From 12f65d1203507f7db3ba59930fe29a3b8eee9945 Mon Sep 17 00:00:00 2001 From: Koichiro Den Date: Mon, 24 Feb 2025 23:31:26 +0900 Subject: [PATCH 1/3] gpio: aggregator: protect driver attr handlers against module unload Both new_device_store and delete_device_store touch module global resources (e.g. gpio_aggregator_lock). To prevent race conditions with module unload, a reference needs to be held. Add try_module_get() in these handlers. For new_device_store, this eliminates what appears to be the most dangerous scenario: if an id is allocated from gpio_aggregator_idr but platform_device_register has not yet been called or completed, a concurrent module unload could fail to unregister/delete the device, leaving behind a dangling platform device/GPIO forwarder. This can result in various issues. The following simple reproducer demonstrates these problems: #!/bin/bash while :; do # note: whether 'gpiochip0 0' exists or not does not matter. echo 'gpiochip0 0' > /sys/bus/platform/drivers/gpio-aggregator/new_device done & while :; do modprobe gpio-aggregator modprobe -r gpio-aggregator done & wait Starting with the following warning, several kinds of warnings will appear and the system may become unstable: ------------[ cut here ]------------ list_del corruption, ffff888103e2e980->next is LIST_POISON1 (dead000000000100) WARNING: CPU: 1 PID: 1327 at lib/list_debug.c:56 __list_del_entry_valid_or_report+0xa3/0x120 [...] RIP: 0010:__list_del_entry_valid_or_report+0xa3/0x120 [...] Call Trace: ? __list_del_entry_valid_or_report+0xa3/0x120 ? __warn.cold+0x93/0xf2 ? __list_del_entry_valid_or_report+0xa3/0x120 ? report_bug+0xe6/0x170 ? __irq_work_queue_local+0x39/0xe0 ? handle_bug+0x58/0x90 ? exc_invalid_op+0x13/0x60 ? asm_exc_invalid_op+0x16/0x20 ? __list_del_entry_valid_or_report+0xa3/0x120 gpiod_remove_lookup_table+0x22/0x60 new_device_store+0x315/0x350 [gpio_aggregator] kernfs_fop_write_iter+0x137/0x1f0 vfs_write+0x262/0x430 ksys_write+0x60/0xd0 do_syscall_64+0x6c/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e [...] ---[ end trace 0000000000000000 ]--- Fixes: 828546e24280 ("gpio: Add GPIO Aggregator") Cc: stable@vger.kernel.org Signed-off-by: Koichiro Den Link: https://lore.kernel.org/r/20250224143134.3024598-2-koichiro.den@canonical.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-aggregator.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/drivers/gpio/gpio-aggregator.c b/drivers/gpio/gpio-aggregator.c index 65f41cc3eafc..d668ddb2e81d 100644 --- a/drivers/gpio/gpio-aggregator.c +++ b/drivers/gpio/gpio-aggregator.c @@ -119,10 +119,15 @@ static ssize_t new_device_store(struct device_driver *driver, const char *buf, struct platform_device *pdev; int res, id; + if (!try_module_get(THIS_MODULE)) + return -ENOENT; + /* kernfs guarantees string termination, so count + 1 is safe */ aggr = kzalloc(sizeof(*aggr) + count + 1, GFP_KERNEL); - if (!aggr) - return -ENOMEM; + if (!aggr) { + res = -ENOMEM; + goto put_module; + } memcpy(aggr->args, buf, count + 1); @@ -161,6 +166,7 @@ static ssize_t new_device_store(struct device_driver *driver, const char *buf, } aggr->pdev = pdev; + module_put(THIS_MODULE); return count; remove_table: @@ -175,6 +181,8 @@ static ssize_t new_device_store(struct device_driver *driver, const char *buf, kfree(aggr->lookups); free_ga: kfree(aggr); +put_module: + module_put(THIS_MODULE); return res; } @@ -203,13 +211,19 @@ static ssize_t delete_device_store(struct device_driver *driver, if (error) return error; + if (!try_module_get(THIS_MODULE)) + return -ENOENT; + mutex_lock(&gpio_aggregator_lock); aggr = idr_remove(&gpio_aggregator_idr, id); mutex_unlock(&gpio_aggregator_lock); - if (!aggr) + if (!aggr) { + module_put(THIS_MODULE); return -ENOENT; + } gpio_aggregator_free(aggr); + module_put(THIS_MODULE); return count; } static DRIVER_ATTR_WO(delete_device); From f02c41f87cfe61440c18bf77d1ef0a884b9ee2b5 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= Date: Tue, 21 Jan 2025 14:58:33 +0100 Subject: [PATCH 2/3] gpio: rcar: Use raw_spinlock to protect register access MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Use raw_spinlock in order to fix spurious messages about invalid context when spinlock debugging is enabled. The lock is only used to serialize register access. [ 4.239592] ============================= [ 4.239595] [ BUG: Invalid wait context ] [ 4.239599] 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 Not tainted [ 4.239603] ----------------------------- [ 4.239606] kworker/u8:5/76 is trying to lock: [ 4.239609] ffff0000091898a0 (&p->lock){....}-{3:3}, at: gpio_rcar_config_interrupt_input_mode+0x34/0x164 [ 4.239641] other info that might help us debug this: [ 4.239643] context-{5:5} [ 4.239646] 5 locks held by kworker/u8:5/76: [ 4.239651] #0: ffff0000080fb148 ((wq_completion)async){+.+.}-{0:0}, at: process_one_work+0x190/0x62c [ 4.250180] OF: /soc/sound@ec500000/ports/port@0/endpoint: Read of boolean property 'frame-master' with a value. [ 4.254094] #1: ffff80008299bd80 ((work_completion)(&entry->work)){+.+.}-{0:0}, at: process_one_work+0x1b8/0x62c [ 4.254109] #2: ffff00000920c8f8 [ 4.258345] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'bitclock-master' with a value. [ 4.264803] (&dev->mutex){....}-{4:4}, at: __device_attach_async_helper+0x3c/0xdc [ 4.264820] #3: ffff00000a50ca40 (request_class#2){+.+.}-{4:4}, at: __setup_irq+0xa0/0x690 [ 4.264840] #4: [ 4.268872] OF: /soc/sound@ec500000/ports/port@1/endpoint: Read of boolean property 'frame-master' with a value. [ 4.273275] ffff00000a50c8c8 (lock_class){....}-{2:2}, at: __setup_irq+0xc4/0x690 [ 4.296130] renesas_sdhi_internal_dmac ee100000.mmc: mmc1 base at 0x00000000ee100000, max clock rate 200 MHz [ 4.304082] stack backtrace: [ 4.304086] CPU: 1 UID: 0 PID: 76 Comm: kworker/u8:5 Not tainted 6.13.0-rc7-arm64-renesas-05496-gd088502a519f #35 [ 4.304092] Hardware name: Renesas Salvator-X 2nd version board based on r8a77965 (DT) [ 4.304097] Workqueue: async async_run_entry_fn [ 4.304106] Call trace: [ 4.304110] show_stack+0x14/0x20 (C) [ 4.304122] dump_stack_lvl+0x6c/0x90 [ 4.304131] dump_stack+0x14/0x1c [ 4.304138] __lock_acquire+0xdfc/0x1584 [ 