Before, I was using p_vaddr to get the offset into the elf file where
the exidx frame starts. I changed that to use p_offset since this already
has the load bias offset in it and some elf files do not set p_vaddr
properly.
Also, use p_filesz instead of p_memsz, since again, some elf files do
not set p_memsz to the same as p_filesz.
Bug: 110704153
Test: All libbacktrace/libunwindstack unit tests pass.
Test: Randomly unwind process on a walleye.
Test: Verified that this properly dumps and unwinds the shared
Test: library that sets p_vaddr and p_memsz differently.
Change-Id: Ic7b1e5d07439f4636fa02cd884a8727a5737372b
It turns out that for the dwarf information, if a FDE indicates it's pc
relative, then pc has to be incremented by the load bias. If not, then
it should not be incremented.
Previously, the code always subtracted load bias values from pcs, and assumed
that all fdes were incremented by load bias values. The new code actually
reads the fdes and adjusted the pcs in the fde and in the eh frame hdr so
that load bias values are already handled properly.
In addition, add dumping of arm exidx values in unwind_reg_info. This allowed
verifying that the debug frame in those elf files was being handled properly.
Added a new unit test that only has a debug frame that has a non-zero load
bias and has fde entries that do not have pc relative encoding.
Fix a couple of other small bugs.
Bug: 109824792
Test: All libbacktrace/libunwindstack unit tests pass.
Test: Ran ART 137-cfi test and 004-ThreadStress.
Test: Verify that displaying the fde start and end pc actually match the
Test: real data for fde that have pc relative set, and that don't.
Test: Verified that the unwind information for arm exidx matches the
Test: debug frame data.
Change-Id: I707555286b5cb05df9f25489e8c5ede753cfe0fb
This object is for doing many local unwinds across different threads
at any point during a program's execution.
Also add LocalUpdatableMaps that will re-read the maps data under certain
circumstances.
This first version does not support jit or dex pc data.
Bug: 74361929
Test: Ran unit tests.
Change-Id: I790662366d3fed677f31b3288182950c494de9ad
The new lld linker uses all non-zero offset executable maps. There was
a bug when trying to find if the stack is in a signal handler that caused
the code to read the wrong place in the elf. Fixed by not adding the elf
offset to the relative pc.
Also fixed the unwind_for_offline tool to dump multiple stacks if necessary.
Added new offline unit test that would have failed with the old code.
Bug: 79936827
Test: Ran unit tests and libbacktrace unit tests.
Test: Dumped backtraces of system pids.
Test: Ran 137-cfi art test.
Change-Id: Iaca8c18c2a314902e64c3f72831234297e8dcb1b
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
Use this for offline stack data so that it's not necessary to
copy any data around.
Add unit tests for the new object.
Bug: 77258731
Bug: 74354410
Test: Ran libunwindstack/libbacktrace unit tests.
Change-Id: I9b0f25d9520c96e64aedef5f295423c60ddb3488
Decoding the DWARF opcodes is expensive so make sure we cache it.
This speeds unwinding in simpleperf by over a factor of 3x.
Add unit tests for this new behavior.
Bug: 77258731
Test: libbacktrace/libunwindstack unit tests on host and target.
Test: Ran debuggerd -b on various processes on target.
Change-Id: Ia516c0fa5d3e5f76746190bb4b6fdf49fd1c9388
Changes:
- Add a new flag to the libbacktrace and libunwindstack map data.
- Modify the unwinder to handle this map to use the raw pc when stepping.
- Add new unit tests for this case.
Bug: http://b/73127105
Test: Run simpleperf to unwind through jit symfiles.
Test: Run new unit tests.
Test: Run 137-cfi test on host.
Change-Id: I10bc0410680accc6d35fe51e9f1098911f667e01
There are a few places where it is assumed that this register is
set to the cfa value when interpreting DWARF information.
Add a testcase for unwinding art_quick_osr_stub on ARM.
Bug: 73954823
Test: Ran libunwindstack/libbacktrace unit tests.
Test: Random debuggerd -b of process on a hikey.
Test: Ran the 137 art test on host.
