iov_iter: transparently handle compat iovecs in import_iovec

Use in compat_syscall to import either native or the compat iovecs, and
remove the now superflous compat_import_iovec.

This removes the need for special compat logic in most callers, and
the remaining ones can still be simplified by using __import_iovec
with a bool compat parameter.

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

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index ef722f0..e08df86 100644 (file)
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -333,16 +333,8 @@ static int sg_io(struct request_queue *q, struct gendisk *bd_disk,
                struct iov_iter i;
                struct iovec *iov = NULL;
 
-#ifdef CONFIG_COMPAT
-               if (in_compat_syscall())
-                       ret = compat_import_iovec(rq_data_dir(rq),
-                                  hdr->dxferp, hdr->iovec_count,
-                                  0, &iov, &i);
-               else
-#endif
-                       ret = import_iovec(rq_data_dir(rq),
-                                  hdr->dxferp, hdr->iovec_count,
-                                  0, &iov, &i);
+               ret = import_iovec(rq_data_dir(rq), hdr->dxferp,
+                                  hdr->iovec_count, 0, &iov, &i);
                if (ret < 0)
                        goto out_free_cdb;
 

diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index 20472aa..bfa8d77 100644 (file)
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1820,14 +1820,7 @@ sg_start_req(Sg_request *srp, unsigned char *cmd)
                struct iovec *iov = NULL;
                struct iov_iter i;
 
-#ifdef CONFIG_COMPAT
-               if (in_compat_syscall())
-                       res = compat_import_iovec(rw, hp->dxferp, iov_count,
-                                                 0, &iov, &i);
-               else
-#endif
-                       res = import_iovec(rw, hp->dxferp, iov_count,
-                                          0, &iov, &i);
+               res = import_iovec(rw, hp->dxferp, iov_count, 0, &iov, &i);
                if (res < 0)
                        return res;
 

diff --git a/fs/aio.c b/fs/aio.c
index 5736bff..247f055 100644 (file)
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1489,12 +1489,8 @@ static ssize_t aio_setup_rw(int rw, const struct iocb *iocb,
                *iovec = NULL;
                return ret;
        }
-#ifdef CONFIG_COMPAT
-       if (compat)
-               return compat_import_iovec(rw, buf, len, UIO_FASTIOV, iovec,
-                               iter);
-#endif
-       return import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter);
+
+       return __import_iovec(rw, buf, len, UIO_FASTIOV, iovec, iter, compat);
 }
 
 static inline void aio_rw_done(struct kiocb *req, ssize_t ret)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 91e2cc8..b75c699 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2846,13 +2846,8 @@ static ssize_t __io_import_iovec(int rw, struct io_kiocb *req,
                return ret;
        }
 
-#ifdef CONFIG_COMPAT
-       if (req->ctx->compat)
-               return compat_import_iovec(rw, buf, sqe_len, UIO_FASTIOV,
-                                               iovec, iter);
-#endif
-
-       return import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter);
+       return __import_iovec(rw, buf, sqe_len, UIO_FASTIOV, iovec, iter,
+                             req->ctx->compat);
 }
 
 static ssize_t io_import_iovec(int rw, struct io_kiocb *req,
@@ -4166,8 +4161,9 @@ static int __io_recvmsg_copy_hdr(struct io_kiocb *req,
                                sr->len);
                iomsg->iov = NULL;
        } else {
-               ret = import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
-                                       &iomsg->iov, &iomsg->msg.msg_iter);
+               ret = __import_iovec(READ, uiov, iov_len, UIO_FASTIOV,
+                                    &iomsg->iov, &iomsg->msg.msg_iter,
+                                    false);
                if (ret > 0)
                        ret = 0;
        }
@@ -4207,9 +4203,9 @@ static int __io_compat_recvmsg_copy_hdr(struct io_kiocb *req,
                sr->len = iomsg->iov[0].iov_len;
                iomsg->iov = NULL;
        } else {
-               ret = compat_import_iovec(READ, uiov, len, UIO_FASTIOV,
-                                               &iomsg->iov,
-                                               &iomsg->msg.msg_iter);
+               ret = __import_iovec(READ, (struct iovec __user *)uiov, len,
+                                  UIO_FASTIOV, &iomsg->iov,
+                                  &iomsg->msg.msg_iter, true);
                if (ret < 0)
                        return ret;
        }

diff --git a/fs/read_write.c b/fs/read_write.c
index e5e891a..0a68037 100644 (file)
--- a/fs/read_write.c
+++ b/fs/read_write.c
@@ -1078,7 +1078,8 @@ static size_t compat_readv(struct file *file,
        struct iov_iter iter;
        ssize_t ret;
 
-       ret = compat_import_iovec(READ, vec, vlen, UIO_FASTIOV, &iov, &iter);
+       ret = import_iovec(READ, (const struct iovec __user *)vec, vlen,
+                          UIO_FASTIOV, &iov, &iter);
        if (ret >= 0) {
                ret = do_iter_read(file, &iter, pos, flags);
                kfree(iov);
@@ -1186,7 +1187,8 @@ static size_t compat_writev(struct file *file,
        struct iov_iter iter;
        ssize_t ret;
 
