zephyr/arch/arm/core/fault.c

725 lines
20 KiB
C

/*
* Copyright (c) 2014 Wind River Systems, Inc.
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Common fault handler for ARM Cortex-M
*
* Common fault handler for ARM Cortex-M processors.
*/
#include <toolchain.h>
#include <linker/sections.h>
#include <kernel.h>
#include <kernel_structs.h>
#include <inttypes.h>
#ifdef CONFIG_PRINTK
#include <misc/printk.h>
#define PR_EXC(...) printk(__VA_ARGS__)
#define STORE_xFAR(reg_var, reg) u32_t reg_var = (u32_t)reg
#else
#define PR_EXC(...)
#define STORE_xFAR(reg_var, reg)
#endif /* CONFIG_PRINTK */
#if (CONFIG_FAULT_DUMP > 0)
#define FAULT_DUMP(reason, esf, fault) reason = _FaultDump(esf, fault)
#else
#define FAULT_DUMP(reason, esf, fault) \
do { \
(void)reason; \
(void) esf; \
(void) fault; \
} while ((0))
#endif
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
/* Exception Return (EXC_RETURN) is provided in LR upon exception entry.
* It is used to perform an exception return and to detect possible state
* transition upon exception.
*/
/* Prefix. Indicates that this is an EXC_RETURN value.
* This field reads as 0b11111111.
*/
#define EXC_RETURN_INDICATOR_PREFIX (0xFF << 24)
/* bit[0]: Exception Secure. The security domain the exception was taken to. */
#define EXC_RETURN_EXCEPTION_SECURE_Pos 0
#define EXC_RETURN_EXCEPTION_SECURE_Msk \
(1 << EXC_RETURN_EXCEPTION_SECURE_Pos)
#define EXC_RETURN_EXCEPTION_SECURE_Non_Secure 0
#define EXC_RETURN_EXCEPTION_SECURE_Secure EXC_RETURN_EXCEPTION_SECURE_Msk
/* bit[2]: Stack Pointer selection. */
#define EXC_RETURN_SPSEL_Pos 2
#define EXC_RETURN_SPSEL_Msk (1 << EXC_RETURN_SPSEL_Pos)
#define EXC_RETURN_SPSEL_MAIN 0
#define EXC_RETURN_SPSEL_PROCESS EXC_RETURN_SPSEL_Msk
/* bit[3]: Mode. Indicates the Mode that was stacked from. */
#define EXC_RETURN_MODE_Pos 3
#define EXC_RETURN_MODE_Msk (1 << EXC_RETURN_MODE_Pos)
#define EXC_RETURN_MODE_HANDLER 0
#define EXC_RETURN_MODE_THREAD EXC_RETURN_MODE_Msk
/* bit[4]: Stack frame type. Indicates whether the stack frame is a standard
* integer only stack frame or an extended floating-point stack frame.
*/
#define EXC_RETURN_STACK_FRAME_TYPE_Pos 4
#define EXC_RETURN_STACK_FRAME_TYPE_Msk (1 << EXC_RETURN_STACK_FRAME_TYPE_Pos)
#define EXC_RETURN_STACK_FRAME_TYPE_EXTENDED 0
#define EXC_RETURN_STACK_FRAME_TYPE_STANDARD EXC_RETURN_STACK_FRAME_TYPE_Msk
/* bit[5]: Default callee register stacking. Indicates whether the default
* stacking rules apply, or whether the callee registers are already on the
* stack.
*/
#define EXC_RETURN_CALLEE_STACK_Pos 5
#define EXC_RETURN_CALLEE_STACK_Msk (1 << EXC_RETURN_CALLEE_STACK_Pos)
#define EXC_RETURN_CALLEE_STACK_SKIPPED 0
#define EXC_RETURN_CALLEE_STACK_DEFAULT EXC_RETURN_CALLEE_STACK_Msk
/* bit[6]: Secure or Non-secure stack. Indicates whether a Secure or
* Non-secure stack is used to restore stack frame on exception return.
