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mlippautz authored
This reverts commit d4fc4a8c. 1. Let X be the aborted slot (slot in an evacuated object in an aborted page) 2. Assume X contains pointer to Y and Y is in the new space, so X is in the store buffer. 3. Store buffer rebuilding will not filter out X (it checks InNewSpace(Y)). 4. The current mark-sweep finishes. The slot X is in free space and is also in the store buffer. 5. A string of length 9 "abcdefghi" is allocated in the new space. The string looks like |MAP|LENGTH|hgfedcba|NNNNNNNi| in memory, where NNNNNNN is previous garbage. Let's assume that NNNNNNN0 was pointing to a new space object before. 6. Scavenge happens. 7. Slot X is still in free space and in store buffer. [It causes scavenge of the object Y in store_buffer()->IteratePointersToNewSpace(&Scavenger::ScavengeObject). But it is not important]. 8. Our string is promoted and is allocated over the slot X, such that NNNNNNNi is written in X. 9. The scavenge finishes. 9. Another scavenge starts. 10. We crash in store_buffer()->IteratePointersToNewSpace(&Scavenger::ScavengeObject) when processing slot X, because it doesn't point to valid map. BUG=chromium:524425, chromium:564498 LOG=N R=hpayer@chromium.org, ulan@chromium.org Review URL: https://codereview.chromium.org/1494503004 Cr-Commit-Position: refs/heads/master@{#32514}
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