netdev - [PATCH v2] sysctl: drop unused argument set

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Message-Id: <20240223-sysctl-const-ownership-v2-1-f9ba1795aaf2@weissschuh.net>
Date: Fri, 23 Feb 2024 16:50:00 +0100
From: Thomas Weißschuh <linux@...ssschuh.net>
To: Luis Chamberlain <mcgrof@...nel.org>, Kees Cook <keescook@...omium.org>, 
 Joel Granados <j.granados@...sung.com>, 
 "David S. Miller" <davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, 
 Jakub Kicinski <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
Cc: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org, 
 netdev@...r.kernel.org, 
 Thomas Weißschuh <linux@...ssschuh.net>
Subject: [PATCH v2] sysctl: drop unused argument set_ownership()::table

The argument is never used and can be removed.

In a future commit the sysctl core will only use
"const struct ctl_table". Removing it here is a preparation for this
consitifcation.

The patch was created with the following coccinelle script:

  @@
  identifier func, head, table, uid, gid;
  @@

  void func(
    struct ctl_table_header *head,
  - struct ctl_table *table,
    kuid_t *uid, kgid_t *gid)
  { ... }

The single changed location was validate through manual inspection and
compilation.

In addition, a search for 'set_ownership' was done over the full tree to
look for places that were missed by coccinelle.
None were found.

Signed-off-by: Thomas Weißschuh <linux@...ssschuh.net>
---
Changes in v2:
- Rework commit message
- Mention potential conflict with upcoming per-namespace kernel.pid_max
  sysctl
- Delete unused parameter table
- Link to v1: https://lore.kernel.org/r/20231226-sysctl-const-ownership-v1-1-d78fdd744ba1@weissschuh.net
---
The patch is meant to be merged via the sysctl tree.

There is an upcoming series that will introduce a new implementation of
.set_ownership which would need to be adapted [0].
The adaption would be trivial as the 'table' parameter also unused
there.

This change was originally part of the sysctl-const series [1].
To slim down that series and reduce the message load on other
maintainers to a minimumble, submit this patch on its own.

[0] https://lore.kernel.org/lkml/20240222160915.315255-1-aleksandr.mikhalitsyn@canonical.com/
[1] https://lore.kernel.org/lkml/20231204-const-sysctl-v2-2-7a5060b11447@weissschuh.net/
---
 include/linux/sysctl.h | 1 -
 net/sysctl_net.c       | 1 -
 2 files changed, 2 deletions(-)

diff --git a/include/linux/sysctl.h b/include/linux/sysctl.h
index ee7d33b89e9e..60333a6b9370 100644
--- a/include/linux/sysctl.h
+++ b/include/linux/sysctl.h
@@ -205,7 +205,6 @@ struct ctl_table_root {
 	struct ctl_table_set default_set;
 	struct ctl_table_set *(*lookup)(struct ctl_table_root *root);
 	void (*set_ownership)(struct ctl_table_header *head,
-			      struct ctl_table *table,
 			      kuid_t *uid, kgid_t *gid);
 	int (*permissions)(struct ctl_table_header *head, struct ctl_table *table);
 };
diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index 051ed5f6fc93..a0a7a79991f9 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -54,7 +54,6 @@ static int net_ctl_permissions(struct ctl_table_header *head,
 }

 static void net_ctl_set_ownership(struct ctl_table_header *head,
-				  struct ctl_table *table,
 				  kuid_t *uid, kgid_t *gid)
 {
 	struct net *net = container_of(head->set, struct net, sysctls);

---
base-commit: ffd2cb6b718e189e7e2d5d0c19c25611f92e061a
change-id: 20231226-sysctl-const-ownership-ff75e67b4eea

Best regards,
-- 
Thomas Weißschuh <linux@...ssschuh.net>