The patch titled Subject: userfaultfd: require UFFDIO_API before other ioctls has been added to the -mm tree. Its filename is userfaultfd-require-uffdio_api-before-other-ioctls.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-require-uffdio_api-before-other-ioctls.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-require-uffdio_api-before-other-ioctls.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Andrea Arcangeli <aarcange@xxxxxxxxxx> Subject: userfaultfd: require UFFDIO_API before other ioctls UFFDIO_API was already forced before read/poll could work. This makes the code more strict to force it also for all other ioctls. All users would already have been required to call UFFDIO_API before invoking other ioctls but this makes it more explicit. This will ensure we can change all ioctls (all but UFFDIO_API/struct uffdio_api) with a bump of uffdio_api.api. There's no actual plan or need to change the API or the ioctl, the current API already should cover fine even the non cooperative usage, but this is just for the longer term future just in case. Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx> Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- fs/userfaultfd.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff -puN fs/userfaultfd.c~userfaultfd-require-uffdio_api-before-other-ioctls fs/userfaultfd.c --- a/fs/userfaultfd.c~userfaultfd-require-uffdio_api-before-other-ioctls +++ a/fs/userfaultfd.c @@ -577,7 +577,6 @@ static ssize_t userfaultfd_read(struct f if (ctx->state == UFFD_STATE_WAIT_API) return -EINVAL; - BUG_ON(ctx->state != UFFD_STATE_RUNNING); for (;;) { if (count < sizeof(msg)) @@ -1115,6 +1114,9 @@ static long userfaultfd_ioctl(struct fil int ret = -EINVAL; struct userfaultfd_ctx *ctx = file->private_data; + if (cmd != UFFDIO_API && ctx->state == UFFD_STATE_WAIT_API) + return -EINVAL; + switch(cmd) { case UFFDIO_API: ret = userfaultfd_api(ctx, arg); _ Patches currently in -mm which might be from aarcange@xxxxxxxxxx are userfaultfd-linux-documentation-vm-userfaultfdtxt.patch userfaultfd-linux-documentation-vm-userfaultfdtxt-fix.patch userfaultfd-waitqueue-add-nr-wake-parameter-to-__wake_up_locked_key.patch userfaultfd-uapi.patch userfaultfd-uapi-add-missing-include-typesh.patch userfaultfd-linux-userfaultfd_kh.patch userfaultfd-add-vm_userfaultfd_ctx-to-the-vm_area_struct.patch userfaultfd-add-vm_uffd_missing-and-vm_uffd_wp.patch userfaultfd-call-handle_userfault-for-userfaultfd_missing-faults.patch userfaultfd-teach-vma_merge-to-merge-across-vma-vm_userfaultfd_ctx.patch userfaultfd-prevent-khugepaged-to-merge-if-userfaultfd-is-armed.patch userfaultfd-add-new-syscall-to-provide-memory-externalization.patch userfaultfd-add-new-syscall-to-provide-memory-externalization-fix.patch userfaultfd-add-new-syscall-to-provide-memory-externalization-fix-fix.patch userfaultfd-add-new-syscall-to-provide-memory-externalization-fix-fix-fix.patch userfaultfd-rename-uffd_apibits-into-features.patch userfaultfd-rename-uffd_apibits-into-features-fixup.patch userfaultfd-change-the-read-api-to-return-a-uffd_msg.patch userfaultfd-change-the-read-api-to-return-a-uffd_msg-fix.patch userfaultfd-change-the-read-api-to-return-a-uffd_msg-fix-2.patch userfaultfd-change-the-read-api-to-return-a-uffd_msg-fix-2-fix.patch userfaultfd-wake-pending-userfaults.patch userfaultfd-optimize-read-and-poll-to-be-o1.patch userfaultfd-optimize-read-and-poll-to-be-o1-fix.patch userfaultfd-allocate-the-userfaultfd_ctx-cacheline-aligned.patch userfaultfd-solve-the-race-between-uffdio_copyzeropage-and-read.patch userfaultfd-buildsystem-activation.patch userfaultfd-activate-syscall.patch userfaultfd-activate-syscall-fix.patch userfaultfd-uffdio_copyuffdio_zeropage-uapi.patch userfaultfd-mcopy_atomicmfill_zeropage-uffdio_copyuffdio_zeropage-preparation.patch userfaultfd-avoid-mmap_sem-read-recursion-in-mcopy_atomic.patch userfaultfd-avoid-mmap_sem-read-recursion-in-mcopy_atomic-fix.patch userfaultfd-uffdio_copy-and-uffdio_zeropage.patch userfaultfd-require-uffdio_api-before-other-ioctls.patch userfaultfd-allow-signals-to-interrupt-a-userfault.patch userfaultfd-propagate-the-full-address-in-thp-faults.patch userfaultfd-avoid-missing-wakeups-during-refile-in-userfaultfd_read.patch userfaultfd-selftest.patch fs-userfaultfdc-work-around-i386-build-error.patch page-flags-trivial-cleanup-for-pagetrans-helpers.patch page-flags-introduce-page-flags-policies-wrt-compound-pages.patch page-flags-define-pg_locked-behavior-on-compound-pages.patch page-flags-define-behavior-of-fs-io-related-flags-on-compound-pages.patch page-flags-define-behavior-of-lru-related-flags-on-compound-pages.patch page-flags-define-behavior-slb-related-flags-on-compound-pages.patch page-flags-define-behavior-of-xen-related-flags-on-compound-pages.patch page-flags-define-pg_reserved-behavior-on-compound-pages.patch page-flags-define-pg_swapbacked-behavior-on-compound-pages.patch page-flags-define-pg_swapcache-behavior-on-compound-pages.patch page-flags-define-pg_mlocked-behavior-on-compound-pages.patch page-flags-define-pg_uncached-behavior-on-compound-pages.patch page-flags-define-pg_uptodate-behavior-on-compound-pages.patch page-flags-look-on-head-page-if-the-flag-is-encoded-in-page-mapping.patch mm-sanitize-page-mapping-for-tail-pages.patch -- 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