aio: shift copyin of iocb into io_submit_one()

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/aio.c b/fs/aio.c
index 06761d5aac1e245f1d2ae845b362cdff43b867c2..90b46560f0ceada3dc7f22e989ce358a138fb891 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1720,22 +1720,26 @@ out_fail:
 }
 
 static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
-                        struct iocb *iocb, bool compat)
+                        bool compat)
 {
        struct aio_kiocb *req;
+       struct iocb iocb;
        ssize_t ret;
 
+       if (unlikely(copy_from_user(&iocb, user_iocb, sizeof(iocb))))
+               return -EFAULT;
+
        /* enforce forwards compatibility on users */
-       if (unlikely(iocb->aio_reserved2)) {
+       if (unlikely(iocb.aio_reserved2)) {
                pr_debug("EINVAL: reserve field set\n");
                return -EINVAL;
        }
 
        /* prevent overflows */
        if (unlikely(
-           (iocb->aio_buf != (unsigned long)iocb->aio_buf) ||
-           (iocb->aio_nbytes != (size_t)iocb->aio_nbytes) ||
-           ((ssize_t)iocb->aio_nbytes < 0)
+           (iocb.aio_buf != (unsigned long)iocb.aio_buf) ||
+           (iocb.aio_nbytes != (size_t)iocb.aio_nbytes) ||
+           ((ssize_t)iocb.aio_nbytes < 0)
           )) {
                pr_debug("EINVAL: overflow check\n");
                return -EINVAL;
@@ -1745,14 +1749,14 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
        if (unlikely(!req))
                return -EAGAIN;
 
-       if (iocb->aio_flags & IOCB_FLAG_RESFD) {
+       if (iocb.aio_flags & IOCB_FLAG_RESFD) {
                /*
                 * If the IOCB_FLAG_RESFD flag of aio_flags is set, get an
                 * instance of the file* now. The file descriptor must be
                 * an eventfd() fd, and will be signaled for each completed
                 * event using the eventfd_signal() function.
                 */
-               req->ki_eventfd = eventfd_ctx_fdget((int) iocb->aio_resfd);
+               req->ki_eventfd = eventfd_ctx_fdget((int) iocb.aio_resfd);
                if (IS_ERR(req->ki_eventfd)) {
                        ret = PTR_ERR(req->ki_eventfd);
                        req->ki_eventfd = NULL;
@@ -1767,32 +1771,32 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
        }
 
        req->ki_user_iocb = user_iocb;
-       req->ki_user_data = iocb->aio_data;
+       req->ki_user_data = iocb.aio_data;
 
-       switch (iocb->aio_lio_opcode) {
+       switch (iocb.aio_lio_opcode) {
        case IOCB_CMD_PREAD:
-               ret = aio_read(&req->rw, iocb, false, compat);
+               ret = aio_read(&req->rw, &iocb, false, compat);
                break;
        case IOCB_CMD_PWRITE:
-               ret = aio_write(&req->rw, iocb, false, compat);
+               ret = aio_write(&req->rw, &iocb, false, compat);
                break;
        case IOCB_CMD_PREADV:
-               ret = aio_read(&req->rw, iocb, true, compat);
+               ret = aio_read(&req->rw, &iocb, true, compat);
                break;
        case IOCB_CMD_PWRITEV:
-               ret = aio_write(&req->rw, iocb, true, compat);
+               ret = aio_write(&req->rw, &iocb, true, compat);
                break;
        case IOCB_CMD_FSYNC:
-               ret = aio_fsync(&req->fsync, iocb, false);
+               ret = aio_fsync(&req->fsync, &iocb, false);
                break;
        case IOCB_CMD_FDSYNC:
-               ret = aio_fsync(&req->fsync, iocb, true);
+               ret = aio_fsync(&req->fsync, &iocb, true);
                break;
        case IOCB_CMD_POLL:
-               ret = aio_poll(req, iocb);
+               ret = aio_poll(req, &iocb);
                break;
        default:
-               pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
+               pr_debug("invalid aio operation %d\n", iocb.aio_lio_opcode);
                ret = -EINVAL;
                break;
        }
@@ -1845,19 +1849,13 @@ static long do_io_submit(aio_context_t ctx_id, long nr,
         */
        for (i=0; i<nr; i++) {
                struct iocb __user *user_iocb;
-               struct iocb tmp;
 
                if (unlikely(__get_user(user_iocb, iocbpp + i))) {
                        ret = -EFAULT;
                        break;
                }
 
-               if (unlikely(copy_from_user(&tmp, user_iocb, sizeof(tmp)))) {
-                       ret = -EFAULT;
-                       break;
-               }
-
-               ret = io_submit_one(ctx, user_iocb, &tmp, compat);
+               ret = io_submit_one(ctx, user_iocb, compat);
                if (ret)
                        break;
        }