Commit Graph

14 Commits

Author SHA1 Message Date
Christopher Ferris 4568f4bc0f Verify that the elf matches the expected arch.
To avoid a case where a malicious app might try and trick the system to
create an elf and register object that mismatches, always verify that they
are the same arch.

Test: Ran unit tests.
Change-Id: I66978e9e02f8e4f396856912e7019528ead4838e
2018-10-29 18:08:09 -07:00
Christopher Ferris e8c4ecf49e Always init gnu_debugdata interface if it exists.
Every real call always sets the value to true to init the gnu_debugdata
interface, so remove this parameter.

Test: Builds, unit tests pass.
Change-Id: I07fb3adbbd5b65b51c0dc7608561e820a5095051
2018-10-23 12:13:54 -07:00
Christopher Ferris 9d5712c123 Implement support for linker rosegment option.
The rosegment linker option results in two maps containing the elf data
existing. One is an execute map where the code lives, and the other is the
read-only segment which contains the elf header information. If the file
backing a shared library in memory is not readable, then the new code
will attempt to find the read-only map that has the same name as the
current execute segment, and that is at offest zero in the file.

Add new unit tests for this functionality.

Add the missing MapInfoCreateMemoryTest.cpp to the list of tests.

Bug: 109657296

Test: Pass new unit tests.
Test: All unit libbacktrace/libunwindstack tests pass with rosegment enabled.
Change-Id: If8f69e4a067d77b3f2a7c31e2e5cd989a0702a8c
2018-10-03 20:48:45 -07:00
Yabin Cui 3841accba8 libprocinfo: add functions reading process map file.
Add test and benchmark.
Also switch libbacktrace, libunwindstack, libmemunreachable
to use libprocinfo for map file reading.
The benchmark shows using libprocinfo speeds up map file reading
in libbacktrace and libunwindstack 18% - 36% on walleye.

Bug: http://b/79118393
Test: run procinfo_test.
Test: run libunwindstack_test.
Test: run libbacktrace_test.
Test: run memunreachable_test.

Change-Id: Icf281c352f4103fc8d4ba6732c5c07b943330ca1
2018-05-14 14:00:18 -07:00
Christopher Ferris 0b79ae155f Add a global elf cache.
Bug: 65682279

Test: Ran new unit tests.
Change-Id: I19c64614b2b11a27f58204d4cc34913c02e04c36
2018-01-25 17:11:33 -08:00
Christopher Ferris e7b6624c3f Fix issues in libunwindstack.
- Add a load_bias field in MapInfo so that it can be loaded offline,
  and also so it can be cached.
- Add an Add function to the Maps class so that it's possible to manually
  create a map.
- Remove the OfflineMaps class since I haven't found a reason for this to
  exist.
- Add a pointer to the gnu debugdata compressed section in the interface
  itself and modify the step path to try eh_frame, then debug_frame, then
  gnu_debugdata. This way arm can add exidx as the last step behind
  gnu_debugdata. Add an offline test to verify the order of unwind.
- Fix x86_64_ucontext_t since it was a different size on 32 bit and 64 bit
  systems.

Test: Pass new unit tests.
Change-Id: I978b70d6c244bd307c62a29886d24c1a8cb2af23
2017-12-15 11:17:45 -08:00
Christopher Ferris b7de5f5429 Demand read load bias for a map.
Add a static GetLoadBias method to the Elf object that only reads just
enough to get the load bias.

Add a method to MapInfo that gets the load bias. First attempt to get
it if the elf object already exists. If no elf object was created, use
the new static method to get the load bias.

In BacktraceMap, add a custom iterator so that when code dereferences
a map element, that's when the load bias will be retrieved if it hasn't
already been set.

Bug: 69871050

Test: New unit tests, verify tombstones have non-zero load bias values for
Test: libraries with a non-zero load bias.
Change-Id: I125f4abc827589957fce2f0df24b0f25d037d732
2017-12-05 13:12:47 -08:00
Christopher Ferris be788d891d Allow multiple threads sharing a map to unwind.
Add a mutex in MapInfo, and a mutex in Elf. Lock the creation of an Elf
file using the MapInfo mutex, and lock when calling Step, GetFunctionName,
or GetSoname since they can modify information in the object. It might
be beneficial to use a fine grained lock in the future.

