In the fallback path, if the non-main thread is the target
to be dumped, then no other threads are dumped when creating
a tombstone. Fix this and add unit tests to verify that
this all threads, including the main thread are dumped.
Bug: 234058038
Test: All unit tests pass.
Test: debuggerd -b media.swcodec process
Test: debuggerd media.swcodec process
Change-Id: Ibb75264f7b3847acdbab939a66902d986c0d0e5c
This is not meant to be enabled long-term, but can be used to assess system
stability with MTE before enabling it.
Bug: 202037138
Change-Id: I9fb9b63ff94da2de0a814fd7150f51559d3af079
This simplifies most of the calls to avoid doing any Android
specific code.
Bug: 120606663
Test: All unit tests pass.
Change-Id: I511e637b9459a1f052a01e501b134e31d65b5fbe
When dumping a tombstone using the fallback path, only the main
thread was showing up. Modify the code to dump the threads using
a slightly different path for the tombstone generation code.
In addition, while looking at this code, two MTE variables were
not set in the tombstone fallback code. Added those variables
so MTE devices will work properly in this fallback path.
Modified the tombstone unit tests for seccomp to have
multiple threads and verify those threads show up in the tombstone.
Bug: 208933016
Test: Ran unit tests.
Test: Ran debuggerd <PID> on a privileged process and verified
Test: all threads dumped. Also verified that the tagged_addr_ctrl
Test: variable is present on the raven device.
Change-Id: I16eadb0cc2c37a7dbc5cac16af9b5051008b5127
When running debuggerd from the command line, it's possible that
the signal will happen on a side thread. The original intercept
in tombstoned is set to only handle crashes from the main thread
pid, so in this case, the intercept doesn't occur. To fix this,
modify the code so that running debuggerd always sends the signal
to the main pid. In addition, modify the signal handler is entered
due to the BIONIC_SIGNAL_DEBUGGER signal, then the crashing tid is
set to the main thread pid instead of the current thread.
Add unit test to cover this case.
Bug: 194346289
Test: All unit tests pass.
Test: Verify the new unit test is getting the signal on the non-main
Test: thread and still properly handling the intercept.
Test: Modify the debuggerd code to send the signal to the non main pid
Test: and verify the dump still occurs correctly.
Change-Id: I2dd1bd11fc8ef4a6fe87f05ecc67ae349a101c82
All but three files are Apache-2.0 already.
Bug: http://b/191499510
Test: /google/src/files/head/depot/google3/wireless/android/busytown/ayeaye/analyzers/copyright/tools/scan_android_project.sh ~/aosp/system/core/debuggerd/ | grep -v APACHE
Change-Id: I430c3382dd160e398f02470d7053ecea39c98f41
The code in the fallback path calls pthread_key_create when using the
normal thread cache. However, this code is executed out of the linker,
which means that the call doesn't see keys created by the libc version
of pthread_key_create. As of now, simply avoid using the thread cache
to avoid this problem.
Bug: 189803009
Test: debuggerd -b on a media process on a 32 bit Android Go device
Test: and observe no crash.
Test: debuggerd unit tests pass.
Change-Id: I9ca1a55e44d3bb69d49450826d7d64d7a64145c3
(cherry picked from commit 49e5a76544)
Talk of "gdb" when we currently mean "gdb or lldb" and will soon mean
"lldb" is starting to confuse people. Let's use the more neutral
"debugger" in places where it really doesn't matter.
The switch from gdbclient.py to lldbclient.py is a change for another
day...
Test: treehugger
Change-Id: If39ca7e1cdf4c8bb9475f1791cdaf201fbea50e0
Revert "Let crash_dump read /proc/$PID."
Revert submission 1556807-tombstone_proto
Reason for revert: b/178455196, Broken test: android.seccomp.cts.SeccompHostJUnit4DeviceTest#testAppZygoteSyscalls on git_master on cf_x86_64_phone-userdebug
Reverted Changes:
Ide6811297:tombstoned: switch from goto to RAII.
I8d285c4b4:tombstoned: make it easier to add more types of ou...
Id0f0fa285:tombstoned: support for protobuf fds.