*/
#define EXC_RETURN_RETURN_STACK_Pos 6
#define EXC_RETURN_RETURN_STACK_Msk (1 << EXC_RETURN_RETURN_STACK_Pos)
#define EXC_RETURN_RETURN_STACK_Non_Secure 0
#define EXC_RETURN_RETURN_STACK_Secure EXC_RETURN_RETURN_STACK_Msk
/* Integrity signature for an ARMv8-M implementation */
#if defined(CONFIG_ARMV7_M_ARMV8_M_FP)
#define INTEGRITY_SIGNATURE_STD 0xFEFA125BUL
#define INTEGRITY_SIGNATURE_EXT 0xFEFA125AUL
#else
#define INTEGRITY_SIGNATURE 0xFEFA125BUL
#endif /* CONFIG_ARMV7_M_ARMV8_M_FP */
/* Size (in words) of the additional state context that is pushed
* to the Secure stack during a Non-Secure exception entry.
*/
#define ADDITIONAL_STATE_CONTEXT_WORDS 10
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
#if (CONFIG_FAULT_DUMP == 1)
/**
*
* @brief Dump information regarding fault (FAULT_DUMP == 1)
*
* Dump information regarding the fault when CONFIG_FAULT_DUMP is set to 1
* (short form).
*
* eg. (precise bus error escalated to hard fault):
*
* Fault! EXC #3, Thread: 0x200000dc, instr: 0x000011d3
* HARD FAULT: Escalation (see below)!
* MMFSR: 0x00000000, BFSR: 0x00000082, UFSR: 0x00000000
* BFAR: 0xff001234
*
* @return default fatal error reason (_NANO_ERR_HW_EXCEPTION)
*/
u32_t _FaultDump(const NANO_ESF *esf, int fault)
{
PR_EXC("Fault! EXC #%d, Thread: %p, instr @ 0x%x\n",
fault,
k_current_get(),
esf->pc);
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
int escalation = 0;
if (3 == fault) { /* hard fault */
escalation = SCB->HFSR & SCB_HFSR_FORCED_Msk;
PR_EXC("HARD FAULT: %s\n",
escalation ? "Escalation (see below)!"
: "Bus fault on vector table read\n");
}
PR_EXC("MMFSR: 0x%x, BFSR: 0x%x, UFSR: 0x%x\n",
SCB_MMFSR, SCB_BFSR, SCB_MMFSR);
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
PR_EXC("SFSR: 0x%x\n", SAU->SFSR);
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
/* In a fault handler, to determine the true faulting address:
* 1. Read and save the MMFAR or BFAR value.
* 2. Read the MMARVALID bit in the MMFSR, or the BFARVALID bit in the
* BFSR. The MMFAR or BFAR address is valid only if this bit is 1.
*
* Software must follow this sequence because another higher priority
* exception might change the MMFAR or BFAR value.
*/
STORE_xFAR(mmfar, SCB->MMFAR);
STORE_xFAR(bfar, SCB->BFAR);
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
STORE_xFAR(sfar, SAU->SFAR);
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
if (SCB->CFSR & SCB_CFSR_MMARVALID_Msk) {
PR_EXC("MMFAR: 0x%x\n", mmfar);
if (escalation) {
/* clear MMAR[VALID] to reset */
SCB->CFSR &= ~SCB_CFSR_MMARVALID_Msk;
}
}
if (SCB->CFSR & SCB_CFSR_BFARVALID_Msk) {
PR_EXC("BFAR: 0x%x\n", bfar);
if (escalation) {
/* clear CFSR_BFAR[VALID] to reset */
SCB->CFSR &= ~SCB_CFSR_BFARVALID_Msk;
}
}
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
if (SAU->SFSR & SAU_SFSR_SFARVALID_Msk) {
PR_EXC("SFAR: 0x%x\n", sfar);
if (escalation) {
/* clear SFSR_SFAR[VALID] to reset */
SAU->SFSR &= ~SAU_SFSR_SFARVALID_Msk;
}
}
/* clear SFSR sticky bits */
SAU->SFSR |= 0xFF;
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
/* clear USFR sticky bits */
SCB->CFSR |= SCB_CFSR_USGFAULTSR_Msk;
#if defined(CONFIG_ARMV8_M_MAINLINE)
/* clear BSFR sticky bits */
SCB->CFSR |= SCB_CFSR_BUSFAULTSR_Msk;
#endif /* CONFIG_ARMV8_M_MAINLINE */
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
return _NANO_ERR_HW_EXCEPTION;
}
#endif
#if (CONFIG_FAULT_DUMP == 2)
/**
*
* @brief Dump thread information
*
* See _FaultDump() for example.
*
* @return N/A
*/
static void _FaultThreadShow(const NANO_ESF *esf)
{
PR_EXC(" Executing thread ID (thread): %p\n"
" Faulting instruction address: 0x%x\n",
k_current_get(), esf->pc);
}
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
/* HardFault is used for all fault conditions on ARMv6-M. */
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
/**
*
* @brief Dump MPU fault information
*
* See _FaultDump() for example.
