xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

userfaultfd: non-cooperative: add event for memory unmaps

Browse Source 
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>
This commit is contained in:
Mike Rapoport
2017-02-24 14:58:22 -08:00
committed by Linus Torvalds
parent 846b1a0f1d
commit 897ab3e0c4
15 changed files with 160 additions and 45 deletions
Download Patch File Download Diff File Expand all files Collapse all files

14
include/linux/mm.h
View File

@@ -2090,18 +2090,22 @@ extern int install_special_mapping(struct mm_struct *mm,
extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
extern unsigned long mmap_region(struct file *file, unsigned long addr,
unsigned long len, vm_flags_t vm_flags, unsigned long pgoff);
unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
struct list_head *uf);
extern unsigned long do_mmap(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot, unsigned long flags,
vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate);
extern int do_munmap(struct mm_struct *, unsigned long, size_t);
vm_flags_t vm_flags, unsigned long pgoff, unsigned long *populate,
struct list_head *uf);
extern int do_munmap(struct mm_struct *, unsigned long, size_t,
struct list_head *uf);
static inline unsigned long
do_mmap_pgoff(struct file *file, unsigned long addr,
unsigned long len, unsigned long prot, unsigned long flags,
unsigned long pgoff, unsigned long *populate)
unsigned long pgoff, unsigned long *populate,
struct list_head *uf)
{
return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate);
return do_mmap(file, addr, len, prot, flags, 0, pgoff, populate, uf);
}
#ifdef CONFIG_MMU