Re: [Crash-utility] [PATCH v2 3/3] kaslr: get offset by walking page tree

> + */ > +static int > +find_kernel_start(ulong *va, ulong *pa) > +{ > + int i, pgd_idx, pud_idx, pmd_idx, pte_idx; > + uint64_t pgd_pte, pud_pte, pmd_pte, pte; > + > + pgd_idx = pgd_index(__START_KERNEL_map); > + pud_idx = pud_index(__START_KERNEL_map); > + pmd_idx = pmd_index(__START_KERNEL_map); > + pte_idx = pte_index(__START_KERNEL_map); > + > + for (; pgd_idx < PTRS_PER_PGD; pgd_idx++) { > + pgd_pte = ULONG(machdep->pgd + pgd_idx * sizeof(uint64_t)); machdep->pgd is not guaranteed to be aligned by PAGE_SIZE. This could refer to the pgd for userland that resides in the next page. I guess it's necessary to get the 1st pgd entry in the page machdep->pgd belongs to. Like this? pgd_pte = ULONG((machdep->pgd & PHYSICAL_PAGE_MASK) + pgd_idx * sizeof(uint64_t));