efi/runtime-wrappers: Use type safe encapsulation of call arguments

The current code that marshalls the EFI runtime call arguments to hand
them off to a async helper does so in a type unsafe and slightly messy
manner - everything is cast to void* except for some integral types that
are passed by reference and dereferenced on the receiver end.

Let's clean this up a bit, and record the arguments of each runtime
service invocation exactly as they are issued, in a manner that permits
the compiler to check the types of the arguments at both ends.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
This commit is contained in:
Ard Biesheuvel 2023-07-02 15:15:18 +02:00
parent d8ea2ffd01
commit c7c7bce093
2 changed files with 138 additions and 76 deletions

View file

@ -44,20 +44,90 @@
#define __efi_call_virt(f, args...) \
__efi_call_virt_pointer(efi.runtime, f, args)
union efi_rts_args {
struct {
efi_time_t *time;
efi_time_cap_t *capabilities;
} GET_TIME;
struct {
efi_time_t *time;
} SET_TIME;
struct {
efi_bool_t *enabled;
efi_bool_t *pending;
efi_time_t *time;
} GET_WAKEUP_TIME;
struct {
efi_bool_t enable;
efi_time_t *time;
} SET_WAKEUP_TIME;
struct {
efi_char16_t *name;
efi_guid_t *vendor;
u32 *attr;
unsigned long *data_size;
void *data;
} GET_VARIABLE;
struct {
unsigned long *name_size;
efi_char16_t *name;
efi_guid_t *vendor;
} GET_NEXT_VARIABLE;
struct {
efi_char16_t *name;
efi_guid_t *vendor;
u32 attr;
unsigned long data_size;
void *data;
} SET_VARIABLE;
struct {
u32 attr;
u64 *storage_space;
u64 *remaining_space;
u64 *max_variable_size;
} QUERY_VARIABLE_INFO;
struct {
u32 *high_count;
} GET_NEXT_HIGH_MONO_COUNT;
struct {
efi_capsule_header_t **capsules;
unsigned long count;
unsigned long sg_list;
} UPDATE_CAPSULE;
struct {
efi_capsule_header_t **capsules;
unsigned long count;
u64 *max_size;
int *reset_type;
} QUERY_CAPSULE_CAPS;
};
struct efi_runtime_work efi_rts_work;
/*
* efi_queue_work: Queue efi_runtime_service() and wait until it's done
* @rts: efi_runtime_service() function identifier
* @rts_arg<1-5>: efi_runtime_service() function arguments
* efi_queue_work: Queue EFI runtime service call and wait for completion
* @_rts: EFI runtime service function identifier
* @_args: Arguments to pass to the EFI runtime service
*
* Accesses to efi_runtime_services() are serialized by a binary
* semaphore (efi_runtime_lock) and caller waits until the work is
* finished, hence _only_ one work is queued at a time and the caller
* thread waits for completion.
*/
#define efi_queue_work(_rts, _arg1, _arg2, _arg3, _arg4, _arg5) \
#define efi_queue_work(_rts, _args...) \
({ \
efi_rts_work.efi_rts_id = EFI_ ## _rts; \
efi_rts_work.args = &(union efi_rts_args){ ._rts = { _args }}; \
efi_rts_work.status = EFI_ABORTED; \
\
if (!efi_enabled(EFI_RUNTIME_SERVICES)) { \
@ -68,12 +138,6 @@ struct efi_runtime_work efi_rts_work;
\
init_completion(&efi_rts_work.efi_rts_comp); \
INIT_WORK(&efi_rts_work.work, efi_call_rts); \
efi_rts_work.arg1 = _arg1; \
efi_rts_work.arg2 = _arg2; \
efi_rts_work.arg3 = _arg3; \
efi_rts_work.arg4 = _arg4; \
efi_rts_work.arg5 = _arg5; \
efi_rts_work.efi_rts_id = _rts; \
\
/* \
* queue_work() returns 0 if work was already on queue, \
@ -170,73 +234,78 @@ extern struct semaphore __efi_uv_runtime_lock __alias(efi_runtime_lock);
/*
* Calls the appropriate efi_runtime_service() with the appropriate
* arguments.
*
* Semantics followed by efi_call_rts() to understand efi_runtime_work:
* 1. If argument was a pointer, recast it from void pointer to original
* pointer type.
* 2. If argument was a value, recast it from void pointer to original
* pointer type and dereference it.
*/
