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author | Will Deacon <will@kernel.org> | 2021-06-24 16:05:25 +0300 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2021-06-24 16:05:25 +0300 |
commit | fdceddb06a5ff5ad3894cf9e8124d5af38ac5793 (patch) | |
tree | 1c0e225ad623ec5d6d02c42f400b2202f4567dc0 | |
parent | 81ad4bb1fe91d28d793d801e462a284c7f82cc40 (diff) | |
parent | c275c5c6d50a0518cdb0584e85905d10e7cefc6e (diff) | |
download | linux-fdceddb06a5ff5ad3894cf9e8124d5af38ac5793.tar.xz |
Merge branch 'for-next/mte' into for-next/core
KASAN optimisations for the hardware tagging (MTE) implementation.
* for-next/mte:
kasan: disable freed user page poisoning with HW tags
arm64: mte: handle tags zeroing at page allocation time
kasan: use separate (un)poison implementation for integrated init
mm: arch: remove indirection level in alloc_zeroed_user_highpage_movable()
kasan: speed up mte_set_mem_tag_range
-rw-r--r-- | arch/alpha/include/asm/page.h | 6 | ||||
-rw-r--r-- | arch/arm64/include/asm/mte-kasan.h | 93 | ||||
-rw-r--r-- | arch/arm64/include/asm/mte.h | 4 | ||||
-rw-r--r-- | arch/arm64/include/asm/page.h | 10 | ||||
-rw-r--r-- | arch/arm64/lib/mte.S | 20 | ||||
-rw-r--r-- | arch/arm64/mm/fault.c | 26 | ||||
-rw-r--r-- | arch/arm64/mm/proc.S | 10 | ||||
-rw-r--r-- | arch/ia64/include/asm/page.h | 6 | ||||
-rw-r--r-- | arch/m68k/include/asm/page_no.h | 6 | ||||
-rw-r--r-- | arch/s390/include/asm/page.h | 6 | ||||
-rw-r--r-- | arch/x86/include/asm/page.h | 6 | ||||
-rw-r--r-- | include/linux/gfp.h | 18 | ||||
-rw-r--r-- | include/linux/highmem.h | 43 | ||||
-rw-r--r-- | include/linux/kasan.h | 64 | ||||
-rw-r--r-- | include/linux/page-flags.h | 9 | ||||
-rw-r--r-- | include/trace/events/mmflags.h | 9 | ||||
-rw-r--r-- | mm/kasan/common.c | 4 | ||||
-rw-r--r-- | mm/kasan/hw_tags.c | 32 | ||||
-rw-r--r-- | mm/mempool.c | 6 | ||||
-rw-r--r-- | mm/page_alloc.c | 66 |
20 files changed, 309 insertions, 135 deletions
diff --git a/arch/alpha/include/asm/page.h b/arch/alpha/include/asm/page.h index 268f99b4602b..18f48a6f2ff6 100644 --- a/arch/alpha/include/asm/page.h +++ b/arch/alpha/include/asm/page.h @@ -17,9 +17,9 @@ extern void clear_page(void *page); #define clear_user_page(page, vaddr, pg) clear_page(page) -#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \ - alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vmaddr) -#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#define alloc_zeroed_user_highpage_movable(vma, vaddr) \ + alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, vma, vmaddr) +#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE extern void copy_page(void * _to, void * _from); #define copy_user_page(to, from, vaddr, pg) copy_page(to, from) diff --git a/arch/arm64/include/asm/mte-kasan.h b/arch/arm64/include/asm/mte-kasan.h index ddd4d17cf9a0..d952352bd008 100644 --- a/arch/arm64/include/asm/mte-kasan.h +++ b/arch/arm64/include/asm/mte-kasan.h @@ -48,43 +48,84 @@ static inline u8 mte_get_random_tag(void) return mte_get_ptr_tag(addr); } +static inline u64 __stg_post(u64 p) +{ + asm volatile(__MTE_PREAMBLE "stg %0, [%0], #16" + : "+r"(p) + : + : "memory"); + return p; +} + +static inline u64 __stzg_post(u64 p) +{ + asm volatile(__MTE_PREAMBLE "stzg %0, [%0], #16" + : "+r"(p) + : + : "memory"); + return p; +} + +static inline void __dc_gva(u64 p) +{ + asm volatile(__MTE_PREAMBLE "dc gva, %0" : : "r"(p) : "memory"); +} + +static inline void __dc_gzva(u64 p) +{ + asm volatile(__MTE_PREAMBLE "dc gzva, %0" : : "r"(p) : "memory"); +} + /* * Assign allocation tags for a region of memory based on the pointer tag. * Note: The address must be non-NULL and MTE_GRANULE_SIZE aligned and - * size must be non-zero and MTE_GRANULE_SIZE aligned. + * size must be MTE_GRANULE_SIZE aligned. */ -static inline void mte_set_mem_tag_range(void *addr, size_t size, - u8 tag, bool init) +static inline void mte_set_mem_tag_range(void *addr, size_t size, u8 tag, + bool init) { - u64 curr, end; + u64 curr, mask, dczid_bs, end1, end2, end3; - if (!size) - return; + /* Read DC G(Z)VA block size from the system register. */ + dczid_bs = 4ul << (read_cpuid(DCZID_EL0) & 0xf); curr = (u64)__tag_set(addr, tag); - end = curr + size; + mask = dczid_bs - 1; + /* STG/STZG up to the end of the first block. */ + end1 = curr | mask; + end3 = curr + size; + /* DC GVA / GZVA in [end1, end2) */ + end2 = end3 & ~mask; /* - * 'asm volatile' is required to prevent the compiler to move - * the statement outside of the loop. + * The following code uses STG on the first DC GVA block even if the + * start address is aligned - it appears to be faster than an alignment + * check + conditional branch. Also, if the range size is at least 2 DC + * GVA blocks, the first two loops can use post-condition to save one + * branch each. */ - if (init) { - do { - asm volatile(__MTE_PREAMBLE "stzg %0, [%0]" - : - : "r" (curr) - : "memory"); - curr += MTE_GRANULE_SIZE; - } while (curr != end); - } else { - do { - asm volatile(__MTE_PREAMBLE "stg %0, [%0]" - : - : "r" (curr) - : "memory"); - curr += MTE_GRANULE_SIZE; - } while (curr != end); - } +#define SET_MEMTAG_RANGE(stg_post, dc_gva) \ + do { \ + if (size >= 2 * dczid_bs) { \ + do { \ + curr = stg_post(curr); \ + } while (curr < end1); \ + \ + do { \ + dc_gva(curr); \ + curr += dczid_bs; \ + } while (curr < end2); \ + } \ + \ + while (curr < end3) \ + curr = stg_post(curr); \ + } while (0) + + if (init) + SET_MEMTAG_RANGE(__stzg_post, __dc_gzva); + else + SET_MEMTAG_RANGE(__stg_post, __dc_gva); +#undef SET_MEMTAG_RANGE } void mte_enable_kernel_sync(void); diff --git a/arch/arm64/include/asm/mte.h b/arch/arm64/include/asm/mte.h index bc88a1ced0d7..67bf259ae768 100644 --- a/arch/arm64/include/asm/mte.h +++ b/arch/arm64/include/asm/mte.h @@ -37,6 +37,7 @@ void mte_free_tag_storage(char *storage); /* track which pages have valid allocation tags */ #define PG_mte_tagged PG_arch_2 +void mte_zero_clear_page_tags(void *addr); void mte_sync_tags(pte_t *ptep, pte_t pte); void mte_copy_page_tags(void *kto, const void *kfrom); void mte_thread_init_user(void); @@ -53,6 +54,9 @@ int mte_ptrace_copy_tags(struct task_struct *child, long request, /* unused if !CONFIG_ARM64_MTE, silence the compiler */ #define PG_mte_tagged 0 +static inline void mte_zero_clear_page_tags(void *addr) +{ +} static inline void mte_sync_tags(pte_t *ptep, pte_t pte) { } diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h index 012cffc574e8..ed1b9dcf12b2 100644 --- a/arch/arm64/include/asm/page.h +++ b/arch/arm64/include/asm/page.h @@ -13,6 +13,7 @@ #ifndef __ASSEMBLY__ #include <linux/personality.h> /* for READ_IMPLIES_EXEC */ +#include <linux/types.h> /* for gfp_t */ #include <asm/pgtable-types.h> struct page; @@ -28,9 +29,12 @@ void copy_user_highpage(struct page *to, struct page *from, void copy_highpage(struct page *to, struct page *from); #define __HAVE_ARCH_COPY_HIGHPAGE -#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \ - alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr) -#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, + unsigned long vaddr); +#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE + +void tag_clear_highpage(struct page *to); +#define __HAVE_ARCH_TAG_CLEAR_HIGHPAGE #define clear_user_page(page, vaddr, pg) clear_page(page) #define copy_user_page(to, from, vaddr, pg) copy_page(to, from) diff --git a/arch/arm64/lib/mte.S b/arch/arm64/lib/mte.S index 351537c12f36..e83643b3995f 100644 --- a/arch/arm64/lib/mte.S +++ b/arch/arm64/lib/mte.S @@ -37,6 +37,26 @@ SYM_FUNC_START(mte_clear_page_tags) SYM_FUNC_END(mte_clear_page_tags) /* + * Zero the page and tags at the same time + * + * Parameters: + * x0 - address to the beginning of the page + */ +SYM_FUNC_START(mte_zero_clear_page_tags) + mrs x1, dczid_el0 + and w1, w1, #0xf + mov x2, #4 + lsl x1, x2, x1 + and x0, x0, #(1 << MTE_TAG_SHIFT) - 1 // clear the tag + +1: dc gzva, x0 + add x0, x0, x1 + tst x0, #(PAGE_SIZE - 1) + b.ne 1b + ret +SYM_FUNC_END(mte_zero_clear_page_tags) + +/* * Copy the tags from the source page to the destination one * x0 - address of the destination page * x1 - address of the source page diff --git a/arch/arm64/mm/fault.c b/arch/arm64/mm/fault.c index d0f972a45099..349c488765ca 100644 --- a/arch/arm64/mm/fault.c +++ b/arch/arm64/mm/fault.c @@ -919,3 +919,29 @@ void do_debug_exception(unsigned long addr_if_watchpoint, unsigned int esr, debug_exception_exit(regs); } NOKPROBE_SYMBOL(do_debug_exception); + +/* + * Used during anonymous page fault handling. + */ +struct page *alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, + unsigned long vaddr) +{ + gfp_t flags = GFP_HIGHUSER_MOVABLE | __GFP_ZERO; + + /* + * If the page is mapped with PROT_MTE, initialise the tags at the + * point of allocation and page zeroing as this is usually faster than + * separate DC ZVA and STGM. + */ + if (vma->vm_flags & VM_MTE) + flags |= __GFP_ZEROTAGS; + + return alloc_page_vma(flags, vma, vaddr); +} + +void tag_clear_highpage(struct page *page) +{ + mte_zero_clear_page_tags(page_address(page)); + page_kasan_tag_reset(page); + set_bit(PG_mte_tagged, &page->flags); +} diff --git a/arch/arm64/mm/proc.S b/arch/arm64/mm/proc.S index 9b0ad5ba77d2..35936c5ae1ce 100644 --- a/arch/arm64/mm/proc.S +++ b/arch/arm64/mm/proc.S @@ -46,9 +46,13 @@ #endif #ifdef CONFIG_KASAN_HW_TAGS -#define TCR_KASAN_HW_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1 | TCR_TBID1 +#define TCR_MTE_FLAGS SYS_TCR_EL1_TCMA1 | TCR_TBI1 | TCR_TBID1 #else -#define TCR_KASAN_HW_FLAGS 0 +/* + * The mte_zero_clear_page_tags() implementation uses DC GZVA, which relies on + * TBI being enabled at EL1. + */ +#define TCR_MTE_FLAGS TCR_TBI1 | TCR_TBID1 #endif /* @@ -454,7 +458,7 @@ SYM_FUNC_START(__cpu_setup) msr_s