*
* @return error code to identify the fatal error reason
*/
static u32_t _MpuFault(const NANO_ESF *esf, int fromHardFault)
{
u32_t reason = _NANO_ERR_HW_EXCEPTION;
PR_EXC("***** MPU FAULT *****\n");
_FaultThreadShow(esf);
if (SCB->CFSR & SCB_CFSR_MSTKERR_Msk) {
PR_EXC(" Stacking error\n");
} else if (SCB->CFSR & SCB_CFSR_MUNSTKERR_Msk) {
PR_EXC(" Unstacking error\n");
} else if (SCB->CFSR & SCB_CFSR_DACCVIOL_Msk) {
PR_EXC(" Data Access Violation\n");
/* In a fault handler, to determine the true faulting address:
* 1. Read and save the MMFAR value.
* 2. Read the MMARVALID bit in the MMFSR.
* The MMFAR address is valid only if this bit is 1.
*
* Software must follow this sequence because another higher
* priority exception might change the MMFAR value.
*/
STORE_xFAR(mmfar, SCB->MMFAR);
if (SCB->CFSR & SCB_CFSR_MMARVALID_Msk) {
PR_EXC(" Address: 0x%x\n", mmfar);
if (fromHardFault) {
/* clear SCB_MMAR[VALID] to reset */
SCB->CFSR &= ~SCB_CFSR_MMARVALID_Msk;
}
#if defined(CONFIG_HW_STACK_PROTECTION)
/* When stack protection is enabled, we need to see
* if the memory violation error is a stack corruption.
* For that we investigate the address fail.
*/
struct k_thread *thread = _current;
u32_t guard_start;
if (thread != NULL) {
#if defined(CONFIG_USERSPACE)
guard_start =
thread->arch.priv_stack_start ?
(u32_t)thread->arch.priv_stack_start :
(u32_t)thread->stack_obj;
#else
guard_start = thread->stack_info.start;
#endif
if (mmfar >= guard_start &&
mmfar < guard_start +
MPU_GUARD_ALIGN_AND_SIZE) {
/* Thread stack corruption */
reason = _NANO_ERR_STACK_CHK_FAIL;
}
}
#endif /* CONFIG_HW_STACK_PROTECTION */
}
} else if (SCB->CFSR & SCB_CFSR_IACCVIOL_Msk) {
PR_EXC(" Instruction Access Violation\n");
#if !defined(CONFIG_ARMV7_M_ARMV8_M_FP)
}
#else
} else if (SCB->CFSR & SCB_CFSR_MLSPERR_Msk) {
PR_EXC(" Floating-point lazy state preservation error\n");
}
#endif /* !defined(CONFIG_ARMV7_M_ARMV8_M_FP) */
return reason;
}
/**
*
* @brief Dump bus fault information
*
* See _FaultDump() for example.
*
* @return N/A
*/
static void _BusFault(const NANO_ESF *esf, int fromHardFault)
{
PR_EXC("***** BUS FAULT *****\n");
_FaultThreadShow(esf);
if (SCB->CFSR & SCB_CFSR_STKERR_Msk) {
PR_EXC(" Stacking error\n");
} else if (SCB->CFSR & SCB_CFSR_UNSTKERR_Msk) {
PR_EXC(" Unstacking error\n");
} else if (SCB->CFSR & SCB_CFSR_PRECISERR_Msk) {
PR_EXC(" Precise data bus error\n");
/* In a fault handler, to determine the true faulting address:
* 1. Read and save the BFAR value.
* 2. Read the BFARVALID bit in the BFSR.
* The BFAR address is valid only if this bit is 1.
*
* Software must follow this sequence because another
* higher priority exception might change the BFAR value.
