From: "Thomas Hellström (VMware)" <thomas_os@shipmail.org>
To: linux-kernel@vger.kernel.org, linux-mm@kvack.org
Cc: torvalds@linux-foundation.org,
"Thomas Hellstrom" <thellstrom@vmware.com>,
"Matthew Wilcox" <willy@infradead.org>,
"Will Deacon" <will.deacon@arm.com>,
"Peter Zijlstra" <peterz@infradead.org>,
"Rik van Riel" <riel@surriel.com>,
"Minchan Kim" <minchan@kernel.org>,
"Michal Hocko" <mhocko@suse.com>,
"Huang Ying" <ying.huang@intel.com>,
"Jérôme Glisse" <jglisse@redhat.com>,
"Kirill A . Shutemov" <kirill@shutemov.name>,
"Kirill A . Shutemov" <kirill.shutemov@linux.intel.com>
Subject: [PATCH v6 2/8] mm: pagewalk: Take the pagetable lock in walk_pte_range()
Date: Mon, 14 Oct 2019 15:21:58 +0200 [thread overview]
Message-ID: <20191014132204.7721-3-thomas_os@shipmail.org> (raw)
In-Reply-To: <20191014132204.7721-1-thomas_os@shipmail.org>
From: Thomas Hellstrom <thellstrom@vmware.com>
Without the lock, anybody modifying a pte from within this function might
have it concurrently modified by someone else.
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Jérôme Glisse <jglisse@redhat.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
mm/pagewalk.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index d48c2a986ea3..c5fa42cab14f 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -10,8 +10,9 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
pte_t *pte;
int err = 0;
const struct mm_walk_ops *ops = walk->ops;
+ spinlock_t *ptl;
- pte = pte_offset_map(pmd, addr);
+ pte = pte_offset_map_lock(walk->mm, pmd, addr, &ptl);
for (;;) {
err = ops->pte_entry(pte, addr, addr + PAGE_SIZE, walk);
if (err)
@@ -22,7 +23,7 @@ static int walk_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
pte++;
}
- pte_unmap(pte);
+ pte_unmap_unlock(pte, ptl);
return err;
}
--
2.20.1
next prev parent reply other threads:[~2019-10-14 13:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-14 13:21 [PATCH v6 0/8] Emulated coherent graphics memory take 2 Thomas Hellström (VMware)
2019-10-14 13:21 ` [PATCH v6 1/8] mm: Remove BUG_ON mmap_sem not held from xxx_trans_huge_lock() Thomas Hellström (VMware)
2019-10-14 13:21 ` Thomas Hellström (VMware) [this message]
2019-10-14 13:21 ` [PATCH v6 3/8] mm: Add a walk_page_mapping() function to the pagewalk code Thomas Hellström (VMware)
2019-11-06 3:49 ` Andrew Morton
2019-10-14 13:22 ` [PATCH v6 4/8] mm: Add write-protect and clean utilities for address space ranges Thomas Hellström (VMware)
2019-11-06 3:51 ` Andrew Morton
2019-10-14 13:22 ` [PATCH v6 5/8] drm/vmwgfx: Implement an infrastructure for write-coherent resources Thomas Hellström (VMware)
2019-10-14 13:22 ` [PATCH v6 6/8] drm/vmwgfx: Use an RBtree instead of linked list for MOB resources Thomas Hellström (VMware)
2019-10-14 13:22 ` [PATCH v6 7/8] drm/vmwgfx: Implement an infrastructure for read-coherent resources Thomas Hellström (VMware)
2019-10-14 13:22 ` [PATCH v6 8/8] drm/vmwgfx: Add surface dirty-tracking callbacks Thomas Hellström (VMware)
2019-10-21 12:24 ` [PATCH v6 0/8] Emulated coherent graphics memory take 2 Thomas Hellstrom
2019-11-04 9:21 ` -mm maintainer? WAS " Thomas Hellström (VMware)
2019-11-04 16:36 ` Linus Torvalds
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