SYS_TFSRE0_EL1, xzr /* set the TCR_EL1 bits */ - mov_q x10, TCR_KASAN_HW_FLAGS + mov_q x10, TCR_MTE_FLAGS orr tcr, tcr, x10 1: #endif diff --git a/arch/ia64/include/asm/page.h b/arch/ia64/include/asm/page.h index f4dc81fa7146..1b990466d540 100644 --- a/arch/ia64/include/asm/page.h +++ b/arch/ia64/include/asm/page.h @@ -82,16 +82,16 @@ do { \ } while (0) -#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \ +#define alloc_zeroed_user_highpage_movable(vma, vaddr) \ ({ \ struct page *page = alloc_page_vma( \ - GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr); \ + GFP_HIGHUSER_MOVABLE | __GFP_ZERO, vma, vaddr); \ if (page) \ flush_dcache_page(page); \ page; \ }) -#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE #define virt_addr_valid(kaddr) pfn_valid(__pa(kaddr) >> PAGE_SHIFT) diff --git a/arch/m68k/include/asm/page_no.h b/arch/m68k/include/asm/page_no.h index 8d0f862ee9d7..c9d0d84158a4 100644 --- a/arch/m68k/include/asm/page_no.h +++ b/arch/m68k/include/asm/page_no.h @@ -13,9 +13,9 @@ extern unsigned long memory_end; #define clear_user_page(page, vaddr, pg) clear_page(page) #define copy_user_page(to, from, vaddr, pg) copy_page(to, from) -#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \ - alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr) -#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#define alloc_zeroed_user_highpage_movable(vma, vaddr) \ + alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, vma, vaddr) +#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE #define __pa(vaddr) ((unsigned long)(vaddr)) #define __va(paddr) ((void *)((unsigned long)(paddr))) diff --git a/arch/s390/include/asm/page.h b/arch/s390/include/asm/page.h index cc98f9b78fd4..479dc76e0eca 100644 --- a/arch/s390/include/asm/page.h +++ b/arch/s390/include/asm/page.h @@ -68,9 +68,9 @@ static inline void copy_page(void *to, void *from) #define clear_user_page(page, vaddr, pg) clear_page(page) #define copy_user_page(to, from, vaddr, pg) copy_page(to, from) -#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \ - alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr) -#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#define alloc_zeroed_user_highpage_movable(vma, vaddr) \ + alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, vma, vaddr) +#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE /* * These are used to make use of C type-checking.. diff --git a/arch/x86/include/asm/page.h b/arch/x86/include/asm/page.h index 7555b48803a8..4d5810c8fab7 100644 --- a/arch/x86/include/asm/page.h +++ b/arch/x86/include/asm/page.h @@ -34,9 +34,9 @@ static inline void copy_user_page(void *to, void *from, unsigned long vaddr, copy_page(to, from); } -#define __alloc_zeroed_user_highpage(movableflags, vma, vaddr) \ - alloc_page_vma(GFP_HIGHUSER | __GFP_ZERO | movableflags, vma, vaddr) -#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#define alloc_zeroed_user_highpage_movable(vma, vaddr) \ + alloc_page_vma(GFP_HIGHUSER_MOVABLE | __GFP_ZERO, vma, vaddr) +#define __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE #ifndef __pa #define __pa(x) __phys_addr((unsigned long)(x)) diff --git a/include/linux/gfp.h b/include/linux/gfp.h index 11da8af06704..e6102dfa4faa 100644 --- a/include/linux/gfp.h +++ b/include/linux/gfp.h @@ -53,8 +53,10 @@ struct vm_area_struct; #define ___GFP_HARDWALL 0x100000u #define ___GFP_THISNODE 0x200000u #define ___GFP_ACCOUNT 0x400000u +#define ___GFP_ZEROTAGS 0x800000u +#define ___GFP_SKIP_KASAN_POISON 0x1000000u #ifdef CONFIG_LOCKDEP -#define ___GFP_NOLOCKDEP 0x800000u +#define ___GFP_NOLOCKDEP 0x2000000u #else #define ___GFP_NOLOCKDEP 0 #endif @@ -229,16 +231,25 @@ struct vm_area_struct; * %__GFP_COMP address compound page metadata. * * %__GFP_ZERO returns a zeroed page on success. + * + * %__GFP_ZEROTAGS returns a page with zeroed memory tags on success, if + * __GFP_ZERO is set. + * + * %__GFP_SKIP_KASAN_POISON returns a page which does not need to be poisoned + * on deallocation. Typically used for userspace pages. Currently only has an + * effect in HW tags mode. */ #define __GFP_NOWARN ((__force gfp_t)___GFP_NOWARN) #define __GFP_COMP ((__force gfp_t)___GFP_COMP) #define __GFP_ZERO ((__force gfp_t)___GFP_ZERO) +#define __GFP_ZEROTAGS ((__force gfp_t)___GFP_ZEROTAGS) +#define __GFP_SKIP_KASAN_POISON ((__force gfp_t)___GFP_SKIP_KASAN_POISON) /* Disable lockdep for GFP context tracking */ #define __GFP_NOLOCKDEP ((__force gfp_t)___GFP_NOLOCKDEP) /* Room for N __GFP_FOO bits */ -#define __GFP_BITS_SHIFT (23 + IS_ENABLED(CONFIG_LOCKDEP)) +#define __GFP_BITS_SHIFT (25 + IS_ENABLED(CONFIG_LOCKDEP)) #define __GFP_BITS_MASK ((__force gfp_t)((1 << __GFP_BITS_SHIFT) - 1)) /** @@ -319,7 +330,8 @@ struct vm_area_struct; #define GFP_DMA __GFP_DMA #define GFP_DMA32 __GFP_DMA32 #define GFP_HIGHUSER (GFP_USER | __GFP_HIGHMEM) -#define GFP_HIGHUSER_MOVABLE (GFP_HIGHUSER | __GFP_MOVABLE) +#define GFP_HIGHUSER_MOVABLE (GFP_HIGHUSER | __GFP_MOVABLE | \ + __GFP_SKIP_KASAN_POISON) #define GFP_TRANSHUGE_LIGHT ((GFP_HIGHUSER_MOVABLE | __GFP_COMP | \ __GFP_NOMEMALLOC | __GFP_NOWARN) & ~__GFP_RECLAIM) #define GFP_TRANSHUGE (GFP_TRANSHUGE_LIGHT | __GFP_DIRECT_RECLAIM) diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 832b49b50c7b..8c6e8e996c87 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -152,28 +152,24 @@ static inline void clear_user_highpage(struct page *page, unsigned long vaddr) } #endif -#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE +#ifndef __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE /** - * __alloc_zeroed_user_highpage - Allocate a zeroed HIGHMEM page for a VMA with caller-specified movable GFP flags - * @movableflags: The GFP flags related to the pages future ability to move like __GFP_MOVABLE + * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move * @vma: The VMA the page is to be allocated for * @vaddr: The virtual address the page will be inserted into * - * This function will allocate a page for a VMA but the caller is expected - * to specify via movableflags whether the page will be movable in the - * future or not + * This function will allocate a page for a VMA that the caller knows will + * be able to migrate in the future using move_pages() or reclaimed * * An architecture may override this function by defining - * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE and providing their own + * __HAVE_ARCH_ALLOC_ZEROED_USER_HIGHPAGE_MOVABLE and providing their own * implementation. */ static