@ -31,9 +31,8 @@
/* Structure to store information about an outstanding dispatch */
typedef struct sdei_dispatch_context {
sdei_ev_map_t * map ;
unsigned int sec_state ;
unsigned int intr_raw ;
uint64_t x [ SDEI_SAVED_GPREGS ] ;
struct jmpbuf * dispatch_jmp ;
/* Exception state registers */
uint64_t elr_el3 ;
@ -153,8 +152,8 @@ static sdei_dispatch_context_t *get_outstanding_dispatch(void)
return & state - > dispatch_stack [ state - > stack_top - 1 ] ;
}
static void save_event_ctx ( sdei_ev_map_t * map , void * tgt_ctx , int sec_state ,
unsigned int intr_raw )
static sdei_dispatch_context_t * save_event_ctx ( sdei_ev_map_t * map ,
void * tgt_ctx )
{
sdei_dispatch_context_t * disp_ctx ;
gp_regs_t * tgt_gpregs ;
@ -166,26 +165,14 @@ static void save_event_ctx(sdei_ev_map_t *map, void *tgt_ctx, int sec_state,
disp_ctx = push_dispatch ( ) ;
assert ( disp_ctx ) ;
disp_ctx - > sec_state = sec_state ;
disp_ctx - > map = map ;
disp_ctx - > intr_raw = intr_raw ;
/* Save general purpose and exception registers */
memcpy ( disp_ctx - > x , tgt_gpregs , sizeof ( disp_ctx - > x ) ) ;
disp_ctx - > spsr_el3 = read_ctx_reg ( tgt_el3 , CTX_SPSR_EL3 ) ;
disp_ctx - > elr_el3 = read_ctx_reg ( tgt_el3 , CTX_ELR_EL3 ) ;
# if DYNAMIC_WORKAROUND_CVE_2018_3639
cve_2018_3639_t * tgt_cve_2018_3639 ;
tgt_cve_2018_3639 = get_cve_2018_3639_ctx ( tgt_ctx ) ;
/* Save CVE-2018-3639 mitigation state */
disp_ctx - > disable_cve_2018_3639 = read_ctx_reg ( tgt_cve_2018_3639 ,
CTX_CVE_2018_3639_DISABLE ) ;
/* Force SDEI handler to execute with mitigation enabled by default */
write_ctx_reg ( tgt_cve_2018_3639 , CTX_CVE_2018_3639_DISABLE , 0 ) ;
# endif
return disp_ctx ;
}
static void restore_event_ctx ( sdei_dispatch_context_t * disp_ctx , void * tgt_ctx )
@ -249,13 +236,12 @@ static cpu_context_t *restore_and_resume_ns_context(void)
* SDEI client .
*/
static void setup_ns_dispatch ( sdei_ev_map_t * map , sdei_entry_t * se ,
cpu_context_t * ctx , int sec_state_to_resume ,
unsigned int intr_raw )
cpu_context_t * ctx , struct jmpbuf * dispatch_jmp )
{
el3_state_t * el3_ctx = get_el3state_ctx ( ctx ) ;
sdei_dispatch_context_t * disp_ctx ;
/* Push the event and context */
save_event_ctx ( map , ctx , sec_state_to_resume , intr_raw ) ;
disp_ctx = save_event_ctx ( map , ctx ) ;
/*
* Setup handler arguments :
@ -267,8 +253,8 @@ static void setup_ns_dispatch(sdei_ev_map_t *map, sdei_entry_t *se,
*/
SMC_SET_GP ( ctx , CTX_GPREG_X0 , map - > ev_num ) ;
SMC_SET_GP ( ctx , CTX_GPREG_X1 , se - > arg ) ;
SMC_SET_GP ( ctx , CTX_GPREG_X2 , read_ctx_reg ( el3_ctx , CTX_ELR_EL3 ) ) ;
SMC_SET_GP ( ctx , CTX_GPREG_X3 , read_ctx_reg ( el3_ctx , CTX_SPSR_EL3 ) ) ;
SMC_SET_GP ( ctx , CTX_GPREG_X2 , disp_ctx - > elr_el3 ) ;
SMC_SET_GP ( ctx , CTX_GPREG_X3 , disp_ctx - > spsr_el3 ) ;
/*
* Prepare for ERET :
@ -279,6 +265,20 @@ static void setup_ns_dispatch(sdei_ev_map_t *map, sdei_entry_t *se,
cm_set_elr_spsr_el3 ( NON_SECURE , ( uintptr_t ) se - > ep ,
SPSR_64 ( sdei_client_el ( ) , MODE_SP_ELX ,
DISABLE_ALL_EXCEPTIONS ) ) ;
# if DYNAMIC_WORKAROUND_CVE_2018_3639
cve_2018_3639_t * tgt_cve_2018_3639 ;
tgt_cve_2018_3639 = get_cve_2018_3639_ctx ( ctx ) ;
/* Save CVE-2018-3639 mitigation state */
disp_ctx - > disable_cve_2018_3639 = read_ctx_reg ( tgt_cve_2018_3639 ,
CTX_CVE_2018_3639_DISABLE ) ;
/* Force SDEI handler to execute with mitigation enabled by default */
write_ctx_reg ( tgt_cve_2018_3639 , CTX_CVE_2018_3639_DISABLE , 0 ) ;
# endif
disp_ctx - > dispatch_jmp = dispatch_jmp ;
}
/* Handle a triggered SDEI interrupt while events were masked on this PE */
@ -348,6 +348,7 @@ int sdei_intr_handler(uint32_t intr_raw, uint32_t flags, void *handle,
unsigned int sec_state ;
sdei_cpu_state_t * state ;
uint32_t intr ;
struct jmpbuf dispatch_jmp ;
/*
* To handle an event , the following conditions must be true :
@ -481,29 +482,60 @@ int sdei_intr_handler(uint32_t intr_raw, uint32_t flags, void *handle,
ctx = restore_and_resume_ns_context ( ) ;
}
setup_ns_dispatch ( map , se , ctx , sec_state , intr_raw ) ;
/* Synchronously dispatch event */
setup_ns_dispatch ( map , se , ctx , & dispatch_jmp ) ;
begin_sdei_synchronous_dispatch ( & dispatch_jmp ) ;
/*
* We reach here when client completes the event .
