It turns out that we weren't actually enabling stack traces due
to a typo in one of the if statements. Fix it.
Bug: 135772972
Change-Id: Ic19352280f65acd621b9d88c361c55680b3327f0
Our various fd debugging facilities get extremely confused by a vforked
process closing file descriptors in preparation to exec: fdsan can
abort, and fdtrack will delete backtraces for any file descriptors that
get closed. Keep track of whether we're in a vforked child in order to
be able to detect this.
Bug: http://b/153926671
Test: 32/64-bit bionic-unit-tests on blueline, x86_64 emulator
Change-Id: I8a082fd06bfdfef0e2a88dbce350b6f667f7df9f
The SYNC tagging level enables stack trace collection for allocations and
deallocations, which allows allocation and deallocation stack traces to
appear in tombstones when encountering a tag check fault in synchronous tag
checking mode.
Bug: 135772972
Change-Id: Ibda9f51b29d2c8e2c993fc74425dea7bfa23ab1e
Some applications may incorrectly assume that a "negative" pointer
indicates error. By setting the top bit in TBI mode, we catch these
cases as well. Although they don't directly indicate incompatibility
with MTE (as MTE uses the 2nd-highest nibble) - this ensures we catch
HWASan errors as well as reserve the bits for future MTE expansion.
Bug: 154272452
Test: Boot flame, device boots successfully.
Change-Id: I94a6821a82ce7ead59e6ca2dd113a5a50ee9e56b
This also removes the ScopedSignalBlocker, which doesn't seem to have
made any sense since threads were invented.
Test: treehugger
Change-Id: I9a323ab4a0b43f14fd5d1f0df1f80184aef63770
1) "fix the system properties design" is written for the old protocol,
so we've already changed the design. There are no other further
planned changes.
2) "don't drag in all the macros, just the types." is not likely to
happen or be particularly impactful.
3) "Find a location suitable for these functions ..." is refering to
legacy code. More likely that this code will be removed before we
find a serious reason to fix this TODO.
4) "(73062966) We still don't have a good way ..." is stale; we fixed
this bug and added the appropriate mechanism.
Test: n/a
Change-Id: I23991692cdeb81ad00844a6a1680900ff384208b
These solves the issue that targetting non-profilable apps crashed them.
There is still a race condition between starting the app and the SIG_IGN
being installed, but that will be fixed in follow-ups.
This also does not cover programs that statically link libc, but those are
rare.
This might be reverted if we find a more general solution to
b/151835887.
Bug: 151328035
Test: java profile sysui, doesn't crash
Test: atest CtsBionicTestCases
Change-Id: I6b99352ed50afe15a609f7ddb85312c2676ddf11
POSIX added these GNU extensions for issue 8.
I've made these always inline without the usual "until API level X"
proviso because they're single instructions that the compiler can inline
and there's really no point providing these if they add function call
overhead --- everyone should just use __builtin_ffs() and friends
instead in that case.
Bug: https://austingroupbugs.net/view.php?id=617
Test: treehugger
Change-Id: I33fc4b8648ea25917329e81c1b4c60eb9a66d667
The double hooking is currently controlled by two separate atomic
booleans. In this state, it is very hard to guard against very subtle
race conditions. Adding an explicit enum to encode the state makes it
easier to reason about the behaviour of the program.
Also introduce a MaybeModifyGlobals to consistently guard accesses to
globals. We would sometimes modify them without swapping the
gGlobalsMutating, introducing a window for race with
HandleHeapprofdSignal.
Test: while true; do atest HeapprofdCtsTest; done
Test: flash blueline and manually test profile
Bug: 150741354
Change-Id: I77102b0bd906b8ec2d6806bd43ba6cbf7191e37c
Simplify:
- Use a single memory-mapped region to hold the table of destructors.
Double its capacity each time it is expanded.
- Add a recompaction pass at the end of __cxa_finalize that shifts
entries forward and uses madvise to clean pages.
