commit 620c85699dbc3ff2c73c9e1471f16110162e91f2
author Mingyang Sun <mingyang.sun@arm.com> Wed Nov 10 11:44:58 2021 +0800
committer Mingyang Sun <mingyang.sun@arm.com> Wed Nov 17 16:52:40 2021 +0800
tree 5b7d238262194f5b05913ac437aa93354068fb70
parent 975c0bd8915f61f985325a328ce37f322f97f852

SPM: Use a standalone lock for scheduling

Use a global 'scheduler_lock' to represent whether scheduling
in pendSV is allowed. When it is SCHEDULER_UNLOCKED, scheduling
is allowed.

Add more critical sections while operating the global handle pool
and the message list in SPM APIs, to avoid race condition.

Change-Id: I38121219942e836d8b75d9578090221f4c577fec
Signed-off-by: Mingyang Sun <mingyang.sun@arm.com>

secure_fw/spm/ffm/backend_ipc.c

diff --git a/secure_fw/spm/ffm/backend_ipc.c b/secure_fw/spm/ffm/backend_ipc.c
index c544f73..a6c8031 100644
--- a/secure_fw/spm/ffm/backend_ipc.c
+++ b/secure_fw/spm/ffm/backend_ipc.c
@@ -6,6 +6,7 @@
  */
 
 #include <stdint.h>
+#include "critical_section.h"
 #include "compiler_ext_defs.h"
 #include "spm_ipc.h"
 #include "tfm_hal_isolation.h"
@@ -48,6 +49,7 @@
 {
     struct partition_t *p_owner = NULL;
     psa_signal_t signal = 0;
+    struct critical_section_t cs_assert = CRITICAL_SECTION_STATIC_INIT;
 
     if (!msg || !service || !service->p_ldinf || !service->partition) {
         tfm_core_panic();
@@ -56,6 +58,7 @@
     p_owner = service->partition;
     signal = service->p_ldinf->signal;
 
+    CRITICAL_SECTION_ENTER(cs_assert);
     /* Add message to partition message list tail */
     BI_LIST_INSERT_BEFORE(&p_owner->msg_list, &msg->msg_node);
 
@@ -67,6 +70,7 @@
                      (p_owner->signals_asserted & p_owner->signals_waiting));
         p_owner->signals_waiting &= ~signal;
     }
+    CRITICAL_SECTION_LEAVE(cs_assert);
 
     /*
      * If it is a NS request via RPC, it is unnecessary to block current