[rtems commit] score: Fix CPU context usage on SMP
Sebastian Huber
sebh at rtems.org
Thu May 8 10:56:21 UTC 2014
Module: rtems
Branch: master
Commit: 11b05f11d4d6d61717e345d20f492977b95ab131
Changeset: http://git.rtems.org/rtems/commit/?id=11b05f11d4d6d61717e345d20f492977b95ab131
Author: Sebastian Huber <sebastian.huber at embedded-brains.de>
Date: Thu May 8 10:11:13 2014 +0200
score: Fix CPU context usage on SMP
We must not alter the is executing indicator in
_CPU_Context_Initialize() since this would cause an invalid state during
a self restart.
The is executing indicator must be valid at creation time since
otherwise _Thread_Kill_zombies() uses an undefined value for not started
threads. This could result in a system life lock.
---
c/src/lib/libbsp/sparc/shared/irq_asm.S | 6 ++--
c/src/lib/libcpu/powerpc/new-exceptions/cpu.c | 6 ----
c/src/lib/libcpu/powerpc/new-exceptions/cpu_asm.S | 14 ++++------
cpukit/score/cpu/arm/cpu.c | 4 ---
cpukit/score/cpu/arm/cpu_asm.S | 20 +++++++--------
cpukit/score/cpu/arm/rtems/score/cpu.h | 16 +++++++++++-
cpukit/score/cpu/i386/cpu_asm.S | 8 +++---
cpukit/score/cpu/i386/rtems/score/cpu.h | 23 +++++++++++-------
cpukit/score/cpu/no_cpu/rtems/score/cpu.h | 26 +++++++++++++++++--
cpukit/score/cpu/powerpc/rtems/score/cpu.h | 16 +++++++++++-
cpukit/score/cpu/sparc/cpu.c | 4 ---
cpukit/score/cpu/sparc/rtems/score/cpu.h | 16 +++++++++++-
cpukit/score/src/threadinitialize.c | 1 +
testsuites/sptests/spcontext01/init.c | 27 +++++++++++++++++++++
14 files changed, 129 insertions(+), 58 deletions(-)
diff --git a/c/src/lib/libbsp/sparc/shared/irq_asm.S b/c/src/lib/libbsp/sparc/shared/irq_asm.S
index 8b15284..bf2dca9 100644
--- a/c/src/lib/libbsp/sparc/shared/irq_asm.S
+++ b/c/src/lib/libbsp/sparc/shared/irq_asm.S
@@ -164,17 +164,17 @@ done_flushing:
nop
#if defined(RTEMS_SMP)
- ! Indicate that this context is no longer executing
+ ! The executing context no longer executes on this processor
stb %g0, [%o0 + SPARC_CONTEXT_CONTROL_IS_EXECUTING_OFFSET]
- ! Wait for context to stop execution if necessary
+ ! Wait for heir context to stop execution
1:
ldub [%o1 + SPARC_CONTEXT_CONTROL_IS_EXECUTING_OFFSET], %g1
cmp %g1, 0
bne 1b
mov 1, %g1
- ! Indicate that this context is executing
+ ! The heir context executes now on this processor
stb %g1, [%o1 + SPARC_CONTEXT_CONTROL_IS_EXECUTING_OFFSET]
#endif
diff --git a/c/src/lib/libcpu/powerpc/new-exceptions/cpu.c b/c/src/lib/libcpu/powerpc/new-exceptions/cpu.c
index 32c0489..c12a04e 100644
--- a/c/src/lib/libcpu/powerpc/new-exceptions/cpu.c
+++ b/c/src/lib/libcpu/powerpc/new-exceptions/cpu.c
@@ -123,17 +123,11 @@ void _CPU_Context_Initialize(
else
msr_value &= ~PPC_MSR_FP;
- memset( the_context, 0, sizeof( *the_context ) );
-
the_ppc_context = ppc_get_context( the_context );
the_ppc_context->gpr1 = sp;
the_ppc_context->msr = msr_value;
the_ppc_context->lr = (uint32_t) entry_point;
-#ifdef RTEMS_SMP
- the_ppc_context->is_executing = false;
-#endif
-
#ifdef __ALTIVEC__
_CPU_Context_initialize_altivec( the_ppc_context );
#endif
diff --git a/c/src/lib/libcpu/powerpc/new-exceptions/cpu_asm.S b/c/src/lib/libcpu/powerpc/new-exceptions/cpu_asm.S
index 4e74996..6bde8bd 100644
--- a/c/src/lib/libcpu/powerpc/new-exceptions/cpu_asm.S
