diff options
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/kasan/Makefile | 2 | ||||
| -rw-r--r-- | mm/kasan/kasan_init.c | 152 | ||||
| -rw-r--r-- | mm/page_alloc.c | 9 | ||||
| -rw-r--r-- | mm/slab.c | 4 | ||||
| -rw-r--r-- | mm/slub.c | 2 |
5 files changed, 162 insertions, 7 deletions
diff --git a/mm/kasan/Makefile b/mm/kasan/Makefile index bd837b8c2f41..64710148941e 100644 --- a/mm/kasan/Makefile +++ b/mm/kasan/Makefile @@ -5,4 +5,4 @@ CFLAGS_REMOVE_kasan.o = -pg # see: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63533 CFLAGS_kasan.o := $(call cc-option, -fno-conserve-stack -fno-stack-protector) -obj-y := kasan.o report.o +obj-y := kasan.o report.o kasan_init.o diff --git a/mm/kasan/kasan_init.c b/mm/kasan/kasan_init.c new file mode 100644 index 000000000000..3f9a41cf0ac6 --- /dev/null +++ b/mm/kasan/kasan_init.c @@ -0,0 +1,152 @@ +/* + * This file contains some kasan initialization code. + * + * Copyright (c) 2015 Samsung Electronics Co., Ltd. + * Author: Andrey Ryabinin <ryabinin.a.a@gmail.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + */ + +#include <linux/bootmem.h> +#include <linux/init.h> +#include <linux/kasan.h> +#include <linux/kernel.h> +#include <linux/memblock.h> +#include <linux/pfn.h> + +#include <asm/page.h> +#include <asm/pgalloc.h> + +/* + * This page serves two purposes: + * - It used as early shadow memory. The entire shadow region populated + * with this page, before we will be able to setup normal shadow memory. + * - Latter it reused it as zero shadow to cover large ranges of memory + * that allowed to access, but not handled by kasan (vmalloc/vmemmap ...). + */ +unsigned char kasan_zero_page[PAGE_SIZE] __page_aligned_bss; + +#if CONFIG_PGTABLE_LEVELS > 3 +pud_t kasan_zero_pud[PTRS_PER_PUD] __page_aligned_bss; +#endif +#if CONFIG_PGTABLE_LEVELS > 2 +pmd_t kasan_zero_pmd[PTRS_PER_PMD] __page_aligned_bss; +#endif +pte_t kasan_zero_pte[PTRS_PER_PTE] __page_aligned_bss; + +static __init void *early_alloc(size_t size, int node) +{ + return memblock_virt_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS), + BOOTMEM_ALLOC_ACCESSIBLE, node); +} + +static void __init zero_pte_populate(pmd_t *pmd, unsigned long addr, + unsigned long end) +{ + pte_t *pte = pte_offset_kernel(pmd, addr); + pte_t zero_pte; + + zero_pte = pfn_pte(PFN_DOWN(__pa(kasan_zero_page)), PAGE_KERNEL); + zero_pte = pte_wrprotect(zero_pte); + + while (addr + PAGE_SIZE <= end) { + set_pte_at(&init_mm, addr, pte, zero_pte); + addr += PAGE_SIZE; + pte = pte_offset_kernel(pmd, addr); + } +} + +static void __init zero_pmd_populate(pud_t *pud, unsigned long addr, + unsigned long end) +{ + pmd_t *pmd = pmd_offset(pud, addr); + unsigned long next; + + do { + next = pmd_addr_end(addr, end); + + if (IS_ALIGNED(addr, PMD_SIZE) && end - addr >= PMD_SIZE) { + pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); + continue; + } + + if (pmd_none(*pmd)) { + pmd_populate_kernel(&init_mm, pmd, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + zero_pte_populate(pmd, addr, next); + } while (pmd++, addr = next, addr != end); +} + +static void __init zero_pud_populate(pgd_t *pgd, unsigned long addr, + unsigned long end) +{ + pud_t *pud = pud_offset(pgd, addr); + unsigned long next; + + do { + next = pud_addr_end(addr, end); + if (IS_ALIGNED(addr, PUD_SIZE) && end - addr >= PUD_SIZE) { + pmd_t *pmd; + + pud_populate(&init_mm, pud, kasan_zero_pmd); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); + continue; + } + + if (pud_none(*pud)) { + pud_populate(&init_mm, pud, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + