The patch titled
Subject: userfaultfd: non-cooperative: report all available features to userland
has been added to the -mm tree. Its filename is
userfaultfd-non-cooperative-report-all-available-features-to-userland.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/userfaultfd-non-cooperative-report-all-available-features-to-userland.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/userfaultfd-non-cooperative-report-all-available-features-to-userland.patch
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*** 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: non-cooperative: report all available features to userland
This will allow userland to probe all features available in the kernel.
It will however only enable the requested features in the open userfaultfd
context.
Link: http://lkml.kernel.org/r/20161216144821.5183-8-aarcange@xxxxxxxxxx
Signed-off-by: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: "Dr. David Alan Gilbert" <dgilbert@xxxxxxxxxx>
Cc: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx>
Cc: Michael Rapoport <RAPOPORT@xxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Pavel Emelyanov <xemul@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/userfaultfd.c | 11 +++++++----
1 file changed, 7 insertions(+), 4 deletions(-)
diff -puN fs/userfaultfd.c~userfaultfd-non-cooperative-report-all-available-features-to-userland fs/userfaultfd.c
--- a/fs/userfaultfd.c~userfaultfd-non-cooperative-report-all-available-features-to-userland
+++ a/fs/userfaultfd.c
@@ -1252,6 +1252,7 @@ static int userfaultfd_api(struct userfa
struct uffdio_api uffdio_api;
void __user *buf = (void __user *)arg;
int ret;
+ __u64 features;
ret = -EINVAL;
if (ctx->state != UFFD_STATE_WAIT_API)
@@ -1259,21 +1260,23 @@ static int userfaultfd_api(struct userfa
ret = -EFAULT;
if (copy_from_user(&uffdio_api, buf, sizeof(uffdio_api)))
goto out;
- if (uffdio_api.api != UFFD_API ||
- (uffdio_api.features & ~UFFD_API_FEATURES)) {
+ features = uffdio_api.features;
+ if (uffdio_api.api != UFFD_API || (features & ~UFFD_API_FEATURES)) {
memset(&uffdio_api, 0, sizeof(uffdio_api));
if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api)))
goto out;
ret = -EINVAL;
goto out;
}
- uffdio_api.features &= UFFD_API_FEATURES;
+ /* report all available features and ioctls to userland */
+ uffdio_api.features = UFFD_API_FEATURES;
uffdio_api.ioctls = UFFD_API_IOCTLS;
ret = -EFAULT;
if (copy_to_user(buf, &uffdio_api, sizeof(uffdio_api)))
goto out;
ctx->state = UFFD_STATE_RUNNING;
- ctx->features = uffd_ctx_features(uffdio_api.features);
+ /* only enable the requested features for this uffd context */
+ ctx->features = uffd_ctx_features(features);
ret = 0;
out:
return ret;
_
Patches currently in -mm which might be from aarcange@xxxxxxxxxx are
userfaultfd-document-_ior-_iow.patch
userfaultfd-correct-comment-about-uffd_feature_pagefault_flag_wp.patch
userfaultfd-convert-bug-to-warn_on_once.patch
userfaultfd-use-vma_is_anonymous.patch
userfaultfd-non-cooperative-report-all-available-features-to-userland.patch
userfaultfd-non-cooperative-add-fork-event-build-warning-fix.patch
userfaultfd-non-cooperative-optimize-mremap_userfaultfd_complete.patch
userfaultfd-non-cooperative-avoid-madv_dontneed-race-condition.patch
userfaultfd-non-cooperative-wake-userfaults-after-uffdio_unregister.patch
userfaultfd-hugetlbfs-gup-support-vm_fault_retry.patch
userfaultfd-hugetlbfs-uffd_feature_missing_hugetlbfs.patch
userfaultfd-shmem-add-tlbflushh-header-for-microblaze.patch
userfaultfd-shmem-lock-the-page-before-adding-it-to-pagecache.patch
userfaultfd-shmem-avoid-leaking-blocks-and-used-blocks-in-uffdio_copy.patch
userfaultfd-hugetlbfs-uffd_feature_missing_shmem.patch
userfaultfd-selftest-test-uffdio_zeropage-on-all-memory-types.patch
mm-mprotect-use-pmd_trans_unstable-instead-of-taking-the-pmd_lock.patch
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