[U-Boot] efi_loader: fix events

Heinrich Schuchardt xypron.glpk at gmx.de
Thu Sep 14 20:51:05 UTC 2017


On 09/12/2017 06:35 PM, Rob Clark wrote:
> An event can be created with type==0, Shell.efi does this for an event
> that is set when Ctrl-C is typed.  So our current approach of having a
> fixed set of timer slots, and determining which slots are unused by
> type==0 doesn't work so well.  But we don't have any particularly good
> reason to have a fixed table of events, so just dynamically allocate
> them and keep a list.
> 
> Also fixes an incorrect implementation of CheckEvent() which was (a)
> incorrectly returning an error if type==0, and (b) didn't handle the
> case of an unsignaled event with a notify callback.
> 
> With these fixes (plus implementation of SIMPLE_TEXT_INPUT_EX protocol),
> Ctrl-C works in Shell.efi.
> 
> Signed-off-by: Rob Clark <robdclark at gmail.com>
> ---
>  include/efi_loader.h          |   1 +
>  lib/efi_loader/efi_boottime.c | 167 +++++++++++++++++++-----------------------
>  2 files changed, 78 insertions(+), 90 deletions(-)
> 
> diff --git a/include/efi_loader.h b/include/efi_loader.h
> index 291ea86568..9dc1ea4b88 100644
> --- a/include/efi_loader.h
> +++ b/include/efi_loader.h
> @@ -149,6 +149,7 @@ struct efi_event {
>  	u64 trigger_time;
>  	enum efi_timer_delay trigger_type;
>  	int signaled;
> +	struct list_head link;

Wouldn't we normally put this first in the structure?

>  };
>  
>  
> diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
> index 5db8ea9090..be3c34b9e0 100644
> --- a/lib/efi_loader/efi_boottime.c
> +++ b/lib/efi_loader/efi_boottime.c
> @@ -255,11 +255,7 @@ static efi_status_t efi_create_handle(void **handle)
>  	return r;
>  }
>  
> -/*
> - * Our event capabilities are very limited. Only a small limited
> - * number of events is allowed to coexist.
> - */
> -static struct efi_event efi_events[16];
> +static LIST_HEAD(efi_events);
>  
>  efi_status_t efi_create_event(uint32_t type, UINTN notify_tpl,
>  			      void (EFIAPI *notify_function) (
> @@ -267,7 +263,7 @@ efi_status_t efi_create_event(uint32_t type, UINTN notify_tpl,
>  					void *context),
>  			      void *notify_context, struct efi_event **event)
>  {
> -	int i;
> +	struct efi_event *evt;
>  
>  	if (event == NULL)
>  		return EFI_INVALID_PARAMETER;
> @@ -279,20 +275,23 @@ efi_status_t efi_create_event(uint32_t type, UINTN notify_tpl,
>  	    notify_function == NULL)
>  		return EFI_INVALID_PARAMETER;
>  
> -	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
> -		if (efi_events[i].type)
> -			continue;
> -		efi_events[i].type = type;
> -		efi_events[i].notify_tpl = notify_tpl;
> -		efi_events[i].notify_function = notify_function;
> -		efi_events[i].notify_context = notify_context;
> -		/* Disable timers on bootup */
> -		efi_events[i].trigger_next = -1ULL;
> -		efi_events[i].signaled = 0;
> -		*event = &efi_events[i];
> -		return EFI_SUCCESS;
> -	}
> -	return EFI_OUT_OF_RESOURCES;
> +	evt = calloc(1, sizeof(*evt));
> +	if (!evt)
> +		return EFI_OUT_OF_RESOURCES;
> +
> +	evt->type = type;
> +	evt->notify_tpl = notify_tpl;
> +	evt->notify_function = notify_function;
> +	evt->notify_context = notify_context;
> +	/* Disable timers on bootup */
> +	evt->trigger_next = -1ULL;
> +	evt->signaled = 0;
> +
> +	list_add_tail(&evt->link, &efi_events);
> +
> +	*event = evt;
> +
> +	return EFI_SUCCESS;
>  }
>  
>  static efi_status_t EFIAPI efi_create_event_ext(
> @@ -315,21 +314,24 @@ static efi_status_t EFIAPI efi_create_event_ext(
>   */
>  void efi_timer_check(void)
>  {
> -	int i;
> +	struct efi_event *evt;
>  	u64 now = timer_get_us();
>  
> -	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
> -		if (!efi_events[i].type ||
> -		    !(efi_events[i].type & EVT_TIMER) ||
> -		    efi_events[i].trigger_type == EFI_TIMER_STOP ||
> -		    now < efi_events[i].trigger_next)
> +	/*
> +	 * TODO perhaps optimize a bit and track the time of next
> +	 * timer expiration?
> +	 */

