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| author | Dan Williams <dan.j.williams@intel.com> | 2016-09-03 20:38:03 +0300 |
|---|---|---|
| committer | Dan Williams <dan.j.williams@intel.com> | 2016-09-10 03:34:45 +0300 |
| commit | ca120cf688874f4423e579e7cc5ddf7244aeca45 (patch) | |
| tree | 84f2c360519322e74fa72d1f3754f01d864a43a4 | |
| parent | 4c3cb6e9a9d94d1553807854a565cd27ff4c22aa (diff) | |
| download | linux-ca120cf688874f4423e579e7cc5ddf7244aeca45.tar.xz | |
mm: fix show_smap() for zone_device-pmd ranges
Attempting to dump /proc/<pid>/smaps for a process with pmd dax mappings
currently results in the following VM_BUG_ONs:
kernel BUG at mm/huge_memory.c:1105!
task: ffff88045f16b140 task.stack: ffff88045be14000
RIP: 0010:[<ffffffff81268f9b>] [<ffffffff81268f9b>] follow_trans_huge_pmd+0x2cb/0x340
[..]
Call Trace:
[<ffffffff81306030>] smaps_pte_range+0xa0/0x4b0
[<ffffffff814c2755>] ? vsnprintf+0x255/0x4c0
[<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0
[<ffffffff8123c8a2>] walk_page_vma+0x62/0x80
[<ffffffff81307656>] show_smap+0xa6/0x2b0
kernel BUG at fs/proc/task_mmu.c:585!
RIP: 0010:[<ffffffff81306469>] [<ffffffff81306469>] smaps_pte_range+0x499/0x4b0
Call Trace:
[<ffffffff814c2795>] ? vsnprintf+0x255/0x4c0
[<ffffffff8123c46e>] __walk_page_range+0x1fe/0x4d0
[<ffffffff8123c8a2>] walk_page_vma+0x62/0x80
[<ffffffff81307696>] show_smap+0xa6/0x2b0
These locations are sanity checking page flags that must be set for an
anonymous transparent huge page, but are not set for the zone_device
pages associated with dax mappings.
Cc: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
| -rw-r--r-- | fs/proc/task_mmu.c | 2 | ||||
| -rw-r--r-- | mm/huge_memory.c | 4 |
2 files changed, 4 insertions, 2 deletions
diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c index 187d84ef9de9..f6fa99eca515 100644 --- a/fs/proc/task_mmu.c +++ b/fs/proc/task_mmu.c @@ -581,6 +581,8 @@ static void smaps_pmd_entry(pmd_t *pmd, unsigned long addr, mss->anonymous_thp += HPAGE_PMD_SIZE; else if (PageSwapBacked(page)) mss->shmem_thp += HPAGE_PMD_SIZE; + else if (is_zone_device_page(page)) + /* pass */; else VM_BUG_ON_PAGE(1, page); smaps_account(mss, page, true, pmd_young(*pmd), pmd_dirty(*pmd)); diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 2db2112aa31e..a6abd76baa72 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -1078,7 +1078,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, goto out; page = pmd_page(*pmd); - VM_BUG_ON_PAGE(!PageHead(page), page); + VM_BUG_ON_PAGE(!PageHead(page) && !is_zone_device_page(page), page); if (flags & FOLL_TOUCH) touch_pmd(vma, addr, pmd); if ((flags & FOLL_MLOCK) && (vma->vm_flags & VM_LOCKED)) { @@ -1116,7 +1116,7 @@ struct page *follow_trans_huge_pmd(struct vm_area_struct *vma, } skip_mlock: page += (addr & ~HPAGE_PMD_MASK) >> PAGE_SHIFT; - VM_BUG_ON_PAGE(!PageCompound(page), page); + VM_BUG_ON_PAGE(!PageCompound(page) && !is_zone_device_page(page), page); if (flags & FOLL_GET) get_page(page); |