Commit Graph

12446 Commits

Author SHA1 Message Date
Kostya Kortchinsky fe6e77f6fb [scudo][standalone] 32-bit improvement
Summary:
This tweaks some behaviors of the allocator wrt 32-bit, notably
tailoring the size-class map.

I had to remove a `printStats` from `__scudo_print_stats` since when
within Bionic they share the same slot so they can't coexist at the
same time. I have to find a solution for that later, but right now we
are not using the Svelte configuration.

Reviewers: rengolin

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74178
2020-02-07 11:16:48 -08:00
Jonas Devlieghere 4fe839ef3a [CMake] Rename EXCLUDE_FROM_ALL and make it an argument to add_lit_testsuite
EXCLUDE_FROM_ALL means something else for add_lit_testsuite as it does
for something like add_executable. Distinguish between the two by
renaming the variable and making it an argument to add_lit_testsuite.

Differential revision: https://reviews.llvm.org/D74168
2020-02-06 15:33:18 -08:00
Dimitry Andric 924c9030a8 [compiler-rt] clang-format FreeBSD-specific sanitizer sources
Formatting only, no functional change intended.
2020-02-06 22:48:08 +01:00
Mitch Phillips 8d19af685c [GWP-ASan] Use weak abort message definition.
Summary:
New shard out of the Check() function for GWP-ASan uses
android_set_abort_message. This is happily present on bionic Android,
but not Android for glibc host x86. Fix up to use the weak definition
always, so we don't have to worry.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: #sanitizers, llvm-commits, pcc, cferris

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74142
2020-02-06 10:36:25 -08:00
Mitch Phillips 25de3f98b8 [GWP-ASan] Fix PRNG to use IE TLS.
Summary:
GWP-ASan's PRNG didn't use Initial-Exec TLS. Fix that to ensure that we don't
have infinite recursion, and also that we don't allocate a DTV on Android when
GWP-ASan is touched.

Test coverage ensuring that the sample counter is UINT32_MAX for an
uninitialised GWP-ASan is provided by gwp_asan/tests/late_init.cpp.

Reviewers: pcc, cferris

Reviewed By: pcc

Subscribers: #sanitizers, llvm-commits, rprichard, eugenis

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74135
2020-02-06 10:08:23 -08:00
Peter Collingbourne dab7bdad04 scudo: Delete unused class ScudoByteMap. NFCI.
The class is only used in SizeClassAllocator32 in 64-bit mode, but we don't
use that class in 64-bit mode.

Differential Revision: https://reviews.llvm.org/D74099
2020-02-06 09:30:24 -08:00
Mitch Phillips 0bfc489093 [GWP-ASan] Fix unused variables from crash handler + clang-format
Summary: NFC - See title

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: merge_guards_bot, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74100
2020-02-05 17:31:32 -08:00
Mitch Phillips 0c3b2986ac [GWP-ASan] Change crash handler constant.
Constant is too large to fit into uintptr_t on 32-bit.
2020-02-05 16:46:51 -08:00
Mitch Phillips a62586846f [GWP-ASan] Crash Handler API.
Summary:
Forewarning: This patch looks big in #LOC changed. I promise it's not that bad, it just moves a lot of content from one file to another. I've gone ahead and left inline comments on Phabricator for sections where this has happened.

This patch:
 1. Introduces the crash handler API (crash_handler_api.h).
 2. Moves information required for out-of-process crash handling into an AllocatorState. This is a trivially-copied POD struct that designed to be recovered from a deceased process, and used by the crash handler to create a GWP-ASan report (along with the other trivially-copied Metadata struct).
 3. Implements the crash handler API using the AllocatorState and Metadata.
 4. Adds tests for the crash handler.
 5. Reimplements the (now optionally linked by the supporting allocator) in-process crash handler (i.e. the segv handler) using the new crash handler API.
 6. Minor updates Scudo & Scudo Standalone to fix compatibility.
 7. Changed capitalisation of errors (e.g. /s/Use after free/Use After Free).

