Summary:
__DATA segments on Darwin contain a large number of separate sections,
many of which cannot actually contain pointers, and contain const values or
objc metadata. Not scanning sections which cannot contain pointers significantly
improves performance.
On a medium-sized (~4000 files) internal project, I saw a speedup of about 30%
in standalone LSan's execution time (30% improvement in the time spent running
LSan, not the total program time).
Reviewers: kcc, kubamracek, alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35432
llvm-svn: 308999
Summary:
This is a pure refactoring change. It just moves code that is
related to filesystem operations from sanitizer_common.{cc,h} to
sanitizer_file.{cc,h}. This makes it cleaner to disable the
filesystem-related code for a new port that doesn't want it.
Submitted on behalf of Roland McGrath.
Reviewers: kcc, eugenis, alekseyshl
Reviewed By: alekseyshl
Subscribers: vitalybuka, llvm-commits, kubamracek, mgorny, phosek
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D35591
llvm-svn: 308819
This is a pure refactoring change. It just moves code that is
related to filesystem operations from sanitizer_common.{cc,h} to
sanitizer_file.{cc,h}. This makes it cleaner to disable the
filesystem-related code for a new port that doesn't want it.
Commiting for mcgrathr.
Reviewers: alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35591
llvm-svn: 308640
Summary:
__DATA segments on Darwin contain a large number of separate sections,
most of which cannot actually contain pointers, and contain const values or
objc metadata. Only scanning sections which can contain pointers greatly improves
performance.
On a medium-sized (~4000 files) internal project, I saw a speedup of about 50%
in standalone LSan's execution time (50% improvement in the time spent running
LSan, not the total program time).
Reviewers: kcc, kubamracek, alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D35432
llvm-svn: 308231
On iOS/AArch64, the address space is very limited and has a dynamic maximum address based on the configuration of the device. We're already using a dynamic shadow, and we find a large-enough "gap" in the VM where we place the shadow memory. In some cases and some device configuration, we might not be able to find a large-enough gap: E.g. if the main executable is linked against a large number of libraries that are not part of the system, these libraries can fragment the address space, and this happens before ASan starts initializing.
This patch has a solution, where we have a "backup plan" when we cannot find a large-enough gap: We will restrict the address space (via MmapFixedNoAccess) to a limit, for which the shadow limit will fit.
Differential Revision: https://reviews.llvm.org/D35098
llvm-svn: 307865
Summary:
Make SizeClassAllocator32 return nullptr when it encounters OOM, which
allows the entire sanitizer's allocator to follow allocator_may_return_null=1
policy, even for small allocations (LargeMmapAllocator is already fixed
by D34243).
Will add a test for OOM in primary allocator later, when
SizeClassAllocator64 can gracefully handle OOM too.
Reviewers: eugenis
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D34433
llvm-svn: 305972
Summary:
AFAICT compiler-rt doesn't have a function that would return 'good' random
bytes to seed a PRNG. Currently, the `SizeClassAllocator64` uses addresses
returned by `mmap` to seed its PRNG, which is not ideal, and
`SizeClassAllocator32` doesn't benefit from the entropy offered by its 64-bit
counterpart address space, so right now it has nothing. This function aims at
solving this, allowing to implement good 32-bit chunk randomization. Scudo also
has a function that does this for Cookie purposes, which would go away in a
later CL once this lands.
This function will try the `getrandom` syscall if available, and fallback to
`/dev/urandom` if not.
Unfortunately, I do not have a way to implement and test a Mac and Windows
version, so those are unimplemented as of now. Note that `kRandomShuffleChunks`
is only used on Linux for now.
Reviewers: alekseyshl
Reviewed By: alekseyshl
Subscribers: zturner, rnk, llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D34412
llvm-svn: 305922
Summary:
Context: https://github.com/google/sanitizers/issues/740.
Making secondary allocator to respect allocator_may_return_null=1 flag
and return nullptr when "out of memory" happens.
More changes in primary allocator and operator new will follow.
Reviewers: eugenis
Subscribers: kubamracek, llvm-commits
Differential Revision: https://reviews.llvm.org/D34243
llvm-svn: 305569
Summary:
This broke thread_local_quarantine_pthread_join.cc on some architectures, due
to the overhead of the stashed regions. Reverting while figuring out the best
way to deal with it.
Reviewers: alekseyshl
Reviewed By: alekseyshl
Subscribers: llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D34213
llvm-svn: 305404
Summary:
The reasoning behind this change is explained in D33454, which unfortunately
broke the Windows version (due to the platform not supporting partial unmapping
of a memory region).
This new approach changes `MmapAlignedOrDie` to allow for the specification of
a `padding_chunk`. If non-null, and the initial allocation is aligned, this
padding chunk will hold the address of the extra memory (of `alignment` bytes).
