• Hugh Dickins's avatar
    [PATCH] mm: dup_mmap down new mmap_sem · 7ee78232
    Hugh Dickins authored
    One anomaly remains from when Andrea rationalized the responsibilities of
    mmap_sem and page_table_lock: in dup_mmap we add vmas to the child holding its
    page_table_lock, but not the mmap_sem which normally guards the vma list and
    rbtree.  Which could be an issue for unuse_mm: though since it just walks down
    the list (today with page_table_lock, tomorrow not), it's probably okay.  Will
    need a memory barrier?  Oh, keep it simple, Nick and I agreed, no harm in
    taking child's mmap_sem here.
    Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
    Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
    Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
fork.c 32.5 KB