diff options
| -rw-r--r-- | arch/x86/kernel/e820.c | 4 | ||||
| -rw-r--r-- | arch/x86/power/hibernate.c | 89 |
2 files changed, 16 insertions, 77 deletions
diff --git a/arch/x86/kernel/e820.c b/arch/x86/kernel/e820.c index 22aad412f965..629c4994f165 100644 --- a/arch/x86/kernel/e820.c +++ b/arch/x86/kernel/e820.c @@ -31,8 +31,8 @@ * - inform the user about the firmware's notion of memory layout * via /sys/firmware/memmap * - * - the hibernation code uses it to generate a kernel-independent MD5 - * fingerprint of the physical memory layout of a system. + * - the hibernation code uses it to generate a kernel-independent CRC32 + * checksum of the physical memory layout of a system. * * - 'e820_table_kexec': a slightly modified (by the kernel) firmware version * passed to us by the bootloader - the major difference between diff --git a/arch/x86/power/hibernate.c b/arch/x86/power/hibernate.c index cd3914fc9f3d..e94e0050a583 100644 --- a/arch/x86/power/hibernate.c +++ b/arch/x86/power/hibernate.c @@ -13,8 +13,8 @@ #include <linux/kdebug.h> #include <linux/cpu.h> #include <linux/pgtable.h> - -#include <crypto/hash.h> +#include <linux/types.h> +#include <linux/crc32.h> #include <asm/e820/api.h> #include <asm/init.h> @@ -54,95 +54,33 @@ int pfn_is_nosave(unsigned long pfn) return pfn >= nosave_begin_pfn && pfn < nosave_end_pfn; } - -#define MD5_DIGEST_SIZE 16 - struct restore_data_record { unsigned long jump_address; unsigned long jump_address_phys; unsigned long cr3; unsigned long magic; - u8 e820_digest[MD5_DIGEST_SIZE]; + unsigned long e820_checksum; }; -#if IS_BUILTIN(CONFIG_CRYPTO_MD5) /** - * get_e820_md5 - calculate md5 according to given e820 table + * compute_e820_crc32 - calculate crc32 of a given e820 table * * @table: the e820 table to be calculated - * @buf: the md5 result to be stored to + * + * Return: the resulting checksum */ -static int get_e820_md5(struct e820_table *table, void *buf) +static inline u32 compute_e820_crc32(struct e820_table *table) { - struct crypto_shash *tfm; - struct shash_desc *desc; - int size; - int ret = 0; - - tfm = crypto_alloc_shash("md5", 0, 0); - if (IS_ERR(tfm)) - return -ENOMEM; - - desc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm), - GFP_KERNEL); - if (!desc) { - ret = -ENOMEM; - goto free_tfm; - } - - desc->tfm = tfm; - - size = offsetof(struct e820_table, entries) + + int size = offsetof(struct e820_table, entries) + sizeof(struct e820_entry) * table->nr_entries; - if (crypto_shash_digest(desc, (u8 *)table, size, buf)) - ret = -EINVAL; - - kfree_sensitive(desc); - -free_tfm: - crypto_free_shash(tfm); - return ret; -} - -static int hibernation_e820_save(void *buf) -{ - return get_e820_md5(e820_table_firmware, buf); -} - -static bool hibernation_e820_mismatch(void *buf) -{ - int ret; - u8 result[MD5_DIGEST_SIZE]; - - memset(result, 0, MD5_DIGEST_SIZE); - /* If there is no digest in suspend kernel, let it go. */ - if (!memcmp(result, buf, MD5_DIGEST_SIZE)) - return false; - - ret = get_e820_md5(e820_table_firmware, result); - if (ret) - return true; - - return memcmp(result, buf, MD5_DIGEST_SIZE) ? true : false; -} -#else -static int hibernation_e820_save(void *buf) -{ - return 0; -} - -static bool hibernation_e820_mismatch(void *buf) -{ - /* If md5 is not builtin for restore kernel, let it go. */ - return false; + return ~crc32_le(~0, (unsigned char const *)table, size); } -#endif #ifdef CONFIG_X86_64 -#define RESTORE_MAGIC 0x23456789ABCDEF01UL +#define RESTORE_MAGIC 0x23456789ABCDEF02UL #else -#define RESTORE_MAGIC 0x12345678UL +#define RESTORE_MAGIC 0x12345679UL #endif /** @@ -179,7 +117,8 @@ int arch_hibernation_header_save(void *addr, unsigned int max_size) */ rdr->cr3 = restore_cr3 & ~CR3_PCID_MASK; - return hibernation_e820_save(rdr->e820_digest); + rdr->e820_checksum = compute_e820_crc32(e820_table_firmware); + return 0; } /** @@ -200,7 +139,7 @@ int arch_hibernation_header_restore(void *addr) jump_address_phys = rdr->jump_address_phys; restore_cr3 = rdr->cr3; - if (hibernation_e820_mismatch(rdr->e820_digest)) { + if (rdr->e820_checksum != compute_e820_crc32(e820_table_firmware)) { pr_crit("Hibernate inconsistent memory map detected!\n"); return -ENODEV; } |