https://reviews.llvm.org/D95835 implements origin tracking for DFSan.
It reuses the chained origin depot of MSan.
This change moves the utility to sanitizer_common to share between
MSan and DFSan.
Reviewed-by: eugenis, morehouse
Differential Revision: https://reviews.llvm.org/D96319
GNU binutils accepts only `.arch_extension memtag` while Clang
accepts either that or `.arch_extension mte` to mean the same thing.
Reviewed By: pcc
Differential Revision: https://reviews.llvm.org/D95996
Adds a new allocation API to GWP-ASan that handles size+alignment
restrictions.
Reviewed By: cryptoad, eugenis
Differential Revision: https://reviews.llvm.org/D94830
This is a part of https://reviews.llvm.org/D95835.
This change is to address two problems
1) When recording stacks in origin tracking, libunwind is not async signal safe. Inside signal callbacks, we need
to use fast unwind. Fast unwind needs threads
2) StackDepot used by origin tracking is not async signal safe, we set a flag per thread inside
a signal callback to prevent from using it.
The thread registration is similar to ASan and MSan.
Related MSan changes are
* 98f5ea0dba
* f653cda269
* 5a7c364343
Some changes in the diff are used in the next diffs
1) The test case pthread.c is not very interesting for now. It will be
extended to test origin tracking later.
2) DFsanThread::InSignalHandler will be used by origin tracking later.
Reviewed-by: morehouse
Differential Revision: https://reviews.llvm.org/D95963
Switch to new logging api added in [[ https://developer.apple.com/documentation/os/os_log_error | macOS 10.12 ]] that is more memory safe and enables us to label the log messages in the future. Falls back to old API if ran on older OS versions.
Commited by Dan Liew on behalf of Emily Shi.
rdar://25181524
Reviewed By: delcypher, yln
Differential Revision: https://reviews.llvm.org/D95977
We want way to set a path to llvm-symbolizer that isn't relative
to the current working directory; this change adds a variable that
expands to the path relative to the current binary.
This approach came from comments in https://reviews.llvm.org/D93070
Differential Revision: https://reviews.llvm.org/D94563
AsanThread::Destroy implementation expected to be called on
child thread.
I missed authors concern regarding this reviewing D95184.
Reviewed By: delcypher
Differential Revision: https://reviews.llvm.org/D95731
Unwinders (like libc's backtrace()) can call their own locks (like the
libdl lock). We need to let the unwinder release the locks before
forking. Wrap a new lock around the unwinder for atfork protection.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D95889
DFSan uses TLS to pass metadata of arguments and return values. When an
instrumented function accesses the TLS, if a signal callback happens, and
the callback calls other instrumented functions with updating the same TLS,
the TLS is in an inconsistent state after the callback ends. This may cause
either under-tainting or over-tainting.
This fix follows MSan's workaround.
cb22c67a21
It simply resets TLS at restore. This prevents from over-tainting. Although
under-tainting may still happen, a taint flow can be found eventually if we
run a DFSan-instrumented program multiple times. The alternative option is
saving the entire TLS. However the TLS storage takes 2k bytes, and signal calls
could be nested. So it does not seem worth.
This diff fixes sigaction. A following diff will be fixing signal.
Reviewed-by: morehouse
Differential Revision: https://reviews.llvm.org/D95642
This fixes an apparent oversight in D91156, where the symbol was defined
without the leading underscore, then the visibility was later declared with it.
rdar://73364185
Differential revision: https://reviews.llvm.org/D95639
Fixes the `FastUnwindTest` unit test for RISC-V.
These changes reflect the different stack organization commonly used for
that architecture.
Differential Revision: https://reviews.llvm.org/D90574
D36116 refactored the logic of tests and removed the definition of TARGET_FLAGS, but left one use of it. Restore its definition for that one use, so that an x86_64 test is compiled with -m64.
Reviewed By: vitalybuka
Differential Revision: https://reviews.llvm.org/D93634
This commit accidentally enabled fgetgrent_r() in the msan tests under
FreeBSD, but this function is not supported. Also remove FreeBSD from
the SANITIZER_INTERCEPT_FGETGRENT_R macro.
