diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/acpi/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/acpi/osl.c | 202 |
2 files changed, 200 insertions, 11 deletions
diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index 0300bf612946..38c5078da11d 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -267,6 +267,15 @@ config ACPI_CUSTOM_DSDT bool default ACPI_CUSTOM_DSDT_FILE != "" +config ACPI_INITRD_TABLE_OVERRIDE + bool "ACPI tables can be passed via uncompressed cpio in initrd" + default n + help + This option provides functionality to override arbitrary ACPI tables + via initrd. No functional change if no ACPI tables are passed via + initrd, therefore it's safe to say Y. + See Documentation/acpi/initrd_table_override.txt for details + config ACPI_BLACKLIST_YEAR int "Disable ACPI for systems before Jan 1st this year" if X86_32 default 0 diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 6dc4a2b1e956..3ff267861541 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -534,6 +534,137 @@ acpi_os_predefined_override(const struct acpi_predefined_names *init_val, return AE_OK; } +#ifdef CONFIG_ACPI_INITRD_TABLE_OVERRIDE +#include <linux/earlycpio.h> +#include <linux/memblock.h> + +static u64 acpi_tables_addr; +static int all_tables_size; + +/* Copied from acpica/tbutils.c:acpi_tb_checksum() */ +u8 __init acpi_table_checksum(u8 *buffer, u32 length) +{ + u8 sum = 0; + u8 *end = buffer + length; + + while (buffer < end) + sum = (u8) (sum + *(buffer++)); + return sum; +} + +/* All but ACPI_SIG_RSDP and ACPI_SIG_FACS: */ +static const char * const table_sigs[] = { + ACPI_SIG_BERT, ACPI_SIG_CPEP, ACPI_SIG_ECDT, ACPI_SIG_EINJ, + ACPI_SIG_ERST, ACPI_SIG_HEST, ACPI_SIG_MADT, ACPI_SIG_MSCT, + ACPI_SIG_SBST, ACPI_SIG_SLIT, ACPI_SIG_SRAT, ACPI_SIG_ASF, + ACPI_SIG_BOOT, ACPI_SIG_DBGP, ACPI_SIG_DMAR, ACPI_SIG_HPET, + ACPI_SIG_IBFT, ACPI_SIG_IVRS, ACPI_SIG_MCFG, ACPI_SIG_MCHI, + ACPI_SIG_SLIC, ACPI_SIG_SPCR, ACPI_SIG_SPMI, ACPI_SIG_TCPA, + ACPI_SIG_UEFI, ACPI_SIG_WAET, ACPI_SIG_WDAT, ACPI_SIG_WDDT, + ACPI_SIG_WDRT, ACPI_SIG_DSDT, ACPI_SIG_FADT, ACPI_SIG_PSDT, + ACPI_SIG_RSDT, ACPI_SIG_XSDT, ACPI_SIG_SSDT, NULL }; + +/* Non-fatal errors: Affected tables/files are ignored */ +#define INVALID_TABLE(x, path, name) \ + { pr_err("ACPI OVERRIDE: " x " [%s%s]\n", path, name); continue; } + +#define ACPI_HEADER_SIZE sizeof(struct acpi_table_header) + +/* Must not increase 10 or needs code modification below */ +#define ACPI_OVERRIDE_TABLES 10 + +void __init acpi_initrd_override(void *data, size_t size) +{ + int sig, no, table_nr = 0, total_offset = 0; + long offset = 0; + struct acpi_table_header *table; + char cpio_path[32] = "kernel/firmware/acpi/"; + struct cpio_data file; + struct cpio_data early_initrd_files[ACPI_OVERRIDE_TABLES]; + char *p; + + if (data == NULL || size == 0) + return; + + for (no = 0; no < ACPI_OVERRIDE_TABLES; no++) { + file = find_cpio_data(cpio_path, data, size, &offset); + if (!file.data) + break; + + data += offset; + size -= offset; + + if (file.size < sizeof(struct acpi_table_header)) + INVALID_TABLE("Table smaller than ACPI header", + cpio_path, file.name); + + table = file.data; + + for (sig = 0; table_sigs[sig]; sig++) + if (!memcmp(table->signature, table_sigs[sig], 4)) + break; + + if (!table_sigs[sig]) + INVALID_TABLE("Unknown signature", + cpio_path, file.name); + if (file.size != table->length) + INVALID_TABLE("File length does not match table length", + cpio_path, file.name); + if (acpi_table_checksum(file.data, table->length)) + INVALID_TABLE("Bad table checksum", + cpio_path, file.name); + + pr_info("%4.4s ACPI table found in initrd [%s%s][0x%x]\n", + table->signature, cpio_path, file.name, table->length); + + all_tables_size += table->length; + early_initrd_files[table_nr].data = file.data; + early_initrd_files[table_nr].size = file.size; + table_nr++; + } + if (table_nr == 0) + return; + + acpi_tables_addr = + memblock_find_in_range(0, max_low_pfn_mapped << PAGE_SHIFT, + all_tables_size, PAGE_SIZE); + if (!acpi_tables_addr) { + WARN_ON(1); + return; + } + /* + * Only calling e820_add_reserve does not work and the + * tables are invalid (memory got used) later. + * memblock_reserve works as expected and the tables won't get modified. + * But it's not enough on X86 because ioremap will + * complain later (used by acpi_os_map_memory) that the pages + * that should get mapped are not marked "reserved". + * Both memblock_reserve and e820_add_region (via arch_reserve_mem_area) + * works fine. + */ + memblock_reserve(acpi_tables_addr, acpi_tables_addr + all_tables_size); + arch_reserve_mem_area(acpi_tables_addr, all_tables_size); + + p = early_ioremap(acpi_tables_addr, all_tables_size); + + for (no = 0; no < table_nr; no++) { + memcpy(p + total_offset, early_initrd_files[no].data, + early_initrd_files[no].size); + total_offset += early_initrd_files[no].size; + } + early_iounmap(p, all_tables_size); +} +#endif /* CONFIG_ACPI_INITRD_TABLE_OVERRIDE */ + +static void acpi_table_taint(struct acpi_table_header *table) +{ + pr_warn(PREFIX + "Override [%4.4s-%8.8s], this is unsafe: tainting kernel\n", + table->signature, table->oem_table_id); + add_taint(TAINT_OVERRIDDEN_ACPI_TABLE); +} + + acpi_status acpi_os_table_override(struct acpi_table_header * existing_table, struct acpi_table_header ** new_table) @@ -547,24 +678,73 @@ acpi_os_table_override(struct acpi_table_header * existing_table, if (strncmp(existing_table->signature, "DSDT", 4) == 0) *new_table = (struct acpi_table_header *)AmlCode; #endif - if (*new_table != NULL) { - printk(KERN_WARNING PREFIX "Override [%4.4s-%8.8s], " - "this is unsafe: tainting kernel\n", - existing_table->signature, - existing_table->oem_table_id); - add_taint(TAINT_OVERRIDDEN_ACPI_TABLE); - } + if (*new_table != NULL) + acpi_table_taint(existing_table); return AE_OK; } acpi_status acpi_os_physical_table_override(struct acpi_table_header *existing_table, - acpi_physical_address * new_address, - u32 *new_table_length) + acpi_physical_address *address, + u32 *table_length) { - return AE_SUPPORT; -} +#ifndef CONFIG_ACPI_INITRD_TABLE_OVERRIDE + *table_length = 0; + *address = 0; + return AE_OK; +#else + int table_offset = 0; + struct acpi_table_header *table; + + *table_length = 0; + *address = 0; + + if (!acpi_tables_addr) + return AE_OK; + + do { + if (table_offset + ACPI_HEADER_SIZE > all_tables_size) { + WARN_ON(1); + return AE_OK; + } + table = acpi_os_map_memory(acpi_tables_addr + table_offset, + ACPI_HEADER_SIZE); + + if (table_offset + table->length > all_tables_size) { + acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); + WARN_ON(1); + return AE_OK; + } + + table_offset += table->length; + + if (memcmp(existing_table->signature, table->signature, 4)) { + acpi_os_unmap_memory(table, + ACPI_HEADER_SIZE); + continue; + } + + /* Only override tables with matching oem id */ + if (memcmp(table->oem_table_id, existing_table->oem_table_id, + ACPI_OEM_TABLE_ID_SIZE)) { + acpi_os_unmap_memory(table, + ACPI_HEADER_SIZE); + continue; + } + + table_offset -= table->length; + *table_length = table->length; + acpi_os_unmap_memory(table, ACPI_HEADER_SIZE); + *address = acpi_tables_addr + table_offset; + break; + } while (table_offset + ACPI_HEADER_SIZE < all_tables_size); + + if (*address != 0) + acpi_table_taint(existing_table); + return AE_OK; +#endif +} static irqreturn_t acpi_irq(int irq, void *dev_id) { |