From 8c703d660450c4df72ff24f79a335dc7973a9dc8 Mon Sep 17 00:00:00 2001 From: Christophe JAILLET Date: Fri, 17 Nov 2017 15:27:32 -0800 Subject: [PATCH] kernel/umh.c: optimize 'proc_cap_handler()' If 'write' is 0, we can avoid a call to spin_lock/spin_unlock. Link: http://lkml.kernel.org/r/20171020193331.7233-1-christophe.jaillet@wanadoo.fr Signed-off-by: Christophe JAILLET Acked-by: Luis R. Rodriguez Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/umh.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/umh.c b/kernel/umh.c index 6ff9905250ff..18e5fa4b0e71 100644 --- a/kernel/umh.c +++ b/kernel/umh.c @@ -537,14 +537,14 @@ static int proc_cap_handler(struct ctl_table *table, int write, /* * Drop everything not in the new_cap (but don't add things) */ - spin_lock(&umh_sysctl_lock); if (write) { + spin_lock(&umh_sysctl_lock); if (table->data == CAP_BSET) usermodehelper_bset = cap_intersect(usermodehelper_bset, new_cap); if (table->data == CAP_PI) usermodehelper_inheritable = cap_intersect(usermodehelper_inheritable, new_cap); + spin_unlock(&umh_sysctl_lock); } - spin_unlock(&umh_sysctl_lock); return 0; }