Bug: http://b/148055738
Test: bionic-unit-tests
Change-Id: Ieb9da2b88640a8a5277d217b43826b5b7e246781
Bug: 137795072
Test: Built using jemalloc, and verified that the two processes that
Test: use libc_scudo do not crash.
Change-Id: Icf773b656d7e2bcdf41b4979e9b6cd980b02d34d
When the heapprofd lazy-initialization dispatch table is installed, two
threads can call malloc() at the same time. One will do the
lazy-initialization, the other will fail the atomic_exchange of
gHeapprofdInitHookInstalled and go to system malloc. The system malloc
still contains the lazy-init malloc, and will recurse.
Fix it so the second thread goes directly to the previous dispatch
table, or to the system allocator directly (instead of through libc
malloc()).
Bug: 150085813
Test: atest perfetto_integrationtests
Test: TracedPerfCtsTest.SystemWideDebuggableApp on cuttlefish x86.
Change-Id: Ia85ad619a0d5e3f558136d84c34dbada4e8b845d
The values of some constants have changed, and the tag mask has changed from
being an exclusion mask to an inclusion mask.
Bug: 135772972
Change-Id: I322fceae7003bee6b391e7187194ed4c0cb28c58
If an alternate signal stack is set and the frame record is in bounds of
that stack, we need to use the top of the alternate signal stack for bounds
checking rather than the normal stack.
Bug: 150215618
Change-Id: I78b760d61b27da44f8e0cfee3fe94a791011fe58
To prevent unnecessary SELinux denials, the check referred to by the
comment is kept in place. This allows us to keep auditing the
SELinux denial in order to catch apps that intentionally send
RTM_GETLINK messages.
Fix: 141455849
Test: atest bionic-unit-tests-static
Test: atest NetworkInterfaceTest
Change-Id: I41e5ad6f071c820a8246177a0c629b3be788a942
Heapprofd uses an ephemeral dispatch table to ensure that GWP-ASan can
be called during heapprofd initialization. Previously, we grabbed the
backup dispatch table from the globals, which is wrong if GWP-ASan isn't
installed (as the malloc_dispatch_table is linker-initialised and not
set to a known good value if a malloc hooker isn't used).
Instead, grab the correct ephemeral dispatch table. When GWP-ASan is
installed, use a copy of its table as the dispatch. When nothing is
installed, fall back to using the native allocator dispatch.
Bug: 135634846
Bug: 150085813
Test: atest perfetto_integrationtests
Test: TracedPerfCtsTest.SystemWideDebuggableApp on cuttlefish x86.
Change-Id: I4beaf9192acadbe00adc02de2e0b0aab6f7a2190
This is a best-effort mitigation for potential crashes when the
profiling signal handler is triggered within certain secomp'd processes.
In particular, we're working around cases where the seccomp policy
doesn't allow some of the handler syscalls, and has a crashing
disposition towards violations via SECCOMP_RET_TRAP, plus a crashing
SIGSYS handler. While not general, this covers the configurations seen
in practice on Android (which are all using minijail in the same way).
By overriding the SIGSYS handling for the duration of the profiling
handler, we can instead receive such SIGSYS signals, and instead recover
from them in a non-crashing manner (the handler is responsible for
filling the syscall return register, since the syscall itself was
skipped).
For simplicity, we're swallowing all SIGSYS signals during this window,
without trying to figure out whether they're something that could be
caused by the profiling signal handler. I've quite convinced myself that
-ENOSYS seems to be safe to return to all of bionic's syscall wrappers
across the four architectures (looking at gensyscalls + the
special-cases like vfork and clone). It is theoretically possible for
all kinds of conflicting (ab)uses of SIGSYS to exist, but I'm assuming
it's not a realistic concern until proven otherwise.
Tested: manually sigqueue'd configstore on crosshatch, confirmed that
the SIGSYS override log was printed, and the process did not
crash (as it does on master).
