| Message ID | 20201102223800.12181-2-ardb@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | wire up IMA secure boot for arm64 | expand |
On Mon, 2020-11-02 at 23:37 +0100, Ard Biesheuvel wrote: > From: Chester Lin <clin@suse.com> > > Generalize the efi_get_secureboot() function so not only efistub but also > other subsystems can use it. > > Note that the MokSbState handling is not factored out: the variable is > boot time only, and so it cannot be parameterized as easily. Also, the > IMA code will switch to this version in a future patch, and it does not > incorporate the MokSbState exception in the first place. > > Note that the new efi_get_secureboot_mode() helper treats any failures > to read SetupMode as setup mode being disabled. > > Co-developed-by: Chester Lin <clin@suse.com> > Signed-off-by: Chester Lin <clin@suse.com> > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Thanks, Ard. Other than one minor thing inline below, the patch looks good. I haven't done any testing yet. > diff --git a/include/linux/efi.h b/include/linux/efi.h > index bd9d83a94173..79b2d4de62e0 100644 > --- a/include/linux/efi.h > +++ b/include/linux/efi.h > @@ -1082,7 +1082,28 @@ enum efi_secureboot_mode { > efi_secureboot_mode_disabled, > efi_secureboot_mode_enabled, > }; > -enum efi_secureboot_mode efi_get_secureboot(void); > + > +static inline > +enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var) get_var() should be defined as "efi_status_t". If this is being upstreamed via integrity, I can make the change. thanks, Mimi
On Tue, 3 Nov 2020 at 19:49, Mimi Zohar <zohar@linux.ibm.com> wrote: > > On Mon, 2020-11-02 at 23:37 +0100, Ard Biesheuvel wrote: > > From: Chester Lin <clin@suse.com> > > > > Generalize the efi_get_secureboot() function so not only efistub but also > > other subsystems can use it. > > > > Note that the MokSbState handling is not factored out: the variable is > > boot time only, and so it cannot be parameterized as easily. Also, the > > IMA code will switch to this version in a future patch, and it does not > > incorporate the MokSbState exception in the first place. > > > > Note that the new efi_get_secureboot_mode() helper treats any failures > > to read SetupMode as setup mode being disabled. > > > > Co-developed-by: Chester Lin <clin@suse.com> > > Signed-off-by: Chester Lin <clin@suse.com> > > Signed-off-by: Ard Biesheuvel <ardb@kernel.org> > > Thanks, Ard. Other than one minor thing inline below, the patch looks > good. I haven't done any testing yet. > > > diff --git a/include/linux/efi.h b/include/linux/efi.h > > index bd9d83a94173..79b2d4de62e0 100644 > > --- a/include/linux/efi.h > > +++ b/include/linux/efi.h > > @@ -1082,7 +1082,28 @@ enum efi_secureboot_mode { > > efi_secureboot_mode_disabled, > > efi_secureboot_mode_enabled, > > }; > > -enum efi_secureboot_mode efi_get_secureboot(void); > > + > > +static inline > > +enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var) > > get_var() should be defined as "efi_status_t". If this is being > upstreamed via integrity, I can make the change. > No, get_var is a pointer to a function returning efi_status_t, check include/linux/efi.h for details.
