This explicitly sets up an ITER_KVEC from an iovec with kernel ranges mapped.
Signed-off-by: Jens Axboe <ax...@kernel.dk> --- include/linux/uio.h | 3 +++ lib/iov_iter.c | 35 ++++++++++++++++++++++++++--------- 2 files changed, 29 insertions(+), 9 deletions(-) diff --git a/include/linux/uio.h b/include/linux/uio.h index 55ce99ddb912..bbefdb421f6d 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -284,6 +284,9 @@ int compat_import_iovec(int type, const struct compat_iovec __user * uvector, int import_single_range(int type, void __user *buf, size_t len, struct iovec *iov, struct iov_iter *i); +int import_kvec(int type, const struct kvec *kvecs, unsigned nr_segs, + size_t bytes, struct iov_iter *iter); + int iov_iter_for_each_range(struct iov_iter *i, size_t bytes, int (*f)(struct kvec *vec, void *context), void *context); diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 7ebccb5c1637..a5b6dd691f37 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -431,25 +431,33 @@ int iov_iter_fault_in_readable(struct iov_iter *i, size_t bytes) } EXPORT_SYMBOL(iov_iter_fault_in_readable); -void iov_iter_init(struct iov_iter *i, unsigned int direction, - const struct iovec *iov, unsigned long nr_segs, - size_t count) +static void iov_iter_init_type(struct iov_iter *i, int type, + unsigned int direction, const struct iovec *iov, + unsigned long nr_segs, size_t count) { WARN_ON(direction & ~(READ | WRITE)); direction &= READ | WRITE; - /* It will get better. Eventually... */ - if (uaccess_kernel()) { - i->type = ITER_KVEC | direction; + i->type = type | direction; + if (i->type == ITER_KVEC) i->kvec = (struct kvec *)iov; - } else { - i->type = ITER_IOVEC | direction; + else i->iov = iov; - } + i->nr_segs = nr_segs; i->iov_offset = 0; i->count = count; } + +void iov_iter_init(struct iov_iter *i, unsigned int direction, + const struct iovec *iov, unsigned long nr_segs, + size_t count) +{ + /* It will get better. Eventually... */ + int type = uaccess_kernel() ? ITER_KVEC : ITER_IOVEC; + + iov_iter_init_type(i, type, direction, iov, nr_segs, count); +} EXPORT_SYMBOL(iov_iter_init); static void memcpy_from_page(char *to, struct page *page, size_t offset, size_t len) @@ -1582,6 +1590,15 @@ int import_iovec(int type, const struct iovec __user * uvector, } EXPORT_SYMBOL(import_iovec); +int import_kvec(int type, const struct kvec *kvecs, unsigned nr_segs, + size_t bytes, struct iov_iter *iter) +{ + const struct iovec *p = (const struct iovec *) kvecs; + + iov_iter_init_type(iter, ITER_KVEC, type, p, nr_segs, bytes); + return 0; +} + #ifdef CONFIG_COMPAT #include <linux/compat.h> -- 2.17.1