Change the Maps object to contain a vector of MapInfo pointers rather
than the total objects. This avoids copying this data around.

Add a test to libbacktrace to verify that sharing a map while doing
unwinds in different threads works.

Add concurrency tests in libunwindstack to verify the locking works.

Add always inline to the RegsGetLocal arm and aarch64 functions. I had
a case where clang did not inline the code, so make sure this is specified.

Bug: 68813077

Test: New unit tests to cover the case. Passes all unit tests.
Test: Ran a monkey test while dumping bugreports and verified that
Test: no crashes in libunwind.
Test: Remove the locking and verified that all of the concurrenty tests fail.
Change-Id: I769e728c676f6bdae9e64ce4cdc03b6749beae03
2017-11-28 15:20:38 -08:00
Christopher Ferris 5f118519fd Add a method to share the process memory object.
New function to create the process memory object. This allows for
a future where different remote process memory objects could be created
depending on the way remote memory can be created. Even different local
memory objects that access memory without doing any checks.

It also allows MemoryRange objects to share one single process memory object
and could help if the process memory object caches data.

Small changes to MapInfo::CreateMemory to when some errors are detected.
- Always check if the map is a device map, instead of only if the name
  is not empty.
- Check if a memory map is readable before creating the memory from process
  memory.

Bug: 23762183

Test: Ran unit tests, unwound on device using the new code.
Change-Id: I12a93c2dc19639689a528ec41c67bfac74d431b3
2017-09-05 14:30:22 -07:00
Christopher Ferris 3f805ac3f8 Add proper support for embedded elf files.
- Add a method to get the max size of an elf file by reading the
  section header offset + size. This will properly map an elf
  file embedded into an apk, instead of just mapping in what is done
  by the dynamic linker. It does assume that the section headers are
  at the end of the elf file.
- Add new tests for the above functionality.
- Update the unwind_symbols tool to take an address for finding a
  function instead of dumping the entire symbol table.

Bug: 23762183

Test: Unit tests pass, unwind through the camera process and verify
Test: the GoogleCamera.apk shows some function names.
Change-Id: I00c021680fe1d43b60d652bf91bbf6667d9617be
2017-08-30 15:50:11 -07:00
Christopher Ferris 6f3981c181 Add support for the new unwind method.
Also add a comment to the GetElf function to indicate that it never returns
nullptr.

Also needed to add this library to the a million and one places that the vndk
has hard-coded this data.

Bug: 23762183

Test: Built, nothing uses the new code.
Test: However, I did run backtrace_test using this code, and all tests pass.
Change-Id: Ib270665dcb7a7607075e36d88be76dbde6e2faa8
(cherry picked from commit dc4104b720)
2017-08-03 10:15:44 -07:00
Christopher Ferris bd625efbca Revert "Add support for the new unwind method."
This reverts commit 5b460d13a4.

Reason for revert: Strange sailfish boot problem.

Change-Id: Ibde9375405cca4343c262335647dac120aab4d73
2017-08-02 01:47:31 +00:00
Christopher Ferris 5b460d13a4 Add support for the new unwind method.
Also add a comment to the GetElf function to indicate that it never returns
nullptr.

Bug: 23762183

Test: Built, nothing uses the new code.
Test: However, I did run backtrace_test using this code, and all tests pass.

Change-Id: I252b9c2497e2d3d94347dd6e506170bf50cbfe16
2017-07-31 13:00:35 -07:00
Christopher Ferris d226a51409 Make the library usable as a library.
- Add namespace unwindstack everywhere so that it's easier for other
  code to use the library.
- Move some of the header files into include/unwindstack so that they
  can be exposed.
- Modify the headers so that only a limited number need to be exposed.
- Update the tools to use the new headers.
- Add a GetLoadBias() call on the Elf object. This prevents the need
  to get the interface object out of the Elf object.
- Move the GetRelPc() call out of the Reg class, to the Elf class. It's
  not always the case that a Reg object will be around when you want to
  get a relative pc. The tests for this moved to ElfTest.cpp.

Bug: 23762183

Test: Unit tests pass.
Change-Id: Iac609dac1dd90ed83d1a1e24ff2579c96c023bc3
2017-07-14 12:20:23 -07:00