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authorHugh Dickins <hughd@google.com>2023-06-08 18:53:23 -0700
committerAndrew Morton <akpm@linux-foundation.org>2023-06-19 16:19:19 -0700
commita92cbb82c8d375d47fbaf0e1ad3fd4074a7cb156 (patch)
tree7c8b1e4ec3000b51a0736e96dbd7b4672e2cf37d /mm/memory.c
parent4f8fcf4ced0b7184149045818dcc2f9e2689b775 (diff)
perf/core: allow pte_offset_map() to fail
In rare transient cases, not yet made possible, pte_offset_map() and pte_offet_map_lock() may not find a page table: handle appropriately. [hughd@google.com: __wp_page_copy_user(): don't call update_mmu_tlb() with NULL] Link: https://lkml.kernel.org/r/1a4db221-7872-3594-57ce-42369945ec8d@google.com Link: https://lkml.kernel.org/r/a194441b-63f3-adb6-5964-7ca3171ae7c2@google.com Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Christoph Hellwig <hch@infradead.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Ira Weiny <ira.weiny@intel.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lorenzo Stoakes <lstoakes@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport (IBM) <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <naoya.horiguchi@nec.com> Cc: Pavel Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Song Liu <song@kernel.org> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <shy828301@gmail.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Zack Rusin <zackr@vmware.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/mm/memory.c b/mm/memory.c
index 11f221953690..63c30f58142b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2843,7 +2843,8 @@ static inline int __wp_page_copy_user(struct page *dst, struct page *src,
* Other thread has already handled the fault
* and update local tlb only
*/
- update_mmu_tlb(vma, addr, vmf->pte);
+ if (vmf->pte)
+ update_mmu_tlb(vma, addr, vmf->pte);
ret = -EAGAIN;
goto pte_unlock;
}
@@ -2867,7 +2868,8 @@ static inline int __wp_page_copy_user(struct page *dst, struct page *src,
vmf->pte = pte_offset_map_lock(mm, vmf->pmd, addr, &vmf->ptl);
if (unlikely(!vmf->pte || !pte_same(*vmf->pte, vmf->orig_pte))) {
/* The PTE changed under us, update local tlb */
- update_mmu_tlb(vma, addr, vmf->pte);
+ if (vmf->pte)
+ update_mmu_tlb(vma, addr, vmf->pte);
ret = -EAGAIN;
goto pte_unlock;
}