forked from luck/tmp_suning_uos_patched
userfaultfd: hugetlbfs: add userfaultfd hugetlb hook
When processing a hugetlb fault for no page present, check the vma to determine if faults are to be handled via userfaultfd. If so, drop the hugetlb_fault_mutex and call handle_userfault(). Link: http://lkml.kernel.org/r/20161216144821.5183-21-aarcange@redhat.com Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Acked-by: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Michael Rapoport <RAPOPORT@il.ibm.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
parent
810a56b943
commit
1a1aad8a9b
33
mm/hugetlb.c
33
mm/hugetlb.c
@ -32,6 +32,7 @@
|
||||
#include <linux/hugetlb.h>
|
||||
#include <linux/hugetlb_cgroup.h>
|
||||
#include <linux/node.h>
|
||||
#include <linux/userfaultfd_k.h>
|
||||
#include "internal.h"
|
||||
|
||||
int hugepages_treat_as_movable;
|
||||
@ -3680,6 +3681,38 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
|
||||
size = i_size_read(mapping->host) >> huge_page_shift(h);
|
||||
if (idx >= size)
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* Check for page in userfault range
|
||||
*/
|
||||
if (userfaultfd_missing(vma)) {
|
||||
u32 hash;
|
||||
struct vm_fault vmf = {
|
||||
.vma = vma,
|
||||
.address = address,
|
||||
.flags = flags,
|
||||
/*
|
||||
* Hard to debug if it ends up being
|
||||
* used by a callee that assumes
|
||||
* something about the other
|
||||
* uninitialized fields... same as in
|
||||
* memory.c
|
||||
*/
|
||||
};
|
||||
|
||||
/*
|
||||
* hugetlb_fault_mutex must be dropped before
|
||||
* handling userfault. Reacquire after handling
|
||||
* fault to make calling code simpler.
|
||||
*/
|
||||
hash = hugetlb_fault_mutex_hash(h, mm, vma, mapping,
|
||||
idx, address);
|
||||
mutex_unlock(&hugetlb_fault_mutex_table[hash]);
|
||||
ret = handle_userfault(&vmf, VM_UFFD_MISSING);
|
||||
mutex_lock(&hugetlb_fault_mutex_table[hash]);
|
||||
goto out;
|
||||
}
|
||||
|
||||
page = alloc_huge_page(vma, address, 0);
|
||||
if (IS_ERR(page)) {
|
||||
ret = PTR_ERR(page);
|
||||
|
Loading…
Reference in New Issue
Block a user