Loading arch/arm64/Kconfig.debug +10 −0 Original line number Diff line number Diff line Loading @@ -34,4 +34,14 @@ config DEBUG_SET_MODULE_RONX against certain classes of kernel exploits. If in doubt, say "N". config FORCE_PAGES bool "Force lowmem to be mapped with 4K pages" help There are some advanced debug features that can only be done when memory is mapped with pages instead of sections. Enable this option to always map lowmem pages with pages. This may have a performance cost due to increased TLB pressure. If unsure say N. endmenu arch/arm64/mm/mmu.c +72 −0 Original line number Diff line number Diff line Loading @@ -419,6 +419,77 @@ static void __init map_mem(void) /* Limit no longer required. */ memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); } #ifdef CONFIG_FORCE_PAGES static noinline void split_pmd(pmd_t *pmd, unsigned long addr, unsigned long end, unsigned long pfn) { pte_t *pte, *start_pte; start_pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); pte = start_pte; do { set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); pfn++; } while (pte++, addr += PAGE_SIZE, addr != end); set_pmd(pmd, __pmd((__pa(start_pte)) | PMD_TYPE_TABLE)); } static noinline void __init remap_pages(void) { struct memblock_region *reg; for_each_memblock(memory, reg) { phys_addr_t phys_pgd = reg->base; phys_addr_t phys_end = reg->base + reg->size; unsigned long addr_pgd = (unsigned long)__va(phys_pgd); unsigned long end = (unsigned long)__va(phys_end); pmd_t *pmd = NULL; pud_t *pud = NULL; pgd_t *pgd = NULL; unsigned long next_pud, next_pmd, next_pgd; unsigned long addr_pmd, addr_pud; phys_addr_t phys_pud, phys_pmd; if (phys_pgd >= phys_end) break; pgd = pgd_offset(&init_mm, addr_pgd); do { next_pgd = pgd_addr_end(addr_pgd, end); pud = pud_offset(pgd, addr_pgd); addr_pud = addr_pgd; phys_pud = phys_pgd; do { next_pud = pud_addr_end(addr_pud, next_pgd); pmd = pmd_offset(pud, addr_pud); addr_pmd = addr_pud; phys_pmd = phys_pud; do { next_pmd = pmd_addr_end(addr_pmd, next_pud); if (pmd_none(*pmd) || pmd_bad(*pmd)) split_pmd(pmd, addr_pmd, next_pmd, __phys_to_pfn(phys_pmd)); pmd++; phys_pmd += next_pmd - addr_pmd; } while (addr_pmd = next_pmd, addr_pmd < next_pud); phys_pud += next_pud - addr_pud; } while (pud++, addr_pud = next_pud, addr_pud < next_pgd); phys_pgd += next_pgd - addr_pgd; } while (pgd++, addr_pgd = next_pgd, addr_pgd < end); } } #else static void __init remap_pages(void) { } #endif /* * paging_init() sets up the page tables, initialises the zone memory Loading @@ -431,6 +502,7 @@ void __init paging_init(void) init_mem_pgprot(); map_mem(); dma_contiguous_remap(); remap_pages(); /* * Finally flush the caches and tlb to ensure that we're in a Loading Loading
arch/arm64/Kconfig.debug +10 −0 Original line number Diff line number Diff line Loading @@ -34,4 +34,14 @@ config DEBUG_SET_MODULE_RONX against certain classes of kernel exploits. If in doubt, say "N". config FORCE_PAGES bool "Force lowmem to be mapped with 4K pages" help There are some advanced debug features that can only be done when memory is mapped with pages instead of sections. Enable this option to always map lowmem pages with pages. This may have a performance cost due to increased TLB pressure. If unsure say N. endmenu
arch/arm64/mm/mmu.c +72 −0 Original line number Diff line number Diff line Loading @@ -419,6 +419,77 @@ static void __init map_mem(void) /* Limit no longer required. */ memblock_set_current_limit(MEMBLOCK_ALLOC_ANYWHERE); } #ifdef CONFIG_FORCE_PAGES static noinline void split_pmd(pmd_t *pmd, unsigned long addr, unsigned long end, unsigned long pfn) { pte_t *pte, *start_pte; start_pte = early_alloc(PTRS_PER_PTE * sizeof(pte_t)); pte = start_pte; do { set_pte(pte, pfn_pte(pfn, PAGE_KERNEL_EXEC)); pfn++; } while (pte++, addr += PAGE_SIZE, addr != end); set_pmd(pmd, __pmd((__pa(start_pte)) | PMD_TYPE_TABLE)); } static noinline void __init remap_pages(void) { struct memblock_region *reg; for_each_memblock(memory, reg) { phys_addr_t phys_pgd = reg->base; phys_addr_t phys_end = reg->base + reg->size; unsigned long addr_pgd = (unsigned long)__va(phys_pgd); unsigned long end = (unsigned long)__va(phys_end); pmd_t *pmd = NULL; pud_t *pud = NULL; pgd_t *pgd = NULL; unsigned long next_pud, next_pmd, next_pgd; unsigned long addr_pmd, addr_pud; phys_addr_t phys_pud, phys_pmd; if (phys_pgd >= phys_end) break; pgd = pgd_offset(&init_mm, addr_pgd); do { next_pgd = pgd_addr_end(addr_pgd, end); pud = pud_offset(pgd, addr_pgd); addr_pud = addr_pgd; phys_pud = phys_pgd; do { next_pud = pud_addr_end(addr_pud, next_pgd); pmd = pmd_offset(pud, addr_pud); addr_pmd = addr_pud; phys_pmd = phys_pud; do { next_pmd = pmd_addr_end(addr_pmd, next_pud); if (pmd_none(*pmd) || pmd_bad(*pmd)) split_pmd(pmd, addr_pmd, next_pmd, __phys_to_pfn(phys_pmd)); pmd++; phys_pmd += next_pmd - addr_pmd; } while (addr_pmd = next_pmd, addr_pmd < next_pud); phys_pud += next_pud - addr_pud; } while (pud++, addr_pud = next_pud, addr_pud < next_pgd); phys_pgd += next_pgd - addr_pgd; } while (pgd++, addr_pgd = next_pgd, addr_pgd < end); } } #else static void __init remap_pages(void) { } #endif /* * paging_init() sets up the page tables, initialises the zone memory Loading @@ -431,6 +502,7 @@ void __init paging_init(void) init_mem_pgprot(); map_mem(); dma_contiguous_remap(); remap_pages(); /* * Finally flush the caches and tlb to ensure that we're in a Loading
