platform/x86: dell-smbios: Fix wrong token data in sysfs
[ 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: 33b9ca1e53 ("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>
This commit is contained in:
Armin Wolf
Greg Kroah-Hartman
parent
2c82e21bbc
commit
b07a62f8c8
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@ -11,6 +11,7 @@
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*/
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#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
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#include <linux/container_of.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/capability.h>
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@ -25,11 +26,16 @@ static u32 da_supported_commands;
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static int da_num_tokens;
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static struct platform_device *platform_device;
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static struct calling_interface_token *da_tokens;
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static struct device_attribute *token_location_attrs;
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static struct device_attribute *token_value_attrs;
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static struct token_sysfs_data *token_entries;
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static struct attribute **token_attrs;
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static DEFINE_MUTEX(smbios_mutex);
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struct token_sysfs_data {
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struct device_attribute location_attr;
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struct device_attribute value_attr;
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struct calling_interface_token *token;
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};
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struct smbios_device {
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struct list_head list;
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struct device *device;
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@ -416,47 +422,26 @@ static void __init find_tokens(const struct dmi_header *dm, void *dummy)
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}
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}
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static int match_attribute(struct device *dev,
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struct device_attribute *attr)
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{
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int i;
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for (i = 0; i < da_num_tokens * 2; i++) {
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if (!token_attrs[i])
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continue;
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if (strcmp(token_attrs[i]->name, attr->attr.name) == 0)
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return i/2;
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}
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dev_dbg(dev, "couldn't match: %s\n", attr->attr.name);
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return -EINVAL;
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}
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static ssize_t location_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int i;
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struct token_sysfs_data *data = container_of(attr, struct token_sysfs_data, location_attr);
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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i = match_attribute(dev, attr);
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if (i > 0)
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return sysfs_emit(buf, "%08x", da_tokens[i].location);
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return 0;
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return sysfs_emit(buf, "%08x", data->token->location);
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}
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static ssize_t value_show(struct device *dev,
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struct device_attribute *attr, char *buf)
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{
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int i;
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struct token_sysfs_data *data = container_of(attr, struct token_sysfs_data, value_attr);
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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i = match_attribute(dev, attr);
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if (i > 0)
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return sysfs_emit(buf, "%08x", da_tokens[i].value);
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return 0;
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return sysfs_emit(buf, "%08x", data->token->value);
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}
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static struct attribute_group smbios_attribute_group = {
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@ -473,22 +458,15 @@ static int build_tokens_sysfs(struct platform_device *dev)
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{
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char *location_name;
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char *value_name;
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size_t size;
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int ret;
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int i, j;
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/* (number of tokens + 1 for null terminated */
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size = sizeof(struct device_attribute) * (da_num_tokens + 1);
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token_location_attrs = kzalloc(size, GFP_KERNEL);
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if (!token_location_attrs)
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token_entries = kcalloc(da_num_tokens, sizeof(*token_entries), GFP_KERNEL);
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if (!token_entries)
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return -ENOMEM;
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token_value_attrs = kzalloc(size, GFP_KERNEL);
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if (!token_value_attrs)
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goto out_allocate_value;
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/* need to store both location and value + terminator*/
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size = sizeof(struct attribute *) * ((2 * da_num_tokens) + 1);
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token_attrs = kzalloc(size, GFP_KERNEL);
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token_attrs = kcalloc((2 * da_num_tokens) + 1, sizeof(*token_attrs), GFP_KERNEL);
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if (!token_attrs)
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goto out_allocate_attrs;
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@ -496,27 +474,32 @@ static int build_tokens_sysfs(struct platform_device *dev)
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/* skip empty */
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if (da_tokens[i].tokenID == 0)
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continue;
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token_entries[i].token = &da_tokens[i];
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/* add location */
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location_name = kasprintf(GFP_KERNEL, "%04x_location",
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da_tokens[i].tokenID);
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if (location_name == NULL)
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goto out_unwind_strings;
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sysfs_attr_init(&token_location_attrs[i].attr);
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token_location_attrs[i].attr.name = location_name;
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token_location_attrs[i].attr.mode = 0444;
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token_location_attrs[i].show = location_show;
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token_attrs[j++] = &token_location_attrs[i].attr;
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sysfs_attr_init(&token_entries[i].location_attr.attr);
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token_entries[i].location_attr.attr.name = location_name;
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token_entries[i].location_attr.attr.mode = 0444;
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token_entries[i].location_attr.show = location_show;
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token_attrs[j++] = &token_entries[i].location_attr.attr;
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/* add value */
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value_name = kasprintf(GFP_KERNEL, "%04x_value",
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da_tokens[i].tokenID);
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if (value_name == NULL)
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goto loop_fail_create_value;
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sysfs_attr_init(&token_value_attrs[i].attr);
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token_value_attrs[i].attr.name = value_name;
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token_value_attrs[i].attr.mode = 0444;
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token_value_attrs[i].show = value_show;
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token_attrs[j++] = &token_value_attrs[i].attr;
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sysfs_attr_init(&token_entries[i].value_attr.attr);
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token_entries[i].value_attr.attr.name = value_name;
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token_entries[i].value_attr.attr.mode = 0444;
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token_entries[i].value_attr.show = value_show;
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token_attrs[j++] = &token_entries[i].value_attr.attr;
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continue;
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loop_fail_create_value:
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@ -532,14 +515,12 @@ loop_fail_create_value:
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out_unwind_strings:
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while (i--) {
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kfree(token_location_attrs[i].attr.name);
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kfree(token_value_attrs[i].attr.name);
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kfree(token_entries[i].location_attr.attr.name);
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kfree(token_entries[i].value_attr.attr.name);
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}
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kfree(token_attrs);
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out_allocate_attrs:
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kfree(token_value_attrs);
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out_allocate_value:
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kfree(token_location_attrs);
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kfree(token_entries);
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return -ENOMEM;
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}
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@ -551,12 +532,11 @@ static void free_group(struct platform_device *pdev)
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sysfs_remove_group(&pdev->dev.kobj,
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&smbios_attribute_group);
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for (i = 0; i < da_num_tokens; i++) {
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kfree(token_location_attrs[i].attr.name);
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kfree(token_value_attrs[i].attr.name);
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kfree(token_entries[i].location_attr.attr.name);
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kfree(token_entries[i].value_attr.attr.name);
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}
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kfree(token_attrs);
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kfree(token_value_attrs);
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kfree(token_location_attrs);
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kfree(token_entries);
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}
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static int __init dell_smbios_init(void)
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