static inline void vmalloc_fault()

in mm/fault.c [116:170]

• 39 lines of code
• 6 McCabe index (conditional complexity)

static inline void vmalloc_fault(struct pt_regs *regs, int code, unsigned long addr)
{
	pgd_t *pgd, *pgd_k;
	pud_t *pud, *pud_k;
	pmd_t *pmd, *pmd_k;
	pte_t *pte_k;
	int offset;

	/* User mode accesses just cause a SIGSEGV */
	if (user_mode(regs)) {
		do_trap(regs, SIGSEGV, code, addr);
		return;
	}

	/*
	 * Synchronize this task's top level page-table
	 * with the 'reference' page table.
	 *
	 * Do _not_ use "tsk" here. We might be inside
	 * an interrupt in the middle of a task switch..
	 */
	offset = pgd_index(addr);

	pgd = get_pgd() + offset;
	pgd_k = init_mm.pgd + offset;

	if (!pgd_present(*pgd_k)) {
		no_context(regs, addr);
		return;
	}
	set_pgd(pgd, *pgd_k);

	pud = (pud_t *)pgd;
	pud_k = (pud_t *)pgd_k;
	if (!pud_present(*pud_k)) {
		no_context(regs, addr);
		return;
	}

	pmd = pmd_offset(pud, addr);
	pmd_k = pmd_offset(pud_k, addr);
	if (!pmd_present(*pmd_k)) {
		no_context(regs, addr);
		return;
	}
	set_pmd(pmd, *pmd_k);

	pte_k = pte_offset_kernel(pmd_k, addr);
	if (!pte_present(*pte_k)) {
		no_context(regs, addr);
		return;
	}

	flush_tlb_one(addr);
}