-fno-lto is in SANITIZER_COMMON_CFLAGS but not here.
Don't use SANITIZER_COMMON_CFLAGS because of performance issues.
See https://bugs.llvm.org/show_bug.cgi?id=46838.
Fixes
$ ninja TScudoCUnitTest-i386-Test
on an LLVM build with -DLLVM_ENABLE_LTO=Thin.
check-scudo now passes.
Reviewed By: cryptoad
Differential Revision: https://reviews.llvm.org/D84805
This adds the code to support calling mallopt and converting the
options to the internal Option enum.
Reviewed By: cryptoad
Differential Revision: https://reviews.llvm.org/D84806
Summary:
Partners have requested the ability to configure more parts of Scudo
at runtime, notably the Secondary cache options (maximum number of
blocks cached, maximum size) as well as the TSD registry options
(the maximum number of TSDs in use).
This CL adds a few more Scudo specific `mallopt` parameters that are
passed down to the various subcomponents of the Combined allocator.
- `M_CACHE_COUNT_MAX`: sets the maximum number of Secondary cached items
- `M_CACHE_SIZE_MAX`: sets the maximum size of a cacheable item in the Secondary
- `M_TSDS_COUNT_MAX`: sets the maximum number of TSDs that can be used (Shared Registry only)
Regarding the TSDs maximum count, this is a one way option, only
allowing to increase the count.
In order to allow for this, I rearranged the code to have some `setOption`
member function to the relevant classes, using the `scudo::Option` class
enum to determine what is to be set.
This also fixes an issue where a static variable (`Ready`) was used in
templated functions without being set back to `false` every time.
Reviewers: pcc, eugenis, hctim, cferris
Subscribers: jfb, llvm-commits, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D84667
make_unique is a C++14 feature, and this prevents us from building on
Ubuntu Trusty. While we do use a C++14 compatible toolchain for building
in general, we fall back to the system toolchain for building the
compiler-rt tests.
The reason is that those tests get cross-compiled for e.g. 32-bit and
64-bit x86, and while the toolchain provides libstdc++ in those
flavours, the resulting compiler-rt test binaries don't get RPATH set
and so won't start if they're linked with that toolchain.
We've tried linking the test binaries against libstdc++ statically, by
passing COMPILER_RT_TEST_COMPILER_CFLAGS=-static-libstdc++. That mostly
works, but some test targets append -lstdc++ to the compiler invocation.
So, after spending way too much time on this, let's just avoid C++14
here for now.
Summary:
On 32-b, the release algo loops multiple times over the freelist for a size
class, which lead to a decrease in performance when there were a lot of free
blocks.
This changes the release functions to loop only once over the freelist, at the
cost of using a little bit more memory for the release process: instead of
working on one region at a time, we pass the whole memory area covered by all
the regions for a given size class, and work on sub-areas of `RegionSize` in
this large area. For 64-b, we just have 1 sub-area encompassing the whole
region. Of course, not all the sub-areas within that large memory area will
belong to the class id we are working on, but those will just be left untouched
(which will not add to the RSS during the release process).
Reviewers: pcc, cferris, hctim, eugenis
Subscribers: llvm-commits, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D83993
This guarantees that we will detect a buffer overflow or underflow
that overwrites an adjacent block. This spatial guarantee is similar
to the temporal guarantee that we provide for immediate use-after-free.
Enabling odd/even tags involves a tradeoff between use-after-free
detection and buffer overflow detection. Odd/even tags make it more
likely for buffer overflows to be detected by increasing the size of
the guaranteed "red zone" around the allocation, but on the other
hand use-after-free is less likely to be detected because the tag
space for any particular chunk is cut in half. Therefore we introduce
a tuning setting to control whether odd/even tags are enabled.
Differential Revision: https://reviews.llvm.org/D84361
Note: Resubmission with frame pointers force-enabled to fix builds with
-DCOMPILER_RT_BUILD_BUILTINS=False
Summary:
Splits the unwinder into a non-segv (for allocation/deallocation traces) and a
segv unwinder. This ensures that implementations can select an accurate, slower
unwinder in the segv handler (if they choose to use the GWP-ASan provided one).