inline struct page * -__alloc_zeroed_user_highpage(gfp_t movableflags, - struct vm_area_struct *vma, - unsigned long vaddr) +alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, + unsigned long vaddr) { - struct page *page = alloc_page_vma(GFP_HIGHUSER | movableflags, - vma, vaddr); + struct page *page = alloc_page_vma(GFP_HIGHUSER_MOVABLE, vma, vaddr); if (page) clear_user_highpage(page, vaddr); @@ -182,21 +178,6 @@ __alloc_zeroed_user_highpage(gfp_t movableflags, } #endif -/** - * alloc_zeroed_user_highpage_movable - Allocate a zeroed HIGHMEM page for a VMA that the caller knows can move - * @vma: The VMA the page is to be allocated for - * @vaddr: The virtual address the page will be inserted into - * - * This function will allocate a page for a VMA that the caller knows will - * be able to migrate in the future using move_pages() or reclaimed - */ -static inline struct page * -alloc_zeroed_user_highpage_movable(struct vm_area_struct *vma, - unsigned long vaddr) -{ - return __alloc_zeroed_user_highpage(__GFP_MOVABLE, vma, vaddr); -} - static inline void clear_highpage(struct page *page) { void *kaddr = kmap_atomic(page); @@ -204,6 +185,14 @@ static inline void clear_highpage(struct page *page) kunmap_atomic(kaddr); } +#ifndef __HAVE_ARCH_TAG_CLEAR_HIGHPAGE + +static inline void tag_clear_highpage(struct page *page) +{ +} + +#endif + /* * If we pass in a base or tail page, we can zero up to PAGE_SIZE. * If we pass in a head page, we can zero up to the size of the compound page. diff --git a/include/linux/kasan.h b/include/linux/kasan.h index b1678a61e6a7..a1c7ce5f3e4f 100644 --- a/include/linux/kasan.h +++ b/include/linux/kasan.h @@ -2,6 +2,7 @@ #ifndef _LINUX_KASAN_H #define _LINUX_KASAN_H +#include <linux/bug.h> #include <linux/static_key.h> #include <linux/types.h> @@ -79,14 +80,6 @@ static inline void kasan_disable_current(void) {} #endif /* CONFIG_KASAN_GENERIC || CONFIG_KASAN_SW_TAGS */ -#ifdef CONFIG_KASAN - -struct kasan_cache { - int alloc_meta_offset; - int free_meta_offset; - bool is_kmalloc; -}; - #ifdef CONFIG_KASAN_HW_TAGS DECLARE_STATIC_KEY_FALSE(kasan_flag_enabled); @@ -101,11 +94,14 @@ static inline bool kasan_has_integrated_init(void) return kasan_enabled(); } +void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags); +void kasan_free_pages(struct page *page, unsigned int order); + #else /* CONFIG_KASAN_HW_TAGS */ static inline bool kasan_enabled(void) { - return true; + return IS_ENABLED(CONFIG_KASAN); } static inline bool kasan_has_integrated_init(void) @@ -113,8 +109,30 @@ static inline bool kasan_has_integrated_init(void) return false; } +static __always_inline void kasan_alloc_pages(struct page *page, + unsigned int order, gfp_t flags) +{ + /* Only available for integrated init. */ + BUILD_BUG(); +} + +static __always_inline void kasan_free_pages(struct page *page, + unsigned int order) +{ + /* Only available for integrated init. */ + BUILD_BUG(); +} + #endif /* CONFIG_KASAN_HW_TAGS */ +#ifdef CONFIG_KASAN + +struct kasan_cache { + int alloc_meta_offset; + int free_meta_offset; + bool is_kmalloc; +}; + slab_flags_t __kasan_never_merge(void); static __always_inline slab_flags_t kasan_never_merge(void) { @@ -130,20 +148,20 @@ static __always_inline void