From ee25fba76acd8324f9de6628872c8c612a684209 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:00 +0100 Subject: [PATCH 01/10] gpiolib: provide gpiochip_dup_line_label() gpiochip_is_requested() not only has a misleading name but it returns a pointer to a string that is freed when the descriptor is released. Provide a new helper meant to replace it, which returns a copy of the label string instead. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/gpio/gpiolib.c | 29 +++++++++++++++++++++++++++++ include/linux/gpio/driver.h | 1 + 2 files changed, 30 insertions(+) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 95d2a7b2ea3e..0147c900afea 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2386,6 +2386,35 @@ const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset) } EXPORT_SYMBOL_GPL(gpiochip_is_requested); +/** + * gpiochip_dup_line_label - Get a copy of the consumer label. + * @gc: GPIO chip controlling this line. + * @offset: Hardware offset of the line. + * + * Returns: + * Pointer to a copy of the consumer label if the line is requested or NULL + * if it's not. If a valid pointer was returned, it must be freed using + * kfree(). In case of a memory allocation error, the function returns %ENOMEM. + * + * Must not be called from atomic context. + */ +char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) +{ + const char *label; + char *copy; + + label = gpiochip_is_requested(gc, offset); + if (!label) + return NULL; + + copy = kstrdup(label, GFP_KERNEL); + if (!copy) + return ERR_PTR(-ENOMEM); + + return copy; +} +EXPORT_SYMBOL_GPL(gpiochip_dup_line_label); + /** * gpiochip_request_own_desc - Allow GPIO chip to request its own descriptor * @gc: GPIO chip diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 0aed62f0c633..5ac6dc30c547 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -532,6 +532,7 @@ struct gpio_chip { }; const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset); +char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset); /** * for_each_requested_gpio_in_range - iterates over requested GPIOs in a given range From 1610cd5f7468d4d8b54a96b82109c6ae66ee24eb Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:01 +0100 Subject: [PATCH 02/10] gpio: wm831x: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/gpio/gpio-wm831x.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpio-wm831x.c b/drivers/gpio/gpio-wm831x.c index 7eaf8a28638c..f7d5120ff8f1 100644 --- a/drivers/gpio/gpio-wm831x.c +++ b/drivers/gpio/gpio-wm831x.c @@ -8,6 +8,7 @@ * */ +#include #include #include #include @@ -160,18 +161,21 @@ static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) for (i = 0; i < chip->ngpio; i++) { int gpio = i + chip->base; int reg; - const char *label, *pull, *powerdomain; + const char *pull, *powerdomain; /* We report the GPIO even if it's not requested since * we're also reporting things like alternate * functions which apply even when the GPIO is not in * use as a GPIO. */ - label = gpiochip_is_requested(chip, i); - if (!label) - label = "Unrequested"; + char *label __free(kfree) = gpiochip_dup_line_label(chip, i); + if (IS_ERR(label)) { + dev_err(wm831x->dev, "Failed to duplicate label\n"); + continue; + } - seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label); + seq_printf(s, " gpio-%-3d (%-20.20s) ", + gpio, label ?: "Unrequested"); reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i); if (reg < 0) { From abeec1ad51da0aa7cd33005f537e54c2422d1218 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:02 +0100 Subject: [PATCH 03/10] gpio: wm8994: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/gpio/gpio-wm8994.