| From | Kamal Mostafa <> | Subject | [PATCH 3.13.y-ckt 036/138] drivers/scsi/sg.c: mark VMA as VM_IO to prevent migration | Date | Wed, 9 Mar 2016 15:12:43 -0800 |
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3.13.11-ckt36 -stable review patch. If anyone has any objections, please let me know.
---8<------------------------------------------------------------
From: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
commit 461c7fa126794157484dca48e88effa4963e3af3 upstream.
Reduced testcase:
#include <fcntl.h> #include <unistd.h> #include <sys/mman.h> #include <numaif.h>
#define SIZE 0x2000
int main() { int fd; void *p;
fd = open("/dev/sg0", O_RDWR); p = mmap(NULL, SIZE, PROT_EXEC, MAP_PRIVATE | MAP_LOCKED, fd, 0); mbind(p, SIZE, 0, NULL, 0, MPOL_MF_MOVE); return 0; }
We shouldn't try to migrate pages in sg VMA as we don't have a way to update Sg_scatter_hold::pages accordingly from mm core.
Let's mark the VMA as VM_IO to indicate to mm core that the VMA is not migratable.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Doug Gilbert <dgilbert@interlog.com> Cc: David Rientjes <rientjes@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Shiraz Hashim <shashim@codeaurora.org> Cc: Hugh Dickins <hughd@google.com> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: syzkaller <syzkaller@googlegroups.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Alexander Potapenko <glider@google.com> Cc: James Bottomley <James.Bottomley@HansenPartnership.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Kamal Mostafa <kamal@canonical.com> --- drivers/scsi/sg.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 721d839..0be16bf 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1258,7 +1258,7 @@ sg_mmap(struct file *filp, struct vm_area_struct *vma) } sfp->mmap_called = 1; - vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; + vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP; vma->vm_private_data = sfp; vma->vm_ops = &sg_mmap_vm_ops; return 0; -- 2.7.0
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