+++ b/c/src/lib/libcpu/powerpc/new-exceptions/cpu_asm.S
@@ -327,28 +327,26 @@ PROC (_CPU_Context_switch):
stw r2, PPC_CONTEXT_OFFSET_GPR2(r3)
#ifdef RTEMS_SMP
- /* Indicate that this context is no longer executing */
+ /* The executing context no longer executes on this processor */
msync
li r5, 0
stb r5, PPC_CONTEXT_OFFSET_IS_EXECUTING(r3)
-#endif
-
- /* Restore context from r4 */
-restore_context:
-#ifdef RTEMS_SMP
- /* Wait for context to stop execution if necessary */
+ /* Wait for heir context to stop execution */
1:
lbz r5, PPC_CONTEXT_OFFSET_IS_EXECUTING(r4)
cmpwi r5, 0
bne 1b
- /* Indicate that this context is executing */
+ /* The heir context executes now on this processor */
li r5, 1
stb r5, PPC_CONTEXT_OFFSET_IS_EXECUTING(r4)
isync
#endif
+ /* Restore context from r4 */
+restore_context:
+
#ifdef __ALTIVEC__
mr r14, r4
.extern _CPU_Context_switch_altivec
diff --git a/cpukit/score/cpu/arm/cpu.c b/cpukit/score/cpu/arm/cpu.c
index 91109e4..089826e 100644
--- a/cpukit/score/cpu/arm/cpu.c
+++ b/cpukit/score/cpu/arm/cpu.c
@@ -101,10 +101,6 @@ void _CPU_Context_Initialize(
the_context->thread_id = (uint32_t) tls_area;
#endif
-#ifdef RTEMS_SMP
- the_context->is_executing = false;
-#endif
-
if ( tls_area != NULL ) {
_TLS_TCB_at_area_begin_initialize( tls_area );
}
diff --git a/cpukit/score/cpu/arm/cpu_asm.S b/cpukit/score/cpu/arm/cpu_asm.S
index f2c4afe..0df5ebb 100644
--- a/cpukit/score/cpu/arm/cpu_asm.S
+++ b/cpukit/score/cpu/arm/cpu_asm.S
@@ -68,31 +68,29 @@ DEFINE_FUNCTION_ARM(_CPU_Context_switch)
#endif
#ifdef RTEMS_SMP
- /* Indicate that this context is no longer executing */
+ /* The executing context no longer executes on this processor */
dmb
mov r3, #0
strb r3, [r0, #ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET]
-#endif
-
-/* Start restoring context */
-_restore:
-#ifdef ARM_MULTILIB_HAS_LOAD_STORE_EXCLUSIVE
- clrex
-#endif
-#ifdef RTEMS_SMP
- /* Wait for context to stop execution if necessary */
+ /* Wait for heir context to stop execution */
1:
ldrb r3, [r1, #ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET]
cmp r3, #0
bne 1b
- /* Indicate that this context is executing */
+ /* The heir context executes now on this processor */
dmb
mov r3, #1
strb r3, [r1, #ARM_CONTEXT_CONTROL_IS_EXECUTING_OFFSET]
#endif
+/* Start restoring context */
+_restore:
+#ifdef ARM_MULTILIB_HAS_LOAD_STORE_EXCLUSIVE
+ clrex
+#endif
+
#ifdef ARM_MULTILIB_HAS_THREAD_ID_REGISTER
ldr r3, [r1, #ARM_CONTEXT_CONTROL_THREAD_ID_OFFSET]
mcr p15, 0, r3, c13, c0, 3
diff --git a/cpukit/score/cpu/arm/rtems/score/cpu.h b/cpukit/score/cpu/arm/rtems/score/cpu.h
index dc57a78..d53be60 100644
--- a/cpukit/score/cpu/arm/rtems/score/cpu.h
+++ b/cpukit/score/cpu/arm/rtems/score/cpu.h
@@ -422,8 +422,20 @@ void _CPU_Context_Initialize(
(_context)->register_sp
#ifdef RTEMS_SMP
- #define _CPU_Context_Get_is_executing( _context ) \
- (_context)->is_executing
+ static inline bool _CPU_Context_Get_is_executing(
+ const Context_Control *context
+ )
+ {
+ return context->is_executing;
+ }
+
+ static inline void _CPU_Context_Set_is_executing(
+ Context_Control *context,
+ bool is_executing
+ )
+ {
+ context->is_executing = is_executing;
+ }
#endif
#define _CPU_Context_Restart_self( _the_context ) \
diff --git a/cpukit/score/cpu/i386/cpu_asm.S b/cpukit/score/cpu/i386/cpu_asm.S
index cc08312..9b39567 100644
--- a/cpukit/score/cpu/i386/cpu_asm.S
+++ b/cpukit/score/cpu/i386/cpu_asm.S
@@ -58,24 +58,24 @@ SYM (_CPU_Context_switch):
movl edi,REG_EDI(eax) /* save destination register */
#ifdef RTEMS_SMP
- /* Indicate that this context is no longer executing */
+ /* The executing context no longer executes on this processor */
movb $0, I386_CONTEXT_CONTROL_IS_EXECUTING_OFFSET(eax)
#endif
movl HEIRCONTEXT_ARG(esp),eax /* eax = heir threads context */
-restore:
#ifdef RTEMS_SMP
- /* Wait for context to stop execution if necessary */
+ /* Wait for heir context to stop execution */
1:
movb I386_CONTEXT_CONTROL_IS_EXECUTING_OFFSET(eax), bl
testb bl, bl
jne 1b
- /* Indicate that this context is executing */
+ /* The heir context executes now on this processor */
movb $1, I386_CONTEXT_CONTROL_IS_EXECUTING_OFFSET(eax)
#endif
+restore:
pushl REG_EFLAGS(eax) /* push eflags */
popf /* restore eflags */
movl REG_ESP(eax),esp /* restore stack pointer */
diff --git a/cpukit/score/cpu/i386/rtems/score/cpu.h b/cpukit/score/cpu/i386/rtems/score/cpu.h
index ba731b0..2d1472d 100644
--- a/cpukit/score/cpu/i386/rtems/score/cpu.h
+++ b/cpukit/score/cpu/i386/rtems/score/cpu.h
@@ -167,8 +167,20 @@ typedef struct {
(_context)->esp
#ifdef RTEMS_SMP
- #define _CPU_Context_Get_is_executing( _context ) \
- (_context)->is_executing
+ static inline bool _CPU_Context_Get_is_executing(
+ const Context_Control *context
+ )
+ {
+ return context->is_executing;
+ }
+
+ static inline void _CPU_Context_Set_is_executing(
+ Context_Control *context,
+ bool is_executing
+ )
+ {
+ context->is_executing = is_executing;
+ }
#endif
/*
@@ -454,12 +466,6 @@ uint32_t _CPU_ISR_Get_level( void );
*/
-#ifdef RTEMS_SMP
- #define _I386_Context_Initialize_is_executing( _the_context ) \
- (_the_context)->is_executing = false
-#else
- #define _I386_Context_Initialize_is_executing( _the_context )
-#endif
#define _CPU_Context_Initialize( _the_context, _stack_base, _size, \
_isr, _entry_point, _is_fp, _tls_area ) \
@@ -475,7 +481,6 @@ uint32_t _CPU_ISR_Get_level( void );
*((proc_ptr *)(_stack)) = (_entry_point); \
(_the_context)->ebp = (void *) 0; \
(_the_context)->esp = (void *) _stack; \
- _I386_Context_Initialize_is_executing( _the_context ); \
} while (0)
#define _CPU_Context_Restart_self( _the_context ) \
diff --git a/cpukit/score/cpu/no_cpu/rtems/score/cpu.h b/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
index 739a6a8..9570fb6 100644
--- a/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
+++ b/cpukit/score/cpu/no_cpu/rtems/score/cpu.h
@@ -1596,10 +1596,30 @@ register struct Per_CPU_Control *_CPU_Per_CPU_current asm( "rX" );
}
/**
- * @brief Macro to return the is executing field of the thread context.
+ * @brief Gets the is executing indicator of the thread context.
+ *
+ * @param[in] context The context.
*/
- #define _CPU_Context_Get_is_executing( _context ) \
- ( ( _context )->is_executing )
+ static inline bool _CPU_Context_Get_is_executing(
+ const Context_Control *context
+ )
+ {
+ return context->is_executing;
+ }
+
+ /**
+ * @brief Sets the is executing indicator of the thread context.
+ *
+ * @param[in] context The context.
+ * @param[in] is_executing The new value for the is executing indicator.