*
* If the cause of dispatch originally interrupted the Secure world , and
* if Non - secure world wasn ' t allowed to preempt Secure execution ,
* resume Secure .
*
* No need to save the Non - secure context ahead of a world switch : the
* Non - secure context was fully saved before dispatch , and has been
* returned to its pre - dispatch state .
*/
if ( ( sec_state = = SECURE ) & & ( ehf_is_ns_preemption_allowed ( ) = = 0 ) )
restore_and_resume_secure_context ( ) ;
/*
* End of interrupt is done in sdei_event_complete , when the client
* signals completion .
* The event was dispatched after receiving SDEI interrupt . With
* the event handling completed , EOI the corresponding
* interrupt .
*/
if ( ( map - > ev_num ! = SDEI_EVENT_0 ) & & is_map_bound ( map ) ) {
ERROR ( " Invalid SDEI mapping: ev=%u \n " , map - > ev_num ) ;
panic ( ) ;
}
plat_ic_end_of_interrupt ( intr_raw ) ;
if ( is_event_shared ( map ) )
sdei_map_unlock ( map ) ;
return 0 ;
}
/* Explicitly dispatch the given SDEI event */
int sdei_dispatch_event ( int ev_num , unsigned int preempted_sec_state )
/*
* Explicitly dispatch the given SDEI event .
*
* When calling this API , the caller must be prepared for the SDEI dispatcher to
* restore and make Non - secure context as active . This call returns only after
* the client has completed the dispatch . Then , the Non - secure context will be
* active , and the following ERET will return to Non - secure .
*
* Should the caller require re - entry to Secure , it must restore the Secure
* context and program registers for ERET .
*/
int sdei_dispatch_event ( int ev_num )
{
sdei_entry_t * se ;
sdei_ev_map_t * map ;
cpu_context_t * ctx ;
cpu_context_t * ns_ ctx;
sdei_dispatch_context_t * disp_ctx ;
sdei_cpu_state_t * state ;
/* Validate preempted security state */
if ( ( preempted_sec_state ! = SECURE ) & &
( preempted_sec_state ! = NON_SECURE ) ) {
return - 1 ;
}
struct jmpbuf dispatch_jmp ;
/* Can't dispatch if events are masked on this PE */
state = sdei_get_this_pe_state ( ) ;
@ -549,21 +581,31 @@ int sdei_dispatch_event(int ev_num, unsigned int preempted_sec_state)
ehf_activate_priority ( sdei_event_priority ( map ) ) ;
/*
* We assume the current context is SECURE , and that it ' s already been
* sa ved .
* Prepare for NS dispatch by restoring the Non - secure context and
* marking that as acti ve.
*/
ctx = restore_and_resume_ns_context ( ) ;
ns_ctx = restore_and_resume_ns_context ( ) ;
/* Dispatch event synchronously */
setup_ns_dispatch ( map , se , ns_ctx , & dispatch_jmp ) ;
begin_sdei_synchronous_dispatch ( & dispatch_jmp ) ;
/*
* The caller has effectively terminated execution . Record to resume the
* preempted context later when the event completes or
* complete - and - resumes .
* We reach here when client completes the event .
*
* Deactivate the priority level that was activated at the time of
* explicit dispatch .
*/
setup_ns_dispatch ( map , se , ctx , preempted_sec_state , 0 ) ;
ehf_deactivate_priority ( sdei_event_priority ( map ) ) ;
return 0 ;
}
static void end_sdei_explicit_dispatch ( struct jmpbuf * buffer )
{
longjmp ( buffer ) ;
}
int sdei_event_complete ( int resume , uint64_t pc )
{
sdei_dispatch_context_t * disp_ctx ;
@ -636,38 +678,8 @@ int sdei_event_complete(int resume, uint64_t pc)
}
}
/*
* If the cause of dispatch originally interrupted the Secure world , and
* if Non - secure world wasn ' t allowed to preempt Secure execution ,
* resume Secure .
*
* No need to save the Non - secure context ahead of a world switch : the
* Non - secure context was fully saved before dispatch , and has been
* returned to its pre - dispatch state .
*/
if ( ( disp_ctx - > sec_state = = SECURE ) & &
( ehf_is_ns_preemption_allowed ( ) = = 0 ) ) {
restore_and_resume_secure_context ( ) ;
}
if ( ( map - > ev_num = = SDEI_EVENT_0 ) | | is_map_bound ( map ) ) {
/*
* The event was dispatched after receiving SDEI interrupt . With
* the event handling completed , EOI the corresponding
* interrupt .
*/
plat_ic_end_of_interrupt ( disp_ctx - > intr_raw ) ;
} else {
/*
* An unbound event must have been dispatched explicitly .
* Deactivate the priority level that was activated at the time
* of explicit dispatch .
*/
ehf_deactivate_priority ( sdei_event_priority ( map ) ) ;
}
if ( is_event_shared ( map ) )
sdei_map_unlock ( map ) ;
/* End the outstanding dispatch */
end_sdei_explicit_dispatch ( disp_ctx - > dispatch_jmp ) ;
return 0 ;
}
Jeenu Viswambharan
7 years ago
