diff options
| author | Ian Lance Taylor <iant@golang.org> | 2020-04-02 17:14:25 -0700 |
|---|---|---|
| committer | Ian Lance Taylor <iant@golang.org> | 2020-04-08 04:18:04 +0000 |
| commit | 08dd4ad7e30313d089793f19baff1855bbaa004e (patch) | |
| tree | 70e5c0c94a50b66c15ac3b261d347c374c870c57 /src/runtime | |
| parent | 8e121b1587bd921ea84c7da49cab3f48dc6b8f36 (diff) | |
| download | go-08dd4ad7e30313d089793f19baff1855bbaa004e.tar.xz | |
runtime: only check for pointers up to ptrdata, not size
Change-Id: I166cf253b7f2483d652c98d2fba36c380e2f3347
Reviewed-on: https://go-review.googlesource.com/c/go/+/227177
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
Reviewed-by: Keith Randall <khr@golang.org>
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/mbarrier.go | 24 | ||||
| -rw-r--r-- | src/runtime/slice.go | 2 |
2 files changed, 21 insertions, 5 deletions
diff --git a/src/runtime/mbarrier.go b/src/runtime/mbarrier.go index df3ab6fc3c..941324782c 100644 --- a/src/runtime/mbarrier.go +++ b/src/runtime/mbarrier.go @@ -158,7 +158,7 @@ func typedmemmove(typ *_type, dst, src unsafe.Pointer) { return } if typ.ptrdata != 0 { - bulkBarrierPreWrite(uintptr(dst), uintptr(src), typ.size) + bulkBarrierPreWrite(uintptr(dst), uintptr(src), typ.ptrdata) } // There's a race here: if some other goroutine can write to // src, it may change some pointer in src after we've @@ -198,12 +198,27 @@ func reflect_typedmemmovepartial(typ *_type, dst, src unsafe.Pointer, off, size if writeBarrier.needed && typ.ptrdata != 0 && size >= sys.PtrSize { // Pointer-align start address for bulk barrier. adst, asrc, asize := dst, src, size + ptrdata := typ.ptrdata + if ptrdata > off { + ptrdata -= off + } else { + ptrdata = 0 + } if frag := -off & (sys.PtrSize - 1); frag != 0 { adst = add(dst, frag) asrc = add(src, frag) asize -= frag + if ptrdata > frag { + ptrdata -= frag + } else { + ptrdata = 0 + } + } + pwsize := asize &^ (sys.PtrSize - 1) + if pwsize > ptrdata { + pwsize = ptrdata } - bulkBarrierPreWrite(uintptr(adst), uintptr(asrc), asize&^(sys.PtrSize-1)) + bulkBarrierPreWrite(uintptr(adst), uintptr(asrc), pwsize) } memmove(dst, src, size) @@ -270,7 +285,8 @@ func typedslicecopy(typ *_type, dst, src slice) int { // before calling typedslicecopy. size := uintptr(n) * typ.size if writeBarrier.needed { - bulkBarrierPreWrite(uintptr(dstp), uintptr(srcp), size) + pwsize := size - typ.size + typ.ptrdata + bulkBarrierPreWrite(uintptr(dstp), uintptr(srcp), pwsize) } // See typedmemmove for a discussion of the race between the // barrier and memmove. @@ -318,7 +334,7 @@ func reflect_typedslicecopy(elemType *_type, dst, src slice) int { //go:nosplit func typedmemclr(typ *_type, ptr unsafe.Pointer) { if typ.ptrdata != 0 { - bulkBarrierPreWrite(uintptr(ptr), 0, typ.size) + bulkBarrierPreWrite(uintptr(ptr), 0, typ.ptrdata) } memclrNoHeapPointers(ptr, typ.size) } diff --git a/src/runtime/slice.go b/src/runtime/slice.go index 9ad814a555..52353ea151 100644 --- a/src/runtime/slice.go +++ b/src/runtime/slice.go @@ -182,7 +182,7 @@ func growslice(et *_type, old slice, cap int) slice { if lenmem > 0 && writeBarrier.enabled { // Only shade the pointers in old.array since we know the destination slice p // only contains nil pointers because it has been cleared during alloc. - bulkBarrierPreWriteSrcOnly(uintptr(p), uintptr(old.array), lenmem) + bulkBarrierPreWriteSrcOnly(uintptr(p), uintptr(old.array), lenmem-et.size+et.ptrdata) } } memmove(p, old.array, lenmem) |