ACPI: avoid empty file name in sysfs
Since commit bc45b1d39a
acpi tables are
allowed to have an empty signature and /sys/firmware/acpi/tables uses the
signature as filename. Applications using naive recursion through /sys
loop forever. A possible solution would be: (replacing the zero length
filename with the string "NULL")
http://bugzilla.kernel.org/show_bug.cgi?id=11539
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
parent
49fdf6785f
commit
4feba70a2c
1 changed files with 17 additions and 8 deletions
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@ -78,9 +78,15 @@ static ssize_t acpi_table_show(struct kobject *kobj,
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container_of(bin_attr, struct acpi_table_attr, attr);
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struct acpi_table_header *table_header = NULL;
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acpi_status status;
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char name[ACPI_NAME_SIZE];
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if (strncmp(table_attr->name, "NULL", 4))
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memcpy(name, table_attr->name, ACPI_NAME_SIZE);
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else
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memcpy(name, "\0\0\0\0", 4);
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status =
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acpi_get_table(table_attr->name, table_attr->instance,
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acpi_get_table(name, table_attr->instance,
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&table_header);
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if (ACPI_FAILURE(status))
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return -ENODEV;
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@ -95,21 +101,24 @@ static void acpi_table_attr_init(struct acpi_table_attr *table_attr,
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struct acpi_table_header *header = NULL;
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struct acpi_table_attr *attr = NULL;
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memcpy(table_attr->name, table_header->signature, ACPI_NAME_SIZE);
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if (table_header->signature[0] != '\0')
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memcpy(table_attr->name, table_header->signature,
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ACPI_NAME_SIZE);
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else
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memcpy(table_attr->name, "NULL", 4);
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list_for_each_entry(attr, &acpi_table_attr_list, node) {
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if (!memcmp(table_header->signature, attr->name,
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ACPI_NAME_SIZE))
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if (!memcmp(table_attr->name, attr->name, ACPI_NAME_SIZE))
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if (table_attr->instance < attr->instance)
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table_attr->instance = attr->instance;
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}
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table_attr->instance++;
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if (table_attr->instance > 1 || (table_attr->instance == 1 &&
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!acpi_get_table(table_header->
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signature, 2,
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&header)))
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sprintf(table_attr->name + 4, "%d", table_attr->instance);
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!acpi_get_table
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(table_header->signature, 2, &header)))
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sprintf(table_attr->name + ACPI_NAME_SIZE, "%d",
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table_attr->instance);
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table_attr->attr.size = 0;
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table_attr->attr.read = acpi_table_show;
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