diff options
Diffstat (limited to 'libgo/go/runtime/map.go')
| -rw-r--r-- | libgo/go/runtime/map.go | 19 |
1 files changed, 14 insertions, 5 deletions
diff --git a/libgo/go/runtime/map.go b/libgo/go/runtime/map.go index 1155fee..5b9d7102 100644 --- a/libgo/go/runtime/map.go +++ b/libgo/go/runtime/map.go @@ -177,8 +177,8 @@ type bmap struct { // If you modify hiter, also change cmd/compile/internal/gc/reflect.go to indicate // the layout of this structure. type hiter struct { - key unsafe.Pointer // Must be in first position. Write nil to indicate iteration end (see cmd/internal/gc/range.go). - elem unsafe.Pointer // Must be in second position (see cmd/internal/gc/range.go). + key unsafe.Pointer // Must be in first position. Write nil to indicate iteration end (see cmd/compile/internal/gc/range.go). + elem unsafe.Pointer // Must be in second position (see cmd/compile/internal/gc/range.go). t *maptype h *hmap buckets unsafe.Pointer // bucket ptr at hash_iter initialization time @@ -634,7 +634,7 @@ again: if h.growing() { growWork(t, h, bucket) } - b := (*bmap)(unsafe.Pointer(uintptr(h.buckets) + bucket*uintptr(t.bucketsize))) + b := (*bmap)(add(h.buckets, bucket*uintptr(t.bucketsize))) top := tophash(hash) var inserti *uint8 @@ -685,7 +685,7 @@ bucketloop: } if inserti == nil { - // all current buckets are full, allocate a new one. + // The current bucket and all the overflow buckets connected to it are full, allocate a new one. newb := h.newoverflow(t, b) inserti = &newb.tophash[0] insertk = add(unsafe.Pointer(newb), dataOffset) @@ -815,6 +815,11 @@ search: } notLast: h.count-- + // Reset the hash seed to make it more difficult for attackers to + // repeatedly trigger hash collisions. See issue 25237. + if h.count == 0 { + h.hash0 = fastrand() + } break search } } @@ -1051,6 +1056,10 @@ func mapclear(t *maptype, h *hmap) { h.noverflow = 0 h.count = 0 + // Reset the hash seed to make it more difficult for attackers to + // repeatedly trigger hash collisions. See issue 25237. + h.hash0 = fastrand() + // Keep the mapextra allocation but clear any extra information. if h.extra != nil { *h.extra = mapextra{} @@ -1429,5 +1438,5 @@ func reflectlite_maplen(h *hmap) int { return h.count } -const maxZero = 1024 // must match value in cmd/compile/internal/gc/walk.go:zeroValSize +const maxZero = 1024 // must match value in reflect/value.go:maxZero cmd/compile/internal/gc/walk.go:zeroValSize var zeroVal [maxZero]byte |