Commit Graph

6 Commits

Author SHA1 Message Date
Mitch Phillips f7c5c0d87b Revert "[Scudo] Make -fsanitize=scudo use standalone. Migrate tests."
This reverts commit 6911114d8c.

Broke the QEMU sanitizer bots due to a missing header dependency. This
actually needs to be fixed on the bot-side, but for now reverting this
patch until I can fix up the bot.
2021-05-26 10:50:26 -07:00
Mitch Phillips 6911114d8c [Scudo] Make -fsanitize=scudo use standalone. Migrate tests.
This patch moves -fsanitize=scudo to link the standalone scudo library,
rather than the original compiler-rt based library. This is one of the
major remaining roadblocks to deleting the compiler-rt based scudo,
which should not be used any more. The standalone Scudo is better in
pretty much every way and is much more suitable for production usage.

As well as patching the litmus tests for checking that the
scudo_standalone lib is linked instead of the scudo lib, this patch also
ports all the scudo lit tests to run under scudo standalone.

This patch also adds a feature to scudo standalone that was under test
in the original scudo - that arguments passed to an aligned operator new
were checked that the alignment was a power of two.

Some lit tests could not be migrated, due to the following issues:
 1. Features that aren't supported in scudo standalone, like the rss
 limit.
 2. Different quarantine implementation where the test needs some more
 thought.
 3. Small bugs in scudo standalone that should probably be fixed, like
 the Secondary allocator having a full page on the LHS of an allocation
 that only contains the chunk header, so underflows by <= a page aren't
 caught.
 4. Slight differences in behaviour that's technically correct, like
 'realloc(malloc(1), 0)' returns nullptr in standalone, but a real
 pointer in old scudo.
 5. Some tests that might be migratable, but not easily.

Tests that are obviously not applicable to scudo standalone (like
testing that no sanitizer symbols made it into the DSO) have been
deleted.

After this patch, the remaining work is:
 1. Update the Scudo documentation. The flags have changed, etc.
 2. Delete the old version of scudo.
 3. Patch up the tests in lit-unmigrated, or fix Scudo standalone.

Reviewed By: cryptoad, vitalybuka

Differential Revision: https://reviews.llvm.org/D102543
2021-05-26 10:03:17 -07:00
Vitaly Buka 1eb78a64c4 [NFC][scudo] Clang-format tests 2021-05-17 12:31:09 -07:00
Kostya Kortchinsky a04584b095 [scudo] Delay allocations in the RSS check test
Summary:
D57116 fails on the armv7 bots, which is I assume due to the timing of
the RSS check on the platform. While I don't have a platform to test
that change on, I assume this would do.

The test could be made more reliable by either delaying more the
allocations, or allocating more large-chunks, but both those options
have a somewhat non negligible impact (more memory used, longer test).

Hence me trying to keep the additional sleeping/allocating to a
minimum.

Reviewers: eugenis, yroux

Reviewed By: yroux

Subscribers: javed.absar, kristof.beyls, delcypher, #sanitizers, llvm-commits

Differential Revision: https://reviews.llvm.org/D57241

llvm-svn: 352220
2019-01-25 17:23:29 +00:00
Kostya Kortchinsky f0fbeaf44a [scudo] Tuning changes based on feedback from current use
Summary:
This tunes several of the default parameters used within the allocator:
- disable the deallocation type mismatch on Android by default; this
  was causing too many issues with third party libraries;
- change the default `SizeClassMap` to `Dense`, it caches less entries
  and is way more memory efficient overall;
- relax the timing of the RSS checks, 10 times per second was too much,
  lower it to 4 times (every 250ms), and update the test so that it
  passes with the new default.

Reviewers: eugenis

Reviewed By: eugenis

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

Differential Revision: https://reviews.llvm.org/D57116

llvm-svn: 352057
2019-01-24 15:56:54 +00:00
Kostya Kortchinsky 58f2656d7e [scudo] Soft and hard RSS limit checks
Summary:
This implements an opportunistic check for the RSS limit.

For ASan, this was implemented thanks to a background thread checking the
current RSS vs the set limit every 100ms. This was deemed problematic for Scudo
due to potential Android concerns (Zygote as pointed out by Aleksey) as well as
the general inconvenience of having a permanent background thread.

If a limit (soft or hard) is specified, we will attempt to update the RSS limit
status (exceeded or not) every 100ms. This is done in an opportunistic way: if
we can update it, we do it, if not we return the current status, mostly because
we don't need it to be fully consistent (it's done every 100ms anyway). If the
limit is exceeded `allocate` will act as if OOM for a soft limit, or just die
for a hard limit.

We use the `common_flags()`'s `hard_rss_limit_mb` & `soft_rss_limit_mb` for
configuration of the limits.

Reviewers: alekseyshl

Reviewed By: alekseyshl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D40038

llvm-svn: 318301
2017-11-15 16:40:27 +00:00