From: Thomas Weißschuh Date: Sat, 21 Dec 2024 14:48:10 +0000 (+0100) Subject: misc: c2port: Calculate bin_attribute size through group callback X-Git-Tag: v6.14-rc1~67^2~101 X-Git-Url: https://git.kernel.dk/?a=commitdiff_plain;h=85aa1342d7a554256611c8e8133bfa5208ffb823;p=linux-block.git misc: c2port: Calculate bin_attribute size through group callback Modifying the size of the global bin_attribute instance can be racy. Instead use the new .bin_size callback to do so safely. For this to work move the initialization of c2dev->ops before the call to device_create() as the size callback will need access to it. Signed-off-by: Thomas Weißschuh Link: https://lore.kernel.org/r/20241221-sysfs-const-bin_attr-misc-drivers-v2-4-ba5e79fe8771@weissschuh.net Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/misc/c2port/core.c b/drivers/misc/c2port/core.c index 2bb1dd2511f9..f455d702b9cd 100644 --- a/drivers/misc/c2port/core.c +++ b/drivers/misc/c2port/core.c @@ -874,9 +874,22 @@ static struct bin_attribute *c2port_bin_attrs[] = { NULL, }; +static size_t c2port_bin_attr_size(struct kobject *kobj, + const struct bin_attribute *attr, + int i) +{ + struct c2port_device *c2dev = dev_get_drvdata(kobj_to_dev(kobj)); + + if (attr == &bin_attr_flash_data) + return c2dev->ops->blocks_num * c2dev->ops->block_size; + + return attr->size; +} + static const struct attribute_group c2port_group = { .attrs = c2port_attrs, .bin_attrs = c2port_bin_attrs, + .bin_size = c2port_bin_attr_size, }; static const struct attribute_group *c2port_groups[] = { @@ -912,8 +925,7 @@ struct c2port_device *c2port_device_register(char *name, if (ret < 0) goto error_idr_alloc; c2dev->id = ret; - - bin_attr_flash_data.size = ops->blocks_num * ops->block_size; + c2dev->ops = ops; c2dev->dev = device_create(c2port_class, NULL, 0, c2dev, "c2port%d", c2dev->id); @@ -924,7 +936,6 @@ struct c2port_device *c2port_device_register(char *name, dev_set_drvdata(c2dev->dev, c2dev); strscpy(c2dev->name, name, sizeof(c2dev->name)); - c2dev->ops = ops; mutex_init(&c2dev->mutex); /* By default C2 port access is off */