diff options
Diffstat (limited to 'src/runtime/lfstack_64bit.go')
| -rw-r--r-- | src/runtime/lfstack_64bit.go | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/src/runtime/lfstack_64bit.go b/src/runtime/lfstack_64bit.go index 8180b0a248..5367f08c56 100644 --- a/src/runtime/lfstack_64bit.go +++ b/src/runtime/lfstack_64bit.go @@ -2,7 +2,7 @@ // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. -// +build arm64 mips64 mips64le ppc64 ppc64le s390x +// +build amd64 arm64 mips64 mips64le ppc64 ppc64le s390x package runtime @@ -22,6 +22,10 @@ const ( // s390x TASK_SIZE 0x020000000000UL (41 bit addresses) // // These values may increase over time. + // + // On AMD64, virtual addresses are 48-bit numbers sign extended to 64. + // We shift the address left 16 to eliminate the sign extended part and make + // room in the bottom for the count. addrBits = 48 // In addition to the 16 bits taken from the top, we can take 3 from the @@ -35,5 +39,10 @@ func lfstackPack(node *lfnode, cnt uintptr) uint64 { } func lfstackUnpack(val uint64) *lfnode { + if GOARCH == "amd64" { + // amd64 systems can place the stack above the VA hole, so we need to sign extend + // val before unpacking. + return (*lfnode)(unsafe.Pointer(uintptr(int64(val) >> cntBits << 3))) + } return (*lfnode)(unsafe.Pointer(uintptr(val >> cntBits << 3))) } |