linux-kernel - [PATCH] module: avoid calling synchronize

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Message-Id: <20220302011306.2054550-1-lv.ruyi@zte.com.cn>
Date:   Wed,  2 Mar 2022 01:13:06 +0000
From:   cgel.zte@...il.com
To:     mcgrof@...nel.org
Cc:     linux-modules@...r.kernel.org, linux-kernel@...r.kernel.org,
        Lv Ruyi <lv.ruyi@....com.cn>, Zeal Robot <zealci@....com.cn>
Subject: [PATCH] module: avoid calling synchronize_rcu()

From: Lv Ruyi (CGEL ZTE) <lv.ruyi@....com.cn>

Kfree_rcu() usually results in even simpler code than does 
synchronize_rcu() without synchronize_rcu()'s multi-millisecond
latency, so replace synchronize_rcu() with kfree_rcu().

Reported-by: Zeal Robot <zealci@....com.cn>
Signed-off-by: Lv Ruyi (CGEL ZTE) <lv.ruyi@....com.cn>
---
 kernel/module.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/module.c b/kernel/module.c
index 6cea788fd965..767b5f9e5819 100644
--- a/kernel/module.c
+++ b/kernel/module.c
@@ -4138,8 +4138,7 @@ static int load_module(struct load_info *info, const char __user *uargs,
  ddebug_cleanup:
 	ftrace_release_mod(mod);
 	dynamic_debug_remove(mod, info->debug);
-	synchronize_rcu();
-	kfree(mod->args);
+	kfree_rcu(mod->args);
  free_arch_cleanup:
 	cfi_cleanup(mod);
 	module_arch_cleanup(mod);
-- 
2.25.1