Re: [PATCH v2 1/2] efi: add secure boot get helper

2020-10-15 Thread Chester Lin 
Hi Ard and Mimi,

On Wed, Oct 14, 2020 at 07:56:17AM -0400, Mimi Zohar wrote:
> On Wed, 2020-10-14 at 13:00 +0200, Ard Biesheuvel wrote:
> > Hello Chester,
> > 
> > Thanks for looking into this.
> > 
> > Some comments below.
> > 
> > On Wed, 14 Oct 2020 at 12:41, Chester Lin  wrote:
> > >
> > > Separate the get_sb_mode() from arch/x86 and treat it as a common function
> > > [rename to efi_get_secureboot_mode] so all EFI-based architectures can
> > > reuse the same logic.
> > >
> > > Signed-off-by: Chester Lin 
> > > ---
> > >  arch/x86/kernel/ima_arch.c | 47 ++
> > >  drivers/firmware/efi/efi.c | 43 ++
> > >  include/linux/efi.h|  5 
> > >  3 files changed, 50 insertions(+), 45 deletions(-)
> > >
> > > diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
> > > index 7dfb1e808928..ed4623ecda6e 100644
> > > --- a/arch/x86/kernel/ima_arch.c
> > > +++ b/arch/x86/kernel/ima_arch.c
> > > @@ -8,49 +8,6 @@
> > >
> > >  extern struct boot_params boot_params;
> > >
> > > -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);
> > > -
> > > -   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", _variable_guid,
> > > - NULL, , );
> > > -   if (status == EFI_NOT_FOUND) {
> > > -   pr_info("ima: secureboot mode disabled\n");
> > > -   return efi_secureboot_mode_disabled;
> > > -   }
> > > -
> > > -   if (status != EFI_SUCCESS) {
> > > -   pr_info("ima: secureboot mode unknown\n");
> > > -   return efi_secureboot_mode_unknown;
> > > -   }
> > > -
> > > -   size = sizeof(setupmode);
> > > -   status = efi.get_variable(L"SetupMode", _variable_guid,
> > > - NULL, , );
> > > -
> > > -   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;
> > > -}
> > > -
> > >  bool arch_ima_get_secureboot(void)
> > >  {
> > > static enum efi_secureboot_mode sb_mode;
> > > @@ -60,7 +17,7 @@ bool arch_ima_get_secureboot(void)
> > > sb_mode = boot_params.secure_boot;
> > >
> > > if (sb_mode == efi_secureboot_mode_unset)
> > > -   sb_mode = get_sb_mode();
> > > +   sb_mode = efi_get_secureboot_mode();
> > > initialized = true;
> > > }
> > >
> > > @@ -70,7 +27,7 @@ bool arch_ima_get_secureboot(void)
> > > return false;
> > >  }
> > >
> > > -/* secureboot arch rules */
> > > +/* secure and trusted boot arch rules */
> > >  static const char * const sb_arch_rules[] = {
> > >  #if !IS_ENABLED(CONFIG_KEXEC_SIG)
> > > "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
> > > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> > > index 5e5480a0a32d..68ffa6a069c0 100644
> > > --- a/drivers/firmware/efi/efi.c
> > > +++ b/drivers/firmware/efi/efi.c
> > > @@ -1022,3 +1022,46 @@ static int __init 
> > > register_update_efi_random_seed(void)
> > >  }
> > >  late_initcall(register_update_efi_random_seed);
> > >  #endif
> > > +
> > > +enum efi_secureboot_mode efi_get_secureboot_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);
> > > +
> > > +   if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
> > > +   pr_info("ima: secureboot mode unknown, no efi\n");
> > 
> > These prints don't belong here anymore.
> > 
> > Also, it would be useful if we could reuse this logic in the EFI stub
> > as well, which is built as a separate executable, and does not provide
> > efi.get_variable().
> > 
> > So, you could you please break this up into
> > 
> > static inline
> > enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t 
> > *get_var)
> > {
> > }
> > 
> > placed into include/linux/efi.h, which encapsulates the core logic,
> > but using get_var(), and without the prints.
> > 
> > Then, we could put

