cuse(3): Make some clarifications in the manual page.

MFC after:	1 week
Sponsored by:	NVIDIA Networking

1 files changed, 9 insertions, 8 deletions

diff --git a/lib/libcuse/cuse.3 b/lib/libcuse/cuse.3
index 0aff43ac2155..52f9ca4d225a 100644
--- a/lib/libcuse/cuse.3
+++ b/lib/libcuse/cuse.3
@@ -1,6 +1,6 @@
 .\" $FreeBSD$
 .\"
-.\" Copyright (c) 2010-2013 Hans Petter Selasky
+.\" Copyright (c) 2010-2022 Hans Petter Selasky
 .\"
 .\" All rights reserved.
 .\"
@@ -25,7 +25,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd April 17, 2019
+.Dd July 18, 2022
 .Dt CUSE 3
 .Os
 .Sh NAME
@@ -124,6 +124,11 @@ mapped by
 This function returns a valid data pointer on success or
 .Dv NULL
 on failure.
+The returned pointer is always aligned to the system page size.
+The number and size of allocations is limited by the
+.Xr mmap 2
+offset having to fit into a 32-bit variable typically for 32-bit
+applications.
 .Pp
 .Ft "int"
 .Fn "cuse_is_vmalloc_addr" "void *"
@@ -137,16 +142,12 @@ Else this function returns zero.
 This function frees memory allocated by
 .Fn cuse_vmalloc .
 This function is NULL safe.
-Note that the
-cuse library will internally not free the memory until the
-.Fn cuse_uninit
-function is called and that the number of unique
-allocations is limited.
 .Pp
 .Ft "unsigned long"
 .Fn "cuse_vmoffset" "void *"
-This function returns the mmap offset that the client must use to
+This function returns the mmap offset the client must use to
 access the allocated memory.
+The passed pointer must be aligned to the system page size.
 .Pp
 .Ft "struct cuse_dev *"
 .Fn "cuse_dev_create" "const struct cuse_methods *mtod" "void *priv0" "void *priv1" "uid_t" "gid_t" "int permission" "const char *fmt" "..."