static void efi_call_rts(struct work_struct *work)
{
void *arg1, *arg2, *arg3, *arg4, *arg5;
const union efi_rts_args *args = efi_rts_work.args;
efi_status_t status = EFI_NOT_FOUND;
arg1 = efi_rts_work.arg1;
arg2 = efi_rts_work.arg2;
arg3 = efi_rts_work.arg3;
arg4 = efi_rts_work.arg4;
arg5 = efi_rts_work.arg5;
switch (efi_rts_work.efi_rts_id) {
case EFI_GET_TIME:
status = efi_call_virt(get_time, (efi_time_t *)arg1,
(efi_time_cap_t *)arg2);
status = efi_call_virt(get_time,
args->GET_TIME.time,
args->GET_TIME.capabilities);
break;
case EFI_SET_TIME:
status = efi_call_virt(set_time, (efi_time_t *)arg1);
status = efi_call_virt(set_time,
args->SET_TIME.time);
break;
case EFI_GET_WAKEUP_TIME:
status = efi_call_virt(get_wakeup_time, (efi_bool_t *)arg1,
(efi_bool_t *)arg2, (efi_time_t *)arg3);
status = efi_call_virt(get_wakeup_time,
args->GET_WAKEUP_TIME.enabled,
args->GET_WAKEUP_TIME.pending,
args->GET_WAKEUP_TIME.time);
break;
case EFI_SET_WAKEUP_TIME:
status = efi_call_virt(set_wakeup_time, *(efi_bool_t *)arg1,
(efi_time_t *)arg2);
status = efi_call_virt(set_wakeup_time,
args->SET_WAKEUP_TIME.enable,
args->SET_WAKEUP_TIME.time);
break;
case EFI_GET_VARIABLE:
status = efi_call_virt(get_variable, (efi_char16_t *)arg1,
(efi_guid_t *)arg2, (u32 *)arg3,
(unsigned long *)arg4, (void *)arg5);
status = efi_call_virt(get_variable,
args->GET_VARIABLE.name,
args->GET_VARIABLE.vendor,
args->GET_VARIABLE.attr,
args->GET_VARIABLE.data_size,
args->GET_VARIABLE.data);
break;
case EFI_GET_NEXT_VARIABLE:
status = efi_call_virt(get_next_variable, (unsigned long *)arg1,
(efi_char16_t *)arg2,
(efi_guid_t *)arg3);
status = efi_call_virt(get_next_variable,
args->GET_NEXT_VARIABLE.name_size,
args->GET_NEXT_VARIABLE.name,
args->GET_NEXT_VARIABLE.vendor);
break;
case EFI_SET_VARIABLE:
status = efi_call_virt(set_variable, (efi_char16_t *)arg1,
(efi_guid_t *)arg2, *(u32 *)arg3,
*(unsigned long *)arg4, (void *)arg5);
status = efi_call_virt(set_variable,
args->SET_VARIABLE.name,
args->SET_VARIABLE.vendor,
args->SET_VARIABLE.attr,
args->SET_VARIABLE.data_size,
args->SET_VARIABLE.data);
break;
case EFI_QUERY_VARIABLE_INFO:
status = efi_call_virt(query_variable_info, *(u32 *)arg1,
(u64 *)arg2, (u64 *)arg3, (u64 *)arg4);
status = efi_call_virt(query_variable_info,
args->QUERY_VARIABLE_INFO.attr,
args->QUERY_VARIABLE_INFO.storage_space,
args->QUERY_VARIABLE_INFO.remaining_space,
args->QUERY_VARIABLE_INFO.max_variable_size);
break;
case EFI_GET_NEXT_HIGH_MONO_COUNT:
status = efi_call_virt(get_next_high_mono_count, (u32 *)arg1);
status = efi_call_virt(get_next_high_mono_count,
args->GET_NEXT_HIGH_MONO_COUNT.high_count);
break;
case EFI_UPDATE_CAPSULE:
status = efi_call_virt(update_capsule,
(efi_capsule_header_t **)arg1,
*(unsigned long *)arg2,
*(unsigned long *)arg3);
args->UPDATE_CAPSULE.capsules,
args->UPDATE_CAPSULE.count,
args->UPDATE_CAPSULE.sg_list);
break;
case EFI_QUERY_CAPSULE_CAPS:
status = efi_call_virt(query_capsule_caps,
(efi_capsule_header_t **)arg1,
*(unsigned long *)arg2, (u64 *)arg3,
(int *)arg4);
args->QUERY_CAPSULE_CAPS.capsules,
args->QUERY_CAPSULE_CAPS.count,
args->QUERY_CAPSULE_CAPS.max_size,
args->QUERY_CAPSULE_CAPS.reset_type);
break;
default:
/*
@ -256,7 +325,7 @@ static efi_status_t virt_efi_get_time(efi_time_t *tm, efi_time_cap_t *tc)
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_GET_TIME, tm, tc, NULL, NULL, NULL);
status = efi_queue_work(GET_TIME, tm, tc);
up(&efi_runtime_lock);
return status;
}
@ -267,7 +336,7 @@ static efi_status_t virt_efi_set_time(efi_time_t *tm)
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_SET_TIME, tm, NULL, NULL, NULL, NULL);
status = efi_queue_work(SET_TIME, tm);
up(&efi_runtime_lock);
