ima: generalize x86/EFI arch glue for other EFI architectures

Move the x86 IMA arch code into security/integrity/ima/ima_efi.c,
so that we will be able to wire it up for arm64 in a future patch.

Co-developed-by: Chester Lin <clin@suse.com>
Signed-off-by: Chester Lin <clin@suse.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/arch/x86/include/asm/efi.h b/arch/x86/include/asm/efi.h
index 7673dc8..c98f783 100644 (file)
--- a/arch/x86/include/asm/efi.h
+++ b/arch/x86/include/asm/efi.h
@@ -380,4 +380,7 @@ static inline void efi_fake_memmap_early(void)
 }
 #endif
 
+#define arch_ima_efi_boot_mode \
+       ({ extern struct boot_params boot_params; boot_params.secure_boot; })
+
 #endif /* _ASM_X86_EFI_H */

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 68608bd..5eeb808 100644 (file)
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -161,5 +161,3 @@ ifeq ($(CONFIG_X86_64),y)
        obj-$(CONFIG_MMCONF_FAM10H)     += mmconf-fam10h_64.o
        obj-y                           += vsmp_64.o
 endif
-
-obj-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT)   += ima_arch.o

diff --git a/security/integrity/ima/Makefile b/security/integrity/ima/Makefile
index 67dabca..2499f24 100644 (file)
--- a/security/integrity/ima/Makefile
+++ b/security/integrity/ima/Makefile
@@ -14,3 +14,7 @@ ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
 ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
 ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o
 ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o
+
+ifeq ($(CONFIG_EFI),y)
+ima-$(CONFIG_IMA_SECURE_AND_OR_TRUSTED_BOOT) += ima_efi.o
+endif

diff --git a/arch/x86/kernel/ima_arch.c b/security/integrity/ima/ima_efi.c
similarity index 60%
rename from arch/x86/kernel/ima_arch.c
rename to security/integrity/ima/ima_efi.c
index 7dfb1e8..71786d0 100644 (file)
--- a/arch/x86/kernel/ima_arch.c
+++ b/security/integrity/ima/ima_efi.c
@@ -5,50 +5,29 @@
 #include <linux/efi.h>
 #include <linux/module.h>
 #include <linux/ima.h>
+#include <asm/efi.h>
 
-extern struct boot_params boot_params;
+#ifndef arch_ima_efi_boot_mode
+#define arch_ima_efi_boot_mode efi_secureboot_mode_unset
+#endif
 
 static enum efi_secureboot_mode get_sb_mode(void)
 {
-       efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID;
-       efi_status_t status;
-       unsigned long size;
-       u8 secboot, setupmode;
-
-       size = sizeof(secboot);
+       enum efi_secureboot_mode mode;
 
        if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
                pr_info("ima: secureboot mode unknown, no efi\n");
                return efi_secureboot_mode_unknown;
        }
 
-       /* Get variable contents into buffer */
-       status = efi.get_variable(L"SecureBoot", &efi_variable_guid,
-                                 NULL, &size, &secboot);
-       if (status == EFI_NOT_FOUND) {
+       mode = efi_get_secureboot_mode(efi.get_variable);
+       if (mode == efi_secureboot_mode_disabled)
                pr_info("ima: secureboot mode disabled\n");
-               return efi_secureboot_mode_disabled;
-       }
-
-       if (status != EFI_SUCCESS) {
+       else if (mode == efi_secureboot_mode_unknown)
                pr_info("ima: secureboot mode unknown\n");
-               return efi_secureboot_mode_unknown;
-       }
-
-       size = sizeof(setupmode);
-       status = efi.get_variable(L"SetupMode", &efi_variable_guid,
-                                 NULL, &size, &setupmode);
-
-       if (status != EFI_SUCCESS)      /* ignore unknown SetupMode */
-               setupmode = 0;
-
-       if (secboot == 0 || setupmode == 1) {
-               pr_info("ima: secureboot mode disabled\n");
-               return efi_secureboot_mode_disabled;
-       }
-
-       pr_info("ima: secureboot mode enabled\n");
-       return efi_secureboot_mode_enabled;
+       else
+               pr_info("ima: secureboot mode enabled\n");
+       return mode;
 }
 
 bool arch_ima_get_secureboot(void)
@@ -57,7 +36,7 @@ bool arch_ima_get_secureboot(void)
        static bool initialized;
 
        if (!initialized && efi_enabled(EFI_BOOT)) {
-               sb_mode = boot_params.secure_boot;
+               sb_mode = arch_ima_efi_boot_mode;
 
                if (sb_mode == efi_secureboot_mode_unset)
                        sb_mode = get_sb_mode();