This is important as fast frame-pointer unwinders (like the sanitizer unwinder)
don't like unwinding through signal handlers.
Reviewers: morehouse, cryptoad
Reviewed By: morehouse, cryptoad
Subscribers: cryptoad, mgorny, eugenis, pcc, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D83994
It was causing tests to fail in -DCOMPILER_RT_BUILD_BUILTINS=OFF builds:
GwpAsan-Unittest :: ./GwpAsan-x86_64-Test/BacktraceGuardedPoolAllocator.DoubleFree
GwpAsan-Unittest :: ./GwpAsan-x86_64-Test/BacktraceGuardedPoolAllocator.UseAfterFree
see comment on the code review.
> Summary:
> Splits the unwinder into a non-segv (for allocation/deallocation traces) and a
> segv unwinder. This ensures that implementations can select an accurate, slower
> unwinder in the segv handler (if they choose to use the GWP-ASan provided one).
> This is important as fast frame-pointer unwinders (like the sanitizer unwinder)
> don't like unwinding through signal handlers.
>
> Reviewers: morehouse, cryptoad
>
> Reviewed By: morehouse, cryptoad
>
> Subscribers: cryptoad, mgorny, eugenis, pcc, #sanitizers
>
> Tags: #sanitizers
>
> Differential Revision: https://reviews.llvm.org/D83994
This reverts commit 502f0cc0e3.
Summary:
Splits the unwinder into a non-segv (for allocation/deallocation traces) and a
segv unwinder. This ensures that implementations can select an accurate, slower
unwinder in the segv handler (if they choose to use the GWP-ASan provided one).
This is important as fast frame-pointer unwinders (like the sanitizer unwinder)
don't like unwinding through signal handlers.
Reviewers: morehouse, cryptoad
Reviewed By: morehouse, cryptoad
Subscribers: cryptoad, mgorny, eugenis, pcc, #sanitizers
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D83994
Summary:
Releasing smaller blocks is costly and only yields significant
results when there is a large percentage of free bytes for a given
size class (see numbers below).
This CL introduces a couple of additional checks for sizes lower
than 256. First we want to make sure that there is enough free bytes,
relatively to the amount of allocated bytes. We are looking at 8X% to
9X% (smaller blocks require higher percentage). We also want to make
sure there has been enough activity with the freelist to make it
worth the time, so we now check that the bytes pushed to the freelist
is at least 1/16th of the allocated bytes for those classes.
Additionally, we clear batches before destroying them now - this
could have prevented some releases to occur (class id 0 rarely
releases anyway).
Here are the numbers, for about 1M allocations in multiple threads:
Size: 16
85% freed -> 0% released
86% freed -> 0% released
87% freed -> 0% released
88% freed -> 0% released
89% freed -> 0% released
90% freed -> 0% released
91% freed -> 0% released
92% freed -> 0% released
93% freed -> 0% released
94% freed -> 0% released
95% freed -> 0% released
96% freed -> 0% released
97% freed -> 2% released
98% freed -> 7% released
99% freed -> 27% released
Size: 32
85% freed -> 0% released
86% freed -> 0% released
87% freed -> 0% released
88% freed -> 0% released
89% freed -> 0% released
90% freed -> 0% released
91% freed -> 0% released
92% freed -> 0% released
93% freed -> 0% released
94% freed -> 0% released
95% freed -> 1% released
96% freed -> 3% released
97% freed -> 7% released
98% freed -> 17% released
99% freed -> 41% released
Size: 48
85% freed -> 0% released
86% freed -> 0% released
87% freed -> 0% released
88% freed -> 0% released
89% freed -> 0% released
90% freed -> 0% released
91% freed -> 0% released
92% freed -> 0% released
93% freed -> 0% released
94% freed -> 1% released
95% freed -> 3% released
96% freed -> 7% released
97% freed -> 13% released
98% freed -> 27% released
99% freed -> 52% released
Size: 64
85% freed -> 0% released
86% freed -> 0% released
87% freed -> 0% released
88% freed -> 0% released
89% freed -> 0% released
90% freed -> 0% released
91% freed -> 0% released
92% freed -> 1% released
93% freed -> 2% released
94% freed -> 3% released
95% freed -> 6% released
96% freed -> 11% released
97% freed -> 20% released
98% freed -> 35% released
99% freed -> 59% released
Size: 80
85% freed -> 0% released
86% freed -> 0% released
