From: Peter Gruber <nokos@xxxxxxx> Taken from http://bugzilla.kernel.org/show_bug.cgi?id=11539 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") Cc: Bob Moore <robert.moore@xxxxxxxxx> Cc: Lin Ming <ming.m.lin@xxxxxxxxx> Cc: Len Brown <len.brown@xxxxxxxxx> Acked-by: Zhang Rui <rui.zhang@xxxxxxxxx> Cc: <stable@xxxxxxxxxx> [2.6.26.x] Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/acpi/system.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) diff -puN drivers/acpi/system.c~acpi-dont-create-empty-filenames-in-sys-firmware-acpi-tables drivers/acpi/system.c --- a/drivers/acpi/system.c~acpi-dont-create-empty-filenames-in-sys-firmware-acpi-tables +++ a/drivers/acpi/system.c @@ -78,9 +78,15 @@ static ssize_t acpi_table_show(struct ko 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 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; _ -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
