diff options
| author | Austin Clements <austin@google.com> | 2016-04-13 11:13:39 -0400 |
|---|---|---|
| committer | Austin Clements <austin@google.com> | 2016-04-13 16:06:51 +0000 |
| commit | d8e8fc292ace5ae59a0da44dfca1dd5b1a71ecf1 (patch) | |
| tree | 50270ff31b042abfd057be10b9208953087b59c5 /src | |
| parent | 6b85a45edc94786c7669823ee47a6ce1156d6a9a (diff) | |
| download | go-d8e8fc292ace5ae59a0da44dfca1dd5b1a71ecf1.tar.xz | |
runtime/internal/atomic: remove write barrier from Storep1 on s390x
atomic.Storep1 is not supposed to invoke a write barrier (that's what
atomicstorep is for), but currently does on s390x. This causes a panic
in runtime.mapzero when it tries to use atomic.Storep1 to store what's
actually a scalar.
Fix this by eliminating the write barrier from atomic.Storep1 on
s390x. Also add some documentation to atomicstorep to explain the
difference between these.
Fixes #15270.
Change-Id: I291846732d82f090a218df3ef6351180aff54e81
Reviewed-on: https://go-review.googlesource.com/21993
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Austin Clements <austin@google.com>
Reviewed-by: Michael Munday <munday@ca.ibm.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/runtime/atomic_pointer.go | 5 | ||||
| -rw-r--r-- | src/runtime/internal/atomic/atomic_s390x.go | 2 |
2 files changed, 3 insertions, 4 deletions
diff --git a/src/runtime/atomic_pointer.go b/src/runtime/atomic_pointer.go index bd21b49945..d54f1d6eef 100644 --- a/src/runtime/atomic_pointer.go +++ b/src/runtime/atomic_pointer.go @@ -15,10 +15,9 @@ import ( // escape analysis decisions about the pointer value being stored. // Instead, these are wrappers around the actual atomics (casp1 and so on) // that use noescape to convey which arguments do not escape. -// -// Additionally, these functions must update the shadow heap for -// write barrier checking. +// atomicstorep performs *ptr = new atomically and invokes a write barrier. +// //go:nosplit func atomicstorep(ptr unsafe.Pointer, new unsafe.Pointer) { atomic.Storep1(noescape(ptr), new) diff --git a/src/runtime/internal/atomic/atomic_s390x.go b/src/runtime/internal/atomic/atomic_s390x.go index f31f1af444..b6d3d84bdf 100644 --- a/src/runtime/internal/atomic/atomic_s390x.go +++ b/src/runtime/internal/atomic/atomic_s390x.go @@ -40,7 +40,7 @@ func Store64(ptr *uint64, val uint64) { //go:noinline //go:nosplit func Storep1(ptr unsafe.Pointer, val unsafe.Pointer) { - *(*unsafe.Pointer)(ptr) = val + *(*uintptr)(ptr) = uintptr(val) } //go:noescape |