[PATCH 12/18] efi: clean up config_parse_tables()
From: Ard Biesheuvel
Date: Sun Feb 16 2020 - 13:24:12 EST
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.
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
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 3b5cf551489c..f69f3fe0532e 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 26d905e6b579..f7025b9075b4 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
@@ -434,7 +434,7 @@ 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;
@@ -457,7 +457,7 @@ 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 a656bfcd7e27..d1f44c847841 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 2bfd6c0806ce..db1fe765380f 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_X64_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 d61c25fd5824..99a7fcbe5e9b 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,
--
2.17.1