This function can be used to transfer EFI status code to string
for printing out debug message. Using this function can improve
the readability of log.
Cc: Ard Biesheuvel <[email protected]>
Cc: Kees Cook <[email protected]>
Cc: Anton Vorontsov <[email protected]>
Cc: Colin Cross <[email protected]>
Cc: Tony Luck <[email protected]>
Signed-off-by: "Lee, Chun-Yi" <[email protected]>
---
include/linux/efi.h | 28 ++++++++++++++++++++++++++++
1 file changed, 28 insertions(+)
diff --git a/include/linux/efi.h b/include/linux/efi.h
index 54357a258b35..a43cb0dc37af 100644
--- a/include/linux/efi.h
+++ b/include/linux/efi.h
@@ -1768,4 +1768,32 @@ struct linux_efi_memreserve {
#define EFI_MEMRESERVE_COUNT(size) (((size) - sizeof(struct linux_efi_memreserve)) \
/ sizeof(((struct linux_efi_memreserve *)0)->entry[0]))
+#define EFI_STATUS_STR(_status) \
+case EFI_##_status: \
+ return "EFI_" __stringify(_status);
+
+static inline char *
+efi_status_to_str(efi_status_t status)
+{
+ switch (status) {
+ EFI_STATUS_STR(SUCCESS)
+ EFI_STATUS_STR(LOAD_ERROR)
+ EFI_STATUS_STR(INVALID_PARAMETER)
+ EFI_STATUS_STR(UNSUPPORTED)
+ EFI_STATUS_STR(BAD_BUFFER_SIZE)
+ EFI_STATUS_STR(BUFFER_TOO_SMALL)
+ EFI_STATUS_STR(NOT_READY)
+ EFI_STATUS_STR(DEVICE_ERROR)
+ EFI_STATUS_STR(WRITE_PROTECTED)
+ EFI_STATUS_STR(OUT_OF_RESOURCES)
+ EFI_STATUS_STR(NOT_FOUND)
+ EFI_STATUS_STR(ABORTED)
+ EFI_STATUS_STR(SECURITY_VIOLATION)
+ default:
+ pr_warn("Unknown efi status: 0x%lx", status);
+ }
+
+ return "Unknown efi status";
+}
+
#endif /* _LINUX_EFI_H */
--
2.16.4
When loading certificates list from UEFI variable, the original error
message direct shows the efi status code from UEFI firmware. It looks
ugly:
[ 2.335031] Couldn't get size: 0x800000000000000e
[ 2.335032] Couldn't get UEFI MokListRT
[ 2.339985] Couldn't get size: 0x800000000000000e
[ 2.339987] Couldn't get UEFI dbx list
So, this patch shows the status string instead of status code.
On the other hand, the error message of EFI_NOT_FOUND
(0x800000000000000e) doesn't need to be exposed because kernel
already prints "Couldn't get UEFI..." message. This patch also
filtered out it.
Link: https://forums.opensuse.org/showthread.php/535324-MODSIGN-Couldn-t-get-UEFI-db-list?p=2897516#post2897516
Cc: James Morris <[email protected]>
Cc: Serge E. Hallyn" <[email protected]>
Cc: David Howells <[email protected]>
Cc: Nayna Jain <[email protected]>
Cc: Josh Boyer <[email protected]>
Cc: Mimi Zohar <[email protected]>
Signed-off-by: "Lee, Chun-Yi" <[email protected]>
---
security/integrity/platform_certs/load_uefi.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
index 81b19c52832b..fe261166621f 100644
--- a/security/integrity/platform_certs/load_uefi.c
+++ b/security/integrity/platform_certs/load_uefi.c
@@ -48,7 +48,9 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
if (status != EFI_BUFFER_TOO_SMALL) {
- pr_err("Couldn't get size: 0x%lx\n", status);
+ if (status != EFI_NOT_FOUND)
+ pr_err("Couldn't get size: %s\n",
+ efi_status_to_str(status));
return NULL;
}
@@ -59,7 +61,8 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
status = efi.get_variable(name, guid, NULL, &lsize, db);
if (status != EFI_SUCCESS) {
kfree(db);
- pr_err("Error reading db var: 0x%lx\n", status);
+ pr_err("Error reading db var: %s\n",
+ efi_status_to_str(status));
return NULL;
}
--
2.16.4
On Fri, 22 Mar 2019 at 11:34, Lee, Chun-Yi <[email protected]> wrote:
>
> When loading certificates list from UEFI variable, the original error
> message direct shows the efi status code from UEFI firmware. It looks
> ugly:
>
> [ 2.335031] Couldn't get size: 0x800000000000000e
> [ 2.335032] Couldn't get UEFI MokListRT
> [ 2.339985] Couldn't get size: 0x800000000000000e
> [ 2.339987] Couldn't get UEFI dbx list
>
Why is it an error in the first place if these EFI variables do not exist?
> So, this patch shows the status string instead of status code.