return status;
}
@ -280,8 +349,7 @@ static efi_status_t virt_efi_get_wakeup_time(efi_bool_t *enabled,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_GET_WAKEUP_TIME, enabled, pending, tm, NULL,
NULL);
status = efi_queue_work(GET_WAKEUP_TIME, enabled, pending, tm);
up(&efi_runtime_lock);
return status;
}
@ -292,8 +360,7 @@ static efi_status_t virt_efi_set_wakeup_time(efi_bool_t enabled, efi_time_t *tm)
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_SET_WAKEUP_TIME, &enabled, tm, NULL, NULL,
NULL);
status = efi_queue_work(SET_WAKEUP_TIME, enabled, tm);
up(&efi_runtime_lock);
return status;
}
@ -308,7 +375,7 @@ static efi_status_t virt_efi_get_variable(efi_char16_t *name,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_GET_VARIABLE, name, vendor, attr, data_size,
status = efi_queue_work(GET_VARIABLE, name, vendor, attr, data_size,
data);
up(&efi_runtime_lock);
return status;
@ -322,8 +389,7 @@ static efi_status_t virt_efi_get_next_variable(unsigned long *name_size,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_GET_NEXT_VARIABLE, name_size, name, vendor,
NULL, NULL);
status = efi_queue_work(GET_NEXT_VARIABLE, name_size, name, vendor);
up(&efi_runtime_lock);
return status;
}
@ -338,7 +404,7 @@ static efi_status_t virt_efi_set_variable(efi_char16_t *name,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_SET_VARIABLE, name, vendor, &attr, &data_size,
status = efi_queue_work(SET_VARIABLE, name, vendor, attr, data_size,
data);
up(&efi_runtime_lock);
return status;
@ -373,8 +439,8 @@ static efi_status_t virt_efi_query_variable_info(u32 attr,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_QUERY_VARIABLE_INFO, &attr, storage_space,
remaining_space, max_variable_size, NULL);
status = efi_queue_work(QUERY_VARIABLE_INFO, attr, storage_space,
remaining_space, max_variable_size);
up(&efi_runtime_lock);
return status;
}
@ -405,8 +471,7 @@ static efi_status_t virt_efi_get_next_high_mono_count(u32 *count)
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_GET_NEXT_HIGH_MONO_COUNT, count, NULL, NULL,
NULL, NULL);
status = efi_queue_work(GET_NEXT_HIGH_MONO_COUNT, count);
up(&efi_runtime_lock);
return status;
}
@ -437,8 +502,7 @@ static efi_status_t virt_efi_update_capsule(efi_capsule_header_t **capsules,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_UPDATE_CAPSULE, capsules, &count, &sg_list,
NULL, NULL);
status = efi_queue_work(UPDATE_CAPSULE, capsules, count, sg_list);
up(&efi_runtime_lock);
return status;
}
@ -455,8 +519,8 @@ static efi_status_t virt_efi_query_capsule_caps(efi_capsule_header_t **capsules,
if (down_interruptible(&efi_runtime_lock))
return EFI_ABORTED;
status = efi_queue_work(EFI_QUERY_CAPSULE_CAPS, capsules, &count,
max_size, reset_type, NULL);
status = efi_queue_work(QUERY_CAPSULE_CAPS, capsules, count,
max_size, reset_type);
up(&efi_runtime_lock);
return status;
}

View file

@ -1264,23 +1264,21 @@ enum efi_rts_ids {
EFI_QUERY_CAPSULE_CAPS,
};
union efi_rts_args;
/*
* efi_runtime_work: Details of EFI Runtime Service work
* @arg<1-5>: EFI Runtime Service function arguments
* @args: Pointer to union describing the arguments
* @status: Status of executing EFI Runtime Service
* @efi_rts_id: EFI Runtime Service function identifier
* @efi_rts_comp: Struct used for handling completions
*/
struct efi_runtime_work {
void *arg1;
void *arg2;
void *arg3;
void *arg4;
void *arg5;
efi_status_t status;
struct work_struct work;
enum efi_rts_ids efi_rts_id;
struct completion efi_rts_comp;
union efi_rts_args *args;
efi_status_t status;
struct work_struct work;
enum efi_rts_ids efi_rts_id;
struct completion efi_rts_comp;
};
extern struct efi_runtime_work efi_rts_work;