From 06c0bd93434c5b9b284773f90bb054aff591d5be Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Wed, 22 Jan 2020 14:40:57 +0100 Subject: [PATCH] efi: Clean up config_parse_tables() config_parse_tables() is a jumble of pointer arithmetic, due to the fact that on x86, we may be dealing with firmware whose native word size differs from the kernel's. This is not a concern on other architectures, and doesn't quite justify the state of the code, so let's clean it up by adding a non-x86 code path, constifying statically allocated tables and replacing preprocessor conditionals with IS_ENABLED() checks. Tested-by: Tony Luck # arch/ia64 Signed-off-by: Ard Biesheuvel --- arch/ia64/kernel/efi.c | 3 +-- arch/x86/platform/efi/efi.c | 6 +++--- drivers/firmware/efi/arm-init.c | 5 ++--- drivers/firmware/efi/efi.c | 47 ++++++++++++++++++++--------------------- include/linux/efi.h | 5 +++-- 5 files changed, 32 insertions(+), 34 deletions(-) diff --git a/arch/ia64/kernel/efi.c b/arch/ia64/kernel/efi.c index 3b5cf55..f69f3fe 100644 --- a/arch/ia64/kernel/efi.c +++ b/arch/ia64/kernel/efi.c @@ -56,7 +56,7 @@ unsigned long __initdata esi_phys = EFI_INVALID_TABLE_ADDR; unsigned long hcdp_phys = EFI_INVALID_TABLE_ADDR; unsigned long sal_systab_phys = EFI_INVALID_TABLE_ADDR; -static __initdata efi_config_table_type_t arch_tables[] = { +static const efi_config_table_type_t arch_tables[] __initconst = { {ESI_TABLE_GUID, "ESI", &esi_phys}, {HCDP_TABLE_GUID, "HCDP", &hcdp_phys}, {MPS_TABLE_GUID, "MPS", &mps_phys}, @@ -533,7 +533,6 @@ efi_init (void) if (efi_config_parse_tables(__va(efi_systab->tables), efi_systab->nr_tables, - sizeof(efi_config_table_t), arch_tables) != 0) return; diff --git a/arch/x86/platform/efi/efi.c b/arch/x86/platform/efi/efi.c index f1033f7..47367f4 100644 --- a/arch/x86/platform/efi/efi.c +++ b/arch/x86/platform/efi/efi.c @@ -60,7 +60,7 @@ static u64 efi_systab_phys __initdata; static unsigned long prop_phys = EFI_INVALID_TABLE_ADDR; static unsigned long uga_phys = EFI_INVALID_TABLE_ADDR; -static efi_config_table_type_t arch_tables[] __initdata = { +static const efi_config_table_type_t arch_tables[] __initconst = { {EFI_PROPERTIES_TABLE_GUID, "PROP", &prop_phys}, {UGA_IO_PROTOCOL_GUID, "UGA", &uga_phys}, #ifdef CONFIG_X86_UV @@ -431,7 +431,7 @@ static int __init efi_systab_init(u64 phys) return 0; } -static int __init efi_config_init(efi_config_table_type_t *arch_tables) +static int __init efi_config_init(const efi_config_table_type_t *arch_tables) { void *config_tables; int sz, ret; @@ -454,7 +454,7 @@ static int __init efi_config_init(efi_config_table_type_t *arch_tables) return -ENOMEM; } - ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, sz, + ret = efi_config_parse_tables(config_tables, efi.systab->nr_tables, arch_tables); early_memunmap(config_tables, efi.systab->nr_tables * sz); diff --git a/drivers/firmware/efi/arm-init.c b/drivers/firmware/efi/arm-init.c index a656bfc..d1f44c8 100644 --- a/drivers/firmware/efi/arm-init.c +++ b/drivers/firmware/efi/arm-init.c @@ -55,7 +55,7 @@ static phys_addr_t efi_to_phys(unsigned long addr) static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR; -static __initdata efi_config_table_type_t arch_tables[] = { +static const efi_config_table_type_t arch_tables[] __initconst = { {LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, NULL, &screen_info_table}, {NULL_GUID, NULL, NULL} }; @@ -85,7 +85,7 @@ static void __init init_screen_info(void) static int __init uefi_init(void) { - void *config_tables; + efi_config_table_t *config_tables; size_t table_size; int retval; @@ -118,7 +118,6 @@ static int __init uefi_init(void) goto out; } retval = efi_config_parse_tables(config_tables, efi.systab->nr_tables, - sizeof(efi_config_table_t), arch_tables); if (!retval) diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 2bfd6c0..45de4c4 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -460,7 +460,7 @@ void __init efi_mem_reserve(phys_addr_t addr, u64 size) efi_arch_mem_reserve(addr, size); } -static __initdata efi_config_table_type_t common_tables[] = { +static const efi_config_table_type_t common_tables[] __initconst = { {ACPI_20_TABLE_GUID, "ACPI 2.0", &efi.acpi20}, {ACPI_TABLE_GUID, "ACPI", &efi.acpi}, {SMBIOS_TABLE_GUID, "SMBIOS", &efi.smbios}, @@ -477,9 +477,9 @@ static __initdata efi_config_table_type_t common_tables[] = { {NULL_GUID, NULL, NULL}, }; -static __init int match_config_table(efi_guid_t *guid, +static __init int match_config_table(const efi_guid_t *guid, unsigned long table, - efi_config_table_type_t *table_types) + const efi_config_table_type_t *table_types) { int i; @@ -498,39 +498,38 @@ static __init int match_config_table(efi_guid_t *guid, return 0; } -int __init efi_config_parse_tables(void *config_tables, int count, int sz, - efi_config_table_type_t *arch_tables) +int __init efi_config_parse_tables(const efi_config_table_t *config_tables, + int count, + const efi_config_table_type_t *arch_tables) { - void *tablep; + const efi_config_table_64_t *tbl64 = (void *)config_tables; + const efi_config_table_32_t *tbl32 = (void *)config_tables; + const efi_guid_t *guid; + unsigned long table; int i; - tablep = config_tables; pr_info(""); for (i = 0; i < count; i++) { - efi_guid_t guid; - unsigned long table; - - if (efi_enabled(EFI_64BIT)) { - u64 table64; - guid = ((efi_config_table_64_t *)tablep)->guid; - table64 = ((efi_config_table_64_t *)tablep)->table; - table = table64; -#ifndef CONFIG_64BIT - if (table64 >> 32) { + if (!IS_ENABLED(CONFIG_X86)) { + guid = &config_tables[i].guid; + table = (unsigned long)config_tables[i].table; + } else if (efi_enabled(EFI_64BIT)) { + guid = &tbl64[i].guid; + table = tbl64[i].table; + + if (IS_ENABLED(CONFIG_X86_32) && + tbl64[i].table > U32_MAX) { pr_cont("\n"); pr_err("Table located above 4GB, disabling EFI.\n"); return -EINVAL; } -#endif } else { - guid = ((efi_config_table_32_t *)tablep)->guid; - table = ((efi_config_table_32_t *)tablep)->table; + guid = &tbl32[i].guid; + table = tbl32[i].table; } - if (!match_config_table(&guid, table, common_tables)) - match_config_table(&guid, table, arch_tables); - - tablep += sz; + if (!match_config_table(guid, table, common_tables)) + match_config_table(guid, table, arch_tables); } pr_cont("\n"); set_bit(EFI_CONFIG_TABLES, &efi.flags); diff --git a/include/linux/efi.h b/include/linux/efi.h index d61c25f..99a7fcb 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -613,8 +613,9 @@ extern void __init efi_esrt_init(void); #else static inline void efi_esrt_init(void) { } #endif -extern int efi_config_parse_tables(void *config_tables, int count, int sz, - efi_config_table_type_t *arch_tables); +extern int efi_config_parse_tables(const efi_config_table_t *config_tables, + int count, + const efi_config_table_type_t *arch_tables); extern int efi_systab_check_header(const efi_table_hdr_t *systab_hdr, int min_major_version); extern void efi_systab_report_header(const efi_table_hdr_t *systab_hdr, -- 2.7.4