Re: [PATCH v2 1/2] efi: add secure boot get helper

2020-10-14 Thread Mimi Zohar 
On Wed, 2020-10-14 at 13:00 +0200, Ard Biesheuvel wrote:
> Hello Chester,
> 
> Thanks for looking into this.
> 
> Some comments below.
> 
> On Wed, 14 Oct 2020 at 12:41, Chester Lin  wrote:
> >
> > Separate the get_sb_mode() from arch/x86 and treat it as a common function
> > [rename to efi_get_secureboot_mode] so all EFI-based architectures can
> > reuse the same logic.
> >
> > Signed-off-by: Chester Lin 
> > ---
> >  arch/x86/kernel/ima_arch.c | 47 ++
> >  drivers/firmware/efi/efi.c | 43 ++
> >  include/linux/efi.h|  5 
> >  3 files changed, 50 insertions(+), 45 deletions(-)
> >
> > diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
> > index 7dfb1e808928..ed4623ecda6e 100644
> > --- a/arch/x86/kernel/ima_arch.c
> > +++ b/arch/x86/kernel/ima_arch.c
> > @@ -8,49 +8,6 @@
> >
> >  extern struct boot_params boot_params;
> >
> > -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);
> > -
> > -   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", _variable_guid,
> > - NULL, , );
> > -   if (status == EFI_NOT_FOUND) {
> > -   pr_info("ima: secureboot mode disabled\n");
> > -   return efi_secureboot_mode_disabled;
> > -   }
> > -
> > -   if (status != EFI_SUCCESS) {
> > -   pr_info("ima: secureboot mode unknown\n");
> > -   return efi_secureboot_mode_unknown;
> > -   }
> > -
> > -   size = sizeof(setupmode);
> > -   status = efi.get_variable(L"SetupMode", _variable_guid,
> > - NULL, , );
> > -
> > -   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;
> > -}
> > -
> >  bool arch_ima_get_secureboot(void)
> >  {
> > static enum efi_secureboot_mode sb_mode;
> > @@ -60,7 +17,7 @@ bool arch_ima_get_secureboot(void)
> > sb_mode = boot_params.secure_boot;
> >
> > if (sb_mode == efi_secureboot_mode_unset)
> > -   sb_mode = get_sb_mode();
> > +   sb_mode = efi_get_secureboot_mode();
> > initialized = true;
> > }
> >
> > @@ -70,7 +27,7 @@ bool arch_ima_get_secureboot(void)
> > return false;
> >  }
> >
> > -/* secureboot arch rules */
> > +/* secure and trusted boot arch rules */
> >  static const char * const sb_arch_rules[] = {
> >  #if !IS_ENABLED(CONFIG_KEXEC_SIG)
> > "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
> > diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> > index 5e5480a0a32d..68ffa6a069c0 100644
> > --- a/drivers/firmware/efi/efi.c
> > +++ b/drivers/firmware/efi/efi.c
> > @@ -1022,3 +1022,46 @@ static int __init 
> > register_update_efi_random_seed(void)
> >  }
> >  late_initcall(register_update_efi_random_seed);
> >  #endif
> > +
> > +enum efi_secureboot_mode efi_get_secureboot_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);
> > +
> > +   if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
> > +   pr_info("ima: secureboot mode unknown, no efi\n");
> 
> These prints don't belong here anymore.
> 
> Also, it would be useful if we could reuse this logic in the EFI stub
> as well, which is built as a separate executable, and does not provide
> efi.get_variable().
> 
> So, you could you please break this up into
> 
> static inline
> enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var)
> {
> }
> 
> placed into include/linux/efi.h, which encapsulates the core logic,
> but using get_var(), and without the prints.
> 
> Then, we could put something like
> 
> bool efi_ima_get_secureboot(void)
> {
> }
> 
> in drivers/firmware/efi/efi.c (guarded by #ifdef CONFIG_IMA_xxx),
> which performs the
> efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) check, calls
> efi_get_secureboot_mode(efi.get_variable), and implements the logic.
> 
> And actually, if the logic is identical

Re: [PATCH v2 1/2] efi: add secure boot get helper

2020-10-14 Thread Ard Biesheuvel 
Hello Chester,

Thanks for looking into this.

Some comments below.

