aboutsummaryrefslogtreecommitdiffstats
path: root/ipc
diff options
context:
space:
mode:
authorMike Rapoport <rppt@linux.vnet.ibm.com>2017-02-24 14:58:22 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2017-02-24 17:46:55 -0800
commit897ab3e0c49e24b62e2d54d165c7afec6bbca65b (patch)
tree5fa7e09864d6c959cef33849f6cb10ed04e459e4 /ipc
parent846b1a0f1db065a8479159dd8fecddb1ebf30547 (diff)
downloadlinux-yocto-4.12-897ab3e0c49e24b62e2d54d165c7afec6bbca65b.tar.gz
linux-yocto-4.12-897ab3e0c49e24b62e2d54d165c7afec6bbca65b.tar.bz2
linux-yocto-4.12-897ab3e0c49e24b62e2d54d165c7afec6bbca65b.zip
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 'ipc')
-rw-r--r--ipc/shm.c8
1 files changed, 4 insertions, 4 deletions
diff --git a/ipc/shm.c b/ipc/shm.c
index 7f6537b84ef5..d7805acb44fd 100644
--- a/ipc/shm.c
+++ b/ipc/shm.c
@@ -1222,7 +1222,7 @@ long do_shmat(int shmid, char __user *shmaddr, int shmflg, ulong *raddr,
goto invalid;
}
- addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate);
+ addr = do_mmap_pgoff(file, addr, size, prot, flags, 0, &populate, NULL);
*raddr = addr;
err = 0;
if (IS_ERR_VALUE(addr))
@@ -1329,7 +1329,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
*/
file = vma->vm_file;
size = i_size_read(file_inode(vma->vm_file));
- do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
/*
* We discovered the size of the shm segment, so
* break out of here and fall through to the next
@@ -1356,7 +1356,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
if ((vma->vm_ops == &shm_vm_ops) &&
((vma->vm_start - addr)/PAGE_SIZE == vma->vm_pgoff) &&
(vma->vm_file == file))
- do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
vma = next;
}
@@ -1365,7 +1365,7 @@ SYSCALL_DEFINE1(shmdt, char __user *, shmaddr)
* given
*/
if (vma && vma->vm_start == addr && vma->vm_ops == &shm_vm_ops) {
- do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start);
+ do_munmap(mm, vma->vm_start, vma->vm_end - vma->vm_start, NULL);
retval = 0;
}