bugfix: correct computation of stack size on Mac Posix port (#816)
Aligns the stack end to a page boundary before computing its
size, since the size depends on both the start and end.
The original change which introduced stack alignment (#674)
only worked for cases where the round + trunc operation would
wind up within the same area, but would lead to segfaults in
other cases.
Also adds a typecast to the `mach_vm_round_page()` call, as
it is actually a macro which casts to `mach_vm_offset_t` and
the result here is used as a `StackType_t` pointer.
Tested on ARM64 and Intel MacOS, as well as ARM64 and Intel
Linux. The test code included a single-task case, as well
as a case with two tasks passing queue messages.
diff --git a/portable/ThirdParty/GCC/Posix/port.c b/portable/ThirdParty/GCC/Posix/port.c
index 8ec8193..5dc3d73 100644
--- a/portable/ThirdParty/GCC/Posix/port.c
+++ b/portable/ThirdParty/GCC/Posix/port.c
@@ -148,10 +148,14 @@
*/
thread = ( Thread_t * ) ( pxTopOfStack + 1 ) - 1;
pxTopOfStack = ( StackType_t * ) thread - 1;
+
+ #ifdef __APPLE__
+ pxEndOfStack = ( StackType_t * ) mach_vm_round_page( pxEndOfStack );
+ #endif
+
ulStackSize = ( size_t ) ( pxTopOfStack + 1 - pxEndOfStack ) * sizeof( *pxTopOfStack );
#ifdef __APPLE__
- pxEndOfStack = mach_vm_round_page( pxEndOfStack );
ulStackSize = mach_vm_trunc_page( ulStackSize );
#endif
