Skip to content

Commit

Permalink
efi: Clean up config_parse_tables()
Browse files Browse the repository at this point in the history 
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 <tony.luck@intel.com> # arch/ia64
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
  • Loading branch information
Ard Biesheuvel committed Feb 23, 2020
1 parent 3a0701d commit 06c0bd9
Show file tree
Hide file tree
Showing 5 changed files with 32 additions and 34 deletions.
3 changes: 1 addition & 2 deletions arch/ia64/kernel/efi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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},
Expand Down Expand Up @@ -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;

Expand Down
6 changes: 3 additions & 3 deletions arch/x86/platform/efi/efi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down Expand Up @@ -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;
Expand All @@ -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);
Expand Down
5 changes: 2 additions & 3 deletions drivers/firmware/efi/arm-init.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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}
};
Expand Down Expand Up @@ -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;

Expand Down Expand Up @@ -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)
Expand Down
47 changes: 23 additions & 24 deletions drivers/firmware/efi/efi.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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},
Expand All @@ -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;

Expand All @@ -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);
Expand Down
5 changes: 3 additions & 2 deletions include/linux/efi.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down

0 comments on commit 06c0bd9

Please sign in to comment.