Re: [PATCH 06/11] iov_iter: handle the compat case in import_iovec
From: Al Viro <viro@zeniv.linux.org.uk>
Date: 2020-09-21 15:20:16
Also in:
io-uring, keyrings, linux-arch, linux-arm-kernel, linux-block, linux-fsdevel, linux-mips, linux-mm, linux-s390, linux-scsi, linux-security-module, linuxppc-dev, lkml, sparclinux
On Mon, Sep 21, 2020 at 04:34:29PM +0200, Christoph Hellwig wrote:
Use in compat_syscall to import either native or the compat iovecs, and remove the now superflous compat_import_iovec, which removes the need for special compat logic in most callers. Only io_uring needs special treatment given that it can call import_iovec from kernel threads acting on behalf of native or compat syscalls. Expose the low-level __import_iovec helper and use it in io_uring to explicitly pick a iovec layout.
fs/aio.c part is not obvious... Might be better to use __import_iovec() there as well and leave the rest of aio.c changes to followup.
quoted hunk ↗ jump to hunk
--- a/lib/iov_iter.c +++ b/lib/iov_iter.c@@ -1683,7 +1683,7 @@ static int compat_copy_iovecs_from_user(struct iovec *iov, return ret; } -static ssize_t __import_iovec(int type, const struct iovec __user *uvector, +ssize_t __import_iovec(int type, const struct iovec __user *uvector, unsigned nr_segs, unsigned fast_segs, struct iovec **iovp, struct iov_iter *i, bool compat) {
Don't make it static in the first place, perhaps?