[PATCH] score: Fix race condition in SMP startup
Sebastian Huber
sebastian.huber at embedded-brains.de
Fri May 23 15:11:15 UTC 2014
Do not use the Per_CPU_Control::started in
_SMP_Start_multitasking_on_secondary_processor() since this field may be
not up to date when a secondary processor reads it. Use the read-only
scheduler assignment instead.
Add a new fatal error SMP_FATAL_MULTITASKING_START_ON_INVALID_PROCESSOR.
This prevents out-of-bounds access.
It is currently not possible to test these fatal errors. One option
would be to fake values of the _CPU_SMP_Get_current_processor(), but
unfortunately this function is inline on some architectures.
---
cpukit/score/include/rtems/score/smpimpl.h | 3 +-
cpukit/score/src/smp.c | 9 +++-
testsuites/smptests/Makefile.am | 1 -
testsuites/smptests/configure.ac | 1 -
testsuites/smptests/smpfatal07/Makefile.am | 19 ------
testsuites/smptests/smpfatal07/init.c | 75 -------------------------
testsuites/smptests/smpfatal07/smpfatal07.doc | 12 ----
testsuites/smptests/smpfatal07/smpfatal07.scn | 2 -
8 files changed, 10 insertions(+), 112 deletions(-)
delete mode 100644 testsuites/smptests/smpfatal07/Makefile.am
delete mode 100644 testsuites/smptests/smpfatal07/init.c
delete mode 100644 testsuites/smptests/smpfatal07/smpfatal07.doc
delete mode 100644 testsuites/smptests/smpfatal07/smpfatal07.scn
diff --git a/cpukit/score/include/rtems/score/smpimpl.h b/cpukit/score/include/rtems/score/smpimpl.h
index ac04833..283c50a 100644
--- a/cpukit/score/include/rtems/score/smpimpl.h
+++ b/cpukit/score/include/rtems/score/smpimpl.h
@@ -59,7 +59,8 @@ typedef enum {
SMP_FATAL_BOOT_PROCESSOR_NOT_ASSIGNED_TO_SCHEDULER,
SMP_FATAL_MANDATORY_PROCESSOR_NOT_PRESENT,
SMP_FATAL_MULTITASKING_START_ON_UNASSIGNED_PROCESSOR,
- SMP_FATAL_START_OF_MANDATORY_PROCESSOR_FAILED
+ SMP_FATAL_START_OF_MANDATORY_PROCESSOR_FAILED,
+ SMP_FATAL_MULTITASKING_START_ON_INVALID_PROCESSOR
} SMP_Fatal_code;
static inline void _SMP_Fatal( SMP_Fatal_code code )
diff --git a/cpukit/score/src/smp.c b/cpukit/score/src/smp.c
index b9d4b0a..f0554fe 100644
--- a/cpukit/score/src/smp.c
+++ b/cpukit/score/src/smp.c
@@ -121,8 +121,15 @@ void _SMP_Request_start_multitasking( void )
void _SMP_Start_multitasking_on_secondary_processor( void )
{
Per_CPU_Control *self_cpu = _Per_CPU_Get();
+ uint32_t cpu_index_self = _Per_CPU_Get_index( self_cpu );
+ const Scheduler_Assignment *assignment =
+ _Scheduler_Get_assignment( cpu_index_self );
- if ( !_Per_CPU_Is_processor_started( self_cpu ) ) {
+ if ( cpu_index_self >= rtems_configuration_get_maximum_processors() ) {
+ _SMP_Fatal( SMP_FATAL_MULTITASKING_START_ON_INVALID_PROCESSOR );
+ }
+
+ if ( !_Scheduler_Should_start_processor( assignment ) ) {
_SMP_Fatal( SMP_FATAL_MULTITASKING_START_ON_UNASSIGNED_PROCESSOR );
}
diff --git a/testsuites/smptests/Makefile.am b/testsuites/smptests/Makefile.am
index c05bf40..8c2ac7b 100644
--- a/testsuites/smptests/Makefile.am
+++ b/testsuites/smptests/Makefile.am
@@ -16,7 +16,6 @@ SUBDIRS += smpfatal02
SUBDIRS += smpfatal03
SUBDIRS += smpfatal04
SUBDIRS += smpfatal05
-SUBDIRS += smpfatal07
SUBDIRS += smpfatal08
SUBDIRS += smpipi01
SUBDIRS += smpload01
diff --git a/testsuites/smptests/configure.ac b/testsuites/smptests/configure.ac
index 33bc655..bdc166b 100644
--- a/testsuites/smptests/configure.ac
+++ b/testsuites/smptests/configure.ac
@@ -71,7 +71,6 @@ smpfatal02/Makefile
smpfatal03/Makefile
smpfatal04/Makefile
smpfatal05/Makefile
-smpfatal07/Makefile
smpfatal08/Makefile
