Re: [PATCH v5 13/14] epoll: implement epoll_create2() syscall

From: Roman Penyaev
Date: Mon Jun 24 2019 - 12:25:57 EST

On 2019-06-24 18:14, Arnd Bergmann wrote:
On Mon, Jun 24, 2019 at 4:42 PM Roman Penyaev <rpenyaev@xxxxxxx> wrote:

epoll_create2() is needed to accept EPOLL_USERPOLL flags
and size, i.e. this patch wires up polling from userspace.

Can you explain in the patch description more what it's needed for?

Sure. Will update on next iteration.

The man page only states that "Since Linux 2.6.8, the size argument
is ignored", so your description above does not explain why you need
to add the size argument back.

diff --git a/arch/alpha/kernel/syscalls/syscall.tbl b/arch/alpha/kernel/syscalls/syscall.tbl
index 1db9bbcfb84e..a1d7b695063d 100644
--- a/arch/alpha/kernel/syscalls/syscall.tbl
+++ b/arch/alpha/kernel/syscalls/syscall.tbl
@@ -474,3 +474,5 @@
542 common fsmount sys_fsmount
543 common fspick sys_fspick
544 common pidfd_open sys_pidfd_open
+# 546 common clone3 sys_clone3
+547 common epoll_create2 sys_epoll_create2
diff --git a/arch/arm/tools/syscall.tbl b/arch/arm/tools/syscall.tbl
index ff45d8807cb8..1497f3c87d54 100644
--- a/arch/arm/tools/syscall.tbl
+++ b/arch/arm/tools/syscall.tbl
@@ -449,3 +449,4 @@
433 common fspick sys_fspick
434 common pidfd_open sys_pidfd_open
436 common clone3 sys_clone3
+437 common epoll_create2 sys_epoll_create2

The table changes all look correct and complete, provided we
don't get another patch picking the same number.

Good. I had doubts, because on some archs there is a gap,
(sys_clone3 was missing). So I left a placeholder, so
can be uncommented when sys_clone3 is implemented.