This allows `AllocateRegion` to get 2 regions if the memory is aligned
properly, and thus help reduce fragmentation (and saves on unmapping
operations). As with the initial D33454, we use a stash in the 32-bit Primary
to hold those extra regions and return them on the fast-path.
The Windows version of `MmapAlignedOrDie` will always return a 0
`padding_chunk` if one was requested.
Reviewers: alekseyshl, dvyukov, kcc
Reviewed By: alekseyshl
Subscribers: llvm-commits, kubamracek
Differential Revision: https://reviews.llvm.org/D34152
llvm-svn: 305391
Summary:
allow_user_segv_handler had confusing name did not allow to control behavior for
signals separately.
Reviewers: eugenis, alekseyshl, kcc
Subscribers: llvm-commits, dberris, kubamracek
Differential Revision: https://reviews.llvm.org/D33371
llvm-svn: 303941
Summary:
The LINKEDIT section is very large and is read-only. Scanning this
section caused LSan on darwin to be very slow. When only writable sections
are scanned for global pointers, performance improved by a factor of about 25x.
Reviewers: alekseyshl, kubamracek
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D33322
llvm-svn: 303422
We seem to assume that OS-provided thread IDs are either uptr or int, neither of which is true on Darwin. This introduces a tid_t type, which holds a OS-provided thread ID (gettid on Linux, pthread_threadid_np on Darwin, pthread_self on FreeBSD).
Differential Revision: https://reviews.llvm.org/D31774
llvm-svn: 300473
Summary: This specifically addresses the Mach-O zero page, which we cannot read from.
Reviewers: kubamracek, samsonov, alekseyshl
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D32044
llvm-svn: 300456
When using ASan and UBSan together, the common sanitizer tool name is
set to "AddressSanitizer". That means that when a UBSan diagnostic is
printed out, it looks like this:
SUMMARY: AddressSanitizer: ...
This can confuse users. Fix it so that we always use the correct tool
name when printing out UBSan diagnostics.
Differential Revision: https://reviews.llvm.org/D32066
llvm-svn: 300358
People keep hitting on spurious failures in malloc/free routines when using sanitizers
with shared libraries dlopened with RTLD_DEEPBIND (see https://github.com/google/sanitizers/issues/611 for details).
Let's check for this flag and bail out with warning message instead of failing in random places.
Differential Revision: https://reviews.llvm.org/D30504
llvm-svn: 297370
This patch add a new sanitizer flag, print_module_map, which enables printing a module map when the process exits, or after each report (for TSan). The output format is very similar to what Crash Reporter produces on Darwin (e.g. the format of module UUIDs). This enables users to use the existing symbol servers to offline symbolicate and aggregate reports.
Differential Revision: https://reviews.llvm.org/D27400
llvm-svn: 291277
This patch adds tracking which modules are instrumented and which are not. On macOS, instrumented modules link against the ASan/TSan/... dylib, so we can just check if such a load command exists or not.
Differential Revision: https://reviews.llvm.org/D28263
llvm-svn: 291268
When we enumerate loaded modules, we only track the module name and base address, which then has several problems on macOS. Dylibs and executables often have several architecture slices and not storing which architecture/UUID is actually loaded creates problems with symbolication: A file path + offset isn't enough to correctly symbolicate, since the offset can be valid in multiple slices. This is especially common for Haswell+ X86_64 machines, where x86_64h slices are preferred, but if one is not available, a regular x86_64 is loaded instead. But the same issue exists for i386 vs. x86_64 as well.
This patch adds tracking of arch and UUID for each LoadedModule. At this point, this information isn't used in reports, but this is the first step. The goal is to correctly identify which slice is loaded in symbolication, and also to output this information in reports so that we can tell which exact slices were loaded in post-mortem analysis.
Differential Revision: https://reviews.llvm.org/D26632
llvm-svn: 288537
Summary:
The current code was sometimes attempting to release huge chunks of
memory due to undesired RoundUp/RoundDown interaction when the requested
range is fully contained within one memory page.
Reviewers: eugenis
Subscribers: kubabrecka, llvm-commits
Patch by Aleksey Shlyapnikov.
Differential Revision: https://reviews.llvm.org/D27228
llvm-svn: 288271
Summary:
In order to avoid starting a separate thread to return unused memory to
the system (the thread interferes with process startup on Android,
Zygota waits for all threads to exit before fork, but this thread never
exits), try to return it right after free.
Reviewers: eugenis
Subscribers: cryptoad, filcab, danalbert, kubabrecka, llvm-commits
Patch by Aleksey Shlyapnikov.
Differential Revision: https://reviews.llvm.org/D27003
llvm-svn: 288091
This patch prints out all CPU registers after a SIGSEGV. These are available in the signal handler context. Only implemented for Darwin. Can be turned off with the dump_registers flag.
