6.6-stable review patch. If anyone has any objections, please let me know.
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From: Armin Wolf W_Armin@gmx.de
[ Upstream commit 1981b296f858010eae409548fd297659b2cc570e ]
When reading token data from sysfs on my Inspiron 3505, the token locations and values are wrong. This happens because match_attribute() blindly assumes that all entries in da_tokens have an associated entry in token_attrs.
This however is not true as soon as da_tokens[] contains zeroed token entries. Those entries are being skipped when initialising token_attrs, breaking the core assumption of match_attribute().
Fix this by defining an extra struct for each pair of token attributes and use container_of() to retrieve token information.
Tested on a Dell Inspiron 3050.
Fixes: 33b9ca1e53b4 ("platform/x86: dell-smbios: Add a sysfs interface for SMBIOS tokens") Signed-off-by: Armin Wolf W_Armin@gmx.de Reviewed-by: Ilpo Järvinen ilpo.jarvinen@linux.intel.com Link: https://lore.kernel.org/r/20240528204903.445546-1-W_Armin@gmx.de Reviewed-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Hans de Goede hdegoede@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/platform/x86/dell/dell-smbios-base.c | 92 ++++++++------------ 1 file changed, 36 insertions(+), 56 deletions(-)
diff --git a/drivers/platform/x86/dell/dell-smbios-base.c b/drivers/platform/x86/dell/dell-smbios-base.c index e61bfaf8b5c48..86b95206cb1bd 100644 --- a/drivers/platform/x86/dell/dell-smbios-base.c +++ b/drivers/platform/x86/dell/dell-smbios-base.c @@ -11,6 +11,7 @@ */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+#include <linux/container_of.h> #include <linux/kernel.h> #include <linux/module.h> #include <linux/capability.h> @@ -25,11 +26,16 @@ static u32 da_supported_commands; static int da_num_tokens; static struct platform_device *platform_device; static struct calling_interface_token *da_tokens; -static struct device_attribute *token_location_attrs; -static struct device_attribute *token_value_attrs; +static struct token_sysfs_data *token_entries; static struct attribute **token_attrs; static DEFINE_MUTEX(smbios_mutex);
+struct token_sysfs_data { + struct device_attribute location_attr; + struct device_attribute value_attr; + struct calling_interface_token *token; +}; + struct smbios_device { struct list_head list; struct device *device; @@ -416,47 +422,26 @@ static void __init find_tokens(const struct dmi_header *dm, void *dummy) } }
-static int match_attribute(struct device *dev, - struct device_attribute *attr) -{ - int i; - - for (i = 0; i < da_num_tokens * 2; i++) { - if (!token_attrs[i]) - continue; - if (strcmp(token_attrs[i]->name, attr->attr.name) == 0) - return i/2; - } - dev_dbg(dev, "couldn't match: %s\n", attr->attr.name); - return -EINVAL; -} - static ssize_t location_show(struct device *dev, struct device_attribute *attr, char *buf) { - int i; + struct token_sysfs_data *data = container_of(attr, struct token_sysfs_data, location_attr);
if (!capable(CAP_SYS_ADMIN)) return -EPERM;
- i = match_attribute(dev, attr); - if (i > 0) - return sysfs_emit(buf, "%08x", da_tokens[i].location); - return 0; + return sysfs_emit(buf, "%08x", data->token->location); }
static ssize_t value_show(struct device *dev, struct device_attribute *attr, char *buf) { - int i; + struct token_sysfs_data *data = container_of(attr, struct token_sysfs_data, value_attr);
if (!capable(CAP_SYS_ADMIN)) return -EPERM;
