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| author |   James Morse <james.morse@arm.com> | 2016-10-07 17:00:06 -0700 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 18:46:28 -0700 |
| commit | 0f30206bf2a42e278c2cec32e4b722626458c75b (patch) | |
| tree | 6fa98b83ca1802acb093413747d2497c6033428f | |
| parent | cpu: fix node state for whether it contains CPU (diff) | |
| download | linux-dev-0f30206bf2a42e278c2cec32e4b722626458c75b.tar.xz linux-dev-0f30206bf2a42e278c2cec32e4b722626458c75b.zip | |
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>
| -rw-r--r-- | fs/proc/task_mmu.c | 2 |
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); |