gpio: sim: fix an invalid __free() usage

gpio_sim_make_line_names() returns NULL or ERR_PTR() so we must not use
__free(kfree) on the returned address. Split this function into two, one
that determines the size of the "gpio-line-names" array to allocate and
one that actually sets the names at correct offsets. The allocation and
assignment of the managed pointer happens in between.

Fixes: 3faf89f27a ("gpio: sim: simplify code with cleanup helpers")
Reported-by: Alexey Dobriyan <adobriyan@gmail.com>
Closes: https://lore.kernel.org/all/07c32bf1-6c1a-49d9-b97d-f0ae4a2b42ab@p183/
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
This commit is contained in:
Bartosz Golaszewski 2023-09-20 09:32:53 +02:00
parent b547b5e52a
commit 5cb9606a90

View File

@ -19,6 +19,7 @@
#include <linux/irq.h>
#include <linux/irq_sim.h>
#include <linux/list.h>
#include <linux/minmax.h>
#include <linux/mod_devicetable.h>
#include <linux/module.h>
#include <linux/mutex.h>
@ -685,52 +686,32 @@ gpio_sim_device_config_live_show(struct config_item *item, char *page)
return sprintf(page, "%c\n", live ? '1' : '0');
}
static char **gpio_sim_make_line_names(struct gpio_sim_bank *bank,
unsigned int *line_names_size)
static unsigned int gpio_sim_get_line_names_size(struct gpio_sim_bank *bank)
{
unsigned int max_offset = 0;
bool has_line_names = false;
struct gpio_sim_line *line;
char **line_names;
unsigned int size = 0;
list_for_each_entry(line, &bank->line_list, siblings) {
if (line->offset >= bank->num_lines)
if (!line->name || (line->offset >= bank->num_lines))
continue;
if (line->name) {
if (line->offset > max_offset)
max_offset = line->offset;
/*
* max_offset can stay at 0 so it's not an indicator
* of whether line names were configured at all.
*/
has_line_names = true;
}
size = max(size, line->offset + 1);
}
if (!has_line_names)
/*
* This is not an error - NULL means, there are no line
* names configured.
*/
return NULL;
return size;
}
*line_names_size = max_offset + 1;
line_names = kcalloc(*line_names_size, sizeof(*line_names), GFP_KERNEL);
if (!line_names)
return ERR_PTR(-ENOMEM);
static void
gpio_sim_set_line_names(struct gpio_sim_bank *bank, char **line_names)
{
struct gpio_sim_line *line;
list_for_each_entry(line, &bank->line_list, siblings) {
if (line->offset >= bank->num_lines)
if (!line->name || (line->offset >= bank->num_lines))
continue;
if (line->name && (line->offset <= max_offset))
line_names[line->offset] = line->name;
line_names[line->offset] = line->name;
}
return line_names;
}
static void gpio_sim_remove_hogs(struct gpio_sim_device *dev)
@ -834,7 +815,7 @@ gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
struct fwnode_handle *parent)
{
struct property_entry properties[GPIO_SIM_PROP_MAX];
unsigned int prop_idx = 0, line_names_size = 0;
unsigned int prop_idx = 0, line_names_size;
char **line_names __free(kfree) = NULL;
memset(properties, 0, sizeof(properties));
@ -845,14 +826,19 @@ gpio_sim_make_bank_swnode(struct gpio_sim_bank *bank,
properties[prop_idx++] = PROPERTY_ENTRY_STRING("gpio-sim,label",
bank->label);
line_names = gpio_sim_make_line_names(bank, &line_names_size);
if (IS_ERR(line_names))
return ERR_CAST(line_names);
line_names_size = gpio_sim_get_line_names_size(bank);
if (line_names_size) {
line_names = kcalloc(line_names_size, sizeof(*line_names),
GFP_KERNEL);
if (!line_names)
return ERR_PTR(-ENOMEM);
gpio_sim_set_line_names(bank, line_names);
if (line_names)
properties[prop_idx++] = PROPERTY_ENTRY_STRING_ARRAY_LEN(
"gpio-line-names",
line_names, line_names_size);
}
return fwnode_create_software_node(properties, parent);
}