This patch introduces GWP-ASan system properties and environment
variables to control the internal sampling rates of GWP-ASan. This can
be used for:
1. "Torture testing" the system, i.e. running it under an extremely
high sampling rate under GWP-ASan.
2. Increasing sampling remotely to allow further crash report
collection of rare issues.
There are three sets of system properites:
1. libc.debug.gwp_asan.*.system_default: Default values for native
executables and system apps.
2. libc.debug.gwp_asan.*.app_default: Default values for non-system
apps, and
3. libc.debug.gwp_asan.*.<basename/app_name>: Default values for an
individual app or native process.
There are three variables that can be changed:
1. The allocation sampling rate (default: 2500) - using the environment
variable GWP_ASAN_SAMPLE_RATE or the libc.debug.gwp_asan.sample_rate.*
system property.
2. The process sampling rate (default: 128 for system apps/processes, 1
for opted-in apps) - using the environment variable
GWP_ASAN_PROCESS_SAMPLING or the libc.debug.gwp_asan.process_sampling.*
system property,
3. The number of slots available (default: 32) - using the environment
variable GWP_ASAN_MAX_ALLOCS or the libc.debug.gwp_asan.max_allocs.*
system property.
If not specified, #3 will be calculated as a ratio of the default
|2500 SampleRate : 32 slots|. So, a sample rate of "1250" (i.e. twice as
frequent sampling) will result in a doubling of the max_allocs to "64".
Bug: 219651032
Test: atest bionic-unit-tests
Change-Id: Idb40a2a4d074e01ce3c4e635ad639a91a32d570f
When calling android_mallopt using M_INITIALIZE_GWP_ASAN, nothing
was being returned. Fix this, add a test, and also refactor the
code a bit so dynamic and static share the same code.
Test: Unit tests pass in dynamic and static versions.
Test: Passed using both jemalloc and scudo.
Change-Id: Ibe54b6ccabdbd44d2378892e793df393978bc02b
Introduces new heap-zero-init API. We've realised that it's better to be
able to individually control MTE and heap zero-init. Having
heap-zero-init not be controllable without affecting MTE affects our
ability to turn off heap-zero-init in zygote-forked applications.
Bug: 135772972
Test: On FVP: atest -s localhost:5555 malloc#zero_init \
Test: malloc#disable_mte heap_tagging_level
Change-Id: I8c6722502733259934c699f4f1269eaf1641a09f
These are available from mallopt() now, and all callers have been
switched over.
Bug: http://b/135772972
Test: treehugger
Change-Id: I90c7a7573b261c27001a2dfd4589b23861ad613b
These were only available internally via android_mallopt(), but they're
likely to be needed by more code in future, so move them into mallopt().
This change leaves the android_mallopt() options for now, but I plan on
coming back to remove them after I've switched the handful of callers
over to mallopt() instead.
Bug: http://b/135772972
Test: treehugger
Change-Id: Ia154614069a7623c6aca85975a91e6a156f04759
aosp/1484976 introduced a breaking change where
DisableMemoryMitigations() now indiscriminately turns tagged pointers
off. When android_mallopt(M_DISABLE_MEMORY_MITIGATIONS) is called, the
correct behaviour is:
- In SYNC/ASYNC MTE mode -> disable all tagged pointers.
- If all tagged pointers are already disabled -> nop.
- If we're in TBI mode -> nop (keep the TBI mode as-is).
In order to do that we have to allow probing of the current heap tagging
mode. In order to prevent TOCTOU between GetHeapTaggingLevel() and
SetHeapTaggingLevel(), we expose a global mutex that should be held when
calling these functions.
Bug: 174263432
Test: atest CtsTaggingHostTestCases on Flame
Change-Id: Ia96f7269d542c9041270458806aee36766d2fbbb
Introduce an android_mallopt(M_DISABLE_MEMORY_MITIGATIONS) API call
that may be used to disable zero- or pattern-init on non-MTE hardware,
or memory tagging on MTE hardware. The intent is that this function
may be called at any time, including when there are multiple threads
running.
