zephyr/arch/arm64/core/fatal.c

425 lines
11 KiB
C

/*
* Copyright (c) 2019 Carlo Caione <ccaione@baylibre.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
/**
* @file
* @brief Kernel fatal error handler for ARM64 Cortex-A
*
* This module provides the z_arm64_fatal_error() routine for ARM64 Cortex-A
* CPUs and z_arm64_do_kernel_oops() routine to manage software-generated fatal
* exceptions
*/
#include <zephyr/debug/symtab.h>
#include <zephyr/drivers/pm_cpu_ops.h>
#include <zephyr/arch/common/exc_handle.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/poweroff.h>
#include <kernel_arch_func.h>
LOG_MODULE_DECLARE(os, CONFIG_KERNEL_LOG_LEVEL);
#ifdef CONFIG_ARM64_SAFE_EXCEPTION_STACK
K_KERNEL_PINNED_STACK_ARRAY_DEFINE(z_arm64_safe_exception_stacks,
CONFIG_MP_MAX_NUM_CPUS,
CONFIG_ARM64_SAFE_EXCEPTION_STACK_SIZE);
void z_arm64_safe_exception_stack_init(void)
{
int cpu_id;
char *safe_exc_sp;
cpu_id = arch_curr_cpu()->id;
safe_exc_sp = K_KERNEL_STACK_BUFFER(z_arm64_safe_exception_stacks[cpu_id]) +
CONFIG_ARM64_SAFE_EXCEPTION_STACK_SIZE;
arch_curr_cpu()->arch.safe_exception_stack = (uint64_t)safe_exc_sp;
write_sp_el0((uint64_t)safe_exc_sp);
arch_curr_cpu()->arch.current_stack_limit = 0UL;
arch_curr_cpu()->arch.corrupted_sp = 0UL;
}
#endif
#ifdef CONFIG_USERSPACE
Z_EXC_DECLARE(z_arm64_user_string_nlen);
static const struct z_exc_handle exceptions[] = {
Z_EXC_HANDLE(z_arm64_user_string_nlen),
};
#endif /* CONFIG_USERSPACE */
#ifdef CONFIG_EXCEPTION_DEBUG
static void dump_esr(uint64_t esr, bool *dump_far)
{
const char *err;
switch (GET_ESR_EC(esr)) {
case 0b000000: /* 0x00 */
err = "Unknown reason";
break;
case 0b000001: /* 0x01 */
err = "Trapped WFI or WFE instruction execution";
break;
case 0b000011: /* 0x03 */
err = "Trapped MCR or MRC access with (coproc==0b1111) that "
"is not reported using EC 0b000000";
break;
case 0b000100: /* 0x04 */
err = "Trapped MCRR or MRRC access with (coproc==0b1111) "
"that is not reported using EC 0b000000";
break;
case 0b000101: /* 0x05 */
err = "Trapped MCR or MRC access with (coproc==0b1110)";
break;
case 0b000110: /* 0x06 */
err = "Trapped LDC or STC access";
break;
case 0b000111: /* 0x07 */
err = "Trapped access to SVE, Advanced SIMD, or "
"floating-point functionality";
break;
case 0b001100: /* 0x0c */
err = "Trapped MRRC access with (coproc==0b1110)";
break;
case 0b001101: /* 0x0d */
err = "Branch Target Exception";
break;
case 0b001110: /* 0x0e */
err = "Illegal Execution state";
break;
case 0b010001: /* 0x11 */
err = "SVC instruction execution in AArch32 state";
break;
case 0b011000: /* 0x18 */
err = "Trapped MSR, MRS or System instruction execution in "
"AArch64 state, that is not reported using EC "
"0b000000, 0b000001 or 0b000111";
break;
case 0b011001: /* 0x19 */
err = "Trapped access to SVE functionality";
break;
case 0b100000: /* 0x20 */
*dump_far = true;
err = "Instruction Abort from a lower Exception level, that "
"might be using AArch32 or AArch64";
break;
case 0b100001: /* 0x21 */
*dump_far = true;
err = "Instruction Abort taken without a change in Exception "
"level.";
break;
case 0b100010: /* 0x22 */
*dump_far = true;
err = "PC alignment fault exception.";
break;
case 0b100100: /* 0x24 */
*dump_far = true;
err = "Data Abort from a lower Exception level, that might "
"be using AArch32 or AArch64";
break;
case 0b100101: /* 0x25 */
*dump_far = true;
err = "Data Abort taken without a change in Exception level";
break;
case 0b100110: /* 0x26 */
err = "SP alignment fault exception";
break;
case 0b101000: /* 0x28 */
err = "Trapped floating-point exception taken from AArch32 "