kasan_unpoison_range(const void *addr, size_t size) __kasan_unpoison_range(addr, size); } -void __kasan_alloc_pages(struct page *page, unsigned int order, bool init); -static __always_inline void kasan_alloc_pages(struct page *page, +void __kasan_poison_pages(struct page *page, unsigned int order, bool init); +static __always_inline void kasan_poison_pages(struct page *page, unsigned int order, bool init) { if (kasan_enabled()) - __kasan_alloc_pages(page, order, init); + __kasan_poison_pages(page, order, init); } -void __kasan_free_pages(struct page *page, unsigned int order, bool init); -static __always_inline void kasan_free_pages(struct page *page, - unsigned int order, bool init) +void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init); +static __always_inline void kasan_unpoison_pages(struct page *page, + unsigned int order, bool init) { if (kasan_enabled()) - __kasan_free_pages(page, order, init); + __kasan_unpoison_pages(page, order, init); } void __kasan_cache_create(struct kmem_cache *cache, unsigned int *size, @@ -285,21 +303,15 @@ void kasan_restore_multi_shot(bool enabled); #else /* CONFIG_KASAN */ -static inline bool kasan_enabled(void) -{ - return false; -} -static inline bool kasan_has_integrated_init(void) -{ - return false; -} static inline slab_flags_t kasan_never_merge(void) { return 0; } static inline void kasan_unpoison_range(const void *address, size_t size) {} -static inline void kasan_alloc_pages(struct page *page, unsigned int order, bool init) {} -static inline void kasan_free_pages(struct page *page, unsigned int order, bool init) {} +static inline void kasan_poison_pages(struct page *page, unsigned int order, + bool init) {} +static inline void kasan_unpoison_pages(struct page *page, unsigned int order, + bool init) {} static inline void kasan_cache_create(struct kmem_cache *cache, unsigned int *size, slab_flags_t *flags) {} diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 04a34c08e0a6..40e2c5000585 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -138,6 +138,9 @@ enum pageflags { #ifdef CONFIG_64BIT PG_arch_2, #endif +#ifdef CONFIG_KASAN_HW_TAGS + PG_skip_kasan_poison, +#endif __NR_PAGEFLAGS, /* Filesystems */ @@ -443,6 +446,12 @@ TESTCLEARFLAG(Young, young, PF_ANY) PAGEFLAG(Idle, idle, PF_ANY) #endif +#ifdef CONFIG_KASAN_HW_TAGS +PAGEFLAG(SkipKASanPoison, skip_kasan_poison, PF_HEAD) +#else +PAGEFLAG_FALSE(SkipKASanPoison) +#endif + /* * PageReported() is used to track reported free pages within the Buddy * allocator. We can use the non-atomic version of the test and set diff --git a/include/trace/events/mmflags.h b/include/trace/events/mmflags.h index 629c7a0eaff2..390270e00a1d 100644 --- a/include/trace/events/mmflags.h +++ b/include/trace/events/mmflags.h @@ -85,6 +85,12 @@ #define IF_HAVE_PG_ARCH_2(flag,string) #endif +#ifdef CONFIG_KASAN_HW_TAGS +#define IF_HAVE_PG_SKIP_KASAN_POISON(flag,string) ,{1UL << flag, string} +#else +#define IF_HAVE_PG_SKIP_KASAN_POISON(flag,string) +#endif + #define __def_pageflag_names \ {1UL << PG_locked, "locked" }, \ {1UL << PG_waiters, "waiters" }, \ @@ -112,7 +118,8 @@ IF_HAVE_PG_UNCACHED(PG_uncached, "uncached" ) \ IF_HAVE_PG_HWPOISON(PG_hwpoison, "hwpoison" ) \ IF_HAVE_PG_IDLE(PG_young, "young" ) \ IF_HAVE_PG_IