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-rw-r--r--c/src/exec/score/ChangeLog21
-rw-r--r--c/src/exec/score/src/threaddispatch.c22
-rw-r--r--c/src/exec/score/src/threadhandler.c11
-rw-r--r--cpukit/score/ChangeLog21
-rw-r--r--cpukit/score/src/threaddispatch.c22
-rw-r--r--cpukit/score/src/threadhandler.c11
6 files changed, 90 insertions, 18 deletions
diff --git a/c/src/exec/score/ChangeLog b/c/src/exec/score/ChangeLog
index e84a79a7e1..64fd0a00d4 100644
--- a/c/src/exec/score/ChangeLog
+++ b/c/src/exec/score/ChangeLog
@@ -1,3 +1,24 @@
+2001-05-14 Till Straumann <strauman@slac.stanford.edu>
+
+ * src/threaddispatch.c, src/threadhandler.c: Per PR211 fix
+ saving/restoring floating point context. The fpsave and fprestore
+ routines are only used in a executing context which _is_ fp and hence
+ has the FPU enabled. The current behavior required the FPU always to
+ be on which is very dangerous if lazy context switching is used.
+ [Joel Note: Some ports explicitly enabled the FPU in the FP save and
+ restore routines to avoid this.]
+
+ The patch also makes sure (on powerpc only) that the FPU is disabled
+ for integer tasks. Note that this is crucial if deferred fp context
+ switching is used. Otherwise, fp context corruption may go undetected!
+ Also note that even tasks which merely push/pop FP registers to/from
+ the stack without modifying them still MUST be FP tasks - otherwise
+ (if lazy FP context switching is used), FP register corruption (of
+ other, FP, tasks may occur)!
+
+ Furthermore, (on PPC) by default, lazy FP context save/restore
+ is _disabled_.
+
2001-04-26 Joel Sherrill <joel@OARcorp.com>
* src/objectcomparenamestring.c: Fix typos.
diff --git a/c/src/exec/score/src/threaddispatch.c b/c/src/exec/score/src/threaddispatch.c
index 66a8996a12..18953ae596 100644
--- a/c/src/exec/score/src/threaddispatch.c
+++ b/c/src/exec/score/src/threaddispatch.c
@@ -93,24 +93,28 @@ void _Thread_Dispatch( void )
*/
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+#if ( CPU_USE_DEFERRED_FP_SWITCH != TRUE )
+ if ( executing->fp_context != NULL )
+ _Context_Save_fp( &executing->fp_context );
+#endif
+#endif
+
+ _Context_Switch( &executing->Registers, &heir->Registers );
+
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
#if ( CPU_USE_DEFERRED_FP_SWITCH == TRUE )
- if ( (heir->fp_context != NULL) && !_Thread_Is_allocated_fp( heir ) ) {
+ if ( (executing->fp_context != NULL) && !_Thread_Is_allocated_fp( executing ) ) {
if ( _Thread_Allocated_fp != NULL )
_Context_Save_fp( &_Thread_Allocated_fp->fp_context );
- _Context_Restore_fp( &heir->fp_context );
- _Thread_Allocated_fp = heir;
+ _Context_Restore_fp( &executing->fp_context );
+ _Thread_Allocated_fp = executing;
}
#else
if ( executing->fp_context != NULL )
- _Context_Save_fp( &executing->fp_context );
-
- if ( heir->fp_context != NULL )
- _Context_Restore_fp( &heir->fp_context );
+ _Context_Restore_fp( &executing->fp_context );
#endif
#endif
- _Context_Switch( &executing->Registers, &heir->Registers );
-
executing = _Thread_Executing;
_ISR_Disable( level );
diff --git a/c/src/exec/score/src/threadhandler.c b/c/src/exec/score/src/threadhandler.c
index e23667c32f..ec09654c5a 100644
--- a/c/src/exec/score/src/threadhandler.c
+++ b/c/src/exec/score/src/threadhandler.c
@@ -78,6 +78,17 @@ void _Thread_Handler( void )
doneConstructors = 1;
#endif
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+#if ( CPU_USE_DEFERRED_FP_SWITCH == TRUE )
+ if ( (executing->fp_context != NULL) && !_Thread_Is_allocated_fp( executing ) ) {
+ if ( _Thread_Allocated_fp != NULL )
+ _Context_Save_fp( &_Thread_Allocated_fp->fp_context );
+ _Thread_Allocated_fp = executing;
+ }
+#endif
+#endif
+
+
/*
* Take care that 'begin' extensions get to complete before
* 'switch' extensions can run. This means must keep dispatch
diff --git a/cpukit/score/ChangeLog b/cpukit/score/ChangeLog
index e84a79a7e1..64fd0a00d4 100644
--- a/cpukit/score/ChangeLog
+++ b/cpukit/score/ChangeLog
@@ -1,3 +1,24 @@
+2001-05-14 Till Straumann <strauman@slac.stanford.edu>
+
+ * src/threaddispatch.c, src/threadhandler.c: Per PR211 fix
+ saving/restoring floating point context. The fpsave and fprestore
+ routines are only used in a executing context which _is_ fp and hence
+ has the FPU enabled. The current behavior required the FPU always to
+ be on which is very dangerous if lazy context switching is used.
