[all-commits] [llvm/llvm-project] dbe36e: tsan: fix latent race size bug in test

[Dmitry Vyukov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: dbe36e4073e708816cbeb693ea52832f54f52f2a
      https://github.com/llvm/llvm-project/commit/dbe36e4073e708816cbeb693ea52832f54f52f2a
  Author: Dmitry Vyukov <dvyukov at google.com>
  Date:   2021-07-30 (Fri, 30 Jul 2021)

  Changed paths:
    M compiler-rt/test/tsan/Linux/syscall.cpp

  Log Message:
  -----------
  tsan: fix latent race size bug in test

The test contains a race in read/write syscalls.
The size of reported race depends on how the accessed
memory range split into granules inside of tsan runtime.
The test used to report access of size 8, because presumably
the buffer ended up being aligned to 8 bytes. But after
some unrelated changes this test started to report accesses
of size 1 (presumably .data layout changed), which makes
the test fail.
Guarantee alignment of the buf object explicitly.

Reviewed By: vitalybuka, melver

Differential Revision: https://reviews.llvm.org/D107131