87% freed -> 0% released
88% freed -> 0% released
89% freed -> 0% released
90% freed -> 1% released
91% freed -> 1% released
92% freed -> 2% released
93% freed -> 4% released
94% freed -> 6% released
95% freed -> 10% released
96% freed -> 17% released
97% freed -> 26% released
98% freed -> 41% released
99% freed -> 64% released
Size: 96
85% freed -> 0% released
86% freed -> 0% released
87% freed -> 0% released
88% freed -> 0% released
89% freed -> 1% released
90% freed -> 1% released
91% freed -> 3% released
92% freed -> 4% released
93% freed -> 6% released
94% freed -> 10% released
95% freed -> 14% released
96% freed -> 21% released
97% freed -> 31% released
98% freed -> 47% released
99% freed -> 68% released
Size: 112
85% freed -> 0% released
86% freed -> 1% released
87% freed -> 1% released
88% freed -> 2% released
89% freed -> 3% released
90% freed -> 4% released
91% freed -> 6% released
92% freed -> 8% released
93% freed -> 11% released
94% freed -> 16% released
95% freed -> 22% released
96% freed -> 30% released
97% freed -> 40% released
98% freed -> 55% released
99% freed -> 74% released
Size: 128
85% freed -> 0% released
86% freed -> 1% released
87% freed -> 1% released
88% freed -> 2% released
89% freed -> 3% released
90% freed -> 4% released
91% freed -> 6% released
92% freed -> 8% released
93% freed -> 11% released
94% freed -> 16% released
95% freed -> 22% released
96% freed -> 30% released
97% freed -> 40% released
98% freed -> 55% released
99% freed -> 74% released
Size: 144
85% freed -> 1% released
86% freed -> 2% released
87% freed -> 3% released
88% freed -> 4% released
89% freed -> 6% released
90% freed -> 7% released
91% freed -> 10% released
92% freed -> 13% released
93% freed -> 17% released
94% freed -> 22% released
95% freed -> 28% released
96% freed -> 37% released
97% freed -> 47% released
98% freed -> 61% released
99% freed -> 78% released
Size: 160
85% freed -> 1% released
86% freed -> 2% released
87% freed -> 3% released
88% freed -> 4% released
89% freed -> 5% released
90% freed -> 7% released
91% freed -> 10% released
92% freed -> 13% released
93% freed -> 17% released
94% freed -> 22% released
95% freed -> 28% released
96% freed -> 37% released
97% freed -> 47% released
98% freed -> 61% released
99% freed -> 78% released
Size: 176
85% freed -> 2% released
86% freed -> 3% released
87% freed -> 4% released
88% freed -> 6% released
89% freed -> 7% released
90% freed -> 9% released
91% freed -> 12% released
92% freed -> 15% released
93% freed -> 20% released
94% freed -> 25% released
95% freed -> 32% released
96% freed -> 40% released
97% freed -> 51% released
98% freed -> 64% released
99% freed -> 80% released
Size: 192
85% freed -> 4% released
86% freed -> 5% released
87% freed -> 6% released
88% freed -> 8% released
89% freed -> 10% released
90% freed -> 13% released
91% freed -> 16% released
92% freed -> 20% released
93% freed -> 24% released
94% freed -> 30% released
95% freed -> 37% released
96% freed -> 45% released
97% freed -> 55% released
98% freed -> 68% released
99% freed -> 82% released
Size: 224
85% freed -> 8% released
86% freed -> 10% released
87% freed -> 12% released
88% freed -> 14% released
89% freed -> 17% released
90% freed -> 20% released
91% freed -> 23% released
92% freed -> 28% released
93% freed -> 33% released
94% freed -> 39% released
95% freed -> 46% released
96% freed -> 53% released
97% freed -> 63% released
98% freed -> 73% released
99% freed -> 85% released
Size: 240
85% freed -> 8% released
86% freed -> 10% released
87% freed -> 12% released
88% freed -> 14% released
89% freed -> 17% released
90% freed -> 20% released
91% freed -> 23% released
92% freed -> 28% released
93% freed -> 33% released
94% freed -> 39% released
95% freed -> 46% released
96% freed -> 54% released
97% freed -> 63% released
98% freed -> 73% released
99% freed -> 85% released
Reviewers: cferris, pcc, hctim, eugenis
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D82031
Summary:
When enabling some malloc debug features on Android, multiple 32 bit
regions become exhausted, and the allocations fail. Allow allocations
to keep trying each bigger class in the Primary until it finds a fit.