With D92696, the Scudo Standalone GWP-ASan flag parsing was changed to
the new GWP-ASan optional one. We do not necessarily want this, as this
duplicates flag parsing code in Scudo Standalone when using the
GWP-ASan integration.
This CL reverts the changes within Scudo Standalone, and increases
`MaxFlags` to 20 as an addionnal option got us to the current max.
Differential Revision: https://reviews.llvm.org/D95542
This fixes the implementation for architectures like CHERI with strong
pointer provenance (pointers, and thus uintptr_t, are represented as
hardware capabilities). Specifically, adding two uintptr_t's together
(as is done for `start + length` and `funcStart + landingPad`) has
ambiguous provenance, whereas using a plain integer (such as size_t) for
the offset operand does not. Also, readULEB128 is creating a plain
integer, not a pointer.
On all currently-supported architectures this should be an NFC, as
size_t and uintptr_t end up being the same underlying plain integer
type.
Reviewed By: MaskRay
Differential Revision: https://reviews.llvm.org/D95537
The `zx_vmar_op_range` allows us to decommit memory pages without
needing a handle to the underlying vmo, as long as we have a handle to
a vmar that contains this mapping. This allows us to implement the
`ReleaseMemoryPagesToOS` function by decommitting the memory using a
handle to the root vmar.
Reviewed By: mcgrathr
Differential Revision: https://reviews.llvm.org/D95384
FreeBSD uses -Ddouble=jagged-little-pill -Dfloat=floaty-mcfloatface to
poison uses of floating point in its standalone environment. It also
deprecates machine/limits.h in favour of sys/limits.h and does not even
provide the former on newer architectures.
This is a cleaner reimplementation of equivalent patches in FreeBSD's
vendored copy of compiler-rt.
Reviewed By: dim
Differential Revision: https://reviews.llvm.org/D95264
zxtest doesn't have `EXPECT_DEATH` and the Scudo unit-tests were
defining it as a no-op.
This enables death tests on Fuchsia by using `ASSERT_DEATH` instead.
I used a lambda to wrap the expressions as this appears to not be
working the same way as `EXPECT_DEATH`.
Additionnally, a death test using `alarm` was failing with the change,
as it's currently not implemented in Fuchsia, so move that test within
a `!SCUDO_FUCHSIA` block.
Differential Revision: https://reviews.llvm.org/D94362
Previously in ASan's `pthread_create` interceptor we would block in the
`pthread_create` interceptor waiting for the child thread to start.
Unfortunately this has bad performance characteristics because the OS
scheduler doesn't know the relationship between the parent and child
thread (i.e. the parent thread cannot make progress until the child
thread makes progress) and may make the wrong scheduling decision which
stalls progress.
It turns out that ASan didn't use to block in this interceptor but was
changed to do so to try to address
http://llvm.org/bugs/show_bug.cgi?id=21621/.
In that bug the problem being addressed was a LeakSanitizer false
positive. That bug concerns a heap object being passed
as `arg` to `pthread_create`. If:
* The calling thread loses a live reference to the object (e.g.
`pthread_create` finishes and the thread no longer has a live
reference to the object).
* Leak checking is triggered.
* The child thread has not yet started (once it starts it will have a
live reference).
then the heap object will incorrectly appear to be leaked.
This bug is covered by the `lsan/TestCases/leak_check_before_thread_started.cpp` test case.
In b029c5101fb49b3577a1c322f42ef9fc616f25bf ASan was changed to block
in `pthread_create()` until the child thread starts so that `arg` is
kept alive for the purposes of leaking check.
While this change "works" its problematic due to the performance
problems it causes. The change is also completely unnecessary if leak
checking is disabled (via detect_leaks runtime option or
CAN_SANITIZE_LEAKS compile time config).
This patch does two things:
1. Takes a different approach to solving the leak false positive by
making LSan's leak checking mechanism treat the `arg` pointer of
created but not started threads as reachable. This is done by
implementing the `ForEachRegisteredThreadContextCb` callback for
ASan.