The next expiration time is set below.
What do you want to change?

> +	list_for_each_entry(evt, &efi_events, link) {
> +		if (!evt->type || !(evt->type & EVT_TIMER) ||
> +		    evt->trigger_type == EFI_TIMER_STOP ||
> +		    now < evt->trigger_next)
>  			continue;
> -		if (efi_events[i].trigger_type == EFI_TIMER_PERIODIC) {
> -			efi_events[i].trigger_next +=
> -				efi_events[i].trigger_time;
> -			efi_events[i].signaled = 0;
> +		if (evt->trigger_type == EFI_TIMER_PERIODIC) {
> +			evt->trigger_next +=
> +				evt->trigger_time;
> +			evt->signaled = 0;
>  		}
> -		efi_signal_event(&efi_events[i]);
> +		efi_signal_event(evt);
>  	}
>  	WATCHDOG_RESET();
>  }
> @@ -337,37 +339,32 @@ void efi_timer_check(void)
>  efi_status_t efi_set_timer(struct efi_event *event, enum efi_timer_delay type,
>  			   uint64_t trigger_time)
>  {
> -	int i;
> -
>  	/*
>  	 * The parameter defines a multiple of 100ns.
>  	 * We use multiples of 1000ns. So divide by 10.
>  	 */
>  	trigger_time = efi_div10(trigger_time);
>  
> -	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
> -		if (event != &efi_events[i])
> -			continue;

Please, check that event relates to an event in our list.
We do not want to accept an invalid pointer.

> +	if (!(event->type & EVT_TIMER))
> +		return EFI_INVALID_PARAMETER;
>  
> -		if (!(event->type & EVT_TIMER))
> -			break;
> -		switch (type) {
> -		case EFI_TIMER_STOP:
> -			event->trigger_next = -1ULL;
> -			break;
> -		case EFI_TIMER_PERIODIC:
> -		case EFI_TIMER_RELATIVE:
> -			event->trigger_next =
> +	switch (type) {
> +	case EFI_TIMER_STOP:
> +		event->trigger_next = -1ULL;
> +		break;
> +	case EFI_TIMER_PERIODIC:
> +	case EFI_TIMER_RELATIVE:
> +		event->trigger_next =
>  				timer_get_us() + trigger_time;
> -			break;
> -		default:
> -			return EFI_INVALID_PARAMETER;
> -		}
> -		event->trigger_type = type;
> -		event->trigger_time = trigger_time;
> -		return EFI_SUCCESS;
> +		break;
> +	default:
> +		return EFI_INVALID_PARAMETER;
>  	}
> -	return EFI_INVALID_PARAMETER;
> +
> +	event->trigger_type = type;
> +	event->trigger_time = trigger_time;
> +
> +	return EFI_SUCCESS;
>  }
>  
>  static efi_status_t EFIAPI efi_set_timer_ext(struct efi_event *event,
> @@ -382,7 +379,7 @@ static efi_status_t EFIAPI efi_wait_for_event(unsigned long num_events,
>  					      struct efi_event **event,
>  					      unsigned long *index)
>  {
> -	int i, j;
> +	int i;
>  
>  	EFI_ENTRY("%ld, %p, %p", num_events, event, index);
>  
> @@ -390,12 +387,6 @@ static efi_status_t EFIAPI efi_wait_for_event(unsigned long num_events,
>  	if (!num_events || !event)
>  		return EFI_EXIT(EFI_INVALID_PARAMETER);
>  	for (i = 0; i < num_events; ++i) {
> -		for (j = 0; j < ARRAY_SIZE(efi_events); ++j) {
> -			if (event[i] == &efi_events[j])
> -				goto known_event;
> -		}
> -		return EFI_EXIT(EFI_INVALID_PARAMETER);
> -known_event:

Check that the event pointer is in our list.