In addition, some Android tests running on 32 bit fail sometimes due
to a running out of space in two regions, and then fail the allocation.
Reviewers: cryptoad
Reviewed By: cryptoad
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D82070
Summary:
Implement pattern initialization of memory (excluding the secondary
allocator because it already has predictable memory contents).
Expose both zero and pattern initialization through the C API.
Reviewers: pcc, cryptoad
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D79133
Summary:
If this is called before the malloc call in a thread (or in the whole
program), the lazy initialization of the allocation can overwrite
Options.
Reviewers: pcc, cryptoad
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D79130
Introduce a function __scudo_get_error_info() that may be called to interpret
a crash resulting from a memory error, potentially in another process,
given information extracted from the crashing process. The crash may be
interpreted as a use-after-free, buffer overflow or buffer underflow.
Also introduce a feature to optionally record a stack trace for each
allocation and deallocation. If this feature is enabled, a stack trace for
the allocation and (if applicable) the deallocation will also be available
via __scudo_get_error_info().
Differential Revision: https://reviews.llvm.org/D77283
Summary:
The function used to log on Android will cut the message past
a certain amount of characters, which mostly materializes when
dumping the size class map on OOM.
This change splits the log message at newline boundaries.
Reviewers: pcc, cferris, hctim, eugenis
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D78018
Summary:
Fuchsia's gcc uses this, which in turn prevents us to compile successfully
due to a few `memset`'ing some non-trivial classes in some `init`.
Change those `memset` to members initialization.
Reviewers: pcc, hctim
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D77902
For MTE error reporting we will need to expose interfaces for crash handlers
to use to interpret scudo headers and metadata. The intent is that these
interfaces will live in scudo/interface.h.
Move the existing interface.h into an include/scudo directory and make it
independent of the internal headers, so that we will be able to add the
interfaces there.
Differential Revision: https://reviews.llvm.org/D76648
Summary:
We introduced a way to fallback to the immediately larger size class for
the Primary in the event a region was full, but in the event of the largest
size class, we would just fail.
This change allows to fallback to the Secondary when the last region of
the Primary is full. We also expand the trick to all platforms as opposed
to being Android only, and update the test to cover the new case.
Reviewers: hctim, cferris, eugenis, morehouse, pcc
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D76430
Summary:
For the 32b primary, whenever we created a region, we would fill it
all at once (eg: create all the transfer batches for all the blocks
in that region). This wasn't ideal as all the potential blocks in
a newly created region might not be consummed right away, and it was
using extra memory (and release cycles) to keep all those free
blocks.
So now we keep track of the current region for a given class, and
how filled it is, carving out at most `MaxNumBatches` worth of
blocks at a time.
Additionally, lower `MaxNumBatches` on Android from 8 to 4. This
lowers the randomness of blocks, which isn't ideal for security, but
keeps things more clumped up for PSS/RSS accounting purposes.