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpio-wm8994.c b/drivers/gpio/gpio-wm8994.c index f4a474cef32d..bf05c9b5882b 100644 --- a/drivers/gpio/gpio-wm8994.c +++ b/drivers/gpio/gpio-wm8994.c @@ -8,6 +8,7 @@ * */ +#include #include #include #include @@ -193,18 +194,20 @@ static void wm8994_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) for (i = 0; i < chip->ngpio; i++) { int gpio = i + chip->base; int reg; - const char *label; /* We report the GPIO even if it's not requested since * we're also reporting things like alternate * functions which apply even when the GPIO is not in * use as a GPIO. */ - label = gpiochip_is_requested(chip, i); - if (!label) - label = "Unrequested"; + char *label __free(kfree) = gpiochip_dup_line_label(chip, i); + if (IS_ERR(label)) { + dev_err(wm8994->dev, "Failed to duplicate label\n"); + continue; + } - seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label); + seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, + label ?: "Unrequested"); reg = wm8994_reg_read(wm8994, WM8994_GPIO_1 + i); if (reg < 0) { From f1b33ce48ae77a04021ea0a5dab09f67315cad44 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:03 +0100 Subject: [PATCH 04/10] gpio: stmpe: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/gpio/gpio-stmpe.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c index 27cc4da53565..6c5ee81d71b3 100644 --- a/drivers/gpio/gpio-stmpe.c +++ b/drivers/gpio/gpio-stmpe.c @@ -5,6 +5,7 @@ * Author: Rabin Vincent for ST-Ericsson */ +#include #include #include #include @@ -255,7 +256,6 @@ static void stmpe_dbg_show_one(struct seq_file *s, { struct stmpe_gpio *stmpe_gpio = gpiochip_get_data(gc); struct stmpe *stmpe = stmpe_gpio->stmpe; - const char *label = gpiochip_is_requested(gc, offset); bool val = !!stmpe_gpio_get(gc, offset); u8 bank = offset / 8; u8 dir_reg = stmpe->regs[STMPE_IDX_GPDR_LSB + bank]; @@ -263,6 +263,10 @@ static void stmpe_dbg_show_one(struct seq_file *s, int ret; u8 dir; + char *label __free(kfree) = gpiochip_dup_line_label(gc, offset); + if (IS_ERR(label)) + return; + ret = stmpe_reg_read(stmpe, dir_reg); if (ret < 0) return; From c76ba937f5ff9b4ee670adbd421be2404745be1f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:04 +0100 Subject: [PATCH 05/10] pinctrl: abx500: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/pinctrl/nomadik/pinctrl-abx500.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/pinctrl/nomadik/pinctrl-abx500.c b/drivers/pinctrl/nomadik/pinctrl-abx500.c index d3c32d809bac..80e3ac333136 100644 --- a/drivers/pinctrl/nomadik/pinctrl-abx500.c +++ b/drivers/pinctrl/nomadik/pinctrl-abx500.c @@ -6,7 +6,9 @@ * * Driver allows to use AxB5xx unused pins to be used as GPIO */ + #include +#include #include #include #include @@ -453,12 +455,11 @@ static void abx500_gpio_dbg_show_one(struct seq_file *s, unsigned offset, unsigned gpio) { struct abx500_pinctrl *pct = pinctrl_dev_get_drvdata(pctldev); - const char *label = gpiochip_is_requested(chip, offset - 1); u8 gpio_offset = offset - 1; int mode = -1; bool is_out; bool pd; - int ret; + int ret = -ENOMEM; const char *modes[] = { [ABX500_DEFAULT] = "default", @@ -474,6 +475,10 @@ static void abx500_gpio_dbg_show_one(struct seq_file *s, [ABX500_GPIO_PULL_UP] = "pull up", }; + char *label __free(kfree) = gpiochip_dup_line_label(chip, offset - 1); + if (IS_ERR(label)) + goto out; + ret = abx500_gpio_get_bit(chip, AB8500_GPIO_DIR1_REG, gpio_offset, &is_out); if (ret < 0) From caf7e135c297e6fceec0a1476da775aa458b5324 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:05 +0100 Subject: [PATCH 06/10] pinctrl: nomadik: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/pinctrl/nomadik/pinctrl-nomadik.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/pinctrl/nomadik/pinctrl-nomadik.c b/drivers/pinctrl/nomadik/pinctrl-nomadik.c index 863732287b1e..7911353ac97d 100644 --- a/drivers/pinctrl/nomadik/pinctrl-nomadik.c +++ b/drivers/pinctrl/nomadik/pinctrl-nomadik.c @@ -8,6 +8,7 @@ * Copyright (C) 2011-2013 Linus Walleij */ #include +#include #include #include #include @@ -917,7 +918,6 @@ static void nmk_gpio_dbg_show_one(struct seq_file *s, struct pinctrl_dev *pctldev, struct gpio_chip *chip, unsigned offset, unsigned gpio) { - const char *label = gpiochip_is_requested(chip, offset); struct nmk_gpio_chip *nmk_chip = gpiochip_get_data(chip); int mode; bool is_out; @@ -934,6 +934,10 @@ static void nmk_gpio_dbg_show_one(struct seq_file *s, [NMK_GPIO_ALT_C+4] = "altC4", }; + char *label = gpiochip_dup_line_label(chip, offset); + if (IS_ERR(label)) + return; + clk_enable(nmk_chip->clk); is_out = !!(readl(nmk_chip->addr + NMK_GPIO_DIR) & BIT(offset)); pull = !