Disabling zero- or pattern-init is quite trivial, we just need to set
a global variable to 0 via a Scudo API call (although there will be
some separate work required on the Scudo side to make this operation
thread-safe).
It is a bit more tricky to disable MTE across a process, because
the kernel does not provide an API for disabling tag checking in all
threads in a process, only per-thread. We need to send a signal to each
of the process's threads with a handler that issues the required prctl
call, and lock thread creation for the duration of the API call to
avoid races between thread enumeration and calls to pthread_create().
Bug: 135772972
Change-Id: I81ece86ace916eb6b435ab516cd431ec4b48a3bf
The WriteProtected mutator for __libc_globals isn't reentrant.
Previously we were calling __libc_globals.mutate() inside of GWP-ASan's
libc initialisation, which is called inside the __libc_globals.mutate().
This causes problems with malloc_debug and other malloc shims, as they
fail to install when GWP-ASan is sampling their processes.
Bug: 135634846
Test: atest bionic
Change-Id: Iae51faa8d78677eeab6204b6ab4f3ae1b7517ba5
This patch introduces GWP-ASan - a sampled allocator framework that
finds use-after-free and heap-buffer-overflow bugs in production
environments.
GWP-ASan is being introduced in an always-disabled mode. This means that
GWP-ASan will be permanently disabled until a further patch turns on
support. As such, there should be no visible functional change for the
time being.
GWP-ASan requires -fno-emulated-tls wherever it's linked from. We
intentionally link GWP-ASan into libc so that it's part of the initial
set of libraries, and thus has static TLS storage (so we can use
Initial-Exec TLS instead of Global-Dynamic). As a benefit, this reduces
overhead for a sampled process.
GWP-ASan is always initialised via. a call to
mallopt(M_INITIALIZE_GWP_ASAN, which must be done before a process is
multithreaded).
More information about GWP-ASan can be found in the upstream
documentation: http://llvm.org/docs/GwpAsan.html
Bug: 135634846
Test: atest bionic
Change-Id: Ib9bd33337d17dab39ac32f4536bff71bd23498b0
This patch introduces tagged pointers to bionic. We add a static tag to
all pointers on arm64 compatible platforms (needs requisite
top-byte-ignore hardware feature and relevant kernel patches).
We dynamically detect TBI-compatible devices (a device with the TBI feature and
kernel support) at process start time, and insert an implementation-dependent
tag into the top byte of the pointer for all heap allocations. We then check
that the tag has not been truncated when deallocating the memory.
If an application incorrectly writes to the top byte of the pointer, we
terminate the process at time of detection. This will allow MTE-incompatible
applications to be caught early.
Bug: 135754954
Bug: 147147490
Test: cd bionic && atest .
Change-Id: Ie424325ba1e3c4443040ac265aeaa28d9e405d28
This reverts commit 43d5f9d4dd.
Bug: 135754954
Bug: 147147490
Exempt-From-Owner-Approval: clean revert
Reason for revert: Breaks ART gtest, see:
https://ci.chromium.org/p/art/builders/ci/angler-armv8-non-gen-cc/561
The crash happens on mprotect of a page, the test crashes with ENOMEM.
Change-Id: I52eea1abbfaf8d8e2226f92d30aa55aba3810528
This patch introduces tagged pointers to bionic. We add a static tag to
all pointers on arm64 compatible platforms (needs requisite
top-byte-ignore hardware feature and relevant kernel patches).
We dynamically detect TBI-compatible devices (a device with the TBI feature and
kernel support) at process start time, and insert an implementation-dependent
tag into the top byte of the pointer for all heap allocations. We then check
that the tag has not been truncated when deallocating the memory.
If an application incorrectly writes to the top byte of the pointer, we
terminate the process at time of detection. This will allow MTE-incompatible
applications to be caught early.
Bug: 135754954
Bug: 147147490
Test: cd bionic && atest .
