return reinterpret_cast<T>(__wrap_dlsym(aHandle, aName));

#else

  return reinterpret_cast<T>(dlsym(aHandle, aName));

#endif  // MOZ_LINKER

}



template <typename T>

static T get_real_symbol(const char* aName, T aReplacementSymbol) {

  // T can only be a function pointer

  static_assert(std::is_function<typename std::remove_pointer<T>::type>::value);



  // Find the corresponding function in the linked libraries

  T real_symbol = dlsym_wrapper<T>(RTLD_NEXT, aName);



#if defined(ANDROID)

  if (real_symbol == nullptr) {

    // On old versions of Android the application runtime links in libc before

    // we get a chance to link libmozglue, so its symbols don't appear when

    // resolving them with RTLD_NEXT but rather with RTLD_DEFAULT. If RTLD_NEXT

    // failed to find a symbol we try again with RTLD_DEFAULT. The checks below

    // make sure that we crash in case the symbol we get matches the

    // replacement one so this is safe albeit a bit weird.

    real_symbol = dlsym_wrapper<T>(RTLD_DEFAULT, aName);

  }

#endif



  if (real_symbol == nullptr) {

    MOZ_CRASH_UNSAFE_PRINTF(

        "%s() interposition failed but the interposer function is "

        "still being called, this won't work!",

        aName);

  }



  if (real_symbol == aReplacementSymbol) {

    MOZ_CRASH_UNSAFE_PRINTF(

        "We could not obtain the real %s(). Calling the symbol we "

        "got would make us enter an infinite loop so stop here instead.",

        aName);

  }



  return real_symbol;

}



#define GET_REAL_SYMBOL(name) get_real_symbol(#name, name)



#endif  // InterposerHelper_h