From: Andrea Arcangeli <aarcange@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Acked-by: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx> Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/userfaultfd.c | 18 +++++------------- 1 file changed, 5 insertions(+), 13 deletions(-) diff -puN fs/userfaultfd.c~userfaultfd-non-cooperative-release-all-ctx-in-dup_userfaultfd_complete fs/userfaultfd.c --- a/fs/userfaultfd.c~userfaultfd-non-cooperative-release-all-ctx-in-dup_userfaultfd_complete +++ a/fs/userfaultfd.c @@ -527,16 +527,12 @@ out: 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_comple 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_comple */ 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_struc 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_f 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); } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
