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| author | Mike Rapoport <rppt@linux.vnet.ibm.com> | 2017-02-25 01:58:22 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-25 04:46:55 +0300 |
| commit | 897ab3e0c49e24b62e2d54d165c7afec6bbca65b (patch) | |
| tree | 5fa7e09864d6c959cef33849f6cb10ed04e459e4 /fs/proc/vmcore.c | |
| parent | 846b1a0f1db065a8479159dd8fecddb1ebf30547 (diff) | |
| download | linux-897ab3e0c49e24b62e2d54d165c7afec6bbca65b.tar.xz | |
userfaultfd: non-cooperative: add event for memory unmaps
When a non-cooperative userfaultfd monitor copies pages in the
background, it may encounter regions that were already unmapped.
Addition of UFFD_EVENT_UNMAP allows the uffd monitor to track precisely
changes in the virtual memory layout.
Since there might be different uffd contexts for the affected VMAs, we
first should create a temporary representation for the unmap event for
each uffd context and then notify them one by one to the appropriate
userfault file descriptors.
The event notification occurs after the mmap_sem has been released.
[arnd@arndb.de: fix nommu build]
Link: http://lkml.kernel.org/r/20170203165141.3665284-1-arnd@arndb.de
[mhocko@suse.com: fix nommu build]
Link: http://lkml.kernel.org/r/20170202091503.GA22823@dhcp22.suse.cz
Link: http://lkml.kernel.org/r/1485542673-24387-3-git-send-email-rppt@linux.vnet.ibm.com
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/proc/vmcore.c')
| -rw-r--r-- | fs/proc/vmcore.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c index f52d8e857ff7..885d445afa0d 100644 --- a/fs/proc/vmcore.c +++ b/fs/proc/vmcore.c @@ -388,7 +388,7 @@ static int remap_oldmem_pfn_checked(struct vm_area_struct *vma, } return 0; fail: - do_munmap(vma->vm_mm, from, len); + do_munmap(vma->vm_mm, from, len, NULL); return -EAGAIN; } @@ -481,7 +481,7 @@ static int mmap_vmcore(struct file *file, struct vm_area_struct *vma) return 0; fail: - do_munmap(vma->vm_mm, vma->vm_start, len); + do_munmap(vma->vm_mm, vma->vm_start, len, NULL); return -EAGAIN; } #else |