From d21f1ddb71fc9e13f4f352f34e2a707a5b7df301 Mon Sep 17 00:00:00 2001 From: Ming Huang Date: Fri, 23 Apr 2021 15:06:17 +0800 Subject: [PATCH] services: Fix pmr_el1 rewrote issue in sdei_disaptch_event() Consider a RAS scenario: Enter EL3 by sync exception, then call spm_mm_sp_call() enter EL0s to handle this error, then call sdei_dispatch_event() to inform OS. Finally, return back to OS from sync exception flow. Similar flow is sgi_ras_intr_handler() in sgi_ras.c. The icc_pmr_el1 register will be change in above flow: 1 cm_el1_sysregs_context_save(NON_SECURE); -> ehf_exited_normal_world(); ##icc_pmr_el1: 0xf8 => 0x80 2 spm_mm_sp_call(); 3 sdei_dispatch_event(); 4 ehf_activate_priority(sdei_event_priority(map)); ##icc_pmr_el1: 0x80 => 0x60 5 restore_and_resume_ns_context(); -> ehf_exited_normal_world(); ##return due to has_valid_pri_activations(pe_data) == 1 6 ehf_deactivate_priority(sdei_event_priority(map)); ##icc_pmr_el1: 0x60 => 0x80 The icc_pmr_el1 was rewrote from 0xf8 to 0x80. This issue will result in OS hang when eret to OS from RAS flow. Move ehf_activate_priority(sdei_event_priority(map)) after restore_and_resume_ns_context() can fix this issue. Signed-off-by: Ming Huang Change-Id: If01ec55cf0aabf1594dece1ad50d3ec3406cdabc --- services/std_svc/sdei/sdei_intr_mgmt.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/services/std_svc/sdei/sdei_intr_mgmt.c b/services/std_svc/sdei/sdei_intr_mgmt.c index f12b2ca3d..5d176c209 100644 --- a/services/std_svc/sdei/sdei_intr_mgmt.c +++ b/services/std_svc/sdei/sdei_intr_mgmt.c @@ -636,15 +636,15 @@ int sdei_dispatch_event(int ev_num) if (!can_sdei_state_trans(se, DO_DISPATCH)) return -1; - /* Activate the priority corresponding to the event being dispatched */ - ehf_activate_priority(sdei_event_priority(map)); - /* * Prepare for NS dispatch by restoring the Non-secure context and * marking that as active. */ ns_ctx = restore_and_resume_ns_context(); + /* Activate the priority corresponding to the event being dispatched */ + ehf_activate_priority(sdei_event_priority(map)); + /* Dispatch event synchronously */ setup_ns_dispatch(map, se, ns_ctx, &dispatch_jmp); begin_sdei_synchronous_dispatch(&dispatch_jmp);