Commit Graph

16 Commits

Author SHA1 Message Date
Josh Gao a48b41bcb8 debuggerd: switch to using platform headers for DEBUGGER_SIGNAL.
Test: treehugger
Change-Id: Ie9736c4a077dba1029d2352bd94d47ce07323aec
2019-12-17 16:36:05 -08:00
David Srbecky b9cc4fbb26 Revert "Check for data races when reading JIT/DEX entries."
This reverts commit 85b5fecec9.

Reason for revert: Breaks ART tests, reverting to investigate.

Change-Id: I1bb905407e87cbd4f832646651133a9caf6fcfc8
2019-04-05 18:23:32 +00:00
David Srbecky 85b5fecec9 Check for data races when reading JIT/DEX entries.
Update the entries only when the list is modified by the runtime.

Check that the list wasn't concurrently modified when being read.

Bug: 124287208
Test: libunwindstack_test
Test: art/test.py -b --host -r -t 137-cfi
Change-Id: I87ba70322053a01b3d5be1fdf6310e1dc21bb084
2019-03-29 14:01:32 +00:00
Christopher Ferris 60eb19795b Replace libbacktrace with libunwindstack directly.
Small modifications to the dump_stack method and added unit tests to
verify the output.

Bug: 120606663

Test: Unit tests pass, debuggerd run on processes on target.
Change-Id: Id385a915b751abda3dd6baebed6c3ce498c3bf6e
2019-01-29 17:57:14 -08:00
Josh Gao 08163cb032 debuggerd_fallback: fix fd leak.
Previously, when we received simultaneous dump requests, we were CASing
a file descriptor value into a variable, and then failing to close it
if the CAS failed.

Bug: http://b/118412443
Test: debuggerd_test
Change-Id: I075c35a239426002eb9416da3d268c3d1a18e9d2
2018-10-30 15:33:58 -07:00
Josh Gao 6f9eeecd2b Fix multithreaded backtraces for seccomp processes.
Add threads to the existing seccomp backtrace test to prevent
regressing this.

Bug: http://b/114139908
Bug: http://b/115349586
Test: debuggerd_test32
Test: debuggerd_test64
Change-Id: I07fbe1619b60f0008deb045a249f9045404478c2
2018-09-12 18:12:13 -07:00
Josh Gao d2b15dd674 debuggerd: fix CrasherTest.seccomp_crash_oom.
Switch from _exit to raising SIGABRT when we recurse in the fallback
handler, so that waiters see an abort instead of a regular exit.

Bug: http://b/79717060
Test: debuggerd_test32
Test: debuggerd_test64
Change-Id: Iddee1cb1b759690adf07bbb8cd0fda2faac87571
2018-05-16 00:16:09 -07:00
Josh Gao 70adac6a8a debuggerd_fallback: don't recursively abort.
Calls to abort() will always result in our signal handler being called,
because abort will manually unblock SIGABRT before raising it. This
can lead to deadlock when handling address space exhaustion in the
fallback handler. To fix this, switch our mutex to a recursive mutex,
and manually keep track of our lock count.

Bug: http://b/72929749
Test: debuggerd_test --gtest_filter="CrasherTest.seccomp_crash_oom"
Change-Id: I609f263ce93550350b17757189326b627129d4a7
2018-02-22 16:31:38 -08:00
Josh Gao c531ed6648 debuggerd_fallback: fix race.
A race condition occurs when one thread takes more than a second to get
scheduled to handle the signal we send to ask it to dump its stack.
When this happens, the main thread will continue on, close the fd, and
then ask the next thread to dump, but the slow thread will then wake up
and try to write to the new thread's fd, or trigger an assertion in
__linker_enable_fallback_allocator.

