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arch: arm64: Add stack check at z_arm64_fatal_error

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Add the stack check function z_arm64_stack_corruption_check at
z_arm64_fatal_error to handle the stack overflow triggered by the
hardware region.

Signed-off-by: Jaxson Han <jaxson.han@arm.com>
This commit is contained in:
Jaxson Han 2023-01-20 10:53:51 +08:00 • committed by Carles Cufí
commit d4dd47b9c5
1 changed files with 51 additions and 1 deletions
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52
arch/arm64/core/fatal.c
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@ -18,6 +18,7 @@
#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);
@ -233,6 +234,47 @@ static void esf_unwind(const z_arch_esf_t *esf)
#endif /* CONFIG_EXCEPTION_DEBUG */
#ifdef CONFIG_ARM64_STACK_PROTECTION
static bool z_arm64_stack_corruption_check(z_arch_esf_t *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).
*/
z_arm64_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(z_arch_esf_t *esf, uint64_t esr, uint64_t far,
uint64_t elr)
{
@ -278,6 +320,12 @@ void z_arm64_fatal_error(unsigned int reason, z_arch_esf_t *esf)
break;
}
#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;
@ -292,8 +340,10 @@ void z_arm64_fatal_error(unsigned int reason, z_arch_esf_t *esf)
LOG_ERR("TPIDRRO: 0x%016llx", read_tpidrro_el0());
#endif /* CONFIG_EXCEPTION_DEBUG */
if (is_recoverable(esf, esr, far, elr))
if (is_recoverable(esf, esr, far, elr) &&
reason != K_ERR_STACK_CHK_FAIL) {
return;
}
}
}