tree 1124fb797a64c8f41d2be2e4781e7a29c1281002
parent 169282c48030ec3126a79daa4e3bf1efb1665421
author Mitch Phillips <mitchphillips@outlook.com> 1561501745 +0000
committer Copybara-Service <copybara-worker@google.com> 1601491326 -0700

[GWP-ASan] Guard against recursive allocs. Pack TLS for perf.

Summary:
Add a recursivity guard for GPA::allocate(). This means that any
recursive allocations will fall back to the supporting allocator. In future
patches, we will introduce stack trace collection support. The unwinder will be
provided by the supporting allocator, and we can't guarantee they don't call
malloc() (e.g. backtrace() on posix may call dlopen(), which may call malloc().

Furthermore, this patch packs the new TLS recursivity guard into a thread local
struct, so that TLS variables should be hopefully not fall across cache lines.

Reviewers: vlad.tsyrklevich, morehouse, eugenis

Reviewed By: eugenis

Subscribers: kubamracek, #sanitizers, llvm-commits, eugenis

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D63736

llvm-svn: 364356
GitOrigin-RevId: 05d1a2bd1bf3c0172334bbdf21cdf97135ab2797