From a7e50de460d7d9230dc065c9d2f1a1b1669c675c Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Tue, 7 Jun 2022 12:49:43 +0200 Subject: [PATCH] tty/vt: consolemap: change refcount only if needed in con_do_clear_unimap() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit con_do_clear_unimap() currently decreases and increases refcount of old dictionary in a back and forth fashion. This makes the code really hard to follow. Decrease the refcount only if everything went well and we really allocated a new one and decoupled from the old dictionary. I sincerelly hope I did not make a mistake in this (ill) logic. Reviewed-by: Ilpo Järvinen Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220607104946.18710-33-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman --- drivers/tty/vt/consolemap.c | 13 +++++++------ 1 file changed, 7 insertions(+), 6 deletions(-) diff --git a/drivers/tty/vt/consolemap.c b/drivers/tty/vt/consolemap.c index 01b7e49f1f913..4d8efe74315c2 100644 --- a/drivers/tty/vt/consolemap.c +++ b/drivers/tty/vt/consolemap.c @@ -535,22 +535,23 @@ static int con_do_clear_unimap(struct vc_data *vc) { struct uni_pagedict *old = *vc->vc_uni_pagedir_loc; - if (!old || --old->refcount) { + if (!old || old->refcount > 1) { struct uni_pagedict *new = kzalloc(sizeof(*new), GFP_KERNEL); - if (!new) { - if (old) - old->refcount++; + if (!new) return -ENOMEM; - } + new->refcount = 1; *vc->vc_uni_pagedir_loc = new; + + if (old) + old->refcount--; } else { if (old == dflt) dflt = NULL; - old->refcount++; old->sum = 0; con_release_unimap(old); } + return 0; } -- 2.30.2