Messages in this thread Patch in this message | | | From | Peter Xu <> | Subject | [PATCH RFC 05/10] mm/hugetlb: Make walk_hugetlb_range() RCU-safe | Date | Sun, 30 Oct 2022 17:29:24 -0400 |
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RCU makes sure the pte_t* won't go away from under us. Please refer to the comment above huge_pte_offset() for more information.
Signed-off-by: Peter Xu <peterx@redhat.com> --- mm/pagewalk.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c index 7f1c9b274906..bbc71c750576 100644 --- a/mm/pagewalk.c +++ b/mm/pagewalk.c @@ -302,6 +302,9 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end, const struct mm_walk_ops *ops = walk->ops; int err = 0; + /* For huge_pte_offset() */ + rcu_read_lock(); + do { next = hugetlb_entry_end(h, addr, end); pte = huge_pte_offset(walk->mm, addr & hmask, sz); @@ -315,6 +318,8 @@ static int walk_hugetlb_range(unsigned long addr, unsigned long end, break; } while (addr = next, addr != end); + rcu_read_unlock(); + return err; } -- 2.37.3
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