From 4fa71ecf168e275b24534a5a20e3dd4e178c7bbd Mon Sep 17 00:00:00 2001 From: Keith Packard Date: Sat, 26 Mar 2016 15:54:24 -0700 Subject: altos/stm: Validate current task SP in interrupt by looking at PSP We use a separate stack pointer for task code, which means we can verify that it is in range in any interrupt handler. This adds checks for the task stack (under #ifdef DEBUG) that run in ao_wakeup as well as at every timer interrupt. Signed-off-by: Keith Packard --- src/stm/ao_arch_funcs.h | 16 ++++++++++++++++ src/stm/ao_timer.c | 1 + 2 files changed, 17 insertions(+) (limited to 'src/stm') diff --git a/src/stm/ao_arch_funcs.h b/src/stm/ao_arch_funcs.h index 02b344b1..6b38032c 100644 --- a/src/stm/ao_arch_funcs.h +++ b/src/stm/ao_arch_funcs.h @@ -366,6 +366,22 @@ static inline void ao_arch_restore_stack(void) { #define HAS_SAMPLE_PROFILE 0 #endif +#if DEBUG +#define HAS_ARCH_VALIDATE_CUR_STACK 1 + +static inline void +ao_validate_cur_stack(void) +{ + uint8_t *psp; + + asm("mrs %0,psp" : "=&r" (psp)); + if (ao_cur_task && + psp <= ao_cur_task->stack && + psp >= ao_cur_task->stack - 256) + ao_panic(AO_PANIC_STACK); +} +#endif + #if !HAS_SAMPLE_PROFILE #define HAS_ARCH_START_SCHEDULER 1 diff --git a/src/stm/ao_timer.c b/src/stm/ao_timer.c index 8db62e76..91ede84b 100644 --- a/src/stm/ao_timer.c +++ b/src/stm/ao_timer.c @@ -41,6 +41,7 @@ volatile __data uint8_t ao_data_count; void stm_systick_isr(void) { + ao_validate_cur_stack(); if (stm_systick.csr & (1 << STM_SYSTICK_CSR_COUNTFLAG)) { ++ao_tick_count; #if HAS_TASK_QUEUE -- cgit v1.2.3