Reviewers: cryptoad, eugenis, jfb

Reviewed By: eugenis

Subscribers: merge_guards_bot, pcc, jfb, dexonsmith, mgorny, cryptoad, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73557
2020-02-05 15:39:17 -08:00
Kostya Kortchinsky a9d5f8989d [scudo][standalone] Fix a race in the secondary release
Summary:
I tried to move the `madvise` calls outside of one of the secondary
mutexes, but this backfired. There is situation when a low release
interval is set combined with secondary pressure that leads to a race:
a thread can get a block from the cache, while another thread is
`madvise`'ing that block, resulting in a null header.

I changed the secondary race test so that this situation would be
triggered, and moved the release into the cache mutex scope.

Reviewers: cferris, pcc, eugenis, hctim, morehouse

Subscribers: jfb, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D74072
2020-02-05 11:02:51 -08:00
Petr Hosek 7800310cb5 [CMake][compiler-rt] Replace Windows backslashes with CMake ones
XRay builds uses llvm-config to obtain the ldflags and libs and then
passes those to CMake. Unfortunately, this breaks on Windows because
CMake tries to interpret backslashes followed by certain characters
as flags. We need to rewrite these into forward slashes that are used
by CMake (even on Windows).

Differential Revision: https://reviews.llvm.org/D73523
2020-02-04 22:35:31 -08:00
Evgenii Stepanov f48c1f5085 [compiler-rt] fix OpenBSD and Solaris build with sigaltstack interception
Summary:
`sigaltstack` interception is implemented D73816. This updated OpenBSD and Solaris bits to fix the build errors.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: fedor.sergeev, krytarowski, emaste, eugenis, dberris, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Patch by Igor Sugak.

Differential Revision: https://reviews.llvm.org/D73976
2020-02-04 15:50:59 -08:00
Kamil Rytarowski b79b7674eb [compiler-rt] [netbsd] Fix build after "implement sigaltstack interception"
Fallout after: https://reviews.llvm.org/D73816
2020-02-04 23:31:58 +01:00
Dimitry Andric 8a1f4feb1b [compiler-rt] Fix sanitizer_common build for FreeBSD
This was broken by 28c91219c7, which added `struct_stack_t_sz` only to
sanitizer_platform_limits_posix.{cpp,h}.
2020-02-04 22:51:07 +01:00
Evgenii Stepanov dd921cb89b [sanitizer] Add missing declarations for sigaltstack syscall wrappers.
Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73987
2020-02-04 13:10:43 -08:00
Peter Collingbourne f7de7084f4 scudo: Simplify getClassIdBySize() logic. NFCI.
By subtracting 1 from Size at the beginning we can simplify the
subsequent calculations. This also saves 4 instructions on aarch64
and 9 instructions on x86_64, but seems to be perf neutral.

Differential Revision: https://reviews.llvm.org/D73936
2020-02-04 09:32:27 -08:00
Evgenii Stepanov 6da6153759 hwasan_symbolize: allow 0x in the address field
Summary:
Fix parsing of mangled stack trace lines where the address has been
replaced with "0x", literally.

Reviewers: vitalybuka

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73823
2020-02-03 18:23:48 -08:00
Evgenii Stepanov 0dc634babf hwasan_symbolize: warn about missing symbols at most once per library
Reviewers: vitalybuka

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73822
2020-02-03 18:23:48 -08:00
Evgenii Stepanov 28c91219c7 [compiler-rt] implement sigaltstack interception
Summary:
An implementation for `sigaltstack` to make its side effect be visible to MSAN.

```
ninja check-msan
```

Reviewers: vitalybuka, eugenis

Reviewed By: eugenis

Subscribers: dberris, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73816

Patch by Igor Sugak.
2020-02-03 16:28:47 -08:00
Peter Collingbourne 47cda0cb36 scudo: Use more size classes in the malloc_free_loop benchmarks.
As a result of recent changes to the Android size classes, the malloc_free_loop
benchmark started exhausting the 8192 size class at 32768 iterations. To avoid
this problem (and to make the test more realistic), change the benchmark to
use a variety of size classes.