4.426274] lock_acquire+0x1c4/0x33c [ 4.429942] _raw_spin_lock_irqsave+0x5c/0x80 [ 4.434307] gpio_rcar_config_interrupt_input_mode+0x34/0x164 [ 4.440061] gpio_rcar_irq_set_type+0xd4/0xd8 [ 4.444422] __irq_set_trigger+0x5c/0x178 [ 4.448435] __setup_irq+0x2e4/0x690 [ 4.452012] request_threaded_irq+0xc4/0x190 [ 4.456285] devm_request_threaded_irq+0x7c/0xf4 [ 4.459398] ata1: link resume succeeded after 1 retries [ 4.460902] mmc_gpiod_request_cd_irq+0x68/0xe0 [ 4.470660] mmc_start_host+0x50/0xac [ 4.474327] mmc_add_host+0x80/0xe4 [ 4.477817] tmio_mmc_host_probe+0x2b0/0x440 [ 4.482094] renesas_sdhi_probe+0x488/0x6f4 [ 4.486281] renesas_sdhi_internal_dmac_probe+0x60/0x78 [ 4.491509] platform_probe+0x64/0xd8 [ 4.495178] really_probe+0xb8/0x2a8 [ 4.498756] __driver_probe_device+0x74/0x118 [ 4.503116] driver_probe_device+0x3c/0x154 [ 4.507303] __device_attach_driver+0xd4/0x160 [ 4.511750] bus_for_each_drv+0x84/0xe0 [ 4.515588] __device_attach_async_helper+0xb0/0xdc [ 4.520470] async_run_entry_fn+0x30/0xd8 [ 4.524481] process_one_work+0x210/0x62c [ 4.528494] worker_thread+0x1ac/0x340 [ 4.532245] kthread+0x10c/0x110 [ 4.535476] ret_from_fork+0x10/0x20 Signed-off-by: Niklas Söderlund Reviewed-by: Geert Uytterhoeven Tested-by: Geert Uytterhoeven Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20250121135833.3769310-1-niklas.soderlund+renesas@ragnatech.se Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-rcar.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c index 2ecee3269a0c..8e0544e92488 100644 --- a/drivers/gpio/gpio-rcar.c +++ b/drivers/gpio/gpio-rcar.c @@ -40,7 +40,7 @@ struct gpio_rcar_info { struct gpio_rcar_priv { void __iomem *base; - spinlock_t lock; + raw_spinlock_t lock; struct device *dev; struct gpio_chip gpio_chip; unsigned int irq_parent; @@ -123,7 +123,7 @@ static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p, * "Setting Level-Sensitive Interrupt Input Mode" */ - spin_lock_irqsave(&p->lock, flags); + raw_spin_lock_irqsave(&p->lock, flags); /* Configure positive or negative logic in POSNEG */ gpio_rcar_modify_bit(p, POSNEG, hwirq, !active_high_rising_edge); @@ -142,7 +142,7 @@ static void gpio_rcar_config_interrupt_input_mode(struct gpio_rcar_priv *p, if (!level_trigger) gpio_rcar_write(p, INTCLR, BIT(hwirq)); - spin_unlock_irqrestore(&p->lock, flags); + raw_spin_unlock_irqrestore(&p->lock, flags); } static int gpio_rcar_irq_set_type(struct irq_data *d, unsigned int type) @@ -246,7 +246,7 @@ static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip, * "Setting General Input Mode" */ - spin_lock_irqsave(&p->lock, flags); + raw_spin_lock_irqsave(&p->lock, flags); /* Configure positive logic in POSNEG */ gpio_rcar_modify_bit(p, POSNEG, gpio, false); @@ -261,7 +261,7 @@ static void gpio_rcar_config_general_input_output_mode(struct gpio_chip *chip, if (p->info.has_outdtsel && output) gpio_rcar_modify_bit(p, OUTDTSEL, gpio, false); - spin_unlock_irqrestore(&p->lock, flags); + raw_spin_unlock_irqrestore(&p->lock, flags); } static int gpio_rcar_request(struct gpio_chip *chip, unsigned offset) @@ -347,7 +347,7 @@ static int gpio_rcar_get_multiple(struct gpio_chip *chip, unsigned long *mask, return 0; } - spin_lock_irqsave(&p->lock, flags); + raw_spin_lock_irqsave(&p->lock, flags); outputs = gpio_rcar_read(p, INOUTSEL); m = outputs & bankmask; if (m) @@ -356,7 +356,7 @@ static int gpio_rcar_get_multiple(struct gpio_chip *chip, unsigned long *mask, m = ~outputs & bankmask; if (m) val |= gpio_rcar_read(p, INDT) & m; - spin_unlock_irqrestore(&p->lock, flags); + raw_spin_unlock_irqrestore(&p->lock, flags); bits[0] = val; return 0; @@ -367,9 +367,9 @@ static void gpio_rcar_set(struct gpio_chip *chip, unsigned offset, int value) struct gpio_rcar_priv *p = gpiochip_get_data(chip); unsigned long flags; - spin_lock_irqsave(&p->lock, flags); + raw_spin_lock_irqsave(&p->lock, flags); gpio_rcar_modify_bit(p, OUTDT, offset, value); - spin_unlock_irqrestore(&p->lock, flags); + raw_spin_unlock_irqrestore(&p->lock, flags); } static void gpio_rcar_set_multiple(struct gpio_chip *chip, unsigned long *mask, @@ -386,12 +386,12 @@ static void gpio_rcar_set_multiple(struct gpio_chip *chip, unsigned long *mask, if (!bankmask) return; - spin_lock_irqsave(&p->lock, flags); + raw_spin_lock_irqsave(&p->lock, flags); val = gpio_rcar_read(p, OUTDT); val &= ~bankmask; val |= (bankmask & bits[0]); gpio_rcar_write(p, OUTDT, val); - spin_unlock_irqrestore(&p->lock, flags); + raw_spin_unlock_irqrestore(&p->lock, flags); } static int gpio_rcar_direction_output(struct gpio_chip *chip, unsigned offset, @@ -505,7 +505,7 @@ static int gpio_rcar_probe(struct platform_device *pdev) return -ENOMEM; p->dev = dev; - spin_lock_init(&p->lock); + raw_spin_lock_init(&p->lock); /* Get device configuration from DT node */ ret = gpio_rcar_parse_dt(p, &npins); From 391b41f983bf7ff853de44704d8e14e7cc648a9b Mon Sep 17 00:00:00 2001 From: Fabrizio Castro Date: Wed, 5 Mar 2025 16:37:50 +0000 Subject: [PATCH 3/3] gpio: rcar: Fix missing of_node_put() call of_parse_phandle_with_fixed_args() requires its caller to call into of_node_put() on the node pointer from the output structure, but such a call is currently missing. Call into of_node_put() to rectify that. Fixes: 159f8a0209af ("gpio-rcar: Add DT support") Signed-off-by: Fabrizio Castro Reviewed-by: Lad Prabhakar Reviewed-by: Geert Uytterhoeven Link: https://lore.kernel.org/r/20250305163753.34913-2-fabrizio.castro.jz@renesas.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpio-rcar.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-rcar.c b/drivers/gpio/gpio-rcar.c index 8e0544e92488..a7a1cdf7ac66 100644 --- a/drivers/gpio/gpio-rcar.c +++ b/drivers/gpio/gpio-rcar.c @@ -468,7 +468,12 @@ static int gpio_rcar_parse_dt(struct gpio_rcar_priv *p, unsigned int *npins) p->info = *info; ret = of_parse_phandle_with_fixed_args(np, "gpio-ranges", 3, 0, &args); - *npins = ret == 0 ? args.args[2] : RCAR_MAX_GPIO_PER_BANK; + if (ret) { + *npins = RCAR_MAX_GPIO_PER_BANK; + } else { + *npins = args.args[2]; + of_node_put(args.np); + } if (*npins == 0 || *npins > RCAR_MAX_GPIO_PER_BANK) { dev_warn(p->dev, "Invalid number of gpio lines %u, using %u\n",