"state";
break;
case 0b101100: /* 0x2c */
err = "Trapped floating-point exception taken from AArch64 "
"state.";
break;
case 0b101111: /* 0x2f */
err = "SError interrupt";
break;
case 0b110000: /* 0x30 */
err = "Breakpoint exception from a lower Exception level, "
"that might be using AArch32 or AArch64";
break;
case 0b110001: /* 0x31 */
err = "Breakpoint exception taken without a change in "
"Exception level";
break;
case 0b110010: /* 0x32 */
err = "Software Step exception from a lower Exception level, "
"that might be using AArch32 or AArch64";
break;
case 0b110011: /* 0x33 */
err = "Software Step exception taken without a change in "
"Exception level";
break;
case 0b110100: /* 0x34 */
*dump_far = true;
err = "Watchpoint exception from a lower Exception level, "
"that might be using AArch32 or AArch64";
break;
case 0b110101: /* 0x35 */
*dump_far = true;
err = "Watchpoint exception taken without a change in "
"Exception level.";
break;
case 0b111000: /* 0x38 */
err = "BKPT instruction execution in AArch32 state";
break;
case 0b111100: /* 0x3c */
err = "BRK instruction execution in AArch64 state.";
break;
default:
err = "Unknown";
}
LOG_ERR("ESR_ELn: 0x%016llx", esr);
LOG_ERR(" EC: 0x%llx (%s)", GET_ESR_EC(esr), err);
LOG_ERR(" IL: 0x%llx", GET_ESR_IL(esr));
LOG_ERR(" ISS: 0x%llx", GET_ESR_ISS(esr));
}
static void esf_dump(const struct arch_esf *esf)
{
LOG_ERR("x0: 0x%016llx x1: 0x%016llx", esf->x0, esf->x1);
LOG_ERR("x2: 0x%016llx x3: 0x%016llx", esf->x2, esf->x3);
LOG_ERR("x4: 0x%016llx x5: 0x%016llx", esf->x4, esf->x5);
LOG_ERR("x6: 0x%016llx x7: 0x%016llx", esf->x6, esf->x7);
LOG_ERR("x8: 0x%016llx x9: 0x%016llx", esf->x8, esf->x9);
LOG_ERR("x10: 0x%016llx x11: 0x%016llx", esf->x10, esf->x11);
LOG_ERR("x12: 0x%016llx x13: 0x%016llx", esf->x12, esf->x13);
LOG_ERR("x14: 0x%016llx x15: 0x%016llx", esf->x14, esf->x15);
LOG_ERR("x16: 0x%016llx x17: 0x%016llx", esf->x16, esf->x17);
LOG_ERR("x18: 0x%016llx lr: 0x%016llx", esf->x18, esf->lr);
}
#ifdef CONFIG_EXCEPTION_STACK_TRACE
static void esf_unwind(const struct arch_esf *esf)
{
/*
* For GCC:
*
* ^ +-----------------+
* | | |
* | | |
* | | |
* | | |
* | | function stack |
* | | |
* | | |
* | | |
* | | |
* | +-----------------+
* | | LR |
* | +-----------------+
* | | previous FP | <---+ FP
* + +-----------------+
*/
uint64_t *fp = (uint64_t *) esf->fp;
unsigned int count = 0;
uint64_t lr;
LOG_ERR("");
for (int i = 0; (fp != NULL) && (i < CONFIG_EXCEPTION_STACK_TRACE_MAX_FRAMES); i++) {
lr = fp[1];
#ifdef CONFIG_SYMTAB
uint32_t offset = 0;
const char *name = symtab_find_symbol_name(lr, &offset);
LOG_ERR("backtrace %2d: fp: 0x%016llx lr: 0x%016llx [%s+0x%x]",
count++, (uint64_t) fp, lr, name, offset);
#else
LOG_ERR("backtrace %2d: fp: 0x%016llx lr: 0x%016llx",
count++, (uint64_t) fp, lr);
#endif
fp = (uint64_t *) fp[0];
}
LOG_ERR("");
}
#endif
#endif /* CONFIG_EXCEPTION_DEBUG */
#ifdef CONFIG_ARM64_STACK_PROTECTION
static bool z_arm64_stack_corruption_check(struct arch_esf *esf, uint64_t esr, uint64_t far)
{
uint64_t sp, sp_limit, guard_start;
/* 0x25 means data abort from current EL */
if (GET_ESR_EC(esr) == 0x25) {
sp_limit = arch_curr_cpu()->arch.current_stack_limit;
guard_start = sp_limit - Z_ARM64_STACK_GUARD_SIZE;
sp = arch_curr_cpu()->arch.corrupted_sp;
if ((sp != 0 && sp <= sp_limit) || (guard_start <= far && far <= sp_limit)) {
#ifdef CONFIG_FPU_SHARING
/*
* We are in exception stack, and now we are sure the stack does overflow,
* so flush the fpu context to its owner, and then set no fpu trap to avoid
* a new nested exception triggered by FPU accessing (var_args).
