From cdb6ac94ecb3c4caa784cd4d7580cf6252146196 Mon Sep 17 00:00:00 2001 From: Jeenu Viswambharan Date: Fri, 16 Feb 2018 12:07:48 +0000 Subject: SDEI: Make dispatches synchronous SDEI event dispatches currently only sets up the Non-secure context before returning to the caller. The actual dispatch only happens upon exiting EL3 next time. However, for various error handling scenarios, it's beneficial to have the dispatch happen synchronously. I.e. when receiving SDEI interrupt, or for a successful sdei_dispatch_event() call, the event handler is executed; and upon the event completion, dispatcher execution resumes after the point of dispatch. The jump primitives introduced in the earlier patch facilitates this feature. With this patch: - SDEI interrupts and calls to sdei_dispatch_event prepares the NS context for event dispatch, then sets a jump point, and immediately exits EL3. This results in the client handler executing in Non-secure. - When the SDEI client completes the dispatched event, the SDEI dispatcher does a longjmp to the jump pointer created earlier. For the caller of the sdei_dispatch_event() in particular, this would appear as if call returned successfully. The dynamic workaround for CVE_2018_3639 is slightly shifted around as part of related minor refactoring. It doesn't affect the workaround functionality. Documentation updated. NOTE: This breaks the semantics of the explicit dispatch API, and any exiting usages should be carefully reviewed. Change-Id: Ib9c876d27ea2af7fb22de49832e55a0da83da3f9 Signed-off-by: Jeenu Viswambharan --- include/services/sdei.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include/services') diff --git a/include/services/sdei.h b/include/services/sdei.h index ee3531cb..79d1d065 100644 --- a/include/services/sdei.h +++ b/include/services/sdei.h @@ -183,6 +183,6 @@ uint64_t sdei_smc_handler(uint32_t smc_fid, void sdei_init(void); /* Public API to dispatch an event to Normal world */ -int sdei_dispatch_event(int ev_num, unsigned int preempted_sec_state); +int sdei_dispatch_event(int ev_num); #endif /* __SDEI_H__ */ -- cgit v1.2.3