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authorJames Morse <james.morse@arm.com>2016-10-08 02:00:06 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-08 03:46:28 +0200
commit0f30206bf2a42e278c2cec32e4b722626458c75b (patch)
tree6fa98b83ca1802acb093413747d2497c6033428f /fs/proc/task_mmu.c
parentcpu: fix node state for whether it contains CPU (diff)
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fs/proc/task_mmu.c: make the task_mmu walk_page_range() limit in clear_refs_write() obvious
Trying to walk all of virtual memory requires architecture specific knowledge. On x86_64, addresses must be sign extended from bit 48, whereas on arm64 the top VA_BITS of address space have their own set of page tables. clear_refs_write() calls walk_page_range() on the range 0 to ~0UL, it provides a test_walk() callback that only expects to be walking over VMAs. Currently walk_pmd_range() will skip memory regions that don't have a VMA, reporting them as a hole. As this call only expects to walk user address space, make it walk 0 to 'highest_vm_end'. Link: http://lkml.kernel.org/r/1472655792-22439-1-git-send-email-james.morse@arm.com Signed-off-by: James Morse <james.morse@arm.com> Acked-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to '')
-rw-r--r--fs/proc/task_mmu.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
index f6fa99eca515..d2a70cf2154e 100644
--- a/fs/proc/task_mmu.c
+++ b/fs/proc/task_mmu.c
@@ -1070,7 +1070,7 @@ static ssize_t clear_refs_write(struct file *file, const char __user *buf,
}
mmu_notifier_invalidate_range_start(mm, 0, -1);
}
- walk_page_range(0, ~0UL, &clear_refs_walk);
+ walk_page_range(0, mm->highest_vm_end, &clear_refs_walk);
if (type == CLEAR_REFS_SOFT_DIRTY)
mmu_notifier_invalidate_range_end(mm, 0, -1);
flush_tlb_mm(mm);