2. Removes the blocking behaviour in the ASan `pthread_create`
interceptor.
rdar://problem/63537240
Differential Revision: https://reviews.llvm.org/D95184
This mechanism is intended to provide a way to treat the `arg` pointer
of a created (but not yet started) thread as reachable. In future
patches this will be implemented in `GetAdditionalThreadContextPtrs`.
A separate implementation of `GetAdditionalThreadContextPtrs` exists
for ASan and LSan runtimes because they need to be implemented
differently in future patches.
rdar://problem/63537240
Differential Revision: https://reviews.llvm.org/D95183
`GetMacosAlignedVersion()` fails for ASan-ified launchd because the
sanitizer initialization code runs before `sysctl` has been setup by
launchd. In this situation, `sysctl kern.osproductversion` returns a
non-empty string that does not match our expectations of a
well-formatted version string.
Retrieving the kernel version (via `sysctl kern.osrelease`) still works,
so we can use it to add a fallback for this corner case.
Differential Revision: https://reviews.llvm.org/D94190
In preparation for the inbuilt options parser, this is a minor refactor
of optional components including:
- Putting certain optional elements in the right header files,
according to their function and their dependencies.
- Cleaning up some old and mostly-dead code.
- Moving some functions into anonymous namespaces to prevent symbol
export.
Reviewed By: cryptoad, eugenis
Differential Revision: https://reviews.llvm.org/D94117
When adding this function in https://reviews.llvm.org/D68794 I did not
notice that internal_prctl has the API of the syscall to prctl rather
than the API of the glibc (posix) wrapper.
This means that the error return value is not necessarily -1 and that
errno is not set by the call.
For InitPrctl this means that the checks do not catch running on a
kernel *without* the required ABI (not caught since I only tested this
function correctly enables the ABI when it exists).
This commit updates the two calls which check for an error condition to
use `internal_iserror`. That function sets a provided integer to an
equivalent errno value and returns a boolean to indicate success or not.
Tested by running on a kernel that has this ABI and on one that does
not. Verified that running on the kernel without this ABI the current
code prints the provided error message and does not attempt to run the
program. Verified that running on the kernel with this ABI the current
code does not print an error message and turns on the ABI.
All tests done on an AArch64 Linux machine.
Reviewed By: eugenis
Differential Revision: https://reviews.llvm.org/D94425
There could be some mis-alignments when copying origins not aligned.
I believe inaligned memcpy is rare so the cases do not matter too much
in practice.
1) About the change at line 50
Let dst be (void*)5,
then d=5, beg=4
so we need to write 3 (4+4-5) bytes from 5 to 7.
2) About the change around line 77.
Let dst be (void*)5,
because of lines 50-55, the bytes from 5-7 were already writen.
So the aligned copy is from 8.
Reviewed-by: eugenis
Differential Revision: https://reviews.llvm.org/D94552
This function is called by the __atomic_is_lock_free() builtin if the value
cannot be resolved to true at compile time. Lack of this function is
causing the non-lockfree atomics tests in libc++ to not be run (see D91911)
This function is also added in D85044, but that review also adds support
for using lock-free atomics in more cases, whereas this is a minimal change
that just adds __atomic_is_lock_free() for the implementation of atomic.c.
Reviewed By: ldionne
Differential Revision: https://reviews.llvm.org/D92302
On Android, when the builtins are linked into a binary, they are
typically linked using -Wl,--exclude-libs so that the symbols aren't
reexported. For the NDK, compiler-rt's default behavior (build the
builtins archive with -fvisibility=hidden) is better so that builtins
are hidden even without -Wl,--exclude-libs.
Android needs the builtins with non-hidden symbols only for a special
case: for backwards compatibility with old binaries, the libc.so and
libm.so DSOs in the platform need to export some builtins for arm32 and
32-bit x86. See D56977.
Control the behavior with a new flag,
`COMPILER_RT_BUILTINS_HIDE_SYMBOLS`, that behaves similarly to the
`*_HERMETIC_STATIC_LIBRARY` in libunwind/libcxx/libcxxabi, so that
Android can build a special builtins variant for libc.so/libm.so.
Unlike the hermetic flags for other projects, this new flag is enabled
by default.
Reviewed By: compnerd, MaskRay
Differential Revision: https://reviews.llvm.org/D93431