(readl(nmk_chip->addr + NMK_GPIO_PDIS) & BIT(offset)); From c73505c8a001f8ce63b8ad92c9cd0176fe3c22a4 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:06 +0100 Subject: [PATCH 07/10] pinctrl: baytrail: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Reviewed-by: Andy Shevchenko Acked-by: Linus Walleij --- drivers/pinctrl/intel/pinctrl-baytrail.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/drivers/pinctrl/intel/pinctrl-baytrail.c b/drivers/pinctrl/intel/pinctrl-baytrail.c index 3cd0798ee631..3c8c02043481 100644 --- a/drivers/pinctrl/intel/pinctrl-baytrail.c +++ b/drivers/pinctrl/intel/pinctrl-baytrail.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include #include @@ -1173,7 +1174,6 @@ static void byt_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) const char *pull_str = NULL; const char *pull = NULL; unsigned long flags; - const char *label; unsigned int pin; pin = vg->soc->pins[i].number; @@ -1200,9 +1200,10 @@ static void byt_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) seq_printf(s, "Pin %i: can't retrieve community\n", pin); continue; } - label = gpiochip_is_requested(chip, i); - if (!label) - label = "Unrequested"; + + char *label __free(kfree) = gpiochip_dup_line_label(chip, i); + if (IS_ERR(label)) + continue; switch (conf0 & BYT_PULL_ASSIGN_MASK) { case BYT_PULL_ASSIGN_UP: @@ -1231,7 +1232,7 @@ static void byt_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) seq_printf(s, " gpio-%-3d (%-20.20s) %s %s %s pad-%-3d offset:0x%03x mux:%d %s%s%s", pin, - label, + label ?: "Unrequested", val & BYT_INPUT_EN ? " " : "in", val & BYT_OUTPUT_EN ? " " : "out", str_hi_lo(val & BYT_LEVEL), From 069ced2206d23e56b89ed118e17a8a71a05e0ca3 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:07 +0100 Subject: [PATCH 08/10] pinctrl: sppctl: use gpiochip_dup_line_label() Use the new gpiochip_dup_line_label() helper to safely retrieve the descriptor label. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/pinctrl/sunplus/sppctl.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/pinctrl/sunplus/sppctl.c b/drivers/pinctrl/sunplus/sppctl.c index bb5ef391dbe4..ae156f779a16 100644 --- a/drivers/pinctrl/sunplus/sppctl.c +++ b/drivers/pinctrl/sunplus/sppctl.c @@ -4,6 +4,7 @@ * Copyright (C) Sunplus Tech / Tibbo Tech. */ +#include #include #include #include @@ -500,16 +501,15 @@ static int sppctl_gpio_set_config(struct gpio_chip *chip, unsigned int offset, static void sppctl_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip) { - const char *label; int i; for (i = 0; i < chip->ngpio; i++) { - label = gpiochip_is_requested(chip, i); - if (!label) - label = ""; + char *label __free(kfree) = gpiochip_dup_line_label(chip, i); + if (IS_ERR(label)) + continue; seq_printf(s, " gpio-%03d (%-16.16s | %-16.16s)", i + chip->base, - chip->names[i], label); + chip->names[i], label ?: ""); seq_printf(s, " %c", sppctl_gpio_get_direction(chip, i) ? 'I' : 'O'); seq_printf(s, ":%d", sppctl_gpio_get(chip, i)); seq_printf(s, " %s", sppctl_first_get(chip, i) ? "gpi" : "mux"); From 6fd9c9933475a3efd7eed2f80c7778908a560a1f Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:08 +0100 Subject: [PATCH 09/10] gpiolib: use gpiochip_dup_line_label() in for_each helpers Rework for_each_requested_gpio_in_range() to use the new helper to retrieve a dynamically allocated copy of the descriptor label and free it at the end of each iteration. We need to leverage the CLASS()' destructor to make sure that the label is freed even when breaking out of the loop. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- include/linux/gpio/driver.h | 37 +++++++++++++++++++++++++++++-------- 1 file changed, 29 insertions(+), 8 deletions(-) diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 5ac6dc30c547..cae4cdaa87db 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -534,17 +534,38 @@ struct gpio_chip { const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset); char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset); + +struct _gpiochip_for_each_data { + const char **label; + unsigned int *i; +}; + +DEFINE_CLASS(_gpiochip_for_each_data, + struct _gpiochip_for_each_data, + if (*_T.label) kfree(*_T.label), + ({ + struct _gpiochip_for_each_data _data = { label, i }; + *_data.i = 0; + _data; + }), + const