From ee273e3906f6678be3367da10dc77a1f41fff46d Mon Sep 17 00:00:00 2001
From: Drew DeVault <sir@cmpwn.com>
Date: Mon, 17 May 2021 18:59:34 -0400
Subject: [PATCH] linux::io_uring: clarify usage of registered buffers

Signed-off-by: Drew DeVault <sir@cmpwn.com>

---
 io_uring/register.ha | 4 +++-

diff --git a/io_uring/register.ha b/io_uring/register.ha
index a7b5a97c0df2f5b76af1a7e6dcb4b7d0ded3fc07..66204a2315f334fc2cf308d95060e21fe4243497 100644
--- a/io_uring/register.ha
+++ b/io_uring/register.ha
@@ -4,7 +4,9 @@ use types;
 
 // Registers a set of fixed buffers with an [[io_uring]]. Note that you must
 // call [[unregister_buffers]] before registering a new set of buffers (even if
-// some of them have similar addresses to the old set).
+// some of them have similar addresses to the old set). The buffers must be
+// anonymous, non-file-backed memory (e.g. the kind returned by alloc or
+// rt::mmap).
 export fn register_buffers(ring: *io_uring, iov: []rt::iovec) (void | error) = {
 	assert(len(iov) <= types::UINT_MAX);
 	return match (rt::io_uring_register(ring.fd, regop::REGISTER_BUFFERS,

-- 
2.48.1