+ */
+ static inline void _CPU_Context_Set_is_executing(
+ Context_Control *context,
+ bool is_executing
+ )
+ {
+ context->is_executing = is_executing;
+ }
#endif
#ifdef __cplusplus
diff --git a/cpukit/score/cpu/powerpc/rtems/score/cpu.h b/cpukit/score/cpu/powerpc/rtems/score/cpu.h
index 18a6770..3cad329 100644
--- a/cpukit/score/cpu/powerpc/rtems/score/cpu.h
+++ b/cpukit/score/cpu/powerpc/rtems/score/cpu.h
@@ -343,8 +343,20 @@ static inline ppc_context *ppc_get_context( const Context_Control *context )
ppc_get_context(_context)->gpr1
#ifdef RTEMS_SMP
- #define _CPU_Context_Get_is_executing( _context ) \
- ppc_get_context(_context)->is_executing
+ static inline bool _CPU_Context_Get_is_executing(
+ const Context_Control *context
+ )
+ {
+ return ppc_get_context(context)->is_executing;
+ }
+
+ static inline void _CPU_Context_Set_is_executing(
+ Context_Control *context,
+ bool is_executing
+ )
+ {
+ ppc_get_context(context)->is_executing = is_executing;
+ }
#endif
#endif /* ASM */
diff --git a/cpukit/score/cpu/sparc/cpu.c b/cpukit/score/cpu/sparc/cpu.c
index d05c511..ee0d622 100644
--- a/cpukit/score/cpu/sparc/cpu.c
+++ b/cpukit/score/cpu/sparc/cpu.c
@@ -330,10 +330,6 @@ void _CPU_Context_Initialize(
*/
the_context->isr_dispatch_disable = 0;
-#if defined(RTEMS_SMP)
- the_context->is_executing = false;
-#endif
-
if ( tls_area != NULL ) {
void *tcb = _TLS_TCB_after_TLS_block_initialize( tls_area );
diff --git a/cpukit/score/cpu/sparc/rtems/score/cpu.h b/cpukit/score/cpu/sparc/rtems/score/cpu.h
index 7bcdbd9..b931d2f 100644
--- a/cpukit/score/cpu/sparc/rtems/score/cpu.h
+++ b/cpukit/score/cpu/sparc/rtems/score/cpu.h
@@ -488,8 +488,20 @@ typedef struct {
(_context)->o6_sp
#ifdef RTEMS_SMP
- #define _CPU_Context_Get_is_executing( _context ) \
- (_context)->is_executing
+ static inline bool _CPU_Context_Get_is_executing(
+ const Context_Control *context
+ )
+ {
+ return context->is_executing;
+ }
+
+ static inline void _CPU_Context_Set_is_executing(
+ Context_Control *context,
+ bool is_executing
+ )
+ {
+ context->is_executing = is_executing;
+ }
#endif
#endif /* ASM */
diff --git a/cpukit/score/src/threadinitialize.c b/cpukit/score/src/threadinitialize.c
index 1a03b0d..2beaed4 100644
--- a/cpukit/score/src/threadinitialize.c
+++ b/cpukit/score/src/threadinitialize.c
@@ -184,6 +184,7 @@ bool _Thread_Initialize(
the_thread->is_scheduled = false;
the_thread->is_in_the_air = false;
the_thread->scheduler = scheduler;
+ _CPU_Context_Set_is_executing( &the_thread->Registers, false );
#endif
_Thread_Debug_set_real_processor( the_thread, cpu );
diff --git a/testsuites/sptests/spcontext01/init.c b/testsuites/sptests/spcontext01/init.c
index f26bc55..e1af302 100644
--- a/testsuites/sptests/spcontext01/init.c
+++ b/testsuites/sptests/spcontext01/init.c
@@ -160,12 +160,39 @@ static void test(test_context *self)
wait_for_finish();
}
+static void test_context_is_executing(void)
+{
+#if defined(RTEMS_SMP)
+ Context_Control context;
+ bool is_executing;
+
+ memset(&context, 0, sizeof(context));
+
+ is_executing = _CPU_Context_Get_is_executing(&context);
+ rtems_test_assert(!is_executing);
+
+ _CPU_Context_Set_is_executing(&context, true);
+ is_executing = _CPU_Context_Get_is_executing(&context);
+ rtems_test_assert(is_executing);
+
+ _CPU_Context_Set_is_executing(&context, false);
+ is_executing = _CPU_Context_Get_is_executing(&context);
+ rtems_test_assert(!is_executing);
+
+ _CPU_Context_Set_is_executing(&context, true);
+ _CPU_Context_Initialize(&context, NULL, 0, 0, NULL, false, NULL);
+ is_executing = _CPU_Context_Get_is_executing(&context);
+ rtems_test_assert(is_executing);
+#endif
+}
+
static void Init(rtems_task_argument arg)
{
test_context *self = &test_instance;
TEST_BEGIN();
+ test_context_is_executing();
test(self);
TEST_END();
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