pinctrl: renesas: rzg2l: Fix NULL pointer dereference in rzg2l_dt_subnode_to_map()

Fix the below random NULL pointer crash during boot by serializing
pinctrl group and function creation/remove calls in
rzg2l_dt_subnode_to_map() with mutex lock.

Crash log:
    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
    rzg2l_dt_subnode_to_map+0x314/0x44c
    rzg2l_dt_node_to_map+0x164/0x194
    pinctrl_dt_to_map+0x218/0x37c
    create_pinctrl+0x70/0x3d8

While at it, add comments for bitmap_lock and lock.

Fixes: c4c4637eb5 ("pinctrl: renesas: Add RZ/G2L pin and gpio controller driver")
Tested-by: Chris Paterson <Chris.Paterson2@renesas.com>
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/20230815131558.33787-2-biju.das.jz@bp.renesas.com
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
This commit is contained in:
Biju Das 2023-08-15 14:15:56 +01:00 committed by Geert Uytterhoeven
parent bfc374a145
commit 661efa2284
1 changed files with 12 additions and 3 deletions

View File

@ -11,6 +11,7 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/seq_file.h>
@ -149,10 +150,11 @@ struct rzg2l_pinctrl {
struct gpio_chip gpio_chip;
struct pinctrl_gpio_range gpio_range;
DECLARE_BITMAP(tint_slot, RZG2L_TINT_MAX_INTERRUPT);
spinlock_t bitmap_lock;
spinlock_t bitmap_lock; /* protect tint_slot bitmap */
unsigned int hwirq[RZG2L_TINT_MAX_INTERRUPT];
spinlock_t lock;
spinlock_t lock; /* lock read/write registers */
struct mutex mutex; /* serialize adding groups and functions */
};
static const unsigned int iolh_groupa_mA[] = { 2, 4, 8, 12 };
@ -362,11 +364,13 @@ static int rzg2l_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;
}
/*
@ -380,6 +384,8 @@ static int rzg2l_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;
@ -391,6 +397,8 @@ static int rzg2l_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);
@ -1509,6 +1517,7 @@ static int rzg2l_pinctrl_probe(struct platform_device *pdev)
spin_lock_init(&pctrl->lock);
spin_lock_init(&pctrl->bitmap_lock);
mutex_init(&pctrl->mutex);
platform_set_drvdata(pdev, pctrl);