Change-Id: I6e5b809fc81f55dd517f845eaf20f3c0ebd4d86e
This doesn't add any functionality for now, but there are
a couple of changes in flight that will want to add enumerators
to the mallopt, so let's give them a place to add them.
Bug: 135772972
Bug: 135754954
Change-Id: I6e810020f66070e844500c6fa99b703963365659
I have no idea why I used the iterate name internally which is
completely unlike every other function name. Change this to match
everyone else so that it's now malloc_iterate everywhere.
This is probably the last chance to change this before mainline
modules begin, so make everything consistent.
Test: Compiles, unit tests passes.
Change-Id: I56d293377fa0fe1a3dc3dd85d6432f877cc2003c
Instead of having platform directories directly include the
private header, create a platform header directory and export it.
Bug: 130763340
Test: Builds.
Change-Id: Ie0f092b3fe077a3de8b90266c0b28bfbc20d0dfa
Merged-In: Ie0f092b3fe077a3de8b90266c0b28bfbc20d0dfa
(cherry picked from commit 8f582ef2f8)
Ensure we call realloc@plt rather than (as was previously happening)
inlining realloc into reallocarray, which makes the allocation invisible
to ASan.
Bug: http://b/129989984
Test: objdump
Change-Id: If8a43cba11aa5a2f2f62bacd02ef6ef4032e0dbb
Bug: 130028357
Test: malloc_hooks unit tests.
Test: Enable backtrace for mediaserver, run dumpsys media.player -m
Test: Enable backtrace for calendar, run am dumpheap -n <PID> <FILE>
Change-Id: I6774e28ccd9b3f2310127a5b39ccd15fe696a787
Merged-In: I6774e28ccd9b3f2310127a5b39ccd15fe696a787
(cherry picked from commit 3aadc5e80a)
Remove this global variable and change the setting of it to non-zero
to a call to android_mallopt.
In addition, change the initialize function to use pass a bool* instead of
int*.
Bug: 130028357
Test: Ran malloc_debug/malloc_hooks/perfetto tests.
Change-Id: I20d382bdeaaf38aac6b9dcabea5b3dfab3c945f6
Merged-In: I20d382bdeaaf38aac6b9dcabea5b3dfab3c945f6
(cherry picked from commit 5225b342f0)
Introduce an M_SET_ALLOCATION_LIMIT enumerator for android_mallopt(),
which can be used to set an upper bound on the total size of all
allocations made using the memory allocation APIs.
This is useful for programs such as audioextractor and mediaserver
which need to set such a limit as a security mitigation. Currently
these programs are using setrlimit(RLIMIT_AS) which isn't exactly
what these programs want to control. RLIMIT_AS is also problematic
under sanitizers which allocate large amounts of address space as
shadow memory, and is especially problematic under shadow call stack,
which requires 16MB of address space per thread.
Add new unit tests for bionic.
Add new unit tests for malloc debug that verify that when the limit
is enabled, malloc debug still functions for nearly every allocation
function.
Bug: 118642754
Test: Ran bionic-unit-tests/bionic-unit-tests-static.
Test: Ran malloc debug tests and perfetto integration tests.
Change-Id: I735403c4d2c87f00fb2cdef81d00af0af446b2bb
malloc_info needs to be per native allocator, but the code treated it
like a global function that doesn't depend on the native memory allocator.
Update malloc debug to dump the actual pointers that it has been tracking.
Test: bionic-unit-tests pass.
Test: malloc debug tests pass.
Test: malloc hook tests pass.
Change-Id: I3b0d4d748489dd84c16d16933479dc8b8d79013e
Merged-In: I3b0d4d748489dd84c16d16933479dc8b8d79013e
(cherry picked from commit a3656a98b1)
The pieces:
- The malloc common shared by static and dynamic code (malloc_common.cpp).
- The code for shared libraries that includes any dlopen'ing
(malloc_common_dynamic.cpp).
- The implementation of perfetto's heapprofd (malloc_heapprofd.cpp).