I6be6082ab:Let crash_dump read /proc/$PID.
Id812ca390:Make protobuf vendor_ramdisk_available.
Ieeece6e6d:libdebuggerd: add protobuf implementation.
Change-Id: Ia0a1ee57e7630e01c495dc166218f665340aad7f
* changes:
libdebuggerd: add protobuf implementation.
tombstoned: support for protobuf fds.
tombstoned: make it easier to add more types of outputs.
tombstoned: switch from goto to RAII.
This commit implements protobuf output for tombstones, along with a
translator that should emit bytewise identical output to the existing
tombstone dumping code, except for ancillary data from GWP-ASan and
Scudo, which haven't been implemented yet.
Test: setprop debug.debuggerd.translate.translate_proto_to_text 1 &&
/data/nativetest64/debuggerd_test/debuggerd_test
Test: for TOMBSTONE in /data/tombstones/tombstone_??; do
pbtombstone $TOMBSTONE.pb | diff $TOMBSTONE -
done
Change-Id: Ieeece6e6d1c26eb608b00ec24e2e725e161c8c92
Sadly, it looks like we do still really use libcutils for some of the
socket functions.
Test: treehugger
Change-Id: Ic71f97507c89b10d2f3b7a2971064a9e6b1d349d
The discussion on LKML is converging on v16 of the fault address tag
bits patch [1]. In this version of the patch the presence of the tag
bits in si_addr is controlled by a sa_flags bit, and a protocol is
introduced to allow userspace to detect kernel support for sa_flags
bits. Update the tombstone signal handler to use this API to read
the tag bits, update the interceptors in libsigchain to implement
the flag support detection protocol and hide the tag bits in si_addr
from chained signal handlers that did not request them to match the
kernel behavior.
[1] https://lore.kernel.org/linux-arm-kernel/cover.1605235762.git.pcc@google.com/
Change-Id: I57f24c07c01ceb3e5b81cfc15edf559ef7dfc740
This simplifies some of the logic and removes the need to pass an
Arch value to functions that should already know about the arch
it is operating on.
Includes fixes for debuggerd/libbacktrace.
Added new unit tests to cover new cases.
Test: All unit tests pass.
Test: Faked unwinder failing to verify debuggerd error messages display
Test: properly in backtrace and tombstone.
Change-Id: I439fcae0695befcfb1cb4c0a786cc74949d33425
If crash_dump dies before it gets a chance to write to the pipe we use
to let the debugged-process know that it successfully started, we
weren't cleaning up the child we fork to start it, leaving a zombie
child.
Bug: http://b/152119184
Test: debuggerd_test
Change-Id: Id01cc05f693995e9998941774f74ab8e3d8b4d8a
On aarch64, the top 8 bits of the address (i.e. the tag bits) of
the fault address in si_addr are always clear. This isn't ideal for
MTE which will require these bits in order to correctly diagnose
tag mismatches.
A proposed kernel patch [1] exposes the full fault address including
the tag bits as part of the ucontext. Change debuggerd to read this
fault address if available.
[1] https://patchwork.kernel.org/patch/11435077/
Bug: 135772972
Change-Id: Ia05be574113860f4e9ecc36a310c4b740e0c4afb
Similar to r.android.com/1247247 I'll be adding more of them for MTE.
Also, change the protocol between the crasher and crash_dump to make
it easier to add new fields and change the referenced data structures
without needing to worry about versioning. The version number for
static executables is now always 1 (where the protocol will never
change), while the version number for dynamic executables is always
4 (where the protocol can change, because the linker and crash_dump
are version locked).
Bug: 135772972
Change-Id: Ib4696d0544d7c87cb429aaaa15f18c3640059e16
A future change will introduce a version lock between linker and
crash_dump. Move crash_dump into the runtime APEX alongside linker in order to
ensure that they will be the same version even if the runtime APEX is updated.
Bug: 135772972
Change-Id: Ic2eae31b6927eb0e8a62315ac141f50933c00bcc
Merged-In: Ic2eae31b6927eb0e8a62315ac141f50933c00bcc
GWP-ASan can provide information about a crash that it caused. Grab the
GWP-ASan regions from the globals shared by the linker for crash-handler
purpopses, pull the information from GWP-ASan, and display it.