*/
STORE_xFAR(bfar, SCB->BFAR);
if (SCB->CFSR & SCB_CFSR_BFARVALID_Msk) {
PR_EXC(" Address: 0x%x\n", bfar);
if (fromHardFault) {
/* clear SCB_CFSR_BFAR[VALID] to reset */
SCB->CFSR &= ~SCB_CFSR_BFARVALID_Msk;
}
}
/* it's possible to have both a precise and imprecise fault */
if (SCB->CFSR & SCB_CFSR_IMPRECISERR_Msk) {
PR_EXC(" Imprecise data bus error\n");
}
} else if (SCB->CFSR & SCB_CFSR_IMPRECISERR_Msk) {
PR_EXC(" Imprecise data bus error\n");
} else if (SCB->CFSR & SCB_CFSR_IBUSERR_Msk) {
PR_EXC(" Instruction bus error\n");
#if !defined(CONFIG_ARMV7_M_ARMV8_M_FP)
}
#else
} else if (SCB->CFSR & SCB_CFSR_LSPERR_Msk) {
PR_EXC(" Floating-point lazy state preservation error\n");
}
#endif /* !defined(CONFIG_ARMV7_M_ARMV8_M_FP) */
#if defined(CONFIG_ARMV8_M_MAINLINE)
/* clear BSFR sticky bits */
SCB->CFSR |= SCB_CFSR_BUSFAULTSR_Msk;
#endif /* CONFIG_ARMV8_M_MAINLINE */
}
/**
*
* @brief Dump usage fault information
*
* See _FaultDump() for example.
*
* @return error code to identify the fatal error reason
*/
static u32_t _UsageFault(const NANO_ESF *esf)
{
u32_t reason = _NANO_ERR_HW_EXCEPTION;
PR_EXC("***** USAGE FAULT *****\n");
_FaultThreadShow(esf);
/* bits are sticky: they stack and must be reset */
if (SCB->CFSR & SCB_CFSR_DIVBYZERO_Msk) {
PR_EXC(" Division by zero\n");
}
if (SCB->CFSR & SCB_CFSR_UNALIGNED_Msk) {
PR_EXC(" Unaligned memory access\n");
}
#if defined(CONFIG_ARMV8_M_MAINLINE)
if (SCB->CFSR & SCB_CFSR_STKOF_Msk) {
PR_EXC(" Stack overflow\n");
#if defined(CONFIG_HW_STACK_PROTECTION)
/* Stack Overflows are reported as stack
* corruption errors.
*/
reason = _NANO_ERR_STACK_CHK_FAIL;
#endif /* CONFIG_HW_STACK_PROTECTION */
}
#endif /* CONFIG_ARMV8_M_MAINLINE */
if (SCB->CFSR & SCB_CFSR_NOCP_Msk) {
PR_EXC(" No coprocessor instructions\n");
}
if (SCB->CFSR & SCB_CFSR_INVPC_Msk) {
PR_EXC(" Illegal load of EXC_RETURN into PC\n");
}
if (SCB->CFSR & SCB_CFSR_INVSTATE_Msk) {
PR_EXC(" Illegal use of the EPSR\n");
}
if (SCB->CFSR & SCB_CFSR_UNDEFINSTR_Msk) {
PR_EXC(" Attempt to execute undefined instruction\n");
}
/* clear USFR sticky bits */
SCB->CFSR |= SCB_CFSR_USGFAULTSR_Msk;
return reason;
}
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
/**
*
* @brief Dump secure fault information
*
* See _FaultDump() for example.
*
* @return N/A
*/
static void _SecureFault(const NANO_ESF *esf)
{
PR_EXC("***** SECURE FAULT *****\n");
_FaultThreadShow(esf);
STORE_xFAR(sfar, SAU->SFAR);
if (SAU->SFSR & SAU_SFSR_SFARVALID_Msk) {
PR_EXC(" Address: 0x%x\n", sfar);
}
/* bits are sticky: they stack and must be reset */
if (SAU->SFSR & SAU_SFSR_INVEP_Msk) {
PR_EXC(" Invalid entry point\n");
} else if (SAU->SFSR & SAU_SFSR_INVIS_Msk) {
PR_EXC(" Invalid integrity signature\n");
} else if (SAU->SFSR & SAU_SFSR_INVER_Msk) {
PR_EXC(" Invalid exception return\n");
} else if (SAU->SFSR & SAU_SFSR_AUVIOL_Msk) {
PR_EXC(" Attribution unit violation\n");
} else if (SAU->SFSR & SAU_SFSR_INVTRAN_Msk) {
PR_EXC(" Invalid transition\n");
} else if (SAU->SFSR & SAU_SFSR_LSPERR_Msk) {
PR_EXC(" Lazy state preservation\n");
} else if (SAU->SFSR & SAU_SFSR_LSERR_Msk) {
PR_EXC(" Lazy state error\n");
}
/* clear SFSR sticky bits */
SAU->SFSR |= 0xFF;
}
#endif /* defined(CONFIG_ARM_SECURE_FIRMWARE) */
/**
*
* @brief Dump debug monitor exception information
*
* See _FaultDump() for example.