Change-Id: Ida6ccdc38c3cfeea6b57fe861a0cc127b150b790
This cleans up a bit of the Unwinder code to make it clear what's
going on.
Modify the offline unit tests to verify the pc and sp to make sure
that those values get computed correctly.
Test: Passes unit tests.
Test: Passes 137-cfi art tests.
Change-Id: I0787a1d77b8726d3defd08f31c7476f6798f8d0d
The dynamic section contained an address, not an offset into the elf
file to indicate where the soname exists. Changed to use the strtab
entries in the section headers to map this address to the actual offset.
Refactor the soname test a bit to make it easier to verify the code.
Bug: 73499044
Test: Passes new unit tests.
Test: Ran unwind_info on the failing shared elf and verified the soinfo
Test: is correct.
Change-Id: I16ba148389bcb9aadd3566fb442dac27f89fe894
GDB wasn't handling the old one gracefully.
- Create a RegsInfo structure that can be used to properly eval expression
data.
- Remove the versions on Dwarf ops. It doesn't work the in the real world
and doesn't add useful information.
- Fix dex pc frame number bug.
Test: testrunner.py -j40 --host --cdex-fast -t 137
Test: libunwindstack_test
Test: All unit tests pass.
Change-Id: Iac4fea651b81cb6087fd237a9a5027a352a49245
Add new unit tests for dex pc being non-zero.
Bug: 73004673
Test: Ran unit tests.
Test: Ran art 137-cfi test on host for interpreter.
Change-Id: I09bbf96d0ed65fc1e5896e4ab2bc67867e3b7fdb
Fixes cdex which was recently changed to have shared data section,
which means the DEX PC cannot be used to find the right symbol,
as the bytecode is no longer within the dex file, and in-fact,
we might have to scan multiple dex files to find the method.
Bug: 72520014
Test: testrunner.py --host --cdex-none -t 137
Test: testrunner.py --host --cdex-fast -t 137
Test: All unit tests pass.
Change-Id: I80265d05ad69dd9cefbe3f8a75e4cd349002af5e
Fixes the ART 137-cfi test, currently failing on buildbot.
Test: testrunner.py -j40 --host --cdex-none -t 137 -b
Change-Id: I16a007b291702207bbd003fd1e78e8e5ced7cd68
Test: Compiles, all unit tests pass.
Test: Ran 137-cfi art test in interpreter and verified interpreter
Test: frames still show up.
Change-Id: Icea90194986faa733a873e8cf467fc2513eb5573
The backtrace offline code uses these error codes to diagnose errors.
In addtion, I've had cases where seeing these errors would help diagnose
failures.
This also allows us to add a few features to indicate why an unwind
terminated (such as max frames exceeded).
Bug: 65682279
Test: Updated unit tests pass.
Change-Id: If82b5092698e8a194016d670efff1320f9b44d50
Changes:
- Change the register type from int16_t to uint32_t for the location data
and the Eval processing. This is because the special dex pc is > 65535.
- Add the ability for Dwarf register location information to point to a
register that is itself a Dwarf location register.
- Add dex_pc to the frame information.
- Modify the unwind tool to print the dex pc if non-zero.
This does not implement the printing of the dex information in anything
but the unwind tool. It's not the final form of this printing.
Bug: 72070049
Test: Ran new unit tests.
Test: Dumped stack while in interpreter running 137-cfi art test and
Test: verified dex pc is set to non-zero.
Change-Id: I6ce8a6b577fb4f92abacbd433b1f68977e272542
Changes:
- New JitDebug class to handle all of the jit gdb interface.
- Add unit tests for all, along with new offline test using debug data.
- Add new Memory type called MemoryOfflineParts that has multiple
MemoryOffline objects to support the offline test.
- Update the tools to use the JitDebug object.
- Modify libbacktrace to use the JitDebug, but only looking in libart.so
and libartd.so.
- Change the Format32Bits to Is32Bit since it's more accurate and I use
it in a different context where original name didn't make sense.
- Add a new function to find global variables in an elf file
(GetGlobalVariable).
- Add a new function to determine if a pc is valid for this elf (IsValidPc).
Bug: 68396769
Test: Ran new unit tests. Added new offline test that uses jit debug data.
