Rather than use a std::vector for backing memory, allocate the memory
using a new with nothrow, and in MemoryBuffer use realloc. Since
the size field is coming from the elf, it could be corrupted or
intentionally crafted to cause problems.
In addition, add some other protections to make sure that overflows
don't occur.
Bug: 146215949
Test: Ran unit tests with jemalloc and scudo to verify that they
Test: both behave the same way.
Change-Id: If14243ce382ba5403a6bacd0ec673452c6b7c3be
The bias for the PT_GNU_EH_FRAME was using the paddr instead of vaddr.
This doesn't match the way the load bias is calculated, which always
use vaddr - offset, so change to use vaddr.
Found on an old x86 device that has a vdso that sets vaddr differently
from paddr.
Add a new offline test to catch this case and update the elf interface
unit tests.
Also, fix a small bug in the unwind_for_offline tool.
Bug: 142365899
Test: Unit tests pass.
Change-Id: I5f0bf062dd8ee45aa8553189ba493ec962e0b059
The original code assumed that the load bias in the program headers
would be exactly the same as in eh_frame/eh_frame_hdr/debug_frame.
This isn't guaranteed, so add a section bias for use when creating
a DwarfSection. In addtion, make the load bias and section bias
a signed value. There is no reason that this value needs to be positive,
so don't force it to be.
Add a new offline test that has a different load bias in eh_frame than
in the executable load.
Add additional unit tests to verify the load bias values are set properly.
Clean up the tests in ElfInterfaceTest, making all tests names follow the
same convention.
Bug: 141888859
Bug: 142094469
Test: New units and old unit tests pass on host and taimen.
Change-Id: Ib878123ab5545f0f315c749cfe0d27b012d873ee
The load bias value set in ReadProgramHeaders is out of sync with the
algorithm used in the static GetLoadBias function.
Sync the two and add tests to verify that they stay in sync.
Test: Unit tests pass.
Change-Id: I20ac0104970a22a92a5314a41dcadad0c9c22e64
Update unit tests and add new build id displaying in offline unwinds.
Bug: 129873279
Test: All unit tests pass.
Test: Verify that debuggerd displays build id properly.
Change-Id: I97f4a204842447a20c812f535a458155b937d5e1
Changes:
- Change GetSoname to always returns a std::string.
- Added new unit tests for the soname printing.
- Modify the GetElf() function to save the same elf when we see rosegment
linkers that split the read-only and read-write across a map. This
avoids creating multiple elf objects for each map.
- Fixed a few offline unwind tests.
Bug: 29218999
Test: Unit tests pass.
Change-Id: Iad7c38b5c2957a8c5fd4ba94ebec335bafcad57d
Change the GetBuildID function to return a std::string.
Added benchmark to check how long it takes to get the build id from
a file versus an elf object.
Added a way to get an elf without passing in a valid process_memory and
added tests for this.
Test: New unit tests.
Change-Id: I3029019767e0181c758d611fe635bc1bf72d6e8e
This will be used by heapprofd to allow us to correlate build ids with
memory leaks in libraries and binaries.
Test: m
Test: host libunwindstack_test
Test: run unwind_info against my phone's libc.so (32/64) and compare
to readelf Build ID output.
Bug: 120186412
Change-Id: I3cefd6cce9a8733509bf35b7175eb0f967783477
Here is the allowable issues with an elf file that will not result in an error:
- The program headers/section headers offset points to unreadable memory.
- Allow missing program header and/or section headers.
- Allow a symbol table section header to point to invalid symbol table values.
There is no real reason to require the elf file be perfect. Everything in
the code has sane defaults, so any missing information won't cause any
problems.
This gets rid of the warning that occurs any time an elf is loaded
from memory. In memory elf files never contain all of the section headers,
and do not contain the symbol table data.
Update tests to test these new cases.
Test: Builds and unit tests all pass.
Change-Id: Iaefe2cd6b6c965a01ed425a112d6afae339f3b78
Modify the code for the no header sections because it turns out that
it is not okay to assume that the fdes are non-overlapping. It's necessary
to read the fdes in order and match as you go.
Modify the code so that it only reads until it finds the given pc rather than
reading all of the cie/fde entries at once.
Rewrote the tests to verify the new behavior.
Bug: 68998033
Bug: 110235461
Test: Ran libbacktrace/libunwindstack unit tests.
Test: Unwind the mediaserver process on a walleye and verify it
Test: unwinds properly.
Change-Id: I7bb59d1db72c13fa34caa9735ec34c1a60e20ed2
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
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
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
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
- 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
- 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
Add the code to parse the Elf section headers.
Add the plumbing through of all the symbol handling code.
Add tests for all of this new functionality.
Bug: 23762183
Test: Pass new unit tests.
Change-Id: Ie2d90cbb3d7653c53251dbcf34d9e5d241278377
This cl includes the code to read arm unwind information from a shared
library.
Bug: 23762183
Test: Passes all unit tests. I can dump the arm unwind information
Test: for an arm shared library.
Change-Id: I43501ea2eab843b81de8bd5128401dd1971af8d3
Christopher Ferris