diff options
| author | Axel Rasmussen <axelrasmussen@google.com> | 2023-03-14 15:12:49 -0700 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-04-05 19:42:48 -0700 |
| commit | d9712937037e0ce887920f321429826e9dbfd960 (patch) | |
| tree | 6471b4a9899a53bc761f464ba7d89d05e594b25d /fs/userfaultfd.c | |
| parent | 61c5004022f56c443b86800e8985d8803f3a22aa (diff) | |
| download | lwn-d9712937037e0ce887920f321429826e9dbfd960.tar.gz lwn-d9712937037e0ce887920f321429826e9dbfd960.zip | |
mm: userfaultfd: combine 'mode' and 'wp_copy' arguments
Many userfaultfd ioctl functions take both a 'mode' and a 'wp_copy'
argument. In future commits we plan to plumb the flags through to more
places, so we'd be proliferating the very long argument list even further.
Let's take the time to simplify the argument list. Combine the two
arguments into one - and generalize, so when we add more flags in the
future, it doesn't imply more function arguments.
Since the modes (copy, zeropage, continue) are mutually exclusive, store
them as an integer value (0, 1, 2) in the low bits. Place combine-able
flag bits in the high bits.
This is quite similar to an earlier patch proposed by Nadav Amit
("userfaultfd: introduce uffd_flags" [1]). The main difference is that
patch only handled flags, whereas this patch *also* combines the "mode"
argument into the same type to shorten the argument list.
[1]: https://lore.kernel.org/all/20220619233449.181323-2-namit@vmware.com/
Link: https://lkml.kernel.org/r/20230314221250.682452-4-axelrasmussen@google.com
Signed-off-by: Axel Rasmussen <axelrasmussen@google.com>
Acked-by: James Houghton <jthoughton@google.com>
Acked-by: Peter Xu <peterx@redhat.com>
Acked-by: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'fs/userfaultfd.c')
| -rw-r--r-- | fs/userfaultfd.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/fs/userfaultfd.c b/fs/userfaultfd.c index d8d432ca81e6..8971c3613cc6 100644 --- a/fs/userfaultfd.c +++ b/fs/userfaultfd.c @@ -1729,6 +1729,7 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, struct uffdio_copy uffdio_copy; struct uffdio_copy __user *user_uffdio_copy; struct userfaultfd_wake_range range; + uffd_flags_t flags = 0; user_uffdio_copy = (struct uffdio_copy __user *) arg; @@ -1755,10 +1756,12 @@ static int userfaultfd_copy(struct userfaultfd_ctx *ctx, goto out; if (uffdio_copy.mode & ~(UFFDIO_COPY_MODE_DONTWAKE|UFFDIO_COPY_MODE_WP)) goto out; + if (uffdio_copy.mode & UFFDIO_COPY_MODE_WP) + flags |= MFILL_ATOMIC_WP; if (mmget_not_zero(ctx->mm)) { ret = mfill_atomic_copy(ctx->mm, uffdio_copy.dst, uffdio_copy.src, uffdio_copy.len, &ctx->mmap_changing, - uffdio_copy.mode); + flags); mmput(ctx->mm); } else { return -ESRCH; |