On Wed, 14 Oct 2020 at 12:41, Chester Lin  wrote:
>
> Separate the get_sb_mode() from arch/x86 and treat it as a common function
> [rename to efi_get_secureboot_mode] so all EFI-based architectures can
> reuse the same logic.
>
> Signed-off-by: Chester Lin 
> ---
>  arch/x86/kernel/ima_arch.c | 47 ++
>  drivers/firmware/efi/efi.c | 43 ++
>  include/linux/efi.h|  5 
>  3 files changed, 50 insertions(+), 45 deletions(-)
>
> diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
> index 7dfb1e808928..ed4623ecda6e 100644
> --- a/arch/x86/kernel/ima_arch.c
> +++ b/arch/x86/kernel/ima_arch.c
> @@ -8,49 +8,6 @@
>
>  extern struct boot_params boot_params;
>
> -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);
> -
> -   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", _variable_guid,
> - NULL, , );
> -   if (status == EFI_NOT_FOUND) {
> -   pr_info("ima: secureboot mode disabled\n");
> -   return efi_secureboot_mode_disabled;
> -   }
> -
> -   if (status != EFI_SUCCESS) {
> -   pr_info("ima: secureboot mode unknown\n");
> -   return efi_secureboot_mode_unknown;
> -   }
> -
> -   size = sizeof(setupmode);
> -   status = efi.get_variable(L"SetupMode", _variable_guid,
> - NULL, , );
> -
> -   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;
> -}
> -
>  bool arch_ima_get_secureboot(void)
>  {
> static enum efi_secureboot_mode sb_mode;
> @@ -60,7 +17,7 @@ bool arch_ima_get_secureboot(void)
> sb_mode = boot_params.secure_boot;
>
> if (sb_mode == efi_secureboot_mode_unset)
> -   sb_mode = get_sb_mode();
> +   sb_mode = efi_get_secureboot_mode();
> initialized = true;
> }
>
> @@ -70,7 +27,7 @@ bool arch_ima_get_secureboot(void)
> return false;
>  }
>
> -/* secureboot arch rules */
> +/* secure and trusted boot arch rules */
>  static const char * const sb_arch_rules[] = {
>  #if !IS_ENABLED(CONFIG_KEXEC_SIG)
> "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 5e5480a0a32d..68ffa6a069c0 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -1022,3 +1022,46 @@ static int __init register_update_efi_random_seed(void)
>  }
>  late_initcall(register_update_efi_random_seed);
>  #endif
> +
> +enum efi_secureboot_mode efi_get_secureboot_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);
> +
> +   if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) {
> +   pr_info("ima: secureboot mode unknown, no efi\n");

These prints don't belong here anymore.

Also, it would be useful if we could reuse this logic in the EFI stub
as well, which is built as a separate executable, and does not provide
efi.get_variable().

So, you could you please break this up into

static inline
enum efi_secureboot_mode efi_get_secureboot_mode(efi_get_variable_t *get_var)
{
}

placed into include/linux/efi.h, which encapsulates the core logic,
but using get_var(), and without the prints.

Then, we could put something like

bool efi_ima_get_secureboot(void)
{
}

in drivers/firmware/efi/efi.c (guarded by #ifdef CONFIG_IMA_xxx),
which performs the
efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE)) check, calls
efi_get_secureboot_mode(efi.get_variable), and implements the logic.

And actually, if the logic is identical between x86 and arm64, I
wonder if it wouldn't be better to put the whole thing into

drivers/firmware/efi/efi-ima.c

or

security/integrity/ima/ima-efi.c

with the only difference being the boot_params->secure_boot access for
x86, which we can factor out to a static inline helper.

Mimi, any thoughts here?



> +   return

Re: [PATCH v2 1/2] efi: add secure boot get helper

2020-10-14 Thread Chester Lin 
Hi Ard and Mimi,

On Wed, Oct 14, 2020 at 06:40:31PM +0800, Chester Lin wrote:
> Separate the get_sb_mode() from arch/x86 and treat it as a common function
> [rename to efi_get_secureboot_mode] so all EFI-based architectures can
> reuse the same logic.
> 
> Signed-off-by: Chester Lin 
> ---
>  arch/x86/kernel/ima_arch.c | 47 ++
>  drivers/firmware/efi/efi.c | 43 ++
>  include/linux/efi.h|  5 
>  3 files changed, 50 insertions(+), 45 deletions(-)
> 
> diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
> index 7dfb1e808928..ed4623ecda6e 100644
> --- a/arch/x86/kernel/ima_arch.c
> +++ b/arch/x86/kernel/ima_arch.c
> @@ -8,49 +8,6 @@
>  
>  extern struct boot_params boot_params;
>  
> -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);
> -
> - 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", _variable_guid,
> -   NULL, , );
> - if (status == EFI_NOT_FOUND) {
> - pr_info("ima: secureboot mode disabled\n");
> - return efi_secureboot_mode_disabled;
> - }
> -
> - if (status != EFI_SUCCESS) {
> - pr_info("ima: secureboot mode unknown\n");
> - return efi_secureboot_mode_unknown;
> - }
> -
> - size = sizeof(setupmode);
> - status = efi.get_variable(L"SetupMode", _variable_guid,
> -   NULL, , );
> -
> - 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;
> -}
> -
>  bool arch_ima_get_secureboot(void)
>  {
>   static enum efi_secureboot_mode sb_mode;
> @@ -60,7 +17,7 @@ bool arch_ima_get_secureboot(void)
>   sb_mode = boot_params.secure_boot;
>  
>   if (sb_mode == efi_secureboot_mode_unset)
> - sb_mode = get_sb_mode();
> + sb_mode = efi_get_secureboot_mode();
>   initialized = true;
>   }
>  
> @@ -70,7 +27,7 @@ bool arch_ima_get_secureboot(void)
>   return false;
>  }
>  
> -/* secureboot arch rules */
> +/* secure and trusted boot arch rules */
>  static const char * const sb_arch_rules[] = {
>  #if !IS_ENABLED(CONFIG_KEXEC_SIG)
>   "appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 5e5480a0a32d..68ffa6a069c0 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c

I hope you don't mind that I temporarily move the get_sb_mode() to efi
since I'm not sure which place is better. Please let me know if any
suggestions.