Differential Revision: https://reviews.llvm.org/D73918
2020-02-03 13:18:25 -08:00
Mitch Phillips 0d6fccb460 [GWP-ASan] Allow late initialisation if single-threaded.
Summary:
This patch allows for late initialisation of the GWP-ASan allocator. Previously, if late initialisation occurred, the sample counter was never updated, meaning we would end up having to wait for 2^32 allocations before getting a sampled allocation.

Now, we initialise the sampling mechanism in init() as well. We require init() to be called single-threaded, so this isn't a problem.

Reviewers: eugenis

Reviewed By: eugenis

Subscribers: merge_guards_bot, mgorny, #sanitizers, llvm-commits, cferris

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73896
2020-02-03 12:34:26 -08:00
Max Moroz ad7b908b4e [libFuzzer] Make dataflow and focus functions more user friendly.
Summary:
- Fail loudly if SetFocusFunction failed when it should not. For more info see
  - https://github.com/google/oss-fuzz/issues/3311
  - https://github.com/google/sanitizers/issues/1190
- Fail loudly if CollectDataFlow is called without seed corpus.

Reviewers: kcc, metzman

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73813
2020-02-03 08:36:03 -08:00
Petr Hosek c96eeebca8 [CMake] compiler-rt: Add COMPILER_RT_BUILTINS_ENABLE_PIC
The configuration for -fPIC in the builtins library when built standalone
is unconditional, stating that the flags would "normally be added... by
the llvm cmake step"

This is untrue, as the llvm cmake step checks LLVM_ENABLE_PIC, which allows
a client to turn off -fPIC.

I've added an option when compiler-rt builtins are configured standalone, such
as when built as part of the LLVM runtimes system, to guard the application of
-fPIC for users that want it.

Patch By: JamesNagurne

Differential Revision: https://reviews.llvm.org/D72950
2020-01-31 15:57:18 -08:00
Kostya Kortchinsky 64cb77b946 [scudo][standalone] Change default Android config
Summary:
This changes a couple of parameters in the default Android config to
address some performance and memory footprint issues (well to be closer
to the default Bionic allocator numbers).

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73750
2020-01-31 14:46:35 -08:00
Kamil Rytarowski 3a200f3f2e [compiler-rt] Fix build on NetBSD 9.99.44
Fix build on >= 9.99.44 after the removal of urio(4).
Add compat code for the device as NetBSD-9.0 is supported.
2020-01-31 14:57:20 +01:00
Kostya Kortchinsky 654f5d6845 [scudo][standalone] Release secondary memory on purge
Summary:
The Secondary's cache needs to be released when the Combined's
`releaseToOS` function is called (via `M_PURGE`) for example,
which this CL adds.

Additionally, if doing a forced release, we'll release the
transfer batch class as well since now we can do that.

There is a couple of other house keeping changes as well:
- read the page size only once in the Secondary Cache `store`
- remove the interval check for `CanRelease`: we are going to
  make that configurable via `mallopt` so this needs not be
  set in stone there.

Reviewers: cferris, hctim, pcc, eugenis

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73730
2020-01-30 13:22:45 -08:00
Yuanfang Chen 29181e5426 [compiler-rt][profile] fix test/instrprof-set-filename.c on windows
Summary: `.cmd` is interpreted as script in windows console.

Reviewers: davidxl, rnk

Reviewed By: davidxl

Differential Revision: https://reviews.llvm.org/D73327
2020-01-29 15:00:56 -08:00
Kostya Kortchinsky 6cb830de6e [scudo][standalone] Revert some perf-degrading changes
Summary:
A couple of seemingly innocuous changes ended up having a large impact
on the 32-bit performance. I still have to make those configurable at
some point, but right now it will have to do.