Do a few things to make this less bad:
  - encode both target tid and fd in the shared atomic, so that we know
    who each fd is for
  - switch __linker_enable_fallback_allocator to return success instead
    of aborting, and bail out if it's already in use
  - write to the output fd right when we get to it, instead of doing it
    whenever the dumping code decides to, to reduce the likelihood that
    the timeout expires

Test: debuggerd_test
Change-Id: Ife0f6dae388b601e7f991605f14d7a0274013f6b
2018-02-09 15:35:40 -08:00
Josh Gao 2b2ae0c88e crash_dump: fork a copy of the target's address space.
Reduce the amount of time that a process remains paused by pausing its
threads, fetching their registers, and then performing unwinding on a
copy of its address space. This also works around a kernel change
that's in 4.9 that prevents ptrace from reading memory of processes
that we don't have immediate permissions to ptrace (even if we
previously ptraced them).

Bug: http://b/62112103
Bug: http://b/63989615
Test: treehugger
Change-Id: I7b9cc5dd8f54a354bc61f1bda0d2b7a8a55733c4
2017-12-15 14:11:12 -08:00
Josh Gao c3706668c6 libdebuggerd: cleanup.
Move libdebuggerd headers into their own directory for namespacing,
move some includes to the top of their implementing files, delete some
dead code.

Test: mma, treehugger
Change-Id: Ie4c44e32e2ab3bc678092899d257fd4ed634aa34
2017-08-29 15:18:46 -07:00
Narayan Kamath a73df601b7 tombstoned: allow intercepts for java traces.
All intercept requests and crash dump requests must now specify a
dump_type, which can be one of kDebuggerdNativeBacktrace,
kDebuggerdTombstone or kDebuggerdJavaBacktrace. Each process can have
only one outstanding intercept registered at a time.

There's only one non-trivial change in this changeset; and that is
to crash_dump. We now pass the type of dump via a command line
argument instead of inferring it from the (resent) signal, this allows
us to connect to tombstoned before we wait for the signal as the
protocol requires.

Test: debuggerd_test

Change-Id: I189b215acfecd08ac52ab29117e3465da00e3a37
2017-05-31 10:35:32 +01:00
Narayan Kamath 2d377cd688 tombstoned: Add a shared library version of libtombstoned_client...
.. for ART and the frameworks to link against. In the new stack dumping
scheme (see related bug), the Java runtime will communicate with
tombstoned in order to obtain a FD to which it can write its traces.

Also move things around to separate headers that are private
implementation details from headers that constitute the public debuggerd
API. There are currently only three such headers :

- tombstoned/tombstoned.h
- debuggerd/client.h
- debuggerd/handler.h

Bug: 32064548
Test: make

Change-Id: If1b8578550e373d84828b180bbe585f1088d1aa3
2017-05-22 16:55:21 +01:00
Christopher Ferris ac225780dd Move libc_logging to libasync_safe.
Move the name of the "private/libc_logging.h" header to <async_safe/log.h>.

For use of libc_malloc_debug_backtrace, remove the libc_logging library.
The library now includes the async safe log functions.

Remove the references to libc_logging.cpp in liblog, it isn't needed because
the code is already protected by a check of the __ANDROID__ define.

Test: Compiled and boot bullhead device.
Test: Run debuggerd unit tests.
Test: Run liblog unit tests on target and host.
Test: Run libmemunreachable unit tests (these tests are flaky though).
Change-Id: Ie79d7274febc31f210b610a2c4da958b5304e402
2017-05-02 18:38:46 -07:00
Josh Gao e1aa0ca58a debuggerd_handler: implement missing fallback functionality.
Allow the fallback implementation to dump traces and create tombstones
in seccomped processes.

Bug: http://b/35858739
Test: debuggerd -b `pidof media.codec`; killall -ABRT media.codec
Change-Id: I381b283de39a66d8900f1c320d32497d6f2b4ec4
2017-03-09 11:26:05 -08:00
Josh Gao e73c932373 libdebuggerd_handler: in-process crash dumping for seccomped processes.
Do an in-process unwind for processes that have PR_SET_NO_NEW_PRIVS
enabled.

Bug: http://b/34684590
Test: debuggerd_test, killall -ABRT media.codec
Change-Id: I62562ec2c419d6643970100ab1cc0288982a1eed
2017-02-15 17:03:44 -08:00