Commit Graph

31 Commits

Author SHA1 Message Date
Elliott Hughes 2baf443a21 Improve SIGILL support.
Include the illegal instruction in the header if we get a
SIGILL. Otherwise (since these tend to be one-off bit flips), we don't
usually have any information to try to confirm our suspicion that any
given instance is actually a one-off bit flip.

Also add `SIGILL` as a crasher option to easily generate such crashes.

Before:
  signal 4 (SIGILL), code 1 (ILL_ILLOPC), fault addr 0xab1456da

After:
  signal 4 (SIGILL), code 1 (ILL_ILLOPC), fault addr 0xab1456da (*pc=0xe7f0def0)

Bug: http://b/77274448
Test: ran crasher
Change-Id: I5f8dedca5eea2b117b1b1e48430214b38e1366ed
2018-05-30 12:58:43 -07:00
Elliott Hughes 70d8f28945 Show signal sender for SI_FROMUSER signals.
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
2018-04-26 08:19:17 -07:00
Josh Gao 83b8ac24b6 libdebuggerd: fix out of bounds write.
Bug: http://b/78363964
Test: treehugger
Change-Id: I79ae818e4e0c29f064335d59789afc3b1bf87c69
2018-04-20 17:46:50 -07:00
Josh Gao 5d1c14f41b libdebuggerd: clone registers before we Unwind with them.
Bug: http://b/77296294
Test: manual inspection of tombstone generated by crasher
Change-Id: I4b017701d7d2041db4aefbbb90977e99b844c328
2018-04-20 13:23:20 -07:00
Josh Gao 1cc7bd80a6 debuggerd: remove maximum abort message length.
Let the logging implementation be the imposer of limits.

Bug: http://b/64759619
Test: debuggerd_test
Change-Id: I8bc73bf2301ce071668993b740880224846a4e75
2018-04-13 17:34:20 -07:00
Elliott Hughes e1415a5c3b Include the map name when dumping memory around a register.
Bug: http://b/19590178
Test: ran tests, ran crasher
Change-Id: Ib9afa34c860d8732ef1943eb4decd0b7c8fb55fd
2018-02-15 16:28:50 -08:00
Christopher Ferris e36afb0429 Fix regression caused by libbacktrace API change.
The stack dump was not printing leading zeros for data after the
change to remove uintptr_t types from the libbacktrace API.

Bug: 65682279

Test: Created an arm tombstone and an arm64 tombstone and verified
Test: that the stack data has leading zeros.
Change-Id: I1fbec2c4fa7c8b0fab18894c5628d18c5a580299
2018-01-20 00:59:11 -08:00
Christopher Ferris 7937a36c8e Change all uintptr_t to uint64_t in API.
In order to support the offline unwinding properly, get rid of the
usage of non-fixed type uintptr_t from all API calls.

In addition, completely remove the old local and remote unwinding code
that used libunwind.

The next step will be to move the offline unwinding to the new unwinder.

Bug: 65682279

Test: Ran unit tests for libbacktrace/debuggerd.
Test: Ran debuggerd -b on a few arm and arm64 processes.
Test: Ran crasher and crasher64 and verified tombstones look correct.
Change-Id: Ib0c6cee3ad6785a102b74908a3d8e5e93e5c6b33
2018-01-18 17:26:20 -08:00
Josh Gao 34c2556d11 debuggerd: restore the location of abort message.
The abort message was accidentally relocated to be printed below the
registers, backtrace, and stack, which isn't very helpful. Move it back
to its rightful place.

Test: treehugger
Change-Id: I8aa5b63e58081f27ccdb42481fed8d9eb3a892a4
2017-12-22 14:20:12 -08:00
chirag honnavar def0888a80 Increased number of Android log lines for tombstones
5 lines are not enough for debug

Bug: b/69815742

Change-Id: I3117f221f4945941ec277064ffd2765dda74e192
2017-12-18 09:28:49 +09:00
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
Christopher Ferris b7de5f5429 Demand read load bias for a map.
Add a static GetLoadBias method to the Elf object that only reads just
enough to get the load bias.

Add a method to MapInfo that gets the load bias. First attempt to get
it if the elf object already exists. If no elf object was created, use
the new static method to get the load bias.

In BacktraceMap, add a custom iterator so that when code dereferences
a map element, that's when the load bias will be retrieved if it hasn't
already been set.

Bug: 69871050

Test: New unit tests, verify tombstones have non-zero load bias values for
Test: libraries with a non-zero load bias.
Change-Id: I125f4abc827589957fce2f0df24b0f25d037d732
2017-12-05 13:12:47 -08:00
Christopher Ferris ab9cf8b4cc Only call one unwinder.
Nobody is looking at the mismatches, and it can cause problems
with tombstone parsers.

Also, fix the dump_header_info test and remove unused properties_fake.cpp.

Test: Ran unit tests, verified tombstones still work.
Change-Id: I4261646016b4e84b26a5aee72f3227f1ce48ec9a
2017-10-27 15:18:27 -07:00
Tom Cherry 4a5a337ef2 Merge "Move some properties users to __system_property_read_callback()" 2017-10-12 16:53:41 +00:00
Tom Cherry 31121cafec Move some properties users to __system_property_read_callback()
This is needed if they will ever handle ro. properties that have
values longer than 92 characters.

