From: Maria Yu Date: Wed, 15 Nov 2023 10:28:24 +0000 (+0800) Subject: pinctrl: avoid reload of p state in list iteration X-Git-Tag: v4.14.332~11 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b872d80d845249cac9c689789107a0c6806df748;p=thirdparty%2Fkernel%2Fstable.git pinctrl: avoid reload of p state in list iteration commit 4198a9b571065978632276264e01d71d68000ac5 upstream. When in the list_for_each_entry iteration, reload of p->state->settings with a local setting from old_state will turn the list iteration into an infinite loop. The typical symptom when the issue happens, will be a printk message like: "not freeing pin xx (xxx) as part of deactivating group xxx - it is already used for some other setting". This is a compiler-dependent problem, one instance occurred using Clang version 10.0 on the arm64 architecture with linux version 4.19. Fixes: 6e5e959dde0d ("pinctrl: API changes to support multiple states per device") Signed-off-by: Maria Yu Cc: Link: https://lore.kernel.org/r/20231115102824.23727-1-quic_aiquny@quicinc.com Signed-off-by: Linus Walleij Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 83f439906d316..7069f5d651990 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -1196,17 +1196,17 @@ EXPORT_SYMBOL_GPL(pinctrl_lookup_state); static int pinctrl_commit_state(struct pinctrl *p, struct pinctrl_state *state) { struct pinctrl_setting *setting, *setting2; - struct pinctrl_state *old_state = p->state; + struct pinctrl_state *old_state = READ_ONCE(p->state); int ret; - if (p->state) { + if (old_state) { /* * For each pinmux setting in the old state, forget SW's record * of mux owner for that pingroup. Any pingroups which are * still owned by the new state will be re-acquired by the call * to pinmux_enable_setting() in the loop below. */ - list_for_each_entry(setting, &p->state->settings, node) { + list_for_each_entry(setting, &old_state->settings, node) { if (setting->type != PIN_MAP_TYPE_MUX_GROUP) continue; pinmux_disable_setting(setting);