From 767126eb6b9b9ea500edc2ff64041d3c2fa45286 Mon Sep 17 00:00:00 2001 From: Mike Rapoport Date: Fri, 7 Apr 2017 16:04:42 -0700 Subject: [PATCH] userfaultfd: report actual registered features in fdinfo fdinfo for userfault file descriptor reports UFFD_API_FEATURES. Up until recently, the UFFD_API_FEATURES was defined as 0, therefore corresponding field in fdinfo always contained zero. Now, with introduction of several additional features, UFFD_API_FEATURES is not longer 0 and it seems better to report actual features requested for the userfaultfd object described by the fdinfo. First, the applications that were using userfault will still see zero at the features field in fdinfo. Next, reporting actual features rather than available features, gives clear indication of what userfault features are used by an application. Link: http://lkml.kernel.org/r/1491140181-22121-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport Reviewed-by: Andrea Arcangeli Cc: Pavel Emelyanov Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/userfaultfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index 1d227b0fcf49f..f7555fc258774 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1756,7 +1756,7 @@ static void userfaultfd_show_fdinfo(struct seq_file *m, struct file *f) * protocols: aa:... bb:... */ seq_printf(m, "pending:\t%lu\ntotal:\t%lu\nAPI:\t%Lx:%x:%Lx\n", - pending, total, UFFD_API, UFFD_API_FEATURES, + pending, total, UFFD_API, ctx->features, UFFD_API_IOCTLS|UFFD_API_RANGE_IOCTLS); } #endif -- 2.39.5