diff options
| author | Jan Kara <jack@suse.cz> | 2019-03-29 06:43:19 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-05-16 20:42:31 +0300 |
| commit | 9aad9f3abc884fcd9ef812da4029b9d40657f0de (patch) | |
| tree | 48d6ad7778d78442adfc56b97a4c4f76bd473ca9 /mm | |
| parent | 9be4eb5b08ae1dd6643e61c70b7583fce2368106 (diff) | |
| download | linux-9aad9f3abc884fcd9ef812da4029b9d40657f0de.tar.xz | |
mm/memory.c: fix modifying of page protection by insert_pfn()
[ Upstream commit cae85cb8add35f678cf487139d05e083ce2f570a ]
Aneesh has reported that PPC triggers the following warning when
excercising DAX code:
IP set_pte_at+0x3c/0x190
LR insert_pfn+0x208/0x280
Call Trace:
insert_pfn+0x68/0x280
dax_iomap_pte_fault.isra.7+0x734/0xa40
__xfs_filemap_fault+0x280/0x2d0
do_wp_page+0x48c/0xa40
__handle_mm_fault+0x8d0/0x1fd0
handle_mm_fault+0x140/0x250
__do_page_fault+0x300/0xd60
handle_page_fault+0x18
Now that is WARN_ON in set_pte_at which is
VM_WARN_ON(pte_hw_valid(*ptep) && !pte_protnone(*ptep));
The problem is that on some architectures set_pte_at() cannot cope with
a situation where there is already some (different) valid entry present.
Use ptep_set_access_flags() instead to modify the pfn which is built to
deal with modifying existing PTE.
Link: http://lkml.kernel.org/r/20190311084537.16029-1-jack@suse.cz
Fixes: b2770da64254 "mm: add vm_insert_mixed_mkwrite()"
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Acked-by: Dan Williams <dan.j.williams@intel.com>
Cc: Chandan Rajendra <chandan@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/mm/memory.c b/mm/memory.c index f99b64ca1303..e9bce27bc18c 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1813,10 +1813,12 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, WARN_ON_ONCE(!is_zero_pfn(pte_pfn(*pte))); goto out_unlock; } - entry = *pte; - goto out_mkwrite; - } else - goto out_unlock; + entry = pte_mkyoung(*pte); + entry = maybe_mkwrite(pte_mkdirty(entry), vma); + if (ptep_set_access_flags(vma, addr, pte, entry, 1)) + update_mmu_cache(vma, addr, pte); + } + goto out_unlock; } /* Ok, finally just insert the thing.. */ @@ -1825,7 +1827,6 @@ static int insert_pfn(struct vm_area_struct *vma, unsigned long addr, else entry = pte_mkspecial(pfn_t_pte(pfn, prot)); -out_mkwrite: if (mkwrite) { entry = pte_mkyoung(entry); entry = maybe_mkwrite(pte_mkdirty(entry), vma); |