diff options
Diffstat (limited to 'src/runtime')
| -rw-r--r-- | src/runtime/export_test.go | 41 |
1 files changed, 31 insertions, 10 deletions
diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go index 1f55717f0a..99c665c6d0 100644 --- a/src/runtime/export_test.go +++ b/src/runtime/export_test.go @@ -1122,8 +1122,6 @@ func CheckScavengedBitsCleared(mismatches []BitsMismatch) (n int, ok bool) { // Lock so that we can safely access the bitmap. lock(&mheap_.lock) - heapBase := mheap_.pages.inUse.ranges[0].base.addr() - secondArenaBase := arenaBase(arenaIndex(heapBase) + 1) chunkLoop: for i := mheap_.pages.start; i < mheap_.pages.end; i++ { chunk := mheap_.pages.tryChunkOf(i) @@ -1140,14 +1138,6 @@ func CheckScavengedBitsCleared(mismatches []BitsMismatch) (n int, ok bool) { want := chunk.scavenged[j] &^ chunk.pallocBits[j] got := chunk.scavenged[j] if want != got { - // When goexperiment.RandomizedHeapBase64 is set we use a - // series of padding pages to generate randomized heap base - // address which have both the alloc and scav bits set. If - // we see this for a chunk between the address of the heap - // base, and the address of the second arena continue. - if goexperiment.RandomizedHeapBase64 && (cb >= heapBase && cb < secondArenaBase) { - continue - } ok = false if n >= len(mismatches) { break chunkLoop @@ -1165,6 +1155,37 @@ func CheckScavengedBitsCleared(mismatches []BitsMismatch) (n int, ok bool) { getg().m.mallocing-- }) + + if goexperiment.RandomizedHeapBase64 && len(mismatches) > 0 { + // When goexperiment.RandomizedHeapBase64 is set we use a series of + // padding pages to generate randomized heap base address which have + // both the alloc and scav bits set. Because of this we expect exactly + // one arena will have mismatches, so check for that explicitly and + // remove the mismatches if that property holds. If we see more than one + // arena with this property, that is an indication something has + // actually gone wrong, so return the mismatches. + // + // We do this, instead of ignoring the mismatches in the chunkLoop, because + // it's not easy to determine which arena we added the padding pages to + // programmatically, without explicitly recording the base address somewhere + // in a global variable (which we'd rather not do as the address of that variable + // is likely to be somewhat predictable, potentially defeating the purpose + // of our randomization). + affectedArenas := map[arenaIdx]bool{} + for _, mismatch := range mismatches { + if mismatch.Base > 0 { + affectedArenas[arenaIndex(mismatch.Base)] = true + } + } + if len(affectedArenas) == 1 { + ok = true + // zero the mismatches + for i := range n { + mismatches[i] = BitsMismatch{} + } + } + } + return } |