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authorHugh Dickins <hughd@google.com>2023-06-08 18:29:22 -0700
committerAndrew Morton <akpm@linux-foundation.org>2023-06-19 16:19:15 -0700
commit04dee9e85cf50a2f24738e456d66b88de109b806 (patch)
tree688fda48b9d814762710f8c9465f27a89b896ab3
parent9f2bad096d2f84751fd4559fcd4cdda1a2af1976 (diff)
mm/various: give up if pte_offset_map[_lock]() fails
Following the examples of nearby code, various functions can just give up if pte_offset_map() or pte_offset_map_lock() fails. And there's no need for a preliminary pmd_trans_unstable() or other such check, since such cases are now safely handled inside. Link: https://lkml.kernel.org/r/7b9bd85d-1652-cbf2-159d-f503b45e5b@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>
-rw-r--r--mm/gup.c9
-rw-r--r--mm/ksm.c7
-rw-r--r--mm/memcontrol.c8
-rw-r--r--mm/memory-failure.c8
-rw-r--r--mm/migrate.c3
5 files changed, 22 insertions, 13 deletions
diff --git a/mm/gup.c b/mm/gup.c
index d448fd286b8c..598e8c98367b 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -545,10 +545,10 @@ static struct page *follow_page_pte(struct vm_area_struct *vma,
if (WARN_ON_ONCE((flags & (FOLL_PIN | FOLL_GET)) ==
(FOLL_PIN | FOLL_GET)))
return ERR_PTR(-EINVAL);
- if (unlikely(pmd_bad(*pmd)))
- return no_page_table(vma, flags);
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (!ptep)
+ return no_page_table(vma, flags);
pte = *ptep;
if (!pte_present(pte))
goto no_page;
@@ -852,8 +852,9 @@ static int get_gate_page(struct mm_struct *mm, unsigned long address,
pmd = pmd_offset(pud, address);
if (!pmd_present(*pmd))
return -EFAULT;
- VM_BUG_ON(pmd_trans_huge(*pmd));
pte = pte_offset_map(pmd, address);
+ if (!pte)
+ return -EFAULT;
if (pte_none(*pte))
goto unmap;
*vma = get_gate_vma(mm);
@@ -2468,6 +2469,8 @@ static int gup_pte_range(pmd_t pmd, pmd_t *pmdp, unsigned long addr,
pte_t *ptep, *ptem;
ptem = ptep = pte_offset_map(&pmd, addr);
+ if (!ptep)
+ return 0;
do {
pte_t pte = ptep_get_lockless(ptep);
struct page *page;
diff --git a/mm/ksm.c b/mm/ksm.c
index df2aa281d49d..3dc15459dd20 100644
--- a/mm/ksm.c
+++ b/mm/ksm.c
@@ -431,10 +431,9 @@ static int break_ksm_pmd_entry(pmd_t *pmd, unsigned long addr, unsigned long nex
pte_t *pte;
int ret;
- if (pmd_leaf(*pmd) || !pmd_present(*pmd))
- return 0;
-
pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
+ if (!pte)
+ return 0;
if (pte_present(*pte)) {
page = vm_normal_page(walk->vma, addr, *pte);
} else if (!pte_none(*pte)) {
@@ -1203,6 +1202,8 @@ static int replace_page(struct vm_area_struct *vma, struct page *page,
mmu_notifier_invalidate_range_start(&range);
ptep = pte_offset_map_lock(mm, pmd, addr, &ptl);
+ if (!ptep)
+ goto out_mn;
if (!pte_same(*ptep, orig_pte)) {
pte_unmap_unlock(ptep, ptl);
goto out_mn;
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index caf6ab55f8e3..77d8d2d14fcf 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -6021,9 +6021,9 @@ static int mem_cgroup_count_precharge_pte_range(pmd_t *pmd,
return 0;
}
- if (pmd_trans_unstable(pmd))
- return 0;
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ if (!pte)
+ return 0;
for (; addr != end; pte++, addr += PAGE_SIZE)
if (get_mctgt_type(vma, addr, *pte, NULL))
mc.precharge++; /* increment precharge temporarily */
@@ -6241,10 +6241,10 @@ static int mem_cgroup_move_charge_pte_range(pmd_t *pmd,
return 0;
}
- if (pmd_trans_unstable(pmd))
- return 0;
retry:
pte = pte_offset_map_lock(vma->vm_mm, pmd, addr, &ptl);
+ if (!pte)
+ return 0;
for (; addr != end; addr += PAGE_SIZE) {
pte_t ptent = *(pte++);
bool device = false;
diff --git a/mm/memory-failure.c b/mm/memory-failure.c
index 004a02f44271..d5116f0eb1b6 100644
--- a/mm/memory-failure.c
+++ b/mm/memory-failure.c
@@ -405,6 +405,8 @@ static unsigned long dev_pagemap_mapping_shift(struct vm_area_struct *vma,
if (pmd_devmap(*pmd))
return PMD_SHIFT;
pte = pte_offset_map(pmd, address);
+ if (!pte)
+ return 0;
if (pte_present(*pte) && pte_devmap(*pte))
ret = PAGE_SHIFT;
pte_unmap(pte);
@@ -791,11 +793,11 @@ static int hwpoison_pte_range(pmd_t *pmdp, unsigned long addr,
goto out;
}
- if (pmd_trans_unstable(pmdp))
- goto out;
-
mapped_pte = ptep = pte_offset_map_lock(walk->vma->vm_mm, pmdp,
addr, &ptl);
+ if (!ptep)
+ goto out;
+
for (; addr != end; ptep++, addr += PAGE_SIZE) {
ret = check_hwpoisoned_entry(*ptep, addr, PAGE_SHIFT,
hwp->pfn, &hwp->tk);
diff --git a/mm/migrate.c b/mm/migrate.c
index c1f2c40441e1..363562992046 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -305,6 +305,9 @@ void migration_entry_wait(struct mm_struct *mm, pmd_t *pmd,
swp_entry_t entry;
ptep = pte_offset_map_lock(mm, pmd, address, &ptl);
+ if (!ptep)
+ return;
+
pte = *ptep;
pte_unmap(ptep);