This makes it easier to see what's going on in the many different areas.
It should also make it easier to add the allocation capping option.
Other related changes:
- Update the unit tests for android_mallopt. All of the current options
don't work on static binaries, so make sure that is reflected in the test.
- A few names changes to make sure that all code is consistent.
Test: Ran tests (malloc hooks/malloc debug/perfetto/bionic unit tests).
Change-Id: I0893bfbc0f83d82506fac5d1f37cf92fbdef6f59
Instead of every function being its own atomic, have a single
pointer that can be used to flip all pointers at once. This avoid cases
where the set of pointers can be in an partial switched state.
Also fix a few inconsistent naming of functions in the file.
Test: Ran unit tests (malloc debug, malloc hooks, perfetto).
Change-Id: I3f66da395414586a3fa87874d80dcdf5f702ed39
Merged-In: I3f66da395414586a3fa87874d80dcdf5f702ed39
(cherry picked from commit 77184aedaf)
This is used to prevent the additional indirection even after heap
profiling has finished, preventing any performance impact on processes
that are not currently being profiled.
Test: m
Test: flash sailfish
Test: try tearing down & re-enabling hooks
Bug: 120186127
Change-Id: Idc5988111a47870d2c093fd6a017b47e65f5616b
On user builds, heapprofd should only be allowed to profile apps that
are either debuggable, or profileable (according to the manifest). This
change exposes extra zygote-specific knowledge to bionic, and makes the
dedicated signal handler check for the special case of being in a zygote child.
With this & the corresponding framework change, we should now be
handling the 4 combinations of:
{java, native} x {profile_at_runtime, profile_at_startup}.
See internal go/heapprofd-java-trigger for further context.
Test: on-device unit tests (shared & static) on blueline-userdebug.
Test: flashed blueline-userdebug, confirmed that java profiling activates from startup and at runtime.
Bug: 120409382
Change-Id: Ic251afeca4324dc650ac1d4f46976b526eae692a
(cherry picked from commit 998792e2b6)
Merged-In: Ic251afeca4324dc650ac1d4f46976b526eae692a
Because we also want to profile Java applications, which have longer
names, the character limit of comm is a problem. To avoid complexity, it
is preferable to apply the same logic for finding running processes
(which includes Java apps), and determining whether to profile a process
from startup.
Test: m
Test: flash sailfish
Test: setprop heapprofd.enable 1
setprop heapprofd.enable.ls 1
ls
/system/bin/ls
/system/bin/ls /
Bug: 120175590
Change-Id: Id0859d4a333efcb05883e611ea6a31a51468f82c
Other minor changes:
* document assignment that relies on _Atomic assignments to use
atomic_store.
* consistently use atomic_store when assigning to atomics.
* remove incorrect comment.
Test: m
Test: flash & boot sailfish
Change-Id: I4789c08f7ac28a2de8d6925d03af354514bfd9d7
Tests: Ran malloc_debug_unit_tests
Tests: Flashed to walleye, sent signal, observed
"Unable to open shared library: heapprofd.so".
Change-Id: Ia8ce216837e29e3edbda8789ca28023d53fa1fda
Originally a BSD extension, now in glibc too. We've used it internally
for a while.
(cherry-pick of e4b13f7e3ca68edfcc5faedc5e7d4e13c4e8edb9.)
Bug: http://b/112163459
Test: ran tests
Change-Id: I813c3a62b13ddb91ba41e32a5a853d09207ea6bc
Merged-In: I813c3a62b13ddb91ba41e32a5a853d09207ea6bc
* Allow sanitization of libc (excluding existing global sanitizers)
and disallow sanitization of linker. The latter has not been
necessary before because HWASan is the first sanitizer to support
static binaries (with the exception of CFI, which is not used
globally).
* Static binary startup: initialize HWASan shadow very early so that
almost entire libc can be sanitized. The rest of initialization is
done in a global constructor; until that is done sanitized code can
run but can't report errors (will simply crash with SIGTRAP).