>
> On the other hand, the error message of EFI_NOT_FOUND
> (0x800000000000000e) doesn't need to be exposed because kernel
> already prints "Couldn't get UEFI..." message. This patch also
> filtered out it.
>
> Link: https://forums.opensuse.org/showthread.php/535324-MODSIGN-Couldn-t-get-UEFI-db-list?p=2897516#post2897516
> Cc: James Morris <[email protected]>
> Cc: Serge E. Hallyn" <[email protected]>
> Cc: David Howells <[email protected]>
> Cc: Nayna Jain <[email protected]>
> Cc: Josh Boyer <[email protected]>
> Cc: Mimi Zohar <[email protected]>
> Signed-off-by: "Lee, Chun-Yi" <[email protected]>
> ---
> security/integrity/platform_certs/load_uefi.c | 7 +++++--
> 1 file changed, 5 insertions(+), 2 deletions(-)
>
> diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
> index 81b19c52832b..fe261166621f 100644
> --- a/security/integrity/platform_certs/load_uefi.c
> +++ b/security/integrity/platform_certs/load_uefi.c
> @@ -48,7 +48,9 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
>
> status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
> if (status != EFI_BUFFER_TOO_SMALL) {
> - pr_err("Couldn't get size: 0x%lx\n", status);
> + if (status != EFI_NOT_FOUND)
> + pr_err("Couldn't get size: %s\n",
> + efi_status_to_str(status));
> return NULL;
> }
>
> @@ -59,7 +61,8 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
> status = efi.get_variable(name, guid, NULL, &lsize, db);
> if (status != EFI_SUCCESS) {
> kfree(db);
> - pr_err("Error reading db var: 0x%lx\n", status);
> + pr_err("Error reading db var: %s\n",
> + efi_status_to_str(status));
> return NULL;
> }
>
> --
> 2.16.4
>
Hi Ard,
On Fri, Mar 22, 2019 at 03:27:46PM +0100, Ard Biesheuvel wrote:
> On Fri, 22 Mar 2019 at 11:34, Lee, Chun-Yi <[email protected]> wrote:
> >
> > When loading certificates list from UEFI variable, the original error
> > message direct shows the efi status code from UEFI firmware. It looks
> > ugly:
> >
> > [ 2.335031] Couldn't get size: 0x800000000000000e
> > [ 2.335032] Couldn't get UEFI MokListRT
> > [ 2.339985] Couldn't get size: 0x800000000000000e
> > [ 2.339987] Couldn't get UEFI dbx list
> >
>
> Why is it an error in the first place if these EFI variables do not exist?
>
As you said, the error message should only be exposed when
these EFI variables exist. I will change it in next version of
my patch.
Thanks a lot!
Joey Lee
>
> > So, this patch shows the status string instead of status code.
> >
> > On the other hand, the error message of EFI_NOT_FOUND
> > (0x800000000000000e) doesn't need to be exposed because kernel
> > already prints "Couldn't get UEFI..." message. This patch also
> > filtered out it.
> >
> > Link: https://forums.opensuse.org/showthread.php/535324-MODSIGN-Couldn-t-get-UEFI-db-list?p=2897516#post2897516
> > Cc: James Morris <[email protected]>
> > Cc: Serge E. Hallyn" <[email protected]>
> > Cc: David Howells <[email protected]>
> > Cc: Nayna Jain <[email protected]>
> > Cc: Josh Boyer <[email protected]>
> > Cc: Mimi Zohar <[email protected]>
> > Signed-off-by: "Lee, Chun-Yi" <[email protected]>
> > ---
> > security/integrity/platform_certs/load_uefi.c | 7 +++++--
> > 1 file changed, 5 insertions(+), 2 deletions(-)
> >
> > diff --git a/security/integrity/platform_certs/load_uefi.c b/security/integrity/platform_certs/load_uefi.c
> > index 81b19c52832b..fe261166621f 100644
> > --- a/security/integrity/platform_certs/load_uefi.c
> > +++ b/security/integrity/platform_certs/load_uefi.c
> > @@ -48,7 +48,9 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
> >
> > status = efi.get_variable(name, guid, NULL, &lsize, &tmpdb);
> > if (status != EFI_BUFFER_TOO_SMALL) {
> > - pr_err("Couldn't get size: 0x%lx\n", status);
> > + if (status != EFI_NOT_FOUND)
> > + pr_err("Couldn't get size: %s\n",
> > + efi_status_to_str(status));
> > return NULL;
> > }
> >
> > @@ -59,7 +61,8 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid,
> > status = efi.get_variable(name, guid, NULL, &lsize, db);
> > if (status != EFI_SUCCESS) {
> > kfree(db);
> > - pr_err("Error reading db var: 0x%lx\n", status);
> > + pr_err("Error reading db var: %s\n",
> > + efi_status_to_str(status));
> > return NULL;
> > }
> >
> > --
> > 2.16.4
> >