From: Peter Xu <peterx@xxxxxxxxxx> Subject: userfaultfd/selftests: use user mode only Patch series "userfaultfd/selftests: A few cleanups", v2. I wanted to cleanup userfaultfd.c fault handling for a long time. If it's not cleaned, when the new code grows the file it'll also grow the size that needs to be cleaned... This is my attempt to cleanup the userfaultfd selftest on fault handling, to use an err() macro instead of either fprintf() or perror() then another exit() call. The huge cleanup is done in the last patch. The first 4 patches are some other standalone cleanups for the same file, so I put them together. This patch (of 5): Userfaultfd selftest does not need to handle kernel initiated fault. Set user mode so it can be run even if unprivileged_userfaultfd=0 (which is the default). Link: https://lkml.kernel.org/r/20210412232753.1012412-2-peterx@xxxxxxxxxx Signed-off-by: Peter Xu <peterx@xxxxxxxxxx> Reviewed-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx> Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Brian Geffon <bgeffon@xxxxxxxxxx> Cc: "Dr . David Alan Gilbert" <dgilbert@xxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Jerome Glisse <jglisse@xxxxxxxxxx> Cc: Joe Perches <joe@xxxxxxxxxxx> Cc: Kirill A. Shutemov <kirill@xxxxxxxxxxxxx> Cc: Lokesh Gidra <lokeshgidra@xxxxxxxxxx> Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Cc: Mina Almasry <almasrymina@xxxxxxxxxx> Cc: Oliver Upton <oupton@xxxxxxxxxx> Cc: Shaohua Li <shli@xxxxxx> Cc: Shuah Khan <shuah@xxxxxxxxxx> Cc: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx> Cc: Wang Qing <wangqing@xxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/vm/userfaultfd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/testing/selftests/vm/userfaultfd.c~userfaultfd-selftests-use-user-mode-only +++ a/tools/testing/selftests/vm/userfaultfd.c @@ -831,7 +831,7 @@ static int userfaultfd_open_ext(uint64_t { struct uffdio_api uffdio_api; - uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK); + uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY); if (uffd < 0) { fprintf(stderr, "userfaultfd syscall not available in this kernel\n"); _