Bug: 149328505
Change-Id: Iab8f09e51169807c9d3e1e0bcfd042f09f7df6a4
For interfaces that didn't get their name set, try to resolve their name
using if_indextoname first, before removing them from the list.
This allows getifaddrs() to keep returning interfaces that only have an
IPv6 address set (as opposed to the previous behavior where only
interfaces with an IPv4 address would be returned).
Change-Id: I0e4e6611948b12794cd3e354538f2964fbf31078
Fix: 148886805
Bug: 141455849
Test: atest NetworkInterfaceTest
Test: atest bionic-unit-tests-static
Test: atest IpSecManagerTunnelTest
The tag level may now be async, which is now the default. When the tag level
is set to none, memory tagging is disabled in the allocator using the new
API proposed in https://reviews.llvm.org/D70762 .
Bug: 135772972
Change-Id: I847f5822a70913c446ed9ffa13792177bbfc96af
Current APEX Namespace is named with APEX name itself, which also uses
.(dot) so linker configuration can keep the syntax safe.
For example, if there are APEX modules named 'A' and 'A.link.A', then
'namespace.A.link.A.link.A = a.so' phrase can be ambiguous from the
linker. To allow any additional linker syntax in the future, we should
avoid dot separator from the namespace name.
Bug: 148826508
Test: m -j passed
Test: boot succeeded from cuttlefish and walleye
Change-Id: Ic3fe396aef6366fc6c7a0677bc7f92a57fd4e229
Exports GWP-ASan allocator information callbacks to libdebuggerd so that
tombstoned can get information from the GWP-ASan allocator in the case
of a crash.
Bug: 135634846
Test: atest bionic-unit-tests
Change-Id: Ie16426af55602fb2a76c4e69217773354c365843
The notification that GWP-ASan is enabled causes ART tests to break.
Remove the log for now.
Bug: 135634846
Bug: 149790891
Test: (Attempt to fix the ART tests).
Change-Id: I8a7751a838a64f160b3b7b9f07752bb64644b9db
This patch enables GWP-ASan with process sampling.
**Note**: If you are visiting this patch because this broke a test or
otherwise is causing failures, please contact mitchp@ directly (or
respond to this patchset). GWP-ASan is designed to cause heap-based
memory safety bugs to manifest in SEGV on a sampled basis.
Bug: 135634846
Test: atest bionic-unit-tests gwp_asan_unittest
Change-Id: I58ca9373def105fdd718cf283482b3220b770698
GWP-ASan + heapprofd don't currently play nice together in some
circumstances. heapprofd thinks it's still an only child, and refuses to
accept the existence of its little brother, GWP-ASan.
If GWP-ASan is installed before heapprofd, then heapprofd is *required*
to respect that libc has a favourite child. If an allocation/free is passed
to heapprofd, then heapprofd *must* (eventually) pass that allocation/free to
GWP-ASan. If heapprofd doesn't do this, then a free() of a GWP-ASan
allocation can be passed to the system allocator.
This can happen in two places right now:
1. The heapprofd hooks simply clobber any trace of what was
previously in the default_dispatch_table when enabled through the
heapprofd signal.
2. Heapprofd can die when the system is under significant pressure.
Some pipes can timeout, which ends up in the client calling ShutdownLazy()
-> mallopt(M_RESET_HOOKS) -> DispatchReset(). This also clobbers any
trace of the previous default_dispatch_table.
To fix both these problems, we fix heapprofd to restore the previous
default_dispatch_table whenever either circumstance happens. We do some
tricky copying to avoid race conditions on the malloc_dispatch_table in
fixing #1.
Bug: 135634846
Test: Run HeapprofdEndToEnd.NativeProfilingActiveAtProcessExit/ForkMode
a significant number of times with large amounts of system pressure (I
just run bionic-unit-tests-scudo in parallel). You will see some test
failures where heapprofd died due to system pressure, but never a death
from the allocator. Tests should never fail when the system isn't under
immense pressure.
Change-Id: I20ab340d4bdc35d6d1012da5ee1a25634428d097