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73658
2020-01-29 14:00:48 -08:00
Bjorn Pettersson f4ca2ac822 [scudo] Skip building scudo standalone if sys/auxv.h can't be found
Summary:
Since commit c299d1981d scudo
standalone can't be built without including sys/auxv.h.
I do not have that file on my system, and my builds have failed
when trying to simply build "all" runtimes. Assuming that "all"
means "all possible given the current environment" we need to
guard the setting of COMPILER_RT_HAS_SCUDO_STANDALONE=TRUE by
first checking if sys/auxv.h can be found.

Reviewers: pcc, cryptoad

Reviewed By: pcc

Subscribers: mgorny, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73631
2020-01-29 18:18:59 +01:00
Shoaib Meenai d8f6950828 [asan] Fix test compilation on Android API <= 17
mlockall and munlockall were introduced in Android API 17, so avoid
referencing them on prior versions.

Differential Revision: https://reviews.llvm.org/D73515
2020-01-28 14:36:19 -08:00
Roland McGrath 90a10f00ff [lsan] Support LeakSanitizer runtime on Fuchsia
Support LeakSanitizer runtime on Fuchsia.

Patch By: mcgrathr

Differential Revision: https://reviews.llvm.org/D72887
2020-01-28 11:34:53 -08:00
Kostya Kortchinsky a1f6ff2681 [scudo][standalone] Fix Android logging
Summary:
Zygote & children's stderr is lost, so use Bionic's provided allocation
free syslog function for `outputRaw`. Get rid of the mutex as it's not
vital and could cause issues with `fork`.

Reviewers: cferris, pcc, eugenis, hctim, morehouse

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73561
2020-01-28 11:03:39 -08:00
Kostya Kortchinsky 993e3c9269 [scudo][standalone] Secondary & general other improvements
Summary:
This CL changes multiple things to improve performance (notably on
Android).We introduce a cache class for the Secondary that is taking
care of this mechanism now.

The changes:
- change the Secondary "freelist" to an array. By keeping free secondary
  blocks linked together through their headers, we were keeping a page
  per block, which isn't great. Also we know touch less pages when
  walking the new "freelist".
- fix an issue with the freelist getting full: if the pattern is an ever
  increasing size malloc then free, the freelist would fill up and
  entries would not be used. So now we empty the list if we get to many
  "full" events;
- use the global release to os interval option for the secondary: it
  was too costly to release all the time, particularly for pattern that
  are malloc(X)/free(X)/malloc(X). Now the release will only occur
  after the selected interval, when going through the deallocate path;
- allow release of the `BatchClassId` class: it is releasable, we just
  have to make sure we don't mark the batches containing batches
  pointers as free.
- change the default release interval to 1s for Android to match the
  current Bionic allocator configuration. A patch is coming up to allow
  changing it through `mallopt`.
- lower the smallest class that can be released to `PageSize/64`.

Reviewers: cferris, pcc, eugenis, morehouse, hctim

Subscribers: phosek, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73507
2020-01-28 07:28:55 -08:00
Petr Hosek 2533bc2361 Revert "[lsan] Support LeakSanitizer runtime on Fuchsia"
This reverts commit d59e3429f3.
2020-01-28 00:24:41 -08:00
Roland McGrath d59e3429f3 [lsan] Support LeakSanitizer runtime on Fuchsia
Support LeakSanitizer runtime on Fuchsia.

Patch By: mcgrathr

Differential Revision: https://reviews.llvm.org/D72887
2020-01-27 23:35:06 -08:00
Evgenii Stepanov 46044a6900 [gwp-asan] Implement malloc_iterate.
Summary:
This is an Android-specific interface for iterating over all live
allocations in a memory range.

Reviewers: hctim, cferris

Subscribers: mgorny, mgrang, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73305
2020-01-27 14:37:33 -08:00
Roland McGrath 38fd1806a1 [lsan] Factor pthread-specific assumptions out of thread tracking code
This is a small refactoring to prepare for porting LSan to Fuchsia.
Factor out parts of lsan_thread.{cpp,h} that don't apply to Fuchsia.
Since existing supported systems are POSIX-based, the affected code
is moved to lsan_posix.{cpp.h}.

