Extends the recoverable native crash handling support to also allow for
MTE crashes to be recovered from in apps. Backs onto the existing
GWP-ASan recoverable handling.
At least for system/core, I've renamed the (now) generic "recoverable
crash" variables to remove the notion of GWP-ASan.
Permissive MTE should no longer crash an app, and crashes are still
visible in the AppExitInfo API and tombstones.
Test: atest CtsTaggingHostTestCases
Bug: 328793166
Change-Id: I4c6ffa85af0e0d9b72d0ccd606bb6e1ca464cfff
This is a no-op but will be used in upcoming scudo changes that allow to
change the depot size at process startup time, and as such we will no
longer be able to call __scudo_get_stack_depot_size in debuggerd.
We already did the equivalent change for the ring buffer size in
https://r.android.com/q/topic:%22scudo_ring_buffer_size%22
Bug: 309446692
Change-Id: I761a7602c54a1f8f2d0575c5e011820d8dbaab63
Commit aosp/1259140 moved fdsan_table into debugger_process_info, which
is populated conditionally. This introduced a bug where the process that
receives BIONIC_SIGNAL_DEBUGGER (35) does not propagate the fdsan_table
pointer to crash_dump:
$ adb shell kill -SIG35 <pid>
$ adb logcat -s DEBUG
E DEBUG : failed to read fdsan table entry 0: I/O error
Fdsan in warn-only mode uses BIONIC_SIGNAL_DEBUGGER[1], so the generated
tombstones don't have any fd ownership info.
Fix it by calling get_process_info() irrespective of the signal being
handled, taking care to preserve the previous behavior of not showing
abort messages set by applications in non-fatal dumps.
Test: debuggerd_test
Test: send SIG35 to arbitrary process and inspect the log and tombstone
Test: crasher fdsan_file
[1] 20ad9129e7/libc/bionic/fdsan.cpp (166)
Change-Id: I76931ca4825e846fc99f26fa590c045130abb850
When using the bootstrap linker, the get_gwp_asan_callbacks is
not set. Therefore, check it is not nullptr before calling it
during crash processing.
Bug: 284098779
Test: Ran crasher64 using /system/bin/bootstrap/linker64 and verify
Test: debuggerd code does not crash.
Test: All unit tests pass.
Change-Id: Ifc710fe4bef24661700444a1b69432bfc29d580f
Currently, debuggerd tells the teacher that an app that received a fatal
signal. On the playground, dobbing on a process that doesn't actually
need to be killed is considered a friendship-ending move.
Because recoverable GWP-ASan is *supposed* to not crash your app,
suppress this behaviour and don't let ActivityManager know about the
crash.
Bug: N/A
Test: Run a use-after-free in an app that's using recoverable GWP-ASan,
through the 'libc.debug.gwp_asan.recoverable.<app_name>=1' and
'libc.debug.gwp_asan.process_sampling.<app_name>=1' sysprops.
Change-Id: I033ea67d577573df10936e37db7302d4f4bc0069
Recoverable GWP-ASan is a mode landed upstream in
https://reviews.llvm.org/D140173. For more information about why/what it
is, see
https://android-review.git.corp.google.com/c/platform/bionic/+/2394588.
This patch makes debuggerd call the required libc callbacks for GWP-ASan
to recover from the memory corruption. It also adds the functionality
that libart/sigchain eventually ends up calling, which dumps a GWP-ASan
report for the first error encountered.
Test: Build the platform, run sanitizer-status in recoverable mode,
asserting that it doesn't crash but we get a debuggerd report.
Bug: 247012630
Change-Id: I27212f7250844c20a8fd1e961417cdb4e5bd3626
This is a no-op but will be used in upcoming scudo changes that allow to
change the buffer size at process startup time, and as such we will no
longer be able to call __scudo_get_ring_buffer_size in debuggerd.
Bug: 263287052
Change-Id: I350421d1fcdf22ce3b8b73780b88c1e10fa8a074
The current logging...
```
F libc : Fatal signal 31 (SIGSYS), code 1 (SYS_SECCOMP) in tid 6640 (logcat), pid 6640 (logcat)
```
...isn't super useful if crash_dump then fails, because you have no idea
what syscall caused the problem.
We already include the fault address in this line for relevant cases,
so include the syscall number in this case.
Bug: http://b/262391724
Test: treehugger
Change-Id: I45ad7d99c9904bab32b65efeb19be232e59ab3a4
This uses an std::string, which causes a heap allocation, which is not
async-safe.
Test: atest --no-bazel-mode permissive_mte_test
Change-Id: I4bd53d42d9a6a659abe62a964f14c81d9ec059d0
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
