• mlippautz's avatar
    Reland of "[heap] Clean up stale store buffer entries for aborted pages." · fc6ff534
    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}
    fc6ff534
mark-compact.cc 143 KB