[rtos] Fixed registers clobbered SVC_Handler in IAR #1905
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The rtx SVC_Handler for IAR clobbers r0-r3 despite the number of arguments. However, in the SVC calls, the __swi function is declared with fewer arguments. IAR doesn't understand that the other registers are clobbered and stores variables in r0-r3 when multiple SVCs are dispatched in a single function. This bug was noticed in osThreadExit, which hard-faults on IAR, preventing any threads from exiting.
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Here is the relevant SVC call: rt_CMSIS.c#L315 |
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@mbed-bot: TEST HOST_OSES=windows |
| @@ -302,7 +302,7 @@ static inline t __##f (t1 a1, t2 a2, t3 a3, t4 a4) { \ | |||
| #define SVC_Setup(f) \ | |||
| __asm( \ | |||
| "mov r12,%0\n" \ | |||
| :: "r"(&f): "r12" \ | |||
| :: "r"(&f): "r0", "r1", "r2", "r3", "r12" \ | |||
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Might want to add "memory" to the clobber list as well. This will force all global variables to be written out before the call.
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It is emitting an IAR specific __swi function declaration and call for each svc, so the compiler should be able to handle the memory ordering appropriately. The issue is that the functions are emitted with fewer arguments than are clobbered in the svc handler.
_Pragma("swi_number=0") __swi t _##f (t1 a1);
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[Build 466] |
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@geky Report this to cmsis repo (https://github.com/ARM-software/CMSIS) ? |
The rtx SVC_Handler for IAR clobbers r0-r3 despite the number of
arguments. However, in the SVC calls, the __swi function is declared
with fewer arguments. IAR doesn't understand that the other registers are
clobbered and stores variables in r0-r3 when multiple SVCs are
dispatched in a single function.
This bug was noticed in osThreadExit, which hard-faults on IAR,
preventing any threads from exiting.