diff options
| author | Huang Ying <ying.huang@intel.com> | 2018-04-21 00:55:38 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-06-20 22:02:46 +0300 |
| commit | a20600762300154bb6ed99eea6b16abd1163dbea (patch) | |
| tree | f930dc2a25470448807e1e7d48504c47e9556164 /fs/proc/task_mmu.c | |
| parent | 6385f2da8b3bda687ae5e9f7c60655cfeb16632a (diff) | |
| download | linux-a20600762300154bb6ed99eea6b16abd1163dbea.tar.xz | |
mm, pagemap: fix swap offset value for PMD migration entry
[ Upstream commit 88c28f2469151b031f8cea9b28ed5be1b74a4172 ]
The swap offset reported by /proc/<pid>/pagemap may be not correct for
PMD migration entries. If addr passed into pagemap_pmd_range() isn't
aligned with PMD start address, the swap offset reported doesn't
reflect this. And in the loop to report information of each sub-page,
the swap offset isn't increased accordingly as that for PFN.
This may happen after opening /proc/<pid>/pagemap and seeking to a page
whose address doesn't align with a PMD start address. I have verified
this with a simple test program.
BTW: migration swap entries have PFN information, do we need to restrict
whether to show them?
[akpm@linux-foundation.org: fix typo, per Huang, Ying]
Link: http://lkml.kernel.org/r/20180408033737.10897-1-ying.huang@intel.com
Signed-off-by: "Huang, Ying" <ying.huang@intel.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: "Jerome Glisse" <jglisse@redhat.com>
Cc: Daniel Colascione <dancol@google.com>
Cc: Zi Yan <zi.yan@cs.rutgers.edu>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/proc/task_mmu.c')
| -rw-r--r-- | fs/proc/task_mmu.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 6744bd706ecf..4cd8328e4039 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -1327,9 +1327,11 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION else if (is_swap_pmd(pmd)) { swp_entry_t entry = pmd_to_swp_entry(pmd); + unsigned long offset = swp_offset(entry); + offset += (addr & ~PMD_MASK) >> PAGE_SHIFT; frame = swp_type(entry) | - (swp_offset(entry) << MAX_SWAPFILES_SHIFT); + (offset << MAX_SWAPFILES_SHIFT); flags |= PM_SWAP; if (pmd_swp_soft_dirty(pmd)) flags |= PM_SOFT_DIRTY; @@ -1349,6 +1351,8 @@ static int pagemap_pmd_range(pmd_t *pmdp, unsigned long addr, unsigned long end, break; if (pm->show_pfn && (flags & PM_PRESENT)) frame++; + else if (flags & PM_SWAP) + frame += (1 << MAX_SWAPFILES_SHIFT); } spin_unlock(ptl); return err; |