Commit 9e781440 authored by Committed by Linus Torvalds
hold task->mempolicy while numa_maps scans.
/proc/<pid>/numa_maps scans vma and show mempolicy under mmap_sem. It sometimes accesses task->mempolicy which can be freed without mmap_sem and numa_maps can show some garbage while scanning. This patch tries to take reference count of task->mempolicy at reading numa_maps before calling get_vma_policy(). By this, task->mempolicy will not be freed until numa_maps reaches its end. V2->v3 - updated comments to be more verbose. - removed task_lock() in numa_maps code. V1->V2 - access task->mempolicy only once and remember it. Becase kernel/exit.c can overwrite it. Signed-off-by: KAMEZAWA Hiroyuki <firstname.lastname@example.org> Acked-by: David Rientjes <email@example.com> Acked-by: KOSAKI Motohiro <firstname.lastname@example.org> Signed-off-by: Linus Torvalds <email@example.com>
Showing with 51 additions and 3 deletions