From 2f55807acb79490f615255e3c933ca0447f61a09 Mon Sep 17 00:00:00 2001
From: ligd <liguiding1@xiaomi.com>
Date: Tue, 13 Jul 2021 21:56:29 +0800
Subject: [PATCH] sched/signal: add spinlock to g_sigfreeaction

To avoid nxsig_alloc_action() & nxsig_release_action() competition

Signed-off-by: ligd <liguiding1@xiaomi.com>
---
 sched/signal/sig_action.c     | 40 +++++++++++++++++++++++++++++++++++
 sched/signal/sig_initialize.c | 35 ------------------------------
 sched/signal/signal.h         |  1 -
 3 files changed, 40 insertions(+), 36 deletions(-)

diff --git a/sched/signal/sig_action.c b/sched/signal/sig_action.c
index 312d07ef09..dae2629c7d 100644
--- a/sched/signal/sig_action.c
+++ b/sched/signal/sig_action.c
@@ -42,6 +42,37 @@
  * Private Functions
  ****************************************************************************/
 
+/****************************************************************************
+ * Name: nxsig_alloc_actionblock
+ *
+ * Description:
+ *   Allocate a block of signal actions and place them
+ *   on the free list.
+ *
+ ****************************************************************************/
+
+static void nxsig_alloc_actionblock(void)
+{
+  FAR sigactq_t *sigact;
+  irqstate_t flags;
+  int i;
+
+  /* Allocate a block of signal actions */
+
+  sigact = kmm_malloc((sizeof(sigactq_t)) * NUM_SIGNAL_ACTIONS);
+  if (sigact != NULL)
+    {
+      flags = spin_lock_irqsave(NULL);
+
+      for (i = 0; i < NUM_SIGNAL_ACTIONS; i++)
+        {
+          sq_addlast((FAR sq_entry_t *)sigact++, &g_sigfreeaction);
+        }
+
+      spin_unlock_irqrestore(NULL, flags);
+    }
+}
+
 /****************************************************************************
  * Name: nxsig_alloc_action
  *
@@ -53,10 +84,13 @@
 static FAR sigactq_t *nxsig_alloc_action(void)
 {
   FAR sigactq_t *sigact;
+  irqstate_t flags;
 
   /* Try to get the signal action structure from the free list */
 
+  flags = spin_lock_irqsave(NULL);
   sigact = (FAR sigactq_t *)sq_remfirst(&g_sigfreeaction);
+  spin_unlock_irqrestore(NULL, flags);
 
   /* Check if we got one. */
 
@@ -68,7 +102,9 @@ static FAR sigactq_t *nxsig_alloc_action(void)
 
       /* And try again */
 
+      flags = spin_lock_irqsave(NULL);
       sigact = (FAR sigactq_t *)sq_remfirst(&g_sigfreeaction);
+      spin_unlock_irqrestore(NULL, flags);
       DEBUGASSERT(sigact);
     }
 
@@ -363,7 +399,11 @@ int sigaction(int signo, FAR const struct sigaction *act,
 
 void nxsig_release_action(FAR sigactq_t *sigact)
 {
+  irqstate_t flags;
+
   /* Just put it back on the free list */
 
+  flags = spin_lock_irqsave(NULL);
   sq_addlast((FAR sq_entry_t *)sigact, &g_sigfreeaction);
+  spin_unlock_irqrestore(NULL, flags);
 }
diff --git a/sched/signal/sig_initialize.c b/sched/signal/sig_initialize.c
index 34e7b082de..5b793889d8 100644
--- a/sched/signal/sig_initialize.c
+++ b/sched/signal/sig_initialize.c
@@ -71,12 +71,6 @@ sq_queue_t  g_sigpendingirqsignal;
  * Private Data
  ****************************************************************************/
 
-/* g_sigactionalloc is a pointer to the start of the allocated blocks of
- * signal actions.
- */
-
-static sigactq_t  *g_sigactionalloc;
-
 /* g_sigpendingactionalloc is a pointer to the start of the allocated
  * blocks of pending signal actions.
  */
@@ -230,32 +224,3 @@ void nxsig_initialize(void)
                                    SIG_ALLOC_IRQ);
   DEBUGASSERT(g_sigpendingirqsignalalloc != NULL);
 }
-
-/****************************************************************************
- * Name: nxsig_alloc_actionblock
- *
- * Description:
- *   Allocate a block of signal actions and place them
- *   on the free list.
- *
- ****************************************************************************/
-
-void nxsig_alloc_actionblock(void)
-{
-  FAR sigactq_t *sigact;
-  int i;
-
-  /* Allocate a block of signal actions */
-
-  g_sigactionalloc =
-    (FAR sigactq_t *)kmm_malloc((sizeof(sigactq_t)) * NUM_SIGNAL_ACTIONS);
-
-  if (g_sigactionalloc != NULL)
-    {
-      sigact = g_sigactionalloc;
-      for (i = 0; i < NUM_SIGNAL_ACTIONS; i++)
-        {
-          sq_addlast((FAR sq_entry_t *)sigact++, &g_sigfreeaction);
-        }
-    }
-}
diff --git a/sched/signal/signal.h b/sched/signal/signal.h
index 8fe4b53e83..b8a3f5e1f6 100644
--- a/sched/signal/signal.h
+++ b/sched/signal/signal.h
@@ -148,7 +148,6 @@ struct task_group_s;
 /* sig_initializee.c */
 
 void weak_function nxsig_initialize(void);
-void               nxsig_alloc_actionblock(void);
 
 /* sig_action.c */