4.19-stable review patch. If anyone has any objections, please let me know.
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From: Maria Yu quic_aiquny@quicinc.com
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 quic_aiquny@quicinc.com Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231115102824.23727-1-quic_aiquny@quicinc.com Signed-off-by: Linus Walleij linus.walleij@linaro.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/pinctrl/core.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -1224,17 +1224,17 @@ 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);