Commit Graph

17 Commits

Author SHA1 Message Date
Leonard Chan bed8882426 [scudo][test] Disable -Wfree-nonheap-object
As of 4f395db86b which contains updates to
-Wfree-nonheap-object, a line in this test will trigger the warning. This
particular line is ok though since it's meant to test a free on a bad pointer.

Differential Revision: https://reviews.llvm.org/D97516
2021-02-26 11:14:50 -08:00
Kostya Kortchinsky e9cc5fef64 [scudo][standalone] Enable death tests on Fuchsia
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
2021-01-25 09:19:10 -08:00
Christopher Ferris f14472a2e3 [scudo][standalone] Add new mallopt options.
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
2020-07-28 16:28:16 -07:00
Kostya Kortchinsky 6f00f3b56e [scudo][standalone] mallopt runtime configuration options
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
2020-07-28 11:57:54 -07:00
Peter Collingbourne b83417aa7e scudo: Interleave odd and even tags for adjacent blocks.
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
2020-07-23 15:09:13 -07:00
Evgenii Stepanov 519959ad82 [scudo] Fix deadlock in ScudoWrappersCTest.DisableForkEnable test.
pthread_cond_wait needs a loop around it to handle spurious wake ups,
as well as the case when signal runs before wait.
2020-05-28 14:31:33 -07:00
Peter Collingbourne 87303fd917 scudo: Fix various test failures, mostly on 32-bit.
Differential Revision: https://reviews.llvm.org/D74429
2020-02-11 12:18:35 -08:00
Peter Collingbourne 9068766b9a scudo: Add a dump of primary allocation sizes to malloc_info output.
This will be useful for optimizing the size class map.

Differential Revision: https://reviews.llvm.org/D74098
2020-02-10 15:05:27 -08:00
Kostya Kortchinsky 9ef6faf496 [scudo][standalone] Fork support
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
2020-01-14 07:51:48 -08:00
Kostya Kortchinsky 77e906ac78 [scudo][standalone] Implement TSD registry disabling
Summary:
In order to implement `malloc_{enable|disable}` we were just disabling
(or really locking) the Primary and the Secondary. That meant that
allocations could still be serviced from the TSD as long as the cache
wouldn't have to be filled from the Primary.

This wasn't working out for Android tests, so this change implements
registry disabling (eg: locking) so that `getTSDAndLock` doesn't
return a TSD if the allocator is disabled. This also means that the
Primary doesn't have to be disabled in this situation.

For the Shared Registry, we loop through all the TSDs and lock them.
For the Exclusive Registry, we add a `Disabled` boolean to the Registry
that forces `getTSDAndLock` to use the Fallback TSD instead of the
thread local one. Disabling the Registry is then done by locking the
Fallback TSD and setting the boolean in question (I don't think this
needed an atomic variable but I might be wrong).

I clang-formatted the whole thing as usual hence the couple of extra
whiteline changes in this CL.

Reviewers: cferris, pcc, hctim, morehouse, eugenis

Subscribers: jfb, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D71719
2019-12-20 06:52:13 -08:00
Peter Collingbourne 0cfe0a7bb0 scudo: Fix the build of wrappers_c_test.cpp on Android.
The Android headers don't provide a declaration of valloc or pvalloc, so we
need to declare them ourselves.

Differential Revision: https://reviews.llvm.org/D71077
2019-12-05 11:15:00 -08:00
Kostya Kortchinsky 0d3d4d3b0f [scudo][standalone] Make tests work on Fuchsia
Summary:
This CL makes unit tests compatible with Fuchsia's zxtest. This
required a few changes here and there, but also unearthed some
incompatibilities that had to be addressed.

A header is introduced to allow to account for the zxtest/gtest
differences, some `#if SCUDO_FUCHSIA` are used to disable incompatible
code (the 32-bit primary, or the exclusive TSD).

It also brought to my attention that I was using
`__scudo_default_options` in different tests, which ended up in a
single binary, and I am not sure how that ever worked. So move
this to the main cpp.

Additionally fully disable the secondary freelist on Fuchsia as we do
not track VMOs for secondary allocations, so no release possible.

With some modifications to Scudo's BUILD.gn in Fuchsia:
```
[==========] 79 tests from 23 test cases ran (10280 ms total).
[  PASSED  ] 79 tests
```

Reviewers: mcgrathr, phosek, hctim, pcc, eugenis, cferris

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

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D70682
2019-11-27 09:17:40 -08:00
Kostya Kortchinsky dc802dbef2 [scudo][standalone] Make malloc_info return a minimal XML
Summary:
Initially, our malloc_info was returning ENOTSUP, but Android would
rather have it return successfully and write a barebone XML to the
stream, so we will oblige.