>  		if (!event[i]->type || event[i]->type & EVT_NOTIFY_SIGNAL)
>  			return EFI_EXIT(EFI_INVALID_PARAMETER);
>  	}
> @@ -424,50 +415,46 @@ out:
>  
>  static efi_status_t EFIAPI efi_signal_event_ext(struct efi_event *event)
>  {
> -	int i;
> -
>  	EFI_ENTRY("%p", event);
> -	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
> -		if (event != &efi_events[i])
> -			continue;
> -		efi_signal_event(event);
> -		break;
> -	}
> +	efi_signal_event(event);
>  	return EFI_EXIT(EFI_SUCCESS);
>  }
>  
>  static efi_status_t EFIAPI efi_close_event(struct efi_event *event)
>  {
> -	int i;
> -
>  	EFI_ENTRY("%p", event);
> -	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
> -		if (event == &efi_events[i]) {
> -			event->type = 0;
> -			event->trigger_next = -1ULL;
> -			event->signaled = 0;
> -			return EFI_EXIT(EFI_SUCCESS);
> -		}
> -	}
> -	return EFI_EXIT(EFI_INVALID_PARAMETER);

Return an error code if the event was not in our list.

> +	list_del(&event->link);
> +	free(event);
> +	return EFI_EXIT(EFI_SUCCESS);
>  }
>  
> +/*
> + * - If Event is in the signaled state, it is cleared and EFI_SUCCESS
> + *   is returned.
> + *
> + * - If Event is not in the signaled state and has no notification
> + *   function, EFI_NOT_READY is returned.
> + *
> + * - If Event is not in the signaled state but does have a notification
> + *   function, the notification function is queued at the event’s
> + *   notification task priority level. If the execution of the
> + *   notification function causes Event to be signaled, then the signaled
> + *   state is cleared and EFI_SUCCESS is returned; if the Event is not
> + *   signaled, then EFI_NOT_READY is returned.
> + */
>  static efi_status_t EFIAPI efi_check_event(struct efi_event *event)
>  {
> -	int i;
> -
>  	EFI_ENTRY("%p", event);
>  	efi_timer_check();
> -	for (i = 0; i < ARRAY_SIZE(efi_events); ++i) {
> -		if (event != &efi_events[i])
> -			continue;
> -		if (!event->type || event->type & EVT_NOTIFY_SIGNAL)
> -			break;
> -		if (event->signaled)
> -			return EFI_EXIT(EFI_SUCCESS);
> -		return EFI_EXIT(EFI_NOT_READY);

Check that the event is on our list.

> +	if (event->type & EVT_NOTIFY_SIGNAL)
> +		return EFI_EXIT(EFI_INVALID_PARAMETER);
> +	if (!event->signaled && event->notify_function)
> +		EFI_CALL(event->notify_function(event, event->notify_context));
> +	if (event->signaled) {
> +		event->signaled = 0;
> +		return EFI_EXIT(EFI_SUCCESS);
>  	}
> -	return EFI_EXIT(EFI_INVALID_PARAMETER);
> +	return EFI_EXIT(EFI_NOT_READY);
>  }
>  
>  static efi_status_t EFIAPI efi_install_protocol_interface(void **handle,
> 

The changes make sense. But unfortunately the patch series is not
applicable to efi-next.

Either rebase it or provide information concerning the prerequisite patches.

Please, check in all functions that the event parameter relates to a
pointer on our list. Otherwise return EFI_INVALID_PARAMETER.

Best regards

Heinrich


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