From f982b9d57e7f834138fc908804fe66f646f2b108 Mon Sep 17 00:00:00 2001 From: Biju Das Date: Tue, 15 Aug 2023 14:15:57 +0100 Subject: [PATCH] pinctrl: renesas: rzv2m: Fix NULL pointer dereference in rzv2m_dt_subnode_to_map() Fix the below random NULL pointer crash during boot by serializing pinctrl group and function creation/remove calls in rzv2m_dt_subnode_to_map() with mutex lock. Crash logs: pc : __pi_strcmp+0x20/0x140 lr : pinmux_func_name_to_selector+0x68/0xa4 Call trace: __pi_strcmp+0x20/0x140 pinmux_generic_add_function+0x34/0xcc rzv2m_dt_subnode_to_map+0x2e4/0x418 rzv2m_dt_node_to_map+0x15c/0x18c pinctrl_dt_to_map+0x218/0x37c create_pinctrl+0x70/0x3d8 While at it, add a comment for lock. Fixes: 92a9b8252576 ("pinctrl: renesas: Add RZ/V2M pin and gpio controller driver") Signed-off-by: Biju Das Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20230815131558.33787-3-biju.das.jz@bp.renesas.com Signed-off-by: Geert Uytterhoeven --- drivers/pinctrl/renesas/pinctrl-rzv2m.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) diff --git a/drivers/pinctrl/renesas/pinctrl-rzv2m.c b/drivers/pinctrl/renesas/pinctrl-rzv2m.c index 35b23c1a5684..9146101ea9e2 100644 --- a/drivers/pinctrl/renesas/pinctrl-rzv2m.c +++ b/drivers/pinctrl/renesas/pinctrl-rzv2m.c @@ -14,6 +14,7 @@ #include #include #include +#include #include #include @@ -123,7 +124,8 @@ struct rzv2m_pinctrl { struct gpio_chip gpio_chip; struct pinctrl_gpio_range gpio_range; - spinlock_t lock; + spinlock_t lock; /* lock read/write registers */ + struct mutex mutex; /* serialize adding groups and functions */ }; static const unsigned int drv_1_8V_group2_uA[] = { 1800, 3800, 7800, 11000 }; @@ -322,11 +324,13 @@ static int rzv2m_dt_subnode_to_map(struct pinctrl_dev *pctldev, name = np->name; } + mutex_lock(&pctrl->mutex); + /* Register a single pin group listing all the pins we read from DT */ gsel = pinctrl_generic_add_group(pctldev, name, pins, num_pinmux, NULL); if (gsel < 0) { ret = gsel; - goto done; + goto unlock; } /* @@ -340,6 +344,8 @@ static int rzv2m_dt_subnode_to_map(struct pinctrl_dev *pctldev, goto remove_group; } + mutex_unlock(&pctrl->mutex); + maps[idx].type = PIN_MAP_TYPE_MUX_GROUP; maps[idx].data.mux.group = name; maps[idx].data.mux.function = name; @@ -351,6 +357,8 @@ static int rzv2m_dt_subnode_to_map(struct pinctrl_dev *pctldev, remove_group: pinctrl_generic_remove_group(pctldev, gsel); +unlock: + mutex_unlock(&pctrl->mutex); done: *index = idx; kfree(configs); @@ -1071,6 +1079,7 @@ static int rzv2m_pinctrl_probe(struct platform_device *pdev) } spin_lock_init(&pctrl->lock); + mutex_init(&pctrl->mutex); platform_set_drvdata(pdev, pctrl);