From: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
To handle all arch-specific peculiarities when calling an EFI protocol
function, a wrapper efi_call_proto() exists on all relevant architectures.
On arm/arm64, this is merely a plain function call. On x86, a special EFI
entry stub needs to be used, however, as the calling convention differs.
To make the efi/random stub arch-independent, use efi_call_proto()
instead of the existing non-portable calls to the EFI get_rng protocol
function. This also requires the addition of some typedefs.
Signed-off-by: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
drivers/firmware/efi/libstub/random.c | 23 ++++++++++++++++++-----
1 file changed, 18 insertions(+), 5 deletions(-)
diff --git a/drivers/firmware/efi/libstub/random.c b/drivers/firmware/efi/libstub/random.c
index b4b1d1dcb5fd..53f1466f7de6 100644
--- a/drivers/firmware/efi/libstub/random.c
+++ b/drivers/firmware/efi/libstub/random.c
@@ -9,6 +9,18 @@
#include "efistub.h"
+typedef struct efi_rng_protocol efi_rng_protocol_t;
+
+typedef struct {
+ u32 get_info;
+ u32 get_rng;
+} efi_rng_protocol_32_t;
+
+typedef struct {
+ u64 get_info;
+ u64 get_rng;
+} efi_rng_protocol_64_t;
+
struct efi_rng_protocol {
efi_status_t (*get_info)(struct efi_rng_protocol *,
unsigned long *, efi_guid_t *);
@@ -28,7 +40,7 @@ efi_status_t efi_get_random_bytes(efi_system_table_t *sys_table_arg,
if (status != EFI_SUCCESS)
return status;
- return rng->get_rng(rng, NULL, size, out);
+ return efi_call_proto(efi_rng_protocol, get_rng, rng, NULL, size, out);
}
/*
@@ -161,15 +173,16 @@ efi_status_t efi_random_get_seed(efi_system_table_t *sys_table_arg)
if (status != EFI_SUCCESS)
return status;
- status = rng->get_rng(rng, &rng_algo_raw, EFI_RANDOM_SEED_SIZE,
- seed->bits);
+ status = efi_call_proto(efi_rng_protocol, get_rng, rng, &rng_algo_raw,
+ EFI_RANDOM_SEED_SIZE, seed->bits);
+
if (status == EFI_UNSUPPORTED)
/*
* Use whatever algorithm we have available if the raw algorithm
* is not implemented.
*/
- status = rng->get_rng(rng, NULL, EFI_RANDOM_SEED_SIZE,
- seed->bits);
+ status = efi_call_proto(efi_rng_protocol, get_rng, rng, NULL,
+ EFI_RANDOM_SEED_SIZE, seed->bits);
if (status != EFI_SUCCESS)
goto err_freepool;
--
2.17.1