Test: Ran art test that generates jit data and verified a crash unwinds
Test: through the jit data.
Change-Id: I6e7ee2f5bab2242028a06feece156dff21c0a974
- 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
This patch requires v3.18 kernel or above, because v3.10 kernel
has a bug (as of 8/1/2017) in the ptrace(GETREGSET) function for mips
and mips64.
Change-Id: I004c1fa190193eebe1c84440b366289122a6bd8a
Signed-off-by: Douglas Leung <douglas.leung@mips.com>
Signed-off-by: Dejan Jovicevic <dejan.jovicevic@mips.com>
Use a generic check if the address is 32 bits when using the default
formating of a backtrace line instead of an arch check.
Test: New unit tests pass.
Change-Id: Id609abc037d7b437a02d52763aa91fbefe5f4d5b
The process_vm_read function is much faster than ptrace, but sometimes
that will not work on a remote process. Modify the libunwindstack
MemoryRemote object to figure out which one it can use.
Wrote new unit test to verify this checking behavior.
Modify libbacktrace so that the read from libunwind is used instead of
using the default ptrace calls.
Add some benchmarks to libbacktrace to compare the two different methods.
Test: Ran unit tests libbacktrace/libunwindstack/debuggerd.
Test: Ran debuggerd -b <SYSTEM_SERVER_PID>
Test: Ran debuggerd -b <MEDIACODEC PID>
Test: Ran debuggerd -b <RANDOM_PID>
Test: Used crasher to create tombstones and verified stack data is
Test: dumped properly.
Change-Id: If75ca238289532dd8e1de430d569cabb2523380a
Add an ArchEnum to express the arch of the Elf objects and Reg objects.
Split out the regs code into per arch pieces and generic parts.
Also, split out the header files for each arch.
Do not break out the test code yet, there isn't enough and it doesn't
help to maintain the tests.
Test: libunwindstack/libbacktrace/debuggerd unit tests pass.
Test: Running debuggerd -b <PIDS> yields valid data on bullhead.
Change-Id: If61f6c730c9ff2249f986b41de8c4d62f7158325
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
When stepping, it's necessary to use both the unaltered relative pc
and the adjusted relative pc. If the adjusted pc is not used, the
wrong unwind information can be used.
Added new offline unit tests that take real data and verifies that it
unwinds properly.
Fix a bug in the map code that would not properly parse map data for
a 64 bit process when done in a 32 bit process.
Fix bug in eh_frame processing that didn't adjust the pc correctly.
Fix unit tests related to the pc adjustment.
Bug: 69475565
Test: Passes libbacktrace/libunwindstack unit tests.
Test: Run debuggerd -b on processes on a hikey.
Change-Id: Ic501a1c4549c5f61d2742a7105c42a960f2c892b
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
Rename Memory::Read to ReadFully to match its semantics with that of
android::base. ReadPartially will be renamed to Read in a follow up
commit, kept intentionally separate so that there aren't any callers
accidentally switched from ReadFully to Read.
Test: treehugger
Change-Id: I7d845ac5244c3025d92c8512e960e5d0d1da05af
Add a way to read while allowing for partial reads.
Test: new tests added to libunwindstack_test, ran 32/64 on hikey960, sailfish
Test: ran unwind on hikey960/sailfish
Change-Id: I8b11d9230fcd3122148ef3f980863ac1404ad70a
Static executables only have a .eh_frame section and no .eh_frame_hdr
section. Add support for this by rearranging the class hierarchy and
creating a DwarfEhFrameWithHdr class and a DwarfEhFrame class to handle
the different cases.
Add new unit tests for DwarfEhFrame and for the new functionality.
Bug: 68820189
Test: Passes new unit tests, unwinds static executables.
Change-Id: I63d7cb8c52a686e96579a2266e18c0d06bbb6e63
Also, change the std::set parameters to std::vector. As jmgao points out,
a small std::set is not really the best choice for performance reasons.
Test: All unit tests pass, enabled the new unwinder and did a kill -3 on
Test: an android process.
Change-Id: I81227d7b79a9b7cf1d54fb0e3331d3cf4d4d3c4f
Add a function to iterate over Regs with a human-friendly name and the
value of the register, to make it easy to string-format registers.
