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From: Joel Granados via B4 Relay <devnull+j.granados.samsung.com@kernel.org>
Date: Tue, 04 Jun 2024 08:29:21 +0200
Subject: [PATCH 3/8] sysctl: Remove check for sentinel element in ctl_table
 arrays
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Message-Id: <20240604-jag-sysctl_remset-v1-3-2df7ecdba0bd@samsung.com>
References: <20240604-jag-sysctl_remset-v1-0-2df7ecdba0bd@samsung.com>
In-Reply-To: <20240604-jag-sysctl_remset-v1-0-2df7ecdba0bd@samsung.com>
To: Peter Zijlstra <peterz@infradead.org>, Ingo Molnar <mingo@redhat.com>, 
 Will Deacon <will@kernel.org>, Waiman Long <longman@redhat.com>, 
 Boqun Feng <boqun.feng@gmail.com>, Suren Baghdasaryan <surenb@google.com>, 
 Kent Overstreet <kent.overstreet@linux.dev>, 
 Andrew Morton <akpm@linux-foundation.org>, 
 Luis Chamberlain <mcgrof@kernel.org>, Kees Cook <keescook@chromium.org>, 
 Joel Granados <j.granados@samsung.com>, 
 "David S. Miller" <davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, 
 Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, 
 linux-fsdevel@vger.kernel.org, netdev@vger.kernel.org
Reply-To: j.granados@samsung.com

From: Joel Granados <j.granados@samsung.com>

Use ARRAY_SIZE exclusively by removing the check to ->procname in the
stopping criteria of the loops traversing ctl_table arrays. This commit
finalizes the removal of the sentinel elements at the end of ctl_table
arrays which reduces the build time size and run time memory bloat by
~64 bytes per sentinel (further information Link :
https://lore.kernel.org/all/ZO5Yx5JFogGi%2FcBo@bombadil.infradead.org/)

Remove the entry->procname evaluation from the for loop stopping
criteria in sysctl and sysctl_net.

Signed-off-by: Joel Granados <j.granados@samsung.com>
---
 fs/proc/proc_sysctl.c |  2 +-
 net/sysctl_net.c      | 11 ++---------
 2 files changed, 3 insertions(+), 10 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index b1c2c0b82116..d4ba7ad9dbe0 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -21,7 +21,7 @@
 
 #define list_for_each_table_entry(entry, header)	\
 	entry = header->ctl_table;			\
-	for (size_t i = 0 ; i < header->ctl_table_size && entry->procname; ++i, entry++)
+	for (size_t i = 0 ; i < header->ctl_table_size; ++i, entry++)
 
 static const struct dentry_operations proc_sys_dentry_operations;
 static const struct file_operations proc_sys_file_operations;
diff --git a/net/sysctl_net.c b/net/sysctl_net.c
index f5017012a049..19e8048241ba 100644
--- a/net/sysctl_net.c
+++ b/net/sysctl_net.c
@@ -127,7 +127,7 @@ static void ensure_safe_net_sysctl(struct net *net, const char *path,
 
 	pr_debug("Registering net sysctl (net %p): %s\n", net, path);
 	ent = table;
-	for (size_t i = 0; i < table_size && ent->procname; ent++, i++) {
+	for (size_t i = 0; i < table_size; ent++, i++) {
 		unsigned long addr;
 		const char *where;
 
@@ -165,17 +165,10 @@ struct ctl_table_header *register_net_sysctl_sz(struct net *net,
 						struct ctl_table *table,
 						size_t table_size)
 {
-	int count;
-	struct ctl_table *entry;
-
 	if (!net_eq(net, &init_net))
 		ensure_safe_net_sysctl(net, path, table, table_size);
 
-	entry = table;
-	for (count = 0 ; count < table_size && entry->procname; entry++, count++)
-		;
-
-	return __register_sysctl_table(&net->sysctls, path, table, count);
+	return __register_sysctl_table(&net->sysctls, path, table, table_size);
 }
 EXPORT_SYMBOL_GPL(register_net_sysctl_sz);
 

-- 
2.43.0