Patch By: mcgrathr

Differential Revision: https://reviews.llvm.org/D73309
2020-01-24 16:55:11 -08:00
Roland McGrath aae707cd88 [lsan] Expose Frontier object to OS-specific LockStuffAndStopTheWorld callback
This is a small refactoring to prepare for porting LSan to Fuchsia.
On Fuchsia, the system supplies a unified API for suspending threads and
enumerating roots from OS-specific places like thread state and global data
ranges. So its LockStuffAndStopTheWorld implementation will make specific
callbacks for all the OS-specific root collection work before making the
common callback that includes the actual leak-checking logic.

Patch By: mcgrathr

Differential Revision: https://reviews.llvm.org/D72988
2020-01-24 16:53:35 -08:00
Roland McGrath 81b700e302 [sanitizer_common] Implement MemoryMappingLayout for Fuchsia
This is needed to port lsan to Fuchsia.

Patch By: mcgrathr

Differential Revision: https://reviews.llvm.org/D72886
2020-01-24 16:35:43 -08:00
Mitch Phillips e1440f594c [GWP-ASan] Add names to anonymous mappings.
Summary:
Adds names to anonymous GWP-ASan mappings. This helps Android with debugging
via. /proc/maps, as GWP-ASan-allocated mappings are now easily identifyable.

Reviewers: eugenis, cferris

Reviewed By: eugenis

Subscribers: merge_guards_bot, #sanitizers, llvm-commits, cryptoad, pcc

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73373
2020-01-24 15:02:02 -08:00
Evgenii Stepanov 596d06145a [GWP-ASan] enable/disable and fork support.
Summary:
* Implement enable() and disable() in GWP-ASan.
* Setup atfork handler.
* Improve test harness sanity and re-enable GWP-ASan in Scudo.

Scudo_standalone disables embedded GWP-ASan as necessary around fork().
Standalone GWP-ASan sets the atfork handler in init() if asked to. This
requires a working malloc(), therefore GWP-ASan initialization in Scudo
is delayed to the post-init callback.

Test harness changes are about setting up a single global instance of
the GWP-ASan allocator so that pthread_atfork() does not create
dangling pointers.

Test case shamelessly stolen from D72470.

Reviewers: cryptoad, hctim, jfb

Subscribers: mgorny, jfb, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73294
2020-01-24 13:53:26 -08:00
Evgenii Stepanov 966b5182ba Change internal_start_thread arguments to match pthread_create.
This avoids a CFI-unfriendly function pointer type cast in
internal_start_thread.
2020-01-23 13:15:16 -08:00
Dan Liew 9d9b470e69 [CMake] Refactor iOS simulator/device test configuration generation code for LibFuzzer.
Summary:
In order to do this `FUZZER_SUPPORTED_OS` had to be pulled out of
`lib/fuzzer/CMakeLists.txt` and into the main config so we can use it
from the `test/fuzzer/CMakeList.txt`. `FUZZER_SUPPORTED_OS` currently
has the same value of `SANITIZER_COMMON_SUPPORTED_OS` which preserves
the existing behaviour but this allows us in the future to adjust the
supported platforms independent of `SANITIZER_COMMON_SUPPORTED_OS`. This
mirrors the other sanitizers.

For non-Apple platforms `FUZZER_SUPPORTED_OS` is not defined and
surprisingly this was the behaviour before this patch because
`SANITIZER_COMMON_SUPPORTED_OS` was actually empty. This appears to
not matter right now because the functions that take an `OS` as an
argument seem to ignore it on non-Apple platforms.

While this change tries to be NFC it is technically not because we
now generate an iossim config whereas previously we didn't. This seems
like the right thing to do because the build system was configured to
compile LibFuzzer for iossim but previously we weren't generating a lit
test config for it. The device/simulator testing configs don't run by
default anyway so this shouldn't break testing.