Bug: 23102347
Bug: 34954705
Test: read and write properties with value length > 92 characters
Change-Id: I44aa135c97ec010f12162c30f743387810ae2c5d
2017-10-10 15:03:33 -07:00
Josh Gao 1ce8e14568 libdebuggerd: fix tombstone tests.
Update the tests to match new output (and stop pluralizing '1 entries').

Test: `debuggerd_test{32,64} --gtest_filter="TombstoneTest.*" on hikey960
Change-Id: I16b0335715303252fad3a35d6a053a50fefdac30
2017-10-10 13:55:44 -07:00
Elliott Hughes 868d39a82f Show the number of VMAs in the tombstone.
Tombstones (especially ones with lots of VMAs) are regularly truncated.
We can at least show the number of VMAs, though, for anyone interested
in knowing whether they got close to the default 64Ki limit.

Bug: http://b/66911122
Test: ran crasher, examined tombstone
Change-Id: I286db66f28f132307d573dbe5164efc969dc6ddc
2017-09-26 12:01:06 -07:00
Josh Gao fdc95c9670 debuggerd_fallback: print maps.
Bug: http://b/63400743
Bug: http://b/65590288
Test: killall -ABRT media.codec
Change-Id: I58e47dcd8e99ad7a5945604c27876dd01259e501
2017-09-13 18:30:11 -07:00
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
Christopher Ferris 9a8c855780 Compare new unwinder to old unwinder in debuggerd.
In debuggerd, when dumping a tombstone, run the new unwinder and verify
the old and new unwinder are the same. If not, dump enough information
in the tombstones to figure out how to duplicate the failure.

Bug: 23762183

Test: Builds, ran and forced a mismatch and verified output.
Change-Id: Ia178bde64d67e623d4f35086ebda68aebbff0c3c
2017-08-11 16:37:59 -07:00
Christopher Ferris 96722b0fa4 Cleanup the libbacktrace interface a bit.
- Change the field name load_base to load_bias (which is what it really is).
- Add a rel_pc field so that callers do not need to compute it themselves.
- Remove the BacktraceMap::GetRelativePc() since nobody should need to
  compute this themselves.

Bug: 23762183

Test: Compiles and unit tests pass (debuggerd, libbacktrace).
Change-Id: I2cb579767120adf08c407a58f3c487ee3f2b45fc
2017-07-19 15:36:32 -07:00
Elliott Hughes 336a52e00c Decode ptrace-induced SIGTRAP si_code values.
Example:

  signal 5 (SIGTRAP), code -32763 (PTRACE_EVENT_STOP), fault addr 0x274e00005fb3

I'm tempted to say that %d isn't the best choice for si_code, but as long as
we're fully decoding all the values, I don't think it matters.

Bug: http://b/62856172
Test: manual debuggerd run
Change-Id: Ieeca690828e1e12f4162bbadece53f4aa7b9537a
2017-06-21 08:45:33 -07:00
Josh Gao 62f5977d4a libdebuggerd: print the build fingerprint in fallback.
Bug: http://b/37798209
Test: killall -ABRT media.codec on internal
Change-Id: I0ff1fc5ca1e0bcec2c1b2553d6af7099deebfeda
2017-05-08 13:15:19 -07:00
Josh Gao 77b00ed429 libdebuggerd: implement fallback register dumping on arm/aarch64.
Bug: http://b/35439781
Test: killall -ABRT media.codec on internal
Change-Id: I7a23d3bfcf07ad584e677b2ef5fff28436ef0972
2017-05-08 13:15:19 -07:00
Christopher Ferris f5e568e653 Do not access device maps.
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
2017-03-22 14:55:05 -07:00
Josh Gao 57f58f8e4a crash_dump: fetch process/thread names before dropping privileges.
Processes that don't have dumpable set to 1 cannot have their
process/thread names read by processes that don't have all of their
capabilities. Fetch these names in crash_dump before dropping
privileges.

Bug: http://b/36237221
Test: debuggerd_test
Test: debuggerd -b `pidof android.hardware.bluetooth@1.0-service`
Change-Id: I174769e7b3c1ea9f11f9c8cbdff83028a4225783
2017-03-15 23:30:14 -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
Elliott Hughes 12b7129406 Small debuggerd improvements.
Include the ABI in seccomp causes.

Slightly improved command-line usage information.

Fix crasher for seccomp failures.

Bug: N/A
Test: crasher
Change-Id: Ie419ecfe72ee4f5ccf49c927be18350a58a66a90
2017-03-02 19:01:20 -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
Elliott Hughes 0ba535976f Better seccomp/kuser_helper diagnostics from debuggerd.
Also switch to Android.bp for crasher.

Bug: http://b/34629282 (seccomp)
Bug: http://b/34705831 (seccomp)
Bug: http://b/34884086 (kuser_helpers)
Test: manual
Change-Id: I8ee79c635518faeba751742919af69a505b5e3e1
2017-02-01 18:43:03 -08:00
Josh Gao cbe70cb0a8 debuggerd: advance our amazing bet.
Remove debuggerd in favor of a helper process that gets execed by
crashing processes.

Bug: http://b/30705528
Test: debuggerd_test
Change-Id: I9906c69473989cbf7fe5ea6cccf9a9c563d75906
2017-01-17 13:57:57 -08:00