The `MockAllocator` used in `ScudoTSDTest` wasn't allocated
properly aligned, which resulted in the `TSDs` of the shared
registry not being aligned either. This lead to some failures
like: https://reviews.llvm.org/D103119#2822008
This changes how the `MockAllocator` is allocated, same as
Vitaly did in the combined tests, properly aligning it, which
results in the `TSDs` being aligned as well.
Add a `DCHECK` in the shared registry to check that it is.
Differential Revision: https://reviews.llvm.org/D104402
Now that everything is forcibly linker initialized, it feels like a
good time to get rid of the `init`/`initLinkerInitialized` split.
This allows to get rid of various `memset` construct in `init` that
gcc complains about (this fixes a Fuchsia open issue).
I added various `DCHECK`s to ensure that we would get a zero-inited
object when entering `init`, which required ensuring that
`unmapTestOnly` leaves the object in a good state (tests are currently
the only location where an allocator can be "de-initialized").
Running the tests with `--gtest_repeat=` showed no issue.
Differential Revision: https://reviews.llvm.org/D103119
Summary:
fork() wasn't well (or at all) supported in Scudo. This materialized
in deadlocks in children.
In order to properly support fork, we will lock the allocator pre-fork
and unlock it post-fork in parent and child. This is done via a
`pthread_atfork` call installing the necessary handlers.
A couple of things suck here: this function allocates - so this has to
be done post initialization as our init path is not reentrance, and it
doesn't allow for an extra pointer - so we can't pass the allocator we
are currently working with.
In order to work around this, I added a post-init template parameter
that gets executed once the allocator is initialized for the current
thread. Its job for the C wrappers is to install the atfork handlers.
I reorganized a bit the impacted area and added some tests, courtesy
of cferris@ that were deadlocking prior to this fix.
Subscribers: jfb, #sanitizers, llvm-commits
Tags: #sanitizers, #llvm
Differential Revision: https://reviews.llvm.org/D72470
The macros INLINE and COMPILER_CHECK always expand to the same thing (inline
and static_assert respectively). Both expansions are standards compliant C++
and are used consistently in the rest of LLVM, so let's improve consistency
with the rest of LLVM by replacing them with the expansions.
Differential Revision: https://reviews.llvm.org/D70793
Summary:
We ran into a problem on Fuchsia where yielding threads would never
be deboosted, ultimately resulting in several threads spinning on the
same TSD, and no possibility for another thread to be scheduled,
dead-locking the process.
While this was fixed in Zircon, this lead to discussions about if
spinning without a break condition was a good decision, and settled on
a new hybrid model that would spin for a while then block.
Currently we are using a number of iterations for spinning that is
mostly arbitrary (based on sanitizer_common values), but this can
be tuned in the future.
Since we are touching `common.h`, we also use this change as a vehicle
for an Android optimization (the page size is fixed in Bionic, so use
a fixed value too).
Reviewers: morehouse, hctim, eugenis, dvyukov, vitalybuka
Reviewed By: hctim
Subscribers: srhines, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D64358
llvm-svn: 365790
Summary:
This is a redo of D63612.
Two problems came up on some bots:
- `__builtin_umull_overflow` was not declared. This is likely due to an
older clang or gcc, so add a guard with `__has_builtin` and fallback
to a division in the event the builtin doesn't exist;
- contradicting definition for `malloc`, etc. This is AFAIU due to the
fact that we ended up transitively including `stdlib.h` in the `.inc`
due to it being the flags parser header: so move the include to the
cc instead.
This should fix the issues, but since those didn't come up in my local
tests it's mostly guesswork.
Rest is the same!
Reviewers: morehouse, hctim, eugenis, vitalybuka, dyung, hans
Reviewed By: morehouse, dyung, hans
Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D63831
llvm-svn: 364547
Makes the build fail with e.g.
llvm/projects/compiler-rt/lib/scudo/standalone/wrappers_c.inc:20:68: error:
declaration of 'void* calloc(size_t, size_t)' has a different exception
specifier
INTERFACE WEAK void *SCUDO_PREFIX(calloc)(size_t nmemb, size_t size) {
^
See llvm-commits thread.
> Summary:
> This CL adds C & C++ wrappers and associated tests. Those use default
> configurations for a Scudo combined allocator that will likely be
> tweaked in the future.
>
> This is the final CL required to have a functional C & C++ allocator
> based on Scudo.
>
> The structure I have chosen is to define the core C allocation
> primitives in an `.inc` file that can be customized through defines.
> This allows to easily have 2 (or more) sets of wrappers backed by
> different combined allocators, as demonstrated by the `Bionic`
> wrappers: one set for the "default" allocator, one set for the "svelte"
> allocator.
>
> Currently all the tests added have been gtests, but I am planning to
> add some more lit tests as well.
>
> Reviewers: morehouse, eugenis, vitalybuka, hctim, rengolin
>
> Reviewed By: morehouse
>
> Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
>
> Tags: #llvm, #sanitizers
>
> Differential Revision: https://reviews.llvm.org/D63612
llvm-svn: 364400
Summary:
This CL adds C & C++ wrappers and associated tests. Those use default
configurations for a Scudo combined allocator that will likely be
tweaked in the future.
This is the final CL required to have a functional C & C++ allocator
based on Scudo.
The structure I have chosen is to define the core C allocation
primitives in an `.inc` file that can be customized through defines.
This allows to easily have 2 (or more) sets of wrappers backed by
different combined allocators, as demonstrated by the `Bionic`
wrappers: one set for the "default" allocator, one set for the "svelte"
allocator.
Currently all the tests added have been gtests, but I am planning to
add some more lit tests as well.
Reviewers: morehouse, eugenis, vitalybuka, hctim, rengolin
Reviewed By: morehouse
Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D63612
llvm-svn: 364332
Summary:
This CL adds the structures dealing with thread specific data for the
allocator. This includes the thread specific data structure itself and
two registries for said structures: an exclusive one, where each thread
will have its own TSD struct, and a shared one, where a pool of TSD
structs will be shared by all threads, with dynamic reassignment at
runtime based on contention.
This departs from the current Scudo implementation: we intend to make
the Registry a template parameter of the allocator (as opposed to a
single global entity), allowing various allocators to coexist with
different TSD registry models. As a result, TSD registry and Allocator
are tightly coupled.
This also corrects a couple of things in other files that I noticed
while adding this.
Reviewers: eugenis, vitalybuka, morehouse, hctim
Reviewed By: morehouse
Subscribers: srhines, mgorny, delcypher, jfb, #sanitizers, llvm-commits
Tags: #llvm, #sanitizers
Differential Revision: https://reviews.llvm.org/D62258
llvm-svn: 362962
Kostya Kortchinsky