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    SubjectRe: [RFC][PATCH] fix move/migrate_pages() race on task struct
    On 02/24/2012 07:20 AM, Christoph Lameter wrote:
    > Subject: migration: Do not do rcu_read_unlock until the last time we need the task_struct pointer
    >
    > Migration functions perform the rcu_read_unlock too early. As a result the
    > task pointed to may change. Bugs were introduced when adding security checks
    > because rcu_unlock/lock sequences were inserted. Plus the security checks
    > and do_move_pages used the task_struct pointer after rcu_unlock.
    >
    > Fix those issues by removing the unlock/lock sequences and moving the
    > rcu_read_unlock after the last use of the task struct pointer.
    >
    > Signed-off-by: Christoph Lameter <cl@linux.com>

    It doesn't fix the code duplication, but it definitely does fix the bug
    I was originally trying to address.

    Acked-by: Dave Hansen <dave@linux.vnet.ibm.com>



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