On Tue, 2020-11-03 at 20:01 +0100, Ard Biesheuvel wrote: > > get_var() should be defined as "efi_status_t". If this is being > > upstreamed via integrity, I can make the change. > > > > No, get_var is a pointer to a function returning efi_status_t, check > include/linux/efi.h for details. Got it. thanks, Mimi
diff --git a/arch/x86/boot/compressed/Makefile b/arch/x86/boot/compressed/Makefile index ee249088cbfe..8d358a6fe6ec 100644 --- a/arch/x86/boot/compressed/Makefile +++ b/arch/x86/boot/compressed/Makefile @@ -35,7 +35,7 @@ cflags-$(CONFIG_X86_32) := -march=i386 cflags-$(CONFIG_X86_64) := -mcmodel=small -mno-red-zone KBUILD_CFLAGS += $(cflags-y) KBUILD_CFLAGS += -mno-mmx -mno-sse -KBUILD_CFLAGS += -ffreestanding +KBUILD_CFLAGS += -ffreestanding -fshort-wchar KBUILD_CFLAGS += -fno-stack-protector KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member) KBUILD_CFLAGS += $(call cc-disable-warning, gnu) diff --git a/drivers/firmware/efi/libstub/efistub.h b/drivers/firmware/efi/libstub/efistub.h index 2d7abcd99de9..b8ec29d6a74a 100644 --- a/drivers/firmware/efi/libstub/efistub.h +++ b/drivers/firmware/efi/libstub/efistub.h @@ -848,4 +848,6 @@ asmlinkage void __noreturn efi_enter_kernel(unsigned long entrypoint, void efi_handle_post_ebs_state(void); +enum efi_secureboot_mode efi_get_secureboot(void); + #endif diff --git a/drivers/firmware/efi/libstub/secureboot.c b/drivers/firmware/efi/libstub/secureboot.c index 5efc524b14be..af18d86c1604 100644 --- a/drivers/firmware/efi/libstub/secureboot.c +++ b/drivers/firmware/efi/libstub/secureboot.c @@ -12,15 +12,16 @@ #include "efistub.h" -/* BIOS variables */ -static const efi_guid_t efi_variable_guid = EFI_GLOBAL_VARIABLE_GUID; -static const efi_char16_t efi_SecureBoot_name[] = L"SecureBoot"; -static const efi_char16_t efi_SetupMode_name[] = L"SetupMode"; - /* SHIM variables */ static const efi_guid_t shim_guid = EFI_SHIM_LOCK_GUID; static const efi_char16_t shim_MokSBState_name[] = L"MokSBState"; +static efi_status_t get_var(efi_char16_t *name, efi_guid_t *vendor, u32 *attr, + unsigned long *data_size, void *data) +{ + return get_efi_var(name, vendor, attr, data_size, data); +} + /* * Determine whether we're in secure boot mode. * @@ -30,26 +31,18 @@ static const efi_char16_t shim_MokSBState_name[] = L"MokSBState"; enum efi_secureboot_mode efi_get_secureboot(void) { u32 attr; - u8 secboot, setupmode, moksbstate; unsigned long size; + enum efi_secureboot_mode mode; efi_status_t status; + u8 moksbstate; - size = sizeof(secboot); - status = get_efi_var(efi_SecureBoot_name, &efi_variable_guid, - NULL, &size, &secboot); - if (status == EFI_NOT_FOUND) - return efi_secureboot_mode_disabled; - if (status != EFI_SUCCESS) - goto out_efi_err; - - size = sizeof(setupmode); - status = get_efi_var(efi_SetupMode_name, &efi_variable_guid, - NULL, &size, &setupmode); - if (status != EFI_SUCCESS) - goto out_efi_err; - - if (secboot == 0 || setupmode == 1) - return efi_secureboot_mode_disabled; + mode = efi_get_secureboot_mode(get_var); + if (mode == efi_secureboot_mode_unknown) { + efi_err("Could not determine UEFI Secure Boot status.\n"); + return efi_secureboot_mode_unknown; + } + if (mode != efi_secureboot_mode_enabled) + return mode; /* * See if a user has put the shim into insecure mode. If so, and if the @@ -69,8 +62,4 @@ enum efi_secureboot_mode efi_get_secureboot(void) secure_boot_enabled: efi_info("UEFI Secure Boot is enabled.\n"); return efi_secureboot_mode_enabled; - -out_efi_err: - efi_err("Could not determine UEFI Secure Boot status.\n"); - return efi_secureboot_mode_unknown; } diff --git a/include/linux/efi.h b/include/linux/efi.h index bd9d83a94173..79b2d4de62e0 100644 --- a/include/linux/efi.h +++ b/include/linux/efi.h @@ -1082,7 +1082,28 @@ enum efi_secureboot_mode { efi_secureboot_mode_disabled, efi_secureboot_mode_enabled, }; -enum efi_secureboot_mode efi_get_secureboot(void); + +static inline +enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var) +{ + u8 secboot, setupmode = 0; + efi_status_t status; + unsigned long size; + + size = sizeof(secboot); + status = get_var(L"SecureBoot", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, + &secboot); + if (status == EFI_NOT_FOUND) + return efi_secureboot_mode_disabled; + if (status != EFI_SUCCESS) + return efi_secureboot_mode_unknown; + + size = sizeof(setupmode); + get_var(L"SetupMode", &EFI_GLOBAL_VARIABLE_GUID, NULL, &size, &setupmode); + if (secboot == 0 || setupmode == 1) + return efi_secureboot_mode_disabled; + return efi_secureboot_mode_enabled; +} #ifdef CONFIG_RESET_ATTACK_MITIGATION void efi_enable_reset_attack_mitigation(void);