* Switch malloc_common from je_* to __sanitizer_*.
* Call hwasan functions when entering and leaving threads. We can not
intercept pthread_create when libc depends on libclang_rt.hwasan.
An alternative to this would be a callback interface like requested
here:
https://sourceware.org/glibc/wiki/ThreadPropertiesAPI
All of the above is behind a compile-time check
__has_feature(hwaddress_sanitizer). This means that HWASan actually
requires libc to be instrumented, and would not work otherwise. It's
an implementation choice that greatly reduces complexity of the tool.
Instrumented libc also guarantees that hwasan is present and
initialized in every process, which allows piecemeal sanitization
(i.e. library w/o main executable, or even individual static
libraries), unlike ASan.
Change-Id: If44c46b79b15049d1745ba46ec910ae4f355d19c
Bump the version from v1.1 to v1.2 and add a build fingerprint line.
Update the heap dump documentation to match the new format and reflect
what made it in P and what made it in Q.
Update the unit tests for this change.
Add -O0 to unit test code to make it easier to debug.
Add an external function that can be used by the framework code
so that there is only one way to dump the heap.
Bug: 110095681
Test: Ran unit tests.
Test: Did a dump of a real process and verified fingerprint.
Test: Did a dump of a process without malloc debug enabled.
Change-Id: I769a476cbeaf4c85c5d75bd6d6385f0e3add948c
Merged-In: I769a476cbeaf4c85c5d75bd6d6385f0e3add948c
(cherry picked from commit c84a2a2601)
Use the malloc debug framework to implement the malloc debug hooks
since it can introduce a performance issue.
Also, modify the bionic/tests/utils.h slightly to dump an error message
when the exe failed.
Bug: 30561479
Test: Ran malloc hook unit tests.
Test: Ran malloc debug unit tests.
Test: Enabled malloc hooks and ran bionic unit tests and verified no
Test: unexpected failures.
Test: Enabled malloc debug and malloc hooks and verified malloc debug wins.
Test: Enabled malloc debug using env, property, and property with name
Test: still works.
Change-Id: Ib50046a0493c5c2050cf831befb812310bdcc249
(cherry picked from commit d6a1dc2379)
Add the mallopt function, and only a single option so far.
Bug: 36401135
Test: Built and booted bullhead.
Test: Ran jemalloc unit tests.
Test: Ran bionic unit tests.
Test: Ran a test that allocated and free'd a large piece of memory,
Test: and verified that after changing the parameter, the PSS
Test: sticks around (decay timer set to 1), the PSS is purged (decay
Test: timer set to 0).
Change-Id: I6927929b0c539c1023d34772d9e26bb6a8a45877
This library is used by a number of different libraries in the system.
Make it easy for platform libraries to use this library and create
an actual exported include file.
Change the names of the functions to reflect the new name of the library.
Run clang_format on the async_safe_log.cpp file since the formatting is
all over the place.
Bug: 31919199
Test: Compiled for angler/bullhead, and booted.
Test: Ran bionic unit tests.
Test: Ran the malloc debug tests.
Change-Id: I8071bf690c17b0ea3bc8dc5749cdd5b6ad58478a
Previously malloc debug can be enabled only using global settings
accessible to the root user only. This CL adds a new option to enable
it using environment variables making it possible to use it with pure
native (shell) applications on production builds (from shell user) and
prepares it for using it from logwrapper on production devices.
Remove the old environment variable and property since they are not
necessary.
Test: Enable malloc debug using environment variable and verify
Test: that it only affects the commands launched from the shell.
Test: Enable malloc debug using the property variable and verify
Test: that it affects all commands.
Test: Run all unit tests in 32 bit and 64 bit.
Change-Id: Iecb75a3471552f619f196ad550c5f41fcd9ce8e5
Do not initialize all of the global function pointers associated with
debug malloc until the initialization has completed correctly.
Bug: 27600760
Change-Id: I0621b54bc2d9fab63805d7992d384e550d6fed2a
