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| author | Peter Gruber <nokos@gmx.net> | 2008-10-27 23:59:36 -0400 |
|---|---|---|
| committer | Len Brown <len.brown@intel.com> | 2008-11-06 22:09:52 -0500 |
| commit | 4feba70a2c1a1a0c96909f657f48b2e11e682370 (patch) | |
| tree | 7b00f31b9ccabfb73ba78f3b3dc92cee3a29b3d1 /drivers/acpi/system.c | |
| parent | 49fdf6785fd660e18a1eb4588928f47e9fa29a9a (diff) | |
| download | linux-4feba70a2c1a1a0c96909f657f48b2e11e682370.tar.gz linux-4feba70a2c1a1a0c96909f657f48b2e11e682370.tar.bz2 linux-4feba70a2c1a1a0c96909f657f48b2e11e682370.zip | |
ACPI: avoid empty file name in sysfs
Since commit bc45b1d39a925b56796bebf8a397a0491489d85c 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>
Diffstat (limited to 'drivers/acpi/system.c')
| -rw-r--r-- | drivers/acpi/system.c | 25 |
1 files changed, 17 insertions, 8 deletions
diff --git a/drivers/acpi/system.c b/drivers/acpi/system.c index 1d74171b7940..62ec75e79120 100644 --- a/drivers/acpi/system.c +++ b/drivers/acpi/system.c @@ -78,9 +78,15 @@ static ssize_t acpi_table_show(struct kobject *kobj, container_of(bin_attr, struct acpi_table_attr, attr); struct acpi_table_header *table_header = NULL; acpi_status status; + char name[ACPI_NAME_SIZE]; + + if (strncmp(table_attr->name, "NULL", 4)) + memcpy(name, table_attr->name, ACPI_NAME_SIZE); + else + memcpy(name, "\0\0\0\0", 4); status = - acpi_get_table(table_attr->name, table_attr->instance, + acpi_get_table(name, table_attr->instance, &table_header); if (ACPI_FAILURE(status)) return -ENODEV; @@ -95,21 +101,24 @@ static void acpi_table_attr_init(struct acpi_table_attr *table_attr, struct acpi_table_header *header = NULL; struct acpi_table_attr *attr = NULL; - memcpy(table_attr->name, table_header->signature, ACPI_NAME_SIZE); + if (table_header->signature[0] != '\0') + memcpy(table_attr->name, table_header->signature, + ACPI_NAME_SIZE); + else + memcpy(table_attr->name, "NULL", 4); list_for_each_entry(attr, &acpi_table_attr_list, node) { - if (!memcmp(table_header->signature, attr->name, - ACPI_NAME_SIZE)) + if (!memcmp(table_attr->name, attr->name, ACPI_NAME_SIZE)) if (table_attr->instance < attr->instance) table_attr->instance = attr->instance; } table_attr->instance++; if (table_attr->instance > 1 || (table_attr->instance == 1 && - !acpi_get_table(table_header-> - signature, 2, - &header))) - sprintf(table_attr->name + 4, "%d", table_attr->instance); + !acpi_get_table + (table_header->signature, 2, &header))) + sprintf(table_attr->name + ACPI_NAME_SIZE, "%d", + table_attr->instance); table_attr->attr.size = 0; table_attr->attr.read = acpi_table_show; |