smpipi01/Makefile
smpload01/Makefile
diff --git a/testsuites/smptests/smpfatal07/Makefile.am b/testsuites/smptests/smpfatal07/Makefile.am
deleted file mode 100644
index 724ff93..0000000
--- a/testsuites/smptests/smpfatal07/Makefile.am
+++ /dev/null
@@ -1,19 +0,0 @@
-rtems_tests_PROGRAMS = smpfatal07
-smpfatal07_SOURCES = init.c
-
-dist_rtems_tests_DATA = smpfatal07.scn smpfatal07.doc
-
-include $(RTEMS_ROOT)/make/custom/@RTEMS_BSP at .cfg
-include $(top_srcdir)/../automake/compile.am
-include $(top_srcdir)/../automake/leaf.am
-
-AM_CPPFLAGS += -I$(top_srcdir)/../support/include
-
-LINK_OBJS = $(smpfatal07_OBJECTS)
-LINK_LIBS = $(smpfatal07_LDLIBS)
-
-smpfatal07$(EXEEXT): $(smpfatal07_OBJECTS) $(smpfatal07_DEPENDENCIES)
- @rm -f smpfatal07$(EXEEXT)
- $(make-exe)
-
-include $(top_srcdir)/../automake/local.am
diff --git a/testsuites/smptests/smpfatal07/init.c b/testsuites/smptests/smpfatal07/init.c
deleted file mode 100644
index 1262742..0000000
--- a/testsuites/smptests/smpfatal07/init.c
+++ /dev/null
@@ -1,75 +0,0 @@
-/*
- * Copyright (c) 2014 embedded brains GmbH. All rights reserved.
- *
- * embedded brains GmbH
- * Dornierstr. 4
- * 82178 Puchheim
- * Germany
- * <rtems at embedded-brains.de>
- *
- * The license and distribution terms for this file may be
- * found in the file LICENSE in this distribution or at
- * http://www.rtems.org/license/LICENSE.
- */
-
-#ifdef HAVE_CONFIG_H
- #include "config.h"
-#endif
-
-#include <rtems.h>
-#include <rtems/test.h>
-#include <rtems/score/smpimpl.h>
-#include <rtems/score/threadimpl.h>
-
-#include <assert.h>
-#include <stdlib.h>
-
-const char rtems_test_name[] = "SMPFATAL 7";
-
-static void Init(rtems_task_argument arg)
-{
- Per_CPU_Control *cpu_self;
-
- _Thread_Disable_dispatch();
- cpu_self = _Per_CPU_Get();
- cpu_self->started = false;
- _SMP_Start_multitasking_on_secondary_processor();
-
- assert(0);
-}
-
-static void fatal_extension(
- rtems_fatal_source source,
- bool is_internal,
- rtems_fatal_code code
-)
-{
- rtems_test_begink();
-
- if (
- source == RTEMS_FATAL_SOURCE_SMP
- && !is_internal
- && code == SMP_FATAL_MULTITASKING_START_ON_UNASSIGNED_PROCESSOR
- ) {
- rtems_test_endk();
- }
-}
-
-#define CONFIGURE_APPLICATION_DOES_NOT_NEED_CLOCK_DRIVER
-#define CONFIGURE_APPLICATION_NEEDS_CONSOLE_DRIVER
-
-#define CONFIGURE_INITIAL_EXTENSIONS \
- { .fatal = fatal_extension }, \
- RTEMS_TEST_INITIAL_EXTENSION
-
-#define CONFIGURE_SMP_APPLICATION
-
-#define CONFIGURE_SMP_MAXIMUM_PROCESSORS 1
-
-#define CONFIGURE_MAXIMUM_TASKS 1
-
-#define CONFIGURE_RTEMS_INIT_TASKS_TABLE
-
-#define CONFIGURE_INIT
-
-#include <rtems/confdefs.h>
diff --git a/testsuites/smptests/smpfatal07/smpfatal07.doc b/testsuites/smptests/smpfatal07/smpfatal07.doc
deleted file mode 100644
index 5f37225..0000000
--- a/testsuites/smptests/smpfatal07/smpfatal07.doc
+++ /dev/null
@@ -1,12 +0,0 @@
-This file describes the directives and concepts tested by this test set.
-
-test set name: smpfatal07
-
-directives:
-
- - _SMP_Start_multitasking_on_secondary_processor()
-
-concepts:
-
- - Ensure that a multitasking start on an unassigned processor leads to a
- fatal error.
diff --git a/testsuites/smptests/smpfatal07/smpfatal07.scn b/testsuites/smptests/smpfatal07/smpfatal07.scn
deleted file mode 100644
index 10252a6..0000000
--- a/testsuites/smptests/smpfatal07/smpfatal07.scn
+++ /dev/null
@@ -1,2 +0,0 @@
-*** TEST SMPFATAL 7 ***
-*** END OF TEST SMPFATAL 7 ***
--
1.7.7
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