Differential Revision: https://reviews.llvm.org/D11365
llvm-svn: 287957
Summary: The new name better corresponds to its logic.
Reviewers: kcc
Subscribers: kubabrecka
Differential Revision: https://reviews.llvm.org/D26821
llvm-svn: 287377
Summary:
This patch is adding support for dynamic shadow allocation.
This is a merge and re-commit of the following patches.
```
[compiler-rt] Fix Asan build on Android
https://reviews.llvm.org/D24768
[compiler-rt] Add support for the dynamic shadow allocation
https://reviews.llvm.org/D23363
```
This patch needed to re-land at the same time:
```
[asan] Support dynamic shadow address instrumentation
https://reviews.llvm.org/D23354
```
Reviewers: rnk, zaks.anna
Subscribers: tberghammer, danalbert, kubabrecka, dberris, chrisha, llvm-commits
Differential Revision: https://reviews.llvm.org/D25104
llvm-svn: 282882
Summary:
This patch is adding the needed code to compiler-rt to support
dynamic shadow.
This is to support this patch:
https://reviews.llvm.org/D23354
It's adding support for using a shadow placed at a dynamic address determined
at runtime.
The dynamic shadow is required to work on windows 64-bits.
Reviewers: rnk, kcc, vitalybuka
Subscribers: kubabrecka, dberris, llvm-commits, chrisha
Differential Revision: https://reviews.llvm.org/D23363
llvm-svn: 281909
The definitions in sanitizer_common may conflict with definitions from system headers because:
The runtime includes the system headers after the project headers (as per LLVM coding guidelines).
lib/sanitizer_common/sanitizer_internal_defs.h pollutes the namespace of everything defined after it, which is all/most of the sanitizer .h and .cc files and the included system headers with: using namespace __sanitizer; // NOLINT
This patch solves the problem by introducing the namespace only within the sanitizer namespaces as proposed by Dmitry.
Differential Revision: https://reviews.llvm.org/D21947
llvm-svn: 281657
Summary: As mentioned in D24394, I'm moving tid to ErrorBase, since basically all errors need it.
Also mentioned in the same review are other cleanups like adding const
to BufferedStackTrace and make sure constructor orders are consistent.
Reviewers: vitalybuka, kcc, eugenis
Subscribers: llvm-commits, kubabrecka
Differential Revision: https://reviews.llvm.org/D24455
llvm-svn: 281236
On OS X, we often get stack trace in a report that ends with a 0x0 frame. To get rid of it, let's trim the stack trace when we find a close-to-zero value, which is obviously not a valid PC.
Differential Revision: http://reviews.llvm.org/D14656
llvm-svn: 273886
Summary:
Adds detection of large stack size rlimits (over 1 TB or unlimited), which
results in an mmap location that our shadow mapping does not support. We
re-exec the application in this situation. Adds a test of this behavior.
Adds general detection of mmap regions outside of our app regions. In the
future we want to try to adaptively handle these but for now we abort.
Moves the existing Linux-specific mmap code into a platform-specific file
where the new rlimit code lives.
Reviewers: eugenis
Subscribers: vitalybuka, zhaoqin, kcc, aizatsky, llvm-commits, kubabrecka
Differential Revision: http://reviews.llvm.org/D20745
llvm-svn: 271079
In short, CVE-2016-2143 will crash the machine if a process uses both >4TB
virtual addresses and fork(). ASan, TSan, and MSan will, by necessity, map
a sizable chunk of virtual address space, which is much larger than 4TB.
Even worse, sanitizers will always use fork() for llvm-symbolizer when a bug
is detected. Disable all three by aborting on process initialization if
the running kernel version is not known to contain a fix.
Unfortunately, there's no reliable way to detect the fix without crashing
the kernel. So, we rely on whitelisting - I've included a list of upstream
kernel versions that will work. In case someone uses a distribution kernel
or applied the fix themselves, an override switch is also included.
Differential Revision: http://reviews.llvm.org/D19576
llvm-svn: 267747
On OS X 10.11+, we have "automatic interceptors", so we don't need to use DYLD_INSERT_LIBRARIES when launching instrumented programs. However, non-instrumented programs that load TSan late (e.g. via dlopen) are currently broken, as TSan will still try to initialize, but the program will crash/hang at random places (because the interceptors don't work). This patch adds an explicit check that interceptors are working, and if not, it aborts and prints out an error message suggesting to explicitly use DYLD_INSERT_LIBRARIES.
TSan unit tests run with a statically linked runtime, where interceptors don't work. To avoid aborting the process in this case, the patch replaces `DisableReexec()` with a weak `ReexecDisabled()` function which is defined to return true in unit tests.
Differential Revision: http://reviews.llvm.org/D18212
llvm-svn: 263695
Francis Ricci