[all-commits] [llvm/llvm-project] d7cbfc: [ELF][AArch64] Fix potentially corrupted section c...

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: d7cbfcf36ace575ec90434624279dd3ebce78c47
      https://github.com/llvm/llvm-project/commit/d7cbfcf36ace575ec90434624279dd3ebce78c47
  Author: Fangrui Song <i at maskray.me>
  Date:   2022-08-05 (Fri, 05 Aug 2022)

  Changed paths:
    M lld/ELF/Arch/AArch64.cpp

  Log Message:
  -----------
  [ELF][AArch64] Fix potentially corrupted section content for PAC

D74537 introduced a bug: if `(config->andFeatures & GNU_PROPERTY_AARCH64_FEATURE_1_PAC) != 0`
with -z pac-plt unspecified, we incorrectly use AArch64BtiPac, whose writePlt will make
out-of-bounds write after the .plt section. This is often benign because the
output section after .plt will usually overwrite the content.

This is very difficult to test without D131247 (Parallelize writes of different OutputSections).