diff options
| author | Maria Yu <quic_aiquny@quicinc.com> | 2023-11-15 18:28:24 +0800 |
|---|---|---|
| committer | Linus Walleij <linus.walleij@linaro.org> | 2023-11-15 11:40:15 +0100 |
| commit | 4198a9b571065978632276264e01d71d68000ac5 (patch) | |
| tree | 616aec36d2ab563b97ac9842660ee8e192808d17 /drivers/pinctrl | |
| parent | df572eba4e6211c6187fa81a0cc1199da1902f63 (diff) | |
| download | linux-4198a9b571065978632276264e01d71d68000ac5.tar.gz | |
pinctrl: avoid reload of p state in list iteration
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>
Diffstat (limited to 'drivers/pinctrl')
| -rw-r--r-- | drivers/pinctrl/core.c | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/drivers/pinctrl/core.c b/drivers/pinctrl/core.c index 1fa89be29b8f9..f2977eb65522e 100644 --- a/drivers/pinctrl/core.c +++ b/drivers/pinctrl/core.c @@ -1262,17 +1262,17 @@ static void pinctrl_link_add(struct pinctrl_dev *pctldev, 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); |