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D75551
Summary:
This patch includes several changes to reduce the overall footprint
of the allocator:
- for realloc'd chunks: only keep the same chunk when lowering the size
if the delta is within a page worth of bytes;
- when draining a cache: drain the beginning, not the end; we add pointers
at the end, so that meant we were draining the most recently added
pointers;
- change the release code to account for an freed up last page: when
scanning the pages, we were looking for pages fully covered by blocks;
in the event of the last page, if it's only partially covered, we
wouldn't mark it as releasable - even what follows the last chunk is
all 0s. So now mark the rest of the page as releasable, and adapt the
test;
- add a missing `setReleaseToOsIntervalMs` to the cacheless secondary;
- adjust the Android classes based on more captures thanks to pcc@'s
tool.
Reviewers: pcc, cferris, hctim, eugenis
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D75142
Summary:
Most of our larger data is dynamically allocated (via `map`) but it
became an hindrance with regard to init time, for a cost to benefit
ratio that is not great. So change the `TSD`s, `RegionInfo`, `ByteMap`
to be static.
Additionally, for reclaiming, we used mapped & unmapped a buffer each
time, which is costly. It turns out that we can have a static buffer,
and that there isn't much contention on it.
One of the other things changed here, is that we hard set the number
of TSDs on Android to the maximum number, as there could be a
situation where cores are put to sleep and we could miss some.
Subscribers: mgorny, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D74696
Summary:
Add a method to set the release to OS value as the system runs,
and allow this to be set differently in the primary and the secondary.
Also, add a default value to use for primary and secondary. This
allows Android to have a default that is different for
primary/secondary.
Update mallopt to support setting the release to OS value.
Reviewers: pcc, cryptoad
Reviewed By: cryptoad
Subscribers: cryptoad, jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D74448
Summary:
Due to Unity, we had to reduce our region sizes, but in some rare
situations, some programs (mostly tests AFAICT) manage to fill up
a region for a given size class.
So this adds a workaround for that attempts to allocate the block
from the immediately larger size class, wasting some memory but
allowing the application to keep going.
Reviewers: pcc, eugenis, cferris, hctim, morehouse
Subscribers: #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D74567
Add an optional table lookup after the existing logarithm computation
for MidSize < Size <= MaxSize during size -> class lookups. The lookup is
O(1) due to indexing a precomputed (via constexpr) table based on a size
table. Switch to this approach for the Android size class maps.
Other approaches considered:
- Binary search was found to have an unacceptable (~30%) performance cost.
- An approach using NEON instructions (see older version of D73824) was found
to be slightly slower than this approach on newer SoCs but significantly
slower on older ones.
By selecting the values in the size tables to minimize wastage (for example,
by passing the malloc_info output of a target program to the included
compute_size_class_config program), we can increase the density of allocations
at a small (~0.5% on bionic malloc_sql_trace as measured using an identity
table) performance cost.
Reduces RSS on specific Android processes as follows (KB):
Before After
zygote (median of 50 runs) 26836 26792 (-0.2%)
zygote64 (median of 50 runs) 30384 30076 (-1.0%)
dex2oat (median of 3 runs) 375792 372952 (-0.8%)
I also measured the amount of whole-system idle dirty heap on Android by
rebooting the system and then running the following script repeatedly until
the results were stable:
for i in $(seq 1 50); do grep -A5 scudo: /proc/*/smaps | grep Pss: | cut -d: -f2 | awk '{s+=$1} END {print s}' ; sleep 1; done
I did this 3 times both before and after this change and the results were:
Before: 365650, 356795, 372663
After: 344521, 356328, 342589
These results are noisy so it is hard to make a definite conclusion, but
there does appear to be a significant effect.
On other platforms, increase the sizes of all size classes by a fixed offset
equal to the size of the allocation header. This has also been found to improve
density, since it is likely for allocation sizes to be a power of 2, which
would otherwise waste space by pushing the allocation into the next size class.
Differential Revision: https://reviews.llvm.org/D73824
This lets us remove two pointer indirections (one by removing the pointer,
and another by making the AllocatorPtr declaration hidden) in the C++ wrappers.
Differential Revision: https://reviews.llvm.org/D74356
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
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
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
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
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
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
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
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
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
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
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
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
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
Arthur Eubanks