Thanks,
Chester

> @@ -1022,3 +1022,46 @@ static int __init register_update_efi_random_seed(void)
>  }
>  late_initcall(register_update_efi_random_seed);
>  #endif
> +
> +enum efi_secureboot_mode efi_get_secureboot_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);
> +
> + 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", _variable_guid,
> +   NULL, , );
> + if (status == EFI_NOT_FOUND) {
> + pr_info("ima: secureboot mode disabled\n");
> + return efi_secureboot_mode_disabled;
> + }
> +
> + if (status != EFI_SUCCESS) {
> + pr_info("ima: secureboot mode unknown\n");
> + return efi_secureboot_mode_unknown;
> + }
> +
> + size = sizeof(setupmode);
> + status = efi.get_variable(L"SetupMode", _variable_guid,
> +   NULL, , );
> +
> + 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;
> +}
> diff --git

[PATCH v2 1/2] efi: add secure boot get helper

2020-10-14 Thread Chester Lin 
Separate the get_sb_mode() from arch/x86 and treat it as a common function
[rename to efi_get_secureboot_mode] so all EFI-based architectures can
reuse the same logic.

Signed-off-by: Chester Lin 
---
 arch/x86/kernel/ima_arch.c | 47 ++
 drivers/firmware/efi/efi.c | 43 ++
 include/linux/efi.h|  5 
 3 files changed, 50 insertions(+), 45 deletions(-)

diff --git a/arch/x86/kernel/ima_arch.c b/arch/x86/kernel/ima_arch.c
index 7dfb1e808928..ed4623ecda6e 100644
--- a/arch/x86/kernel/ima_arch.c
+++ b/arch/x86/kernel/ima_arch.c
@@ -8,49 +8,6 @@
 
 extern struct boot_params boot_params;
 
-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);
-
-   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", _variable_guid,
- NULL, , );
-   if (status == EFI_NOT_FOUND) {
-   pr_info("ima: secureboot mode disabled\n");
-   return efi_secureboot_mode_disabled;
-   }
-
-   if (status != EFI_SUCCESS) {
-   pr_info("ima: secureboot mode unknown\n");
-   return efi_secureboot_mode_unknown;
-   }
-
-   size = sizeof(setupmode);
-   status = efi.get_variable(L"SetupMode", _variable_guid,
- NULL, , );
-
-   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;
-}
-
 bool arch_ima_get_secureboot(void)
 {
static enum efi_secureboot_mode sb_mode;
@@ -60,7 +17,7 @@ bool arch_ima_get_secureboot(void)
sb_mode = boot_params.secure_boot;
 
if (sb_mode == efi_secureboot_mode_unset)
-   sb_mode = get_sb_mode();
+   sb_mode = efi_get_secureboot_mode();
initialized = true;
}
 
@@ -70,7 +27,7 @@ bool arch_ima_get_secureboot(void)
return false;
 }
 
-/* secureboot arch rules */
+/* secure and trusted boot arch rules */
 static const char * const sb_arch_rules[] = {
 #if !IS_ENABLED(CONFIG_KEXEC_SIG)
"appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig",
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 5e5480a0a32d..68ffa6a069c0 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -1022,3 +1022,46 @@ static int __init register_update_efi_random_seed(void)
 }
 late_initcall(register_update_efi_random_seed);
 #endif
+
+enum efi_secureboot_mode efi_get_secureboot_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);
+
+   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", _variable_guid,
+ NULL, , );
+   if (status == EFI_NOT_FOUND) {
+   pr_info("ima: secureboot mode disabled\n");
+   return efi_secureboot_mode_disabled;
+   }
+
+   if (status != EFI_SUCCESS) {
+   pr_info("ima: secureboot mode unknown\n");
+   return efi_secureboot_mode_unknown;
+   }
+
+   size = sizeof(setupmode);
+   status = efi.get_variable(L"SetupMode", _variable_guid,
+ NULL, , );
+
+   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;
+}
diff --git a/include/linux/efi.h b/include/linux/efi.h
index d7c0e73af2b9..a73e5ae04672 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1076,8 +1076,13 @@ static inline int efi_runtime_map_copy(void *buf, size_t 
bufsz)
 
 #ifdef CONFIG_EFI
 extern bool efi_runtime_disabled(void);
+extern enum efi_secureboot_mode efi_get_secureboot_mode(void);
 #else
 static inline bool