- i = match_attribute(dev, attr); - if (i > 0) - return sysfs_emit(buf, "%08x", da_tokens[i].value); - return 0; + return sysfs_emit(buf, "%08x", data->token->value); }
static struct attribute_group smbios_attribute_group = { @@ -473,22 +458,15 @@ static int build_tokens_sysfs(struct platform_device *dev) { char *location_name; char *value_name; - size_t size; int ret; int i, j;
- /* (number of tokens + 1 for null terminated */ - size = sizeof(struct device_attribute) * (da_num_tokens + 1); - token_location_attrs = kzalloc(size, GFP_KERNEL); - if (!token_location_attrs) + token_entries = kcalloc(da_num_tokens, sizeof(*token_entries), GFP_KERNEL); + if (!token_entries) return -ENOMEM; - token_value_attrs = kzalloc(size, GFP_KERNEL); - if (!token_value_attrs) - goto out_allocate_value;
/* need to store both location and value + terminator*/ - size = sizeof(struct attribute *) * ((2 * da_num_tokens) + 1); - token_attrs = kzalloc(size, GFP_KERNEL); + token_attrs = kcalloc((2 * da_num_tokens) + 1, sizeof(*token_attrs), GFP_KERNEL); if (!token_attrs) goto out_allocate_attrs;
@@ -496,27 +474,32 @@ static int build_tokens_sysfs(struct platform_device *dev) /* skip empty */ if (da_tokens[i].tokenID == 0) continue; + + token_entries[i].token = &da_tokens[i]; + /* add location */ location_name = kasprintf(GFP_KERNEL, "%04x_location", da_tokens[i].tokenID); if (location_name == NULL) goto out_unwind_strings; - sysfs_attr_init(&token_location_attrs[i].attr); - token_location_attrs[i].attr.name = location_name; - token_location_attrs[i].attr.mode = 0444; - token_location_attrs[i].show = location_show; - token_attrs[j++] = &token_location_attrs[i].attr; + + sysfs_attr_init(&token_entries[i].location_attr.attr); + token_entries[i].location_attr.attr.name = location_name; + token_entries[i].location_attr.attr.mode = 0444; + token_entries[i].location_attr.show = location_show; + token_attrs[j++] = &token_entries[i].location_attr.attr;
/* add value */ value_name = kasprintf(GFP_KERNEL, "%04x_value", da_tokens[i].tokenID); if (value_name == NULL) goto loop_fail_create_value; - sysfs_attr_init(&token_value_attrs[i].attr); - token_value_attrs[i].attr.name = value_name; - token_value_attrs[i].attr.mode = 0444; - token_value_attrs[i].show = value_show; - token_attrs[j++] = &token_value_attrs[i].attr; + + sysfs_attr_init(&token_entries[i].value_attr.attr); + token_entries[i].value_attr.attr.name = value_name; + token_entries[i].value_attr.attr.mode = 0444; + token_entries[i].value_attr.show = value_show; + token_attrs[j++] = &token_entries[i].value_attr.attr; continue;
loop_fail_create_value: @@ -532,14 +515,12 @@ static int build_tokens_sysfs(struct platform_device *dev)
out_unwind_strings: while (i--) { - kfree(token_location_attrs[i].attr.name); - kfree(token_value_attrs[i].attr.name); + kfree(token_entries[i].location_attr.attr.name); + kfree(token_entries[i].value_attr.attr.name); } kfree(token_attrs); out_allocate_attrs: - kfree(token_value_attrs); -out_allocate_value: - kfree(token_location_attrs); + kfree(token_entries);
return -ENOMEM; } @@ -551,12 +532,11 @@ static void free_group(struct platform_device *pdev) sysfs_remove_group(&pdev->dev.kobj, &smbios_attribute_group); for (i = 0; i < da_num_tokens; i++) { - kfree(token_location_attrs[i].attr.name); - kfree(token_value_attrs[i].attr.name); + kfree(token_entries[i].location_attr.attr.name); + kfree(token_entries[i].value_attr.attr.name); } kfree(token_attrs); - kfree(token_value_attrs); - kfree(token_location_attrs); + kfree(token_entries); }
static int __init dell_smbios_init(void)