This change relies on the get_capitalized_apple_platform() function
added in a previous commit.

rdar://problem/58798733

Reviewers: kubamracek, yln

Subscribers: mgorny, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73243
2020-01-23 12:44:00 -08:00
Dan Liew 06569361d0 [CMake][NFC] Refactor iOS simulator/device test configuration generation code for TSan.
Summary:
The previous code hard-coded platform names but compiler-rt's CMake
build system actually already knows which Apple platforms TSan supports.

This change uses this information to enumerate the different Apple
platforms.

This change relies on the `get_capitalized_apple_platform()` function
added in a previous commit.

rdar://problem/58798733

Reviewers: kubamracek, yln

Subscribers: mgorny, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73238
2020-01-23 12:44:00 -08:00
Dan Liew 1262745060 [CMake][NFC] Refactor iOS simulator/device test configuration generation code for ASan.
Summary:
The previous code hard-coded platform names but compiler-rt's CMake
build system actually already knows which Apple platforms ASan supports.

This change uses this information to enumerate the different Apple
platforms.

rdar://problem/58798733

Reviewers: kubamracek, yln

Subscribers: mgorny, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73232
2020-01-23 12:44:00 -08:00
Max Moroz 15f1d5d144 [libFuzzer] Add INFO output when LLVMFuzzerCustomMutator is found.
Summary:
there is an ongoing work on interchangeable custom mutators
(https://github.com/google/clusterfuzz/pull/1333/files#r367706283)
and having some sort of signalling from libFuzzer that it has loaded
a custom mutator would be helpful.

The initial idea was to make the mutator to print something, but given
the anticipated variety of different mutators, it does not seem possible
to make all of them print the same message to signal their execution.

Reviewers: kcc, metzman

Reviewed By: metzman

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73136
2020-01-22 12:56:16 -08:00
Kostya Kortchinsky 990acd450c [scudo][standalone] Reduce Android region sizes to 128MB
Summary:
Unity is making irresponsible assumptions as to how clumped up memory
should be. With larger regions, we break those, resulting in errors
like:

"Using memoryadresses from more that 16GB of memory"

This is unfortunately one of those situations where we have to bend to
existing code because we doubt it's going to change any time soon.

128MB should be enough, but we could be flirting with OOMs in the
higher class sizes.

Reviewers: cferris, eugenis, hctim, morehouse, pcc

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73143
2020-01-22 09:42:07 -08:00
Michał Górny 3215f7c7a8 [compiler-rt] [builtins] Fix clear_cache_test to work with MPROTECT
Fix clear_cache_test to work on NetBSD with PaX MPROTECT enabled, that
is when creating W+X mmaps is prohibited.  Use the recommended solution:
create two mappings for the same memory area, make one of them RW, while
the other RX.  Copy the function into the RW area but run it from the RX
area.

In order to implement this, I've split the pointer variables to
'write_buffer' and 'execution_buffer'.  Both are separate pointers
on NetBSD, while they have the same value on other systems.

I've also split the memcpy_f() into two: new memcpy_f() that only takes
care of copying memory and discards the (known) result of memcpy(),
and realign_f() that applies ARM realignment to the given pointer.
Again, there should be no difference on non-NetBSD systems but on NetBSD
copying is done on write_buffer, while realignment on pointer
to the execution_buffer.

I have tested this change on NetBSD and Linux.

Differential Revision: https://reviews.llvm.org/D72578
2020-01-22 17:04:54 +01:00
Kostya Kortchinsky 561fa84477 [scudo][standalone] Allow sched_getaffinity to fail
Summary:
In some configuration, `sched_getaffinity` can fail. Some reasons for
that being the lack of `CAP_SYS_NICE` capability or some syscall
filtering and so on.

This should not be fatal to the allocator, so in this situation, we
will fallback to the `MaxTSDCount` value specified in the allocator
configuration.

Reviewers: cferris, eugenis, hctim, morehouse, pcc

Subscribers: #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D73055
2020-01-21 11:18:18 -08:00
Peter Collingbourne 9b9c68a2d6 hwasan: Remove dead code. NFCI.
Differential Revision: https://reviews.llvm.org/D72896
2020-01-17 15:12:38 -08:00