Nazım Can Altınova
0bc1946f4e
After legacy packaging was disabled (bug 1867280), native libraries like libxul.so are loaded directly from inside the APK/AAB instead of being extracted uncompressed to disk. The dynamic linker reports their path using the "<apk>!/<entry>" syntax (for example: ".../split_config.arm64_v8a.apk!/lib/ arm64-v8a/libxul.so"), which is not a real filesystem path. Bug 1773313 already moved breakpadId/codeId extraction to read from memory, so that metadata was correct. But LUL still obtained unwinding information by `open()`ing the library file from disk. With the "<apk>!/" path, that `open()` fails, and because of that, `NotifyAfterMap()` never gets called for libxul and libmozglue, and stack walking gets broken due to this. The library is stored uncompressed and page-aligned inside the APK, so it can still be mapped by opening the APK and mapping at the library's offset within it. It is the file offset of the mapping that backs the library's first loaded page, which we recover from /proc/self/maps. If the offset can't be resolved we fall back to NotifyExecutableArea() so that stack scanning still works. Differential Revision: https://phabricator.services.mozilla.com/D307383
71 lines
2.6 KiB
C++
71 lines
2.6 KiB
C++
/* 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 AutoObjectMapper_h
|
|
#define AutoObjectMapper_h
|
|
|
|
#include <cstdint>
|
|
#include <string>
|
|
|
|
#include "mozilla/Attributes.h"
|
|
#include "mozilla/ProfilerPlatformMacros.h"
|
|
|
|
// A (nearly-) RAII class that maps an object in and then unmaps it on
|
|
// destruction. This base class version uses the "normal" POSIX
|
|
// functions: open, fstat, close, mmap, munmap.
|
|
|
|
class MOZ_STACK_CLASS AutoObjectMapperPOSIX {
|
|
public:
|
|
// The constructor does not attempt to map the file, because that
|
|
// might fail. Instead, once the object has been constructed,
|
|
// call Map() to attempt the mapping. There is no corresponding
|
|
// Unmap() since the unmapping is done in the destructor. Failure
|
|
// messages are sent to |aLog|.
|
|
explicit AutoObjectMapperPOSIX(void (*aLog)(const char*));
|
|
|
|
// Unmap the file on destruction of this object.
|
|
~AutoObjectMapperPOSIX();
|
|
|
|
// Map |fileName| into the address space and return the mapping
|
|
// extents. If the file is zero sized this will fail. The file is
|
|
// mapped read-only and private. Returns true iff the mapping
|
|
// succeeded, in which case *start and *length hold its extent.
|
|
// Once a call to Map succeeds, all subsequent calls to it will
|
|
// fail.
|
|
//
|
|
// |offset| is the offset within |fileName| at which to start the mapping;
|
|
// it must be a multiple of the page size. It is used to map an ELF object
|
|
// (e.g. libxul.so) that is embedded uncompressed inside another file, such
|
|
// as an APK on Android. *start then points at the embedded object's ELF
|
|
// header and *length covers the rest of the file.
|
|
bool Map(/*OUT*/ void** start, /*OUT*/ size_t* length, std::string fileName,
|
|
uint64_t offset = 0);
|
|
|
|
protected:
|
|
// If we are currently holding a mapped object, these record the
|
|
// mapped address range.
|
|
void* mImage;
|
|
size_t mSize;
|
|
|
|
// A logging sink, for complaining about mapping failures.
|
|
void (*mLog)(const char*);
|
|
|
|
private:
|
|
// Are we currently holding a mapped object? This is private to
|
|
// the base class. Derived classes need to have their own way to
|
|
// track whether they are holding a mapped object.
|
|
bool mIsMapped;
|
|
|
|
// Disable copying and assignment.
|
|
AutoObjectMapperPOSIX(const AutoObjectMapperPOSIX&);
|
|
AutoObjectMapperPOSIX& operator=(const AutoObjectMapperPOSIX&);
|
|
// Disable heap allocation of this class.
|
|
void* operator new(size_t);
|
|
void* operator new[](size_t);
|
|
void operator delete(void*);
|
|
void operator delete[](void*);
|
|
};
|
|
|
|
#endif // AutoObjectMapper_h
|