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Merge pull request #15086 from maribu/ibs-after-stackpointer

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cpu/cortexm_common: Flush pipeline after triggering PendSV
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Kaspar Schleiser 2020-09-26 21:05:04 +02:00 committed by GitHub
commit 9334897ab9
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1 changed files with 5 additions and 2 deletions
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7
cpu/cortexm_common/thread_arch.c
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@ -297,6 +297,9 @@ void thread_yield_higher(void)
/* trigger the PENDSV interrupt to run scheduler and schedule new thread if /* trigger the PENDSV interrupt to run scheduler and schedule new thread if
* applicable */ * applicable */
SCB->ICSR = SCB_ICSR_PENDSVSET_Msk; SCB->ICSR = SCB_ICSR_PENDSVSET_Msk;
/* flush the pipeline. Otherwise we risk that subsequent instructions are
* executed before the IRQ has actually triggered */
__ISB();
} }
void __attribute__((naked)) __attribute__((used)) isr_pendsv(void) { void __attribute__((naked)) __attribute__((used)) isr_pendsv(void) {
@ -384,7 +387,7 @@ void __attribute__((naked)) __attribute__((used)) isr_pendsv(void) {
"mov r1, r9 \n" "mov r1, r9 \n"
"mov r2, r10 \n" "mov r2, r10 \n"
"mov r3, r11 \n" "mov r3, r11 \n"
"push {r0-r7,lr} \n" /* now push them onto the stack */ "push {r0-r7,lr} \n" /* now push them onto the stack */
/* SP should match the expected SP calculated above from here on */ /* SP should match the expected SP calculated above from here on */
/* current thread context is now saved */ /* current thread context is now saved */
@ -404,7 +407,7 @@ void __attribute__((naked)) __attribute__((used)) isr_pendsv(void) {
/* restore the application mode stack pointer PSP */ /* restore the application mode stack pointer PSP */
"mov r1, sp \n" /* restore the user mode SP */ "mov r1, sp \n" /* restore the user mode SP */
"msr psp, r1 \n" /* for this write it to the PSP reg */ "msr psp, r1 \n" /* for this write it to the PSP reg */
"mov sp, r12 \n" /* and get the parked MSR SP back */ "mov sp, r12 \n" /* and get the parked MSR SP back */
"bx r0 \n" /* load exception return value to PC, "bx r0 \n" /* load exception return value to PC,
* causes end of exception*/ * causes end of exception*/
#endif #endif