*/
arch_flush_local_fpu();
write_cpacr_el1(read_cpacr_el1() | CPACR_EL1_FPEN_NOTRAP);
#endif
arch_curr_cpu()->arch.corrupted_sp = 0UL;
LOG_ERR("STACK OVERFLOW FROM KERNEL, SP: 0x%llx OR FAR: 0x%llx INVALID,"
" SP LIMIT: 0x%llx", sp, far, sp_limit);
return true;
}
}
#ifdef CONFIG_USERSPACE
else if ((_current->base.user_options & K_USER) != 0 && GET_ESR_EC(esr) == 0x24) {
sp_limit = (uint64_t)_current->stack_info.start;
guard_start = sp_limit - Z_ARM64_STACK_GUARD_SIZE;
sp = esf->sp;
if (sp <= sp_limit || (guard_start <= far && far <= sp_limit)) {
LOG_ERR("STACK OVERFLOW FROM USERSPACE, SP: 0x%llx OR FAR: 0x%llx INVALID,"
" SP LIMIT: 0x%llx", sp, far, sp_limit);
return true;
}
}
#endif
return false;
}
#endif
static bool is_recoverable(struct arch_esf *esf, uint64_t esr, uint64_t far,
uint64_t elr)
{
if (!esf)
return false;
#ifdef CONFIG_USERSPACE
for (int i = 0; i < ARRAY_SIZE(exceptions); i++) {
/* Mask out instruction mode */
uint64_t start = (uint64_t)exceptions[i].start;
uint64_t end = (uint64_t)exceptions[i].end;
if (esf->elr >= start && esf->elr < end) {
esf->elr = (uint64_t)(exceptions[i].fixup);
return true;
}
}
#endif
return false;
}
void z_arm64_fatal_error(unsigned int reason, struct arch_esf *esf)
{
uint64_t esr = 0;
uint64_t elr = 0;
uint64_t far = 0;
uint64_t el;
if (reason != K_ERR_SPURIOUS_IRQ) {
el = read_currentel();
switch (GET_EL(el)) {
case MODE_EL1:
esr = read_esr_el1();
far = read_far_el1();
elr = read_elr_el1();
break;
#if !defined(CONFIG_ARMV8_R)
case MODE_EL3:
esr = read_esr_el3();
far = read_far_el3();
elr = read_elr_el3();
break;
#endif /* CONFIG_ARMV8_R */
}
#ifdef CONFIG_ARM64_STACK_PROTECTION
if (z_arm64_stack_corruption_check(esf, esr, far)) {
reason = K_ERR_STACK_CHK_FAIL;
}
#endif
if (GET_EL(el) != MODE_EL0) {
#ifdef CONFIG_EXCEPTION_DEBUG
bool dump_far = false;
LOG_ERR("ELR_ELn: 0x%016llx", elr);
dump_esr(esr, &dump_far);
if (dump_far)
LOG_ERR("FAR_ELn: 0x%016llx", far);
LOG_ERR("TPIDRRO: 0x%016llx", read_tpidrro_el0());
#endif /* CONFIG_EXCEPTION_DEBUG */
if (is_recoverable(esf, esr, far, elr) &&
reason != K_ERR_STACK_CHK_FAIL) {
return;
}
}
}
#ifdef CONFIG_EXCEPTION_DEBUG
if (esf != NULL) {
esf_dump(esf);
}
#ifdef CONFIG_EXCEPTION_STACK_TRACE
esf_unwind(esf);
#endif /* CONFIG_EXCEPTION_STACK_TRACE */
#endif /* CONFIG_EXCEPTION_DEBUG */
z_fatal_error(reason, esf);
CODE_UNREACHABLE;
}
/**
* @brief Handle a software-generated fatal exception
* (e.g. kernel oops, panic, etc.).
*
* @param esf exception frame
*/
void z_arm64_do_kernel_oops(struct arch_esf *esf)
{
/* x8 holds the exception reason */
unsigned int reason = esf->x8;
#if defined(CONFIG_USERSPACE)
/*
* User mode is only allowed to induce oopses and stack check
* failures via software-triggered system fatal exceptions.
*/
if (((_current->base.user_options & K_USER) != 0) &&
reason != K_ERR_STACK_CHK_FAIL) {
reason = K_ERR_KERNEL_OOPS;
}
#endif
z_arm64_fatal_error(reason, esf);
}
#ifdef CONFIG_USERSPACE
FUNC_NORETURN void arch_syscall_oops(void *ssf_ptr)
{
z_arm64_fatal_error(K_ERR_KERNEL_OOPS, ssf_ptr);
CODE_UNREACHABLE;
}
#endif
#if defined(CONFIG_PM_CPU_OPS_PSCI)
FUNC_NORETURN void arch_system_halt(unsigned int reason)
{
ARG_UNUSED(reason);
(void)arch_irq_lock();
#ifdef CONFIG_POWEROFF
sys_poweroff();
#endif /* CONFIG_POWEROFF */
for (;;) {
/* Spin endlessly as fallback */
}
}
#endif