[PATCH v8 RESEND 16/38] efi: Add an EFI table address match function

Tom Lendacky
2017-06-27T15:10:17Z

Add a function that will determine if a supplied physical address matches
the address of an EFI table.

Reviewed-by: Matt Fleming <matt@codeblueprint.co.uk>
Reviewed-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>
---
drivers/firmware/efi/efi.c | 33 +++++++++++++++++++++++++++++++++
include/linux/efi.h | 7 +++++++
2 files changed, 40 insertions(+)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 045d6d3..69d4d13 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -55,6 +55,25 @@ struct efi __read_mostly efi = {
};
EXPORT_SYMBOL(efi);

+static unsigned long *efi_tables[] = {
+ &efi.mps,
+ &efi.acpi,
+ &efi.acpi20,
+ &efi.smbios,
+ &efi.smbios3,
+ &efi.sal_systab,
+ &efi.boot_info,
+ &efi.hcdp,
+ &efi.uga,
+ &efi.uv_systab,
+ &efi.fw_vendor,
+ &efi.runtime,
+ &efi.config_table,
+ &efi.esrt,
+ &efi.properties_table,
+ &efi.mem_attr_table,
+};
+
static bool disable_runtime;
static int __init setup_noefi(char *arg)
{
@@ -855,6 +874,20 @@ int efi_status_to_err(efi_status_t status)
return err;
}

+bool efi_is_table_address(unsigned long phys_addr)
+{
+ unsigned int i;
+
+ if (phys_addr == EFI_INVALID_TABLE_ADDR)
+ return false;
+
+ for (i = 0; i < ARRAY_SIZE(efi_tables); i++)
+ if (*(efi_tables[i]) == phys_addr)
+ return true;
+
+ return false;
+}
+
#ifdef CONFIG_KEXEC
static int update_efi_random_seed(struct notifier_block *nb,
unsigned long code, void *unused)
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 8269bcb..8e24f09 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1091,6 +1091,8 @@ static inline bool efi_enabled(int feature)
return test_bit(feature, &efi.flags) != 0;
}
extern void efi_reboot(enum reboot_mode reboot_mode, const char *__unused);
+
+extern bool efi_is_table_address(unsigned long phys_addr);
#else
static inline bool efi_enabled(int feature)
{
@@ -1104,6 +1106,11 @@ static inline bool efi_enabled(int feature)
{
return false;
}
+
+static inline bool efi_is_table_address(unsigned long phys_addr)
+{
+ return false;
+}
#endif

extern int efi_status_to_err(efi_status_t status);

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