Function abort_handler

freebsd/arm/arm/trap-v6.c:278–538

* Abort handler. * * FAR, FSR, and everything what can be lost after enabling * interrupts must be grabbed before the interrupts will be * enabled. Note that when interrupts will be enabled, we * could even migrate to another CPU ... * * TODO: move quick cases to ASM */

 * TODO: move quick cases to ASM
 */
void
abort_handler(struct trapframe *tf, int prefetch)
{
	struct thread *td;
	vm_offset_t far, va;
	int idx, rv;
	uint32_t fsr;
	struct ksig ksig;
	struct proc *p;
	struct pcb *pcb;
	struct vm_map *map;
	struct vmspace *vm;
	vm_prot_t ftype;
	bool usermode;
	int bp_harden, ucode;
#ifdef INVARIANTS
	void *onfault;
#endif

	VM_CNT_INC(v_trap);
	td = curthread;

	fsr = (prefetch) ? cp15_ifsr_get(): cp15_dfsr_get();
#if __ARM_ARCH >= 7
	far = (prefetch) ? cp15_ifar_get() : cp15_dfar_get();
#else
	far = (prefetch) ? TRAPF_PC(tf) : cp15_dfar_get();
#endif

	idx = FSR_TO_FAULT(fsr);
	usermode = TRAPF_USERMODE(tf);	/* Abort came from user mode? */

	/*
	 * Apply BP hardening by flushing the branch prediction cache
	 * for prefaults on kernel addresses.
	 */
	if (__predict_false(prefetch && far > VM_MAXUSER_ADDRESS &&
	    (idx == FAULT_TRAN_L2 || idx == FAULT_PERM_L2))) {
		bp_harden = PCPU_GET(bp_harden_kind);
		if (bp_harden == PCPU_BP_HARDEN_KIND_BPIALL)
			_CP15_BPIALL();
		else if (bp_harden == PCPU_BP_HARDEN_KIND_ICIALLU)
			_CP15_ICIALLU();
	}

	if (usermode)
		td->td_frame = tf;

	CTR6(KTR_TRAP, "%s: fsr %#x (idx %u) far %#x prefetch %u usermode %d",
	    __func__, fsr, idx, far, prefetch, usermode);

	/*
	 * Firstly, handle aborts that are not directly related to mapping.
	 */
	if (__predict_false(idx == FAULT_EA_IMPREC)) {
		abort_imprecise(tf, fsr, prefetch, usermode);
		return;
	}