char **label, int *i) + /** * for_each_requested_gpio_in_range - iterates over requested GPIOs in a given range - * @chip: the chip to query - * @i: loop variable - * @base: first GPIO in the range - * @size: amount of GPIOs to check starting from @base - * @label: label of current GPIO + * @_chip: the chip to query + * @_i: loop variable + * @_base: first GPIO in the range + * @_size: amount of GPIOs to check starting from @base + * @_label: label of current GPIO */ -#define for_each_requested_gpio_in_range(chip, i, base, size, label) \ - for (i = 0; i < size; i++) \ - if ((label = gpiochip_is_requested(chip, base + i)) == NULL) {} else +#define for_each_requested_gpio_in_range(_chip, _i, _base, _size, _label) \ + for (CLASS(_gpiochip_for_each_data, _data)(&_label, &_i); \ + *_data.i < _size; \ + (*_data.i)++, kfree(*(_data.label)), *_data.label = NULL) \ + if ((*_data.label = \ + gpiochip_dup_line_label(_chip, _base + *_data.i)) == NULL) {} \ + else if (IS_ERR(*_data.label)) {} \ + else /* Iterates over all requested GPIO of the given @chip */ #define for_each_requested_gpio(chip, i, label) \ From f8d05e276b45e3097dfddd628fa991ce69c05c99 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Mon, 4 Dec 2023 10:35:09 +0100 Subject: [PATCH 10/10] gpiolib: remove gpiochip_is_requested() We have no external users of gpiochip_is_requested(). Let's remove it and replace its internal calls with direct testing of the REQUESTED flag. Signed-off-by: Bartosz Golaszewski Acked-by: Linus Walleij --- drivers/gpio/gpiolib.c | 48 ++++++++++--------------------------- include/linux/gpio/driver.h | 1 - 2 files changed, 13 insertions(+), 36 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 0147c900afea..0ca33397812c 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1071,7 +1071,7 @@ void gpiochip_remove(struct gpio_chip *gc) spin_lock_irqsave(&gpio_lock, flags); for (i = 0; i < gdev->ngpio; i++) { - if (gpiochip_is_requested(gc, i)) + if (test_bit(FLAG_REQUESTED, &gdev->descs[i].flags)) break; } spin_unlock_irqrestore(&gpio_lock, flags); @@ -2359,33 +2359,6 @@ void gpiod_free(struct gpio_desc *desc) gpio_device_put(desc->gdev); } -/** - * gpiochip_is_requested - return string iff signal was requested - * @gc: controller managing the signal - * @offset: of signal within controller's 0..(ngpio - 1) range - * - * Returns NULL if the GPIO is not currently requested, else a string. - * The string returned is the label passed to gpio_request(); if none has been - * passed it is a meaningless, non-NULL constant. - * - * This function is for use by GPIO controller drivers. The label can - * help with diagnostics, and knowing that the signal is used as a GPIO - * can help avoid accidentally multiplexing it to another controller. - */ -const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset) -{ - struct gpio_desc *desc; - - desc = gpiochip_get_desc(gc, offset); - if (IS_ERR(desc)) - return NULL; - - if (test_bit(FLAG_REQUESTED, &desc->flags) == 0) - return NULL; - return desc->label; -} -EXPORT_SYMBOL_GPL(gpiochip_is_requested); - /** * gpiochip_dup_line_label - Get a copy of the consumer label. * @gc: GPIO chip controlling this line. @@ -2400,18 +2373,23 @@ EXPORT_SYMBOL_GPL(gpiochip_is_requested); */ char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset) { - const char *label; - char *copy; + struct gpio_desc *desc; + char *label; - label = gpiochip_is_requested(gc, offset); - if (!label) + desc = gpiochip_get_desc(gc, offset); + if (IS_ERR(desc)) return NULL; - copy = kstrdup(label, GFP_KERNEL); - if (!copy) + guard(spinlock_irqsave)(&gpio_lock); + + if (!test_bit(FLAG_REQUESTED, &desc->flags)) + return NULL; + + label = kstrdup(desc->label, GFP_KERNEL); + if (!label) return ERR_PTR(-ENOMEM); - return copy; + return label; } EXPORT_SYMBOL_GPL(gpiochip_dup_line_label); diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index cae4cdaa87db..d1a3cb061927 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -531,7 +531,6 @@ struct gpio_chip { #endif /* CONFIG_OF_GPIO */ }; -const char *gpiochip_is_requested(struct gpio_chip *gc, unsigned int offset); char *gpiochip_dup_line_label(struct gpio_chip *gc, unsigned int offset);