diff options
| -rw-r--r-- | pkg/safemem/BUILD | 1 | ||||
| -rw-r--r-- | pkg/safemem/block_unsafe.go | 19 |
2 files changed, 18 insertions, 2 deletions
diff --git a/pkg/safemem/BUILD b/pkg/safemem/BUILD index 3fda3a9cc..2c7cc8769 100644 --- a/pkg/safemem/BUILD +++ b/pkg/safemem/BUILD @@ -14,6 +14,7 @@ go_library( deps = [ "//pkg/gohacks", "//pkg/safecopy", + "//pkg/sync", "@org_golang_x_sys//unix:go_default_library", ], ) diff --git a/pkg/safemem/block_unsafe.go b/pkg/safemem/block_unsafe.go index 93879bb4f..4af534385 100644 --- a/pkg/safemem/block_unsafe.go +++ b/pkg/safemem/block_unsafe.go @@ -20,6 +20,7 @@ import ( "gvisor.dev/gvisor/pkg/gohacks" "gvisor.dev/gvisor/pkg/safecopy" + "gvisor.dev/gvisor/pkg/sync" ) // A Block is a range of contiguous bytes, similar to []byte but with the @@ -223,8 +224,22 @@ func Copy(dst, src Block) (int, error) { func Zero(dst Block) (int, error) { if !dst.needSafecopy { bs := dst.ToSlice() - for i := range bs { - bs[i] = 0 + if !sync.RaceEnabled { + // If the race detector isn't enabled, the golang + // compiler replaces the next loop with memclr + // (https://github.com/golang/go/issues/5373). + for i := range bs { + bs[i] = 0 + } + } else { + bsLen := len(bs) + if bsLen == 0 { + return 0, nil + } + bs[0] = 0 + for i := 1; i < bsLen; i *= 2 { + copy(bs[i:], bs[:i]) + } } return len(bs), nil } |