6.1-stable review patch. If anyone has any objections, please let me know.
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From: Biju Das biju.das.jz@bp.renesas.com
[ Upstream commit f982b9d57e7f834138fc908804fe66f646f2b108 ]
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 biju.das.jz@bp.renesas.com Reviewed-by: Geert Uytterhoeven geert+renesas@glider.be Link: https://lore.kernel.org/r/20230815131558.33787-3-biju.das.jz@bp.renesas.com Signed-off-by: Geert Uytterhoeven geert+renesas@glider.be Signed-off-by: Sasha Levin sashal@kernel.org --- 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 35f382b055e83..2858800288bb7 100644 --- a/drivers/pinctrl/renesas/pinctrl-rzv2m.c +++ b/drivers/pinctrl/renesas/pinctrl-rzv2m.c @@ -14,6 +14,7 @@ #include <linux/gpio/driver.h> #include <linux/io.h> #include <linux/module.h> +#include <linux/mutex.h> #include <linux/of_device.h> #include <linux/pinctrl/pinconf-generic.h> #include <linux/pinctrl/pinconf.h> @@ -121,7 +122,8 @@ 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 }; @@ -320,11 +322,13 @@ 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; }
/* @@ -338,6 +342,8 @@ 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; @@ -349,6 +355,8 @@ 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); @@ -1070,6 +1078,7 @@ static int rzv2m_pinctrl_probe(struct platform_device *pdev) }
spin_lock_init(&pctrl->lock); + mutex_init(&pctrl->mutex);
platform_set_drvdata(pdev, pctrl);