*
* @return N/A
*/
static void _DebugMonitor(const NANO_ESF *esf)
{
ARG_UNUSED(esf);
PR_EXC("***** Debug monitor exception (not implemented) *****\n");
}
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
/**
*
* @brief Dump hard fault information
*
* See _FaultDump() for example.
*
* @return error code to identify the fatal error reason
*/
static u32_t _HardFault(const NANO_ESF *esf)
{
u32_t reason = _NANO_ERR_HW_EXCEPTION;
PR_EXC("***** HARD FAULT *****\n");
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
_FaultThreadShow(esf);
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
if (SCB->HFSR & SCB_HFSR_VECTTBL_Msk) {
PR_EXC(" Bus fault on vector table read\n");
} else if (SCB->HFSR & SCB_HFSR_FORCED_Msk) {
PR_EXC(" Fault escalation (see below)\n");
if (SCB_MMFSR) {
reason = _MpuFault(esf, 1);
} else if (SCB_BFSR) {
_BusFault(esf, 1);
} else if (SCB_UFSR) {
reason = _UsageFault(esf);
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
} else if (SAU->SFSR) {
_SecureFault(esf);
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
}
}
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
return reason;
}
/**
*
* @brief Dump reserved exception information
*
* See _FaultDump() for example.
*
* @return N/A
*/
static void _ReservedException(const NANO_ESF *esf, int fault)
{
ARG_UNUSED(esf);
PR_EXC("***** %s %d) *****\n",
fault < 16 ? "Reserved Exception (" : "Spurious interrupt (IRQ ",
fault - 16);
}
/**
*
* @brief Dump information regarding fault (FAULT_DUMP == 2)
*
* Dump information regarding the fault when CONFIG_FAULT_DUMP is set to 2
* (long form), and return the error code for the kernel to identify the fatal
* error reason.
*
* eg. (precise bus error escalated to hard fault):
*
* Executing thread ID (thread): 0x200000dc
* Faulting instruction address: 0x000011d3
* ***** HARD FAULT *****
* Fault escalation (see below)
* ***** BUS FAULT *****
* Precise data bus error
* Address: 0xff001234
*
* @return error code to identify the fatal error reason
*/
static u32_t _FaultDump(const NANO_ESF *esf, int fault)
{
u32_t reason = _NANO_ERR_HW_EXCEPTION;
switch (fault) {
case 3:
reason = _HardFault(esf);
break;
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
/* HardFault is used for all fault conditions on ARMv6-M. */
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
case 4:
reason = _MpuFault(esf, 0);
break;
case 5:
_BusFault(esf, 0);
break;
case 6:
reason = _UsageFault(esf);
break;
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
case 7:
_SecureFault(esf);
break;
#endif /* CONFIG_ARM_SECURE_FIRMWARE */
case 12:
_DebugMonitor(esf);
break;
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
default:
_ReservedException(esf, fault);
break;
}
return reason;
}
#endif /* FAULT_DUMP == 2 */
/**
*
* @brief Fault handler
*
* This routine is called when fatal error conditions are detected by hardware
* and is responsible only for reporting the error. Once reported, it then
* invokes the user provided routine _SysFatalErrorHandler() which is
* responsible for implementing the error handling policy.
*
* Since the ESF can be either on the MSP or PSP depending if an exception or
* interrupt was already being handled, it is passed a pointer to both and has
* to find out on which the ESP is present.
*
* @param esf ESF on the stack, either MSP or PSP depending at what processor
* state the exception was taken.
*
* @param exc_return EXC_RETURN value present in LR after exception entry.
*
* Note: exc_return argument shall only be used by the Fault handler if we are
* building Secure Firmware.
*/
void _Fault(const NANO_ESF *esf, u32_t exc_return)
{
u32_t reason = _NANO_ERR_HW_EXCEPTION;
int fault = SCB->ICSR & SCB_ICSR_VECTACTIVE_Msk;
#if defined(CONFIG_ARM_SECURE_FIRMWARE)
if ((exc_return & EXC_RETURN_INDICATOR_PREFIX) !=
EXC_RETURN_INDICATOR_PREFIX) {
/* Invalid EXC_RETURN value */
_SysFatalErrorHandler(_NANO_ERR_HW_EXCEPTION, esf);
}
if ((exc_return & EXC_RETURN_EXCEPTION_SECURE_Secure) == 0) {
/* Secure Firmware shall only handle Secure Exceptions.
