Commit Graph

5 Commits

Author SHA1 Message Date
Kostya Kortchinsky aeb3826228 [scudo][standalone] Merge Spin & Blocking mutex into a Hybrid one
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
2019-07-11 15:32:26 +00:00
Kostya Kortchinsky 3fad6a206f [scudo][standalone] Introduce the SizeClassMap
Summary:
As with the sanitizer_common allocator, the SCM allows for efficient
mapping between sizes and size-classes, table-free.

It doesn't depart significantly from the original, except that we
allow the use of size-class 0 for other purposes (as opposed to
chunks of size 0). The Primary will use it to hold TransferBatches.

Reviewers: vitalybuka, eugenis, hctim, morehouse

Reviewed By: vitalybuka

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

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D61088

llvm-svn: 359199
2019-04-25 15:49:34 +00:00
Kostya Kortchinsky 475585655d [scudo][standalone] Introduce the Secondary allocator
Summary:
The Secondary allocator wraps the platform allocation primitives. It is
meant to be used for larger sizes that the Primary can't fullfill, as
it will be slower, and sizes are multiple of the system page size.

This also changes some of the existing code, notably the opaque
platform data being passed to the platform specific functions: we can
shave a couple of syscalls on Fuchsia by storing additional data (this
addresses a TODO).

Reviewers: eugenis, vitalybuka, hctim, morehouse

Reviewed By: morehouse

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

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D60787

llvm-svn: 359097
2019-04-24 14:20:49 +00:00
Kostya Kortchinsky b3a924afd6 [scudo][standalone] Add a standalone vector class
Summary:
This CL adds a standalone vector class that will be used by the scoped
strings when they land. We reimplement our own vector class because we
can't use the std library one.

It's mostly borrowed from the current sanitizer_common one, with LLVM
code style changes.

Additionnally a casing change in a function name that slipped through
the previous review (the function isn't used yet).

Reviewers: vitalybuka, eugenis, flowerhack, dmmoore415, mcgrathr, morehouse

Reviewed By: vitalybuka

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

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D58689

llvm-svn: 354999
2019-02-27 16:30:05 +00:00
Kostya Kortchinsky 41aba567d9 [scudo][standalone] Introduce platform specific code & mutexes
Summary:
This CL adds the platform specific code for Fuchsia, Linux & Android,
as well as some tests related to those (more tests to come later).
While some of it is pretty much a straight port of the existing scudo &
sanitizer_common code, the memory mapping functions have been reworked
a bit to fit the limited usage scenario that Scudo has for them.

For Fuchsia, I can now track the Vmar/Vmo pair for memory mappings if
there is an intent to grow or decommit some mapping (that will be
useful for the Primary).

Reviewers: eugenis, vitalybuka, mcgrathr, phosek, flowerhack, morehouse, dmmoore415

Reviewed By: vitalybuka, morehouse

Subscribers: kcc, dvyukov, srhines, mgorny, delcypher, jfb, jdoerfert, #sanitizers, llvm-commits

Tags: #llvm, #sanitizers

Differential Revision: https://reviews.llvm.org/D58184

llvm-svn: 354895
2019-02-26 16:47:25 +00:00