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mm, uprobes: convert __replace_page() to use page_vma_mapped_walk()
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For consistency, it worth converting all page_check_address() to
page_vma_mapped_walk(), so we could drop the former.

Link: http://lkml.kernel.org/r/20170129173858.45174-10-kirill.shutemov@linux.intel.com
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Kirill A. Shutemov authored and Linus Torvalds committed Feb 25, 2017
1 parent 36eaff3 commit 14fa2da
Showing 1 changed file with 14 additions and 8 deletions.
22 changes: 14 additions & 8 deletions kernel/events/uprobes.c
Original file line number Diff line number Diff line change
Expand Up @@ -153,14 +153,19 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
struct page *old_page, struct page *new_page)
{
struct mm_struct *mm = vma->vm_mm;
spinlock_t *ptl;
pte_t *ptep;
struct page_vma_mapped_walk pvmw = {
.page = old_page,
.vma = vma,
.address = addr,
};
int err;
/* For mmu_notifiers */
const unsigned long mmun_start = addr;
const unsigned long mmun_end = addr + PAGE_SIZE;
struct mem_cgroup *memcg;

VM_BUG_ON_PAGE(PageTransHuge(old_page), old_page);

err = mem_cgroup_try_charge(new_page, vma->vm_mm, GFP_KERNEL, &memcg,
false);
if (err)
Expand All @@ -171,11 +176,11 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,

mmu_notifier_invalidate_range_start(mm, mmun_start, mmun_end);
err = -EAGAIN;
ptep = page_check_address(old_page, mm, addr, &ptl, 0);
if (!ptep) {
if (!page_vma_mapped_walk(&pvmw)) {
mem_cgroup_cancel_charge(new_page, memcg, false);
goto unlock;
}
VM_BUG_ON_PAGE(addr != pvmw.address, old_page);

get_page(new_page);
page_add_new_anon_rmap(new_page, vma, addr, false);
Expand All @@ -187,14 +192,15 @@ static int __replace_page(struct vm_area_struct *vma, unsigned long addr,
inc_mm_counter(mm, MM_ANONPAGES);
}

flush_cache_page(vma, addr, pte_pfn(*ptep));
ptep_clear_flush_notify(vma, addr, ptep);
set_pte_at_notify(mm, addr, ptep, mk_pte(new_page, vma->vm_page_prot));
flush_cache_page(vma, addr, pte_pfn(*pvmw.pte));
ptep_clear_flush_notify(vma, addr, pvmw.pte);
set_pte_at_notify(mm, addr, pvmw.pte,
mk_pte(new_page, vma->vm_page_prot));

page_remove_rmap(old_page, false);
if (!page_mapped(old_page))
try_to_free_swap(old_page);
pte_unmap_unlock(ptep, ptl);
page_vma_mapped_walk_done(&pvmw);

if (vma->vm_flags & VM_LOCKED)
munlock_vma_page(old_page);
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