+ [Joel Note: Some ports explicitly enabled the FPU in the FP save and
+ restore routines to avoid this.]
+
+ The patch also makes sure (on powerpc only) that the FPU is disabled
+ for integer tasks. Note that this is crucial if deferred fp context
+ switching is used. Otherwise, fp context corruption may go undetected!
+ Also note that even tasks which merely push/pop FP registers to/from
+ the stack without modifying them still MUST be FP tasks - otherwise
+ (if lazy FP context switching is used), FP register corruption (of
+ other, FP, tasks may occur)!
+
+ Furthermore, (on PPC) by default, lazy FP context save/restore
+ is _disabled_.
+
2001-04-26 Joel Sherrill <joel@OARcorp.com>
* src/objectcomparenamestring.c: Fix typos.
diff --git a/cpukit/score/src/threaddispatch.c b/cpukit/score/src/threaddispatch.c
index 66a8996a12..18953ae596 100644
--- a/cpukit/score/src/threaddispatch.c
+++ b/cpukit/score/src/threaddispatch.c
@@ -93,24 +93,28 @@ void _Thread_Dispatch( void )
*/
#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+#if ( CPU_USE_DEFERRED_FP_SWITCH != TRUE )
+ if ( executing->fp_context != NULL )
+ _Context_Save_fp( &executing->fp_context );
+#endif
+#endif
+
+ _Context_Switch( &executing->Registers, &heir->Registers );
+
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
#if ( CPU_USE_DEFERRED_FP_SWITCH == TRUE )
- if ( (heir->fp_context != NULL) && !_Thread_Is_allocated_fp( heir ) ) {
+ if ( (executing->fp_context != NULL) && !_Thread_Is_allocated_fp( executing ) ) {
if ( _Thread_Allocated_fp != NULL )
_Context_Save_fp( &_Thread_Allocated_fp->fp_context );
- _Context_Restore_fp( &heir->fp_context );
- _Thread_Allocated_fp = heir;
+ _Context_Restore_fp( &executing->fp_context );
+ _Thread_Allocated_fp = executing;
}
#else
if ( executing->fp_context != NULL )
- _Context_Save_fp( &executing->fp_context );
-
- if ( heir->fp_context != NULL )
- _Context_Restore_fp( &heir->fp_context );
+ _Context_Restore_fp( &executing->fp_context );
#endif
#endif
- _Context_Switch( &executing->Registers, &heir->Registers );
-
executing = _Thread_Executing;
_ISR_Disable( level );
diff --git a/cpukit/score/src/threadhandler.c b/cpukit/score/src/threadhandler.c
index e23667c32f..ec09654c5a 100644
--- a/cpukit/score/src/threadhandler.c
+++ b/cpukit/score/src/threadhandler.c
@@ -78,6 +78,17 @@ void _Thread_Handler( void )
doneConstructors = 1;
#endif
+#if ( CPU_HARDWARE_FP == TRUE ) || ( CPU_SOFTWARE_FP == TRUE )
+#if ( CPU_USE_DEFERRED_FP_SWITCH == TRUE )
+ if ( (executing->fp_context != NULL) && !_Thread_Is_allocated_fp( executing ) ) {
+ if ( _Thread_Allocated_fp != NULL )
+ _Context_Save_fp( &_Thread_Allocated_fp->fp_context );
+ _Thread_Allocated_fp = executing;
+ }
+#endif
+#endif
+
+
/*
* Take care that 'begin' extensions get to complete before
* 'switch' extensions can run. This means must keep dispatch
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-02 11:20:12 +0000