Add an associated test.

Reviewers: cferris, morehouse, hctim, eugenis, vitalybuka

Reviewed By: morehouse

Subscribers: delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D68427

llvm-svn: 373754
2019-10-04 15:46:34 +00:00
Kostya Kortchinsky 161cca266a [scudo][standalone] Android related improvements
Summary:
This changes a few things to improve memory footprint and performances
on Android, and fixes a test compilation error:
- add `stdlib.h` to `wrappers_c_test.cc` to address
  https://bugs.llvm.org/show_bug.cgi?id=42810
- change Android size class maps, based on benchmarks, to improve
  performances and lower the Svelte memory footprint. Also change the
  32-bit region size for said configuration
- change the `reallocate` logic to reallocate in place for sizes larger
  than the original chunk size, when they still fit in the same block.
  This addresses patterns from `memory_replay` dumps like the following:
```
202: realloc 0xb48fd000 0xb4930650 12352
202: realloc 0xb48fd000 0xb48fd000 12420
202: realloc 0xb48fd000 0xb48fd000 12492
202: realloc 0xb48fd000 0xb48fd000 12564
202: realloc 0xb48fd000 0xb48fd000 12636
202: realloc 0xb48fd000 0xb48fd000 12708
202: realloc 0xb48fd000 0xb48fd000 12780
202: realloc 0xb48fd000 0xb48fd000 12852
202: realloc 0xb48fd000 0xb48fd000 12924
202: realloc 0xb48fd000 0xb48fd000 12996
202: realloc 0xb48fd000 0xb48fd000 13068
202: realloc 0xb48fd000 0xb48fd000 13140
202: realloc 0xb48fd000 0xb48fd000 13212
202: realloc 0xb48fd000 0xb48fd000 13284
202: realloc 0xb48fd000 0xb48fd000 13356
202: realloc 0xb48fd000 0xb48fd000 13428
202: realloc 0xb48fd000 0xb48fd000 13500
202: realloc 0xb48fd000 0xb48fd000 13572
202: realloc 0xb48fd000 0xb48fd000 13644
202: realloc 0xb48fd000 0xb48fd000 13716
202: realloc 0xb48fd000 0xb48fd000 13788
...
```
  In this situation we were deallocating the old chunk, and
  allocating a new one for every single one of those, but now we can
  keep the same chunk (we just updated the header), which saves some
  heap operations.

Reviewers: hctim, morehouse, vitalybuka, eugenis, cferris, rengolin

Reviewed By: morehouse

Subscribers: srhines, delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D67293

llvm-svn: 371628
2019-09-11 14:48:41 +00:00
Kostya Kortchinsky 3e5360f194 [scudo][standalone] Fix malloc_iterate
Summary:
cferris's Bionic tests found an issue in Scudo's `malloc_iterate`.

We were inclusive of both boundaries, which resulted in a `Block` that
was located on said boundary to be possibly accounted for twice, or
just being accounted for while iterating on regions that are not ours
(usually the unmapped ones in between Primary regions).

The fix is to exclude the upper boundary in `iterateOverChunks`, and
add a regression test.

This additionally corrects a typo in a comment, and change the 64-bit
Primary iteration function to not assume that `BatchClassId` is 0.

Reviewers: cferris, morehouse, hctim, vitalybuka, eugenis

Reviewed By: hctim

Subscribers: delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D66231

llvm-svn: 369400
2019-08-20 16:17:08 +00:00
Kostya Kortchinsky 2be59170d4 [scudo][standalone] Add more stats to mallinfo
Summary:
Android requires additional stats in mallinfo. While we can provide
right away the number of bytes mapped (Primary+Secondary), there was
no way to get the number of free bytes (only makes sense for the
Primary since the Secondary unmaps everything on deallocation).

An approximation could be `StatMapped - StatAllocated`, but since we
are mapping in `1<<17` increments for the 64-bit Primary, it's fairly
inaccurate.

So we introduce `StatFree` (note it's `Free`, not `Freed`!), which
keeps track of the amount of Primary blocks currently unallocated.

Reviewers: cferris, eugenis, vitalybuka, hctim, morehouse

Reviewed By: morehouse

Subscribers: delcypher, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D66112

llvm-svn: 368866
2019-08-14 16:04:01 +00:00
Nico Weber 3fa3831830 compiler-rt: Rename .cc file in lib/scudo/standalone/tests to .cpp
Like r367463, but for scudo/standalone/tests.

With this, all files in compiler-rt/lib have extension cpp.

llvm-svn: 367569
2019-08-01 14:38:49 +00:00