It's possible that a device map has memory controlled by a single entry
device driver. Thus, you can deadlock if a process is touching that
device memory and we try to unwind it and also touch that device memory.
Simply skip any attempts to step through, or get function names from
device memory maps.
Bug: 36130325
Test: Ran new unit tests, ran bionic unit tests, ran art ThreadStress.
Change-Id: Ibc62d7ec8106c619ee08968f05e04aea55d7cbfa
Some extra initialization needs to occur before calling the local/remote
GetFunctioneName.
Also, cleanup the test code a bit:
- Make all local functions static.
- Create a common function to create and finish remote processes.
- Remove unused function.
- Fix the formatting a bit by making it match clang format.
Test: Ran the unit tests.
Change-Id: I998bed1378d582df59fdf9263df6f208db5d795a
Remove the logging of an error if a thread disappears before the unwind
can begin. This can happen, so allow the caller to determine if this
is really a problem worth logging.
Bug: 27449879
(cherry picked from commit 206a3b9798)
Change-Id: If9e7cfeb6eb7b122679a734c1a9eacee8354ef18
Under some conditions, /proc/<pid>/maps might return nothing. If we
try and unwind in this case, we'll crash. Check this case and fail
the unwind.
Add checks that no other functions try and use map_ without
checking for nullptr.
Add logging when an unwind fails so it's clear what happened.
Bug: 21162746
Change-Id: I56ce51dda0cfc9db20475a441f118108196aa07c
The object hierarchy was confusing and convoluted. This removes
a lot of unnecessary code, and consolidates the BacktraceCurrent
and BacktraceThread code into BacktraceCurrent.
Change-Id: I01c8407d493712a48169df49dd3ff46db4a7c3ae
The backtrace structure used to include a pointer to a backtrace_map_t
that represented the map data for a particular pc. This introduced a
race condition where the pointer could be discarded, but the backtrace
structure still contained a pointer to garbage memory. Now all of the map
information is right in the structure.
Bug: 19028453
Change-Id: If7088a73f3c6bf1f3bc8cdd2bb4b62e7cab831c0
This new version doesn't require any specialized thread
implementation, it uses the Current implementation to do its job.
In addition, it runs much faster when multiple threads are trying
to unwind at the same time since the global signal lock is held for
only a small amount of time. Even running through the threads one at
a time should be faster since it no longer requires two passes through
the unwound stacks.
The new code now allows multiple simultaneous unwinds of the
same thread.
Finally, add the ability to unwind from a ucontext_t passed in. This
functionality doesn't work for remote unwinds yet.
Change-Id: I4d181d7ca5ffd2acfd1686e668e6d21e36b425cb
The way libunwind handles local unwinds is different from remote unwinds,
so create a new map object to handle the differences.
Add new test to verify the map data is being generated correctly.
Add new tests to check for leaks.
Refactor the BACK_LOGW code into a single header file.
Change-Id: I01f3cbfc4b927646174ea1b614fa25d23b9b3427
Update to handle the new optimized way that libunwind works.
In addition, a small refactor of the BacktraceMap code.
A few new tests of for good measure.
Change-Id: I2f9b4f5ad5a0dfe907b31febee76e4b9b94fb76f
This includes removing the map_info.c source and replacing it with the
BacktraceMap class to handle all map related code.
Change all callers of libbacktrace map functionality.
Also modify the corkscrew thread code so that it doesn't need to build
the map twice (once in the corkscrew format and once in the libbacktrace
format).
Change-Id: I32865a39f83a3dd6f958fc03c2759ba47d12382e
Use the libbacktrace C++ interface instead of the C interface in debuggerd.
Reformat the debuggerd code to be closer to Google C++ style.
Fix all debuggerd casts to be C++ casts.
Add a frame number to the frame data structure for ease of formatting and
add another FormatFrameData function.
Change the format_test to use the new FormatFrameData function.
Modify all of the backtrace_test to use the C++ interface.
Change-Id: I10e1610861acf7f4a3ad53276b74971cfbfda464
Allow the use of the same map info to be shared when getting information on
multiple threads from the same pid.
Change-Id: I2e460e20154a10f4894ae563331fb32179e4551f
Included in minor fix ups is the addition of a warning macro to replace
all of the ALOGW calls.
Fix a race where multiple threads could be attempting to unwind the threads
of the current process at the same time.
Bug: 8410085
Change-Id: I02a65dc778dde690e5f95fc8ff069a32d0832fd1
The old code was essentially trying to be C++ in C and was awkward. This
change makes it all objects with a thin layer that C code can use.
There is a C++ backtrace object that is not very useful, this code will
replace it.
This change also includes moving the backtrace test to a gtest, and adding
coverage of all major functionality.
Bug: 8410085
Change-Id: Iae0f1b09b3dd60395f71ed66010c1ea5cdd37841