-       ret = compat_import_iovec(WRITE, vec, vlen, UIO_FASTIOV, &iov, &iter);
+       ret = import_iovec(WRITE, (const struct iovec __user *)vec, vlen,
+                          UIO_FASTIOV, &iov, &iter);
        if (ret >= 0) {
                file_start_write(file);
                ret = do_iter_write(file, &iter, pos, flags);

diff --git a/fs/splice.c b/fs/splice.c
index d7c8a7c..132d42b 100644 (file)
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1387,7 +1387,7 @@ COMPAT_SYSCALL_DEFINE4(vmsplice, int, fd, const struct compat_iovec __user *, io
        if (error)
                return error;
 
-       error = compat_import_iovec(type, iov32, nr_segs,
+       error = import_iovec(type, (struct iovec __user *)iov32, nr_segs,
                             ARRAY_SIZE(iovstack), &iov, &iter);
        if (error >= 0) {
                error = do_vmsplice(f.file, &iter, flags);

diff --git a/include/linux/uio.h b/include/linux/uio.h
index 92c11fe..daedc61 100644 (file)
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -275,14 +275,6 @@ ssize_t import_iovec(int type, const struct iovec __user *uvec,
 ssize_t __import_iovec(int type, const struct iovec __user *uvec,
                 unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
                 struct iov_iter *i, bool compat);
-
-#ifdef CONFIG_COMPAT
-struct compat_iovec;
-ssize_t compat_import_iovec(int type, const struct compat_iovec __user * uvector,
-                unsigned nr_segs, unsigned fast_segs,
-                struct iovec **iov, struct iov_iter *i);
-#endif
-
 int import_single_range(int type, void __user *buf, size_t len,
                 struct iovec *iov, struct iov_iter *i);
 

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index e6cb51d..2e452ce 100644 (file)
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1806,21 +1806,11 @@ ssize_t import_iovec(int type, const struct iovec __user *uvec,
                 unsigned nr_segs, unsigned fast_segs,
                 struct iovec **iovp, struct iov_iter *i)
 {
-       return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i, false);
+       return __import_iovec(type, uvec, nr_segs, fast_segs, iovp, i,
+                             in_compat_syscall());
 }
 EXPORT_SYMBOL(import_iovec);
 
-#ifdef CONFIG_COMPAT
-ssize_t compat_import_iovec(int type, const struct compat_iovec __user *uvec,
-               unsigned nr_segs, unsigned fast_segs, struct iovec **iovp,
-               struct iov_iter *i)
-{
-       return __import_iovec(type, (const struct iovec __user *)uvec, nr_segs,
-                            fast_segs, iovp, i, true);
-}
-EXPORT_SYMBOL(compat_import_iovec);
-#endif
-
 int import_single_range(int rw, void __user *buf, size_t len,
                 struct iovec *iov, struct iov_iter *i)
 {

diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c
index 5e728c2..3f2156a 100644 (file)
--- a/mm/process_vm_access.c
+++ b/mm/process_vm_access.c
@@ -326,7 +326,8 @@ compat_process_vm_rw(compat_pid_t pid,
        if (flags != 0)
                return -EINVAL;
 
-       rc = compat_import_iovec(dir, lvec, liovcnt, UIO_FASTIOV, &iov_l, &iter);
+       rc = import_iovec(dir, (const struct iovec __user *)lvec, liovcnt,
+                         UIO_FASTIOV, &iov_l, &iter);
        if (rc < 0)
                return rc;
        if (!iov_iter_count(&iter))

diff --git a/net/compat.c b/net/compat.c
index 95ce707..ddd15af 100644 (file)
--- a/net/compat.c
+++ b/net/compat.c
@@ -98,8 +98,8 @@ int get_compat_msghdr(struct msghdr *kmsg,
        if (err)
                return err;
 
-       err = compat_import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr),
-                                  len, UIO_FASTIOV, iov, &kmsg->msg_iter);
+       err = import_iovec(save_addr ? READ : WRITE, compat_ptr(ptr), len,
+                          UIO_FASTIOV, iov, &kmsg->msg_iter);
        return err < 0 ? err : 0;
 }
 

diff --git a/security/keys/compat.c b/security/keys/compat.c
index 6ee9d8f..7ae531d 100644 (file)
--- a/security/keys/compat.c
+++ b/security/keys/compat.c
@@ -33,9 +33,8 @@ static long compat_keyctl_instantiate_key_iov(
        if (!_payload_iov)
                ioc = 0;
 
-       ret = compat_import_iovec(WRITE, _payload_iov, ioc,
-                                 ARRAY_SIZE(iovstack), &iov,
-                                 &from);
+       ret = import_iovec(WRITE, (const struct iovec __user *)_payload_iov,
+                          ioc, ARRAY_SIZE(iovstack), &iov, &from);
        if (ret < 0)
                return ret;