* This is a fatal error.
*/
_SysFatalErrorHandler(_NANO_ERR_HW_EXCEPTION, esf);
}
if (exc_return & EXC_RETURN_RETURN_STACK_Secure) {
/* Exception entry occurred in Secure stack. */
FAULT_DUMP(reason, esf, fault);
} else {
/* Exception entry occurred in Non-Secure stack. Therefore, the
* exception stack frame is located in the Non-Secure stack.
*/
NANO_ESF *esf_ns;
if (exc_return & EXC_RETURN_MODE_THREAD) {
esf_ns = (NANO_ESF *)__TZ_get_PSP_NS();
if ((SCB->ICSR & SCB_ICSR_RETTOBASE_Msk) == 0) {
PR_EXC("RETTOBASE does not match EXC_RETURN\n");
_SysFatalErrorHandler(_NANO_ERR_HW_EXCEPTION, esf);
}
} else {
esf_ns = (NANO_ESF *)__TZ_get_MSP_NS();
if ((SCB->ICSR & SCB_ICSR_RETTOBASE_Msk) != 0) {
PR_EXC("RETTOBASE does not match EXC_RETURN\n");
_SysFatalErrorHandler(_NANO_ERR_HW_EXCEPTION, esf);
}
}
FAULT_DUMP(reason, esf_ns, fault);
/* Dumping the Secure Stack, too.
* In case a Non-Secure exception interrupted the Secure
* execution, the Secure state has stacked the additional
* state context and the top of the stack contains the
* integrity signature.
*
* In case of a Non-Secure function call the top of the
* stack contains the return address to Secure state.
*/
u32_t *top_of_sec_stack = (u32_t *)esf;
u32_t sec_ret_addr;
#if defined(CONFIG_ARMV7_M_ARMV8_M_FP)
if ((*top_of_sec_stack == INTEGRITY_SIGNATURE_STD) ||
(*top_of_sec_stack == INTEGRITY_SIGNATURE_EXT)) {
#else
if (*top_of_sec_stack == INTEGRITY_SIGNATURE) {
#endif /* CONFIG_ARMV7_M_ARMV8_M_FP */
/* Secure state interrupted by a Non-Secure exception.
* The return address after the additional state
* context, stacked by the Secure code upon
* Non-Secure exception entry.
*/
top_of_sec_stack += ADDITIONAL_STATE_CONTEXT_WORDS;
esf = (const NANO_ESF *)top_of_sec_stack;
sec_ret_addr = esf->pc;
} else {
/* Exception during Non-Secure function call.
* The return address is located on top of stack.
*/
sec_ret_addr = *top_of_sec_stack;
}
PR_EXC(" S instruction address: 0x%x\n", sec_ret_addr);
}
#else
(void) exc_return;
FAULT_DUMP(reason, esf, fault);
#endif /* CONFIG_ARM_SECURE_FIRMWARE*/
_SysFatalErrorHandler(reason, esf);
}
/**
*
* @brief Initialization of fault handling
*
* Turns on the desired hardware faults.
*
* @return N/A
*/
void _FaultInit(void)
{
#if defined(CONFIG_ARMV6_M_ARMV8_M_BASELINE)
#elif defined(CONFIG_ARMV7_M_ARMV8_M_MAINLINE)
SCB->CCR |= SCB_CCR_DIV_0_TRP_Msk;
#else
#error Unknown ARM architecture
#endif /* CONFIG_ARMV6_M_ARMV8_M_BASELINE */
#if defined(CONFIG_BUILTIN_STACK_GUARD)
/* If Stack guarding via SP limit checking is enabled, disable
* SP limit checking inside HardFault and NMI. This is done
* in order to allow for the desired fault logging to execute
* properly in all cases.
*
* Note that this could allow a Secure Firmware Main Stack
* to descend into non-secure region during HardFault and
* NMI exception entry. To prevent from this, non-secure
* memory regions must be located higher than secure memory
* regions.
*
* For Non-Secure Firmware this could allow the Non-Secure Main
* Stack to attempt to descend into secure region, in which case a
* Secure Hard Fault will occur and we can track the fault from there.
*/
SCB->CCR |= SCB_CCR_STKOFHFNMIGN_Msk;
#endif /* CONFIG_BUILTIN_STACK_GUARD */
}