cmd/go: enable -msan on freebsd/amd64

Enable -msan flag on freebsd/amd64 and amend PIE comment in internal/work/init.go to indicate that MSAN requires PIE on all platforms except linux/amd64. R=go1.20 For #53298 Change-Id: I93d94efa95d7f292c23c433fb1d3f4301d820bde Reviewed-on: https://go-review.googlesource.com/c/go/+/411275 Reviewed-by: Bryan Mills <[email protected]> Reviewed-by: Ian Lance Taylor <[email protected]>
cloudflare · Oct 14, 2022 · e56c93f · e56c93f
1 parent 5fde02e
commit e56c93f
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Showing 4 changed files with 9 additions and 7 deletions.
diff --git a/src/cmd/go/alldocs.go b/src/cmd/go/alldocs.go
diff --git a/src/cmd/go/internal/work/build.go b/src/cmd/go/internal/work/build.go
@@ -71,9 +71,9 @@ and test commands:
  linux/ppc64le and linux/arm64 (only for 48-bit VMA).
  -msan
  enable interoperation with memory sanitizer.
- Supported only on linux/amd64, linux/arm64
+ Supported only on linux/amd64, linux/arm64, freebsd/amd64
  and only with Clang/LLVM as the host C compiler.
- On linux/arm64, pie build mode will be used.
+ PIE build mode will be used on all platforms except linux/amd64.
  -asan
  enable interoperation with address sanitizer.
  Supported only on linux/arm64, linux/amd64.

diff --git a/src/cmd/go/internal/work/init.go b/src/cmd/go/internal/work/init.go
@@ -149,9 +149,9 @@ func instrumentInit() {
  mode := "race"
  if cfg.BuildMSan {
  mode = "msan"
- // MSAN does not support non-PIE binaries on ARM64.
- // See issue #33712 for details.
- if cfg.Goos == "linux" && cfg.Goarch == "arm64" && cfg.BuildBuildmode == "default" {
+ // MSAN needs PIE on all platforms except linux/amd64.
+ // https://github.com/llvm/llvm-project/blob/llvmorg-13.0.1/clang/lib/Driver/SanitizerArgs.cpp#L621
+ if cfg.BuildBuildmode == "default" && (cfg.Goos != "linux" || cfg.Goarch != "amd64") {
  cfg.BuildBuildmode = "pie"
  }
  }

diff --git a/src/internal/platform/supported.go b/src/internal/platform/supported.go
@@ -29,6 +29,8 @@ func MSanSupported(goos, goarch string) bool {
  switch goos {
  case "linux":
  return goarch == "amd64" || goarch == "arm64"
+ case "freebsd":
+ return goarch == "amd64"
  default:
  return false
  }