Block SIG_RESUME in the main thread of the Posix port so that sigwait works as expected (#532)
Co-authored-by: alfred gedeon <28123637+alfred2g@users.noreply.github.com>
diff --git a/portable/ThirdParty/GCC/Posix/port.c b/portable/ThirdParty/GCC/Posix/port.c
index 98b1294..57905bc 100644
--- a/portable/ThirdParty/GCC/Posix/port.c
+++ b/portable/ThirdParty/GCC/Posix/port.c
@@ -191,13 +191,19 @@
* Interrupts are disabled here already. */
prvSetupTimerInterrupt();
+ /*
+ * Block SIG_RESUME before starting any tasks so the main thread can sigwait on it.
+ * To sigwait on an unblocked signal is undefined.
+ * https://pubs.opengroup.org/onlinepubs/009604499/functions/sigwait.html
+ */
+ sigemptyset( &xSignals );
+ sigaddset( &xSignals, SIG_RESUME );
+ ( void ) pthread_sigmask( SIG_BLOCK, &xSignals, NULL );
+
/* Start the first task. */
vPortStartFirstTask();
/* Wait until signaled by vPortEndScheduler(). */
- sigemptyset( &xSignals );
- sigaddset( &xSignals, SIG_RESUME );
-
while( xSchedulerEnd != pdTRUE )
{
sigwait( &xSignals, &iSignal );
@@ -543,23 +549,10 @@
&xAllSignals,
&xSchedulerOriginalSignalMask );
- /* SIG_RESUME is only used with sigwait() so doesn't need a
- * handler. */
- sigresume.sa_flags = 0;
- sigresume.sa_handler = SIG_IGN;
- sigfillset( &sigresume.sa_mask );
-
sigtick.sa_flags = 0;
sigtick.sa_handler = vPortSystemTickHandler;
sigfillset( &sigtick.sa_mask );
- iRet = sigaction( SIG_RESUME, &sigresume, NULL );
-
- if( iRet == -1 )
- {
- prvFatalError( "sigaction", errno );
- }
-
iRet = sigaction( SIGALRM, &sigtick, NULL );
if( iRet == -1 )