zero_pmd_populate(pud, addr, next); + } while (pud++, addr = next, addr != end); +} + +/** + * kasan_populate_zero_shadow - populate shadow memory region with + * kasan_zero_page + * @shadow_start - start of the memory range to populate + * @shadow_end - end of the memory range to populate + */ +void __init kasan_populate_zero_shadow(const void *shadow_start, + const void *shadow_end) +{ + unsigned long addr = (unsigned long)shadow_start; + unsigned long end = (unsigned long)shadow_end; + pgd_t *pgd = pgd_offset_k(addr); + unsigned long next; + + do { + next = pgd_addr_end(addr, end); + + if (IS_ALIGNED(addr, PGDIR_SIZE) && end - addr >= PGDIR_SIZE) { + pud_t *pud; + pmd_t *pmd; + + /* + * kasan_zero_pud should be populated with pmds + * at this moment. + * [pud,pmd]_populate*() below needed only for + * 3,2 - level page tables where we don't have + * puds,pmds, so pgd_populate(), pud_populate() + * is noops. + */ + pgd_populate(&init_mm, pgd, kasan_zero_pud); + pud = pud_offset(pgd, addr); + pud_populate(&init_mm, pud, kasan_zero_pmd); + pmd = pmd_offset(pud, addr); + pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); + continue; + } + + if (pgd_none(*pgd)) { + pgd_populate(&init_mm, pgd, + early_alloc(PAGE_SIZE, NUMA_NO_NODE)); + } + zero_pud_populate(pgd, addr, next); + } while (pgd++, addr = next, addr != end); +} diff --git a/mm/page_alloc.c b/mm/page_alloc.c index df959b7d6085..5b5240b7f642 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -1343,12 +1343,15 @@ static int prep_new_page(struct page *page, unsigned int order, gfp_t gfp_flags, set_page_owner(page, order, gfp_flags); /* - * page->pfmemalloc is set when ALLOC_NO_WATERMARKS was necessary to + * page is set pfmemalloc when ALLOC_NO_WATERMARKS was necessary to * allocate the page. The expectation is that the caller is taking * steps that will free more memory. The caller should avoid the page * being used for !PFMEMALLOC purposes. */ - page->pfmemalloc = !!(alloc_flags & ALLOC_NO_WATERMARKS); + if (alloc_flags & ALLOC_NO_WATERMARKS) + set_page_pfmemalloc(page); + else + clear_page_pfmemalloc(page); return 0; } @@ -3345,7 +3348,7 @@ refill: atomic_add(size - 1, &page->_count); /* reset page count bias and offset to start of new frag */ - nc->pfmemalloc = page->pfmemalloc; + nc->pfmemalloc = page_is_pfmemalloc(page); nc->pagecnt_bias = size; nc->offset = size; } diff --git a/mm/slab.c b/mm/slab.c index 200e22412a16..bbd0b47dc6a9 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -1603,7 +1603,7 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, } /* Record if ALLOC_NO_WATERMARKS was set when allocating the slab */ - if (unlikely(page->pfmemalloc)) + if (page_is_pfmemalloc(page)) pfmemalloc_active = true; nr_pages = (1 << cachep->gfporder); @@ -1614,7 +1614,7 @@ static struct page *kmem_getpages(struct kmem_cache *cachep, gfp_t flags, add_zone_page_state(page_zone(page), NR_SLAB_UNRECLAIMABLE, nr_pages); __SetPageSlab(page); - if (page->pfmemalloc) + if (page_is_pfmemalloc(page)) SetPageSlabPfmemalloc(page); if (kmemcheck_enabled && !(cachep->flags & SLAB_NOTRACK)) { diff --git a/mm/slub.c b/mm/slub.c index 816df0016555..f68c0e50f3c0 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1427,7 +1427,7 @@ static struct page *new_slab(struct kmem_cache *s, gfp_t flags, int node) inc_slabs_node(s, page_to_nid(page), page->objects); page->slab_cache = s; __SetPageSlab(page); - if (page->pfmemalloc) + if (page_is_pfmemalloc(page)) SetPageSlabPfmemalloc(page); start = page_address(page); |