This adds two regions:
1. Causality tracking by GWP-ASan. We now print a cause header about
the crash, like `Cause: [GWP-ASan]: Use After Free on a 1-byte
allocation at 0x7365bb3ff8`
2. Allocation and deallocation stack traces.
Bug: 135634846
Test: atest debuggerd_test
Change-Id: Id28d5400c9a9a053fcde83a4788f971e677d4643
1 page isn't enough to log on AArch64, and clean pages are free, so
increase the stack size to 8 pages.
Bug: http://b/144887737
Test: treehugger
Change-Id: I731b3bc27ab37f4b830a9478a04cd34d4f7648d3
C++20 wants members to be ordered unlike C99.
Bug: 139945549
Test: mm
Change-Id: I3cbca589511c1e0bbc10c691949e18de77e16031
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
There appears to be a kernel bug that causes SIGHUP and SIGCONT to be
sent to the parent process group we spawn from if the process group
contains stopped jobs (e.g. the parent itself, because of wait_for_gdb).
Call setsid in all of our children to prevent this from happening.
Bug: http://b/31124563
Test: adb shell 'setprop debug.debuggerd.wait_for_gdb 1; killall -ABRT surfaceflinger'
Change-Id: I1a48d70886880a5bfbe2deb80d48deece55faf09
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
If a process is ptraced already, we might not be able to exec crash_dump
due to selinux. Since we can be called for non-fatal events, we
shouldn't abort in that case.
Bug: http://b/128054996
Test: treehugger
Change-Id: I1442041caa7af908df2ab87b9e010c44082e7587
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
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
Make it possible for code such as fdsan that generates debugging
tombstones via raise(DEBUGGER_SIGNAL) to pass an abort message as well.
Bug: http://b/112770187
Test: debuggerd_test
Change-Id: Idc34263241c18033573e466da3a45aa6f716ddb3
Pass the address of the fdsan table down to crash_dump so that we can
dump the fdsan table along with the open file descriptor list.
Test: debuggerd_test
Test: manually ran an old static_crasher
Change-Id: Icbac5487109f2db1e1061c4d46de11b016b299e3
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
Suicide doesn't change:
signal 6 (SIGABRT), code -6 (SI_TKILL), fault addr --------
But homicide now looks like this (this is `sleep 666` killed by
`kill -SEGV` as root:
signal 11 (SIGSEGV), code 0 (SI_USER from pid 4446, uid 0), fault addr --------
Bug: http://b/78594105
Test: manual
Change-Id: I8c2feafba8cc5a3db85e8250004d428a464c5d9e
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
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
Set and restore PR_SET_PTRACER when performing a dump, so that when
Android is running on a kernel that has the Yama LSM enabled (and the
value of ptrace_scope is > 0), crash_dump can attach to processes and
print nice, symbolized stack traces.
Bug: 70992745
Test: kill -6 `pidof surfaceflinger` && logcat -d -b crash
# in both sailfish and Chrome OS
Change-Id: If4646442c6000fdcc69cf4ab95fdc71ae74baaaf
When a process crashes, both ActivityManager and init will try to kill
its process group when they notice. The recent change to minimize the
amount of time a process is paused results in crash dumps being killed
before they finish as a result of this. Since anything that needs to be
low-latency is probably not going to be too happy if it crashes, just
wait for completion whenever we're processing a real crash.
Bug: http://b/70343110
Test: debuggerd_test
Change-Id: I894bb06efd264b1ba005df06f7326a72f4b767bb
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
Always check to see if the fallback handler has been called and is
not trying to dump a specific thread.
Bug: 69110957
Test: Verified on a system where the prctl value changes, that before the
Test: change it dumps multiple tombstones, and after the change it
Test: works as expected.
Test: Ran debuggerd unit tests.
Test: Dumped process using debuggerd -b <PID> and debuggerd <PID>.
Change-Id: Id98bbe96cced9335f7c3e17088bb4ab2ad2e7a64
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