Test: mma
Change-Id: I8f33830fa79b245b5030b7bc9bc3c1c7ced80c75
- Move the load bias stored out of ElfInterface into Elf. For the compressed
sections, the load bias was not the same as the data from the uncompressed
section.
- Move the initialization of the compressed section into Init. It was too easy
to forget to call the init of the compressed section.
- Do not automatically add in load bias to the pc before calling ElfInterface
code. Do all of the pc manipulations in the Elf object.
- Change the interface GetFunctionName code to pass in the load_bias instead
of modifying the pc inside the code.
- Modify the Step function to pass in the elf offset, not add it to the pc.
It is necessary to have two different relative values when executing the
Step: a pc that is relative to the beginning of the elf for the reading data
the actual instructions when trying to determine if this is in a signal
frame, and a pc that is relative to the map for finding the appropriate
unwind information.
- Add a feature to Unwinder so that an unwind can be stopped if it ends up
in map that has a specified suffix. This is so that the ART unwinding
code doesn't require skipping the compressed section. Instead, stop at
if trying to unwind through a known suffix code that means the code is
in java code. This is important because the compressed section data is
not only used by the jave compiled code, so that will continue to work.
- Fix tests for restructuring, add new tests for new functionality.
Test: Ran art test 137-cfi using new unwinder as default.
Test: Ran new unit tests.
Change-Id: I42e658c64c5e14f698ba34944a3043afac967884
Changes:
- Remove unused GetReturnAddressFromDefault function and tests.
- Modify the unwinder to stop when a pc/sp in a device map.
- Modify the unwinder to skip initial frames based on map names.
- Unit tests that exercise all of the paths in the unwinder code.
- Move the test Elf/ElfInterface objects into their own file.
- Update RegsFake to handle extra cases.
- Modify libbacktrace code to use this unwinder.
The new unwinder does not implement the ignore frame functionality since
this is not used very often and is better implemented using a skip frames
in named libraries functionality.
Test: Ran new unit tests, ran backtrace tests.
Change-Id: Ifd65e9acd66ac5e2d0e04bd32a9ad870b54610ff
If a function crashes by jumping into unexecutable code, the old method
could not unwind through that. Add a fallback method to set the pc from
the default return address location.
In addition, add a new finished check for steps. This will provide a method
to indicate that this step is the last step. This prevents cases where
the fallback method might be triggered incorrectly.
Update the libbacktrace code to unwind using the new methodology.
Update the unwind tool to use the new unwind methodology.
Add a new option to crasher that calls through a null function.
Create a new object, Unwinder, that encapsulates the a basic unwind. For now,
libbacktrace will still use the custom code.
Added new unit tests to cover the new cases. Also add a test that
crashes calling a nullptr as a function, and then has call frames in
the signal stack.
Bug: 65842173
Test: Pass all unit tests, verify crasher dumps properly.
Change-Id: Ia18430ab107e9f7bdf0e14a9b74710b1280bd7f4
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
- 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
There are no actual users of the machine type output parameter to
Regs::RemoteGet. The concrete implementations of Regs know what machine
type they represent anyway, so provide an accessor to query.
Test: treehugger
Test: libunwindstack tests on 32/64-bit host, hikey960
Change-Id: Ia25910531d36c41b2b6919f154cfa914aae63117
- Rewrite the Maps::Parse to use open, and a buffer on the stack.
- Rewrite the line parser away from sscanf. The current way sscanf
is used does not catch many malformed lines. In addition, this
new version improves performance by 50% over sscanf on sailfish.
- Add a lot of unit tests for the parser to make sure there are
no problems. In addition, add a special line that was not rejected
with the previous version of the code.
- Add new accessor to get the map at a particular index.
- Add a backtrace benchmark for map creation for both new and old.
This cl results in ~5% speedup and makes the new unwinder map creation
about the same for 64 bit. It's still a bit slower, but not by much.
On 32 bit, we are still about 5% slower than the old creation method,
though.
Bug: 23762183
Test: libunwindstack unit tests pass. Ran the new benchmarks.
Change-Id: Id4431e539f400984e6fad62153fdf4152d518322
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)
