From: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: Christophe JAILLET <christophe.jaillet@xxxxxxxxxx> Acked-by: Luis R. Rodriguez <mcgrof@xxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- kernel/umh.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff -puN kernel/umh.c~umh-optimize-proc_cap_handler kernel/umh.c --- a/kernel/umh.c~umh-optimize-proc_cap_handler +++ a/kernel/umh.c @@ -537,14 +537,14 @@ static int proc_cap_handler(struct ctl_t /* * 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; } _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
