userfaultfd: non-cooperative: release all ctx in dup_userfaultfd_complete
Don't stop running dup_fctx() even if userfaultfd_event_wait_completion
fails as it has to run userfaultfd_ctx_put on all ctx to pair against
the userfaultfd_ctx_get that was run on all fctx->orig in
dup_userfaultfd.
Link: http://lkml.kernel.org/r/20170224181957.19736-4-aarcange@redhat.com
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Hillf Danton <hillf.zj@alibaba-inc.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c
index 668bbbd..dd48052 100644
--- a/fs/userfaultfd.c
+++ b/fs/userfaultfd.c
@@ -527,16 +527,12 @@ int handle_userfault(struct vm_fault *vmf, unsigned long reason)
return ret;
}
-static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
- struct userfaultfd_wait_queue *ewq)
+static void userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
+ struct userfaultfd_wait_queue *ewq)
{
- int ret;
-
- ret = -1;
if (WARN_ON_ONCE(current->flags & PF_EXITING))
goto out;
- ret = 0;
ewq->ctx = ctx;
init_waitqueue_entry(&ewq->wq, current);
@@ -552,7 +548,6 @@ static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
break;
if (ACCESS_ONCE(ctx->released) ||
fatal_signal_pending(current)) {
- ret = -1;
__remove_wait_queue(&ctx->event_wqh, &ewq->wq);
break;
}
@@ -573,7 +568,6 @@ static int userfaultfd_event_wait_completion(struct userfaultfd_ctx *ctx,
*/
out:
userfaultfd_ctx_put(ctx);
- return ret;
}
static void userfaultfd_event_complete(struct userfaultfd_ctx *ctx,
@@ -631,7 +625,7 @@ int dup_userfaultfd(struct vm_area_struct *vma, struct list_head *fcs)
return 0;
}
-static int dup_fctx(struct userfaultfd_fork_ctx *fctx)
+static void dup_fctx(struct userfaultfd_fork_ctx *fctx)
{
struct userfaultfd_ctx *ctx = fctx->orig;
struct userfaultfd_wait_queue ewq;
@@ -641,17 +635,15 @@ static int dup_fctx(struct userfaultfd_fork_ctx *fctx)
ewq.msg.event = UFFD_EVENT_FORK;
ewq.msg.arg.reserved.reserved1 = (unsigned long)fctx->new;
- return userfaultfd_event_wait_completion(ctx, &ewq);
+ userfaultfd_event_wait_completion(ctx, &ewq);
}
void dup_userfaultfd_complete(struct list_head *fcs)
{
- int ret = 0;
struct userfaultfd_fork_ctx *fctx, *n;
list_for_each_entry_safe(fctx, n, fcs, list) {
- if (!ret)
- ret = dup_fctx(fctx);
+ dup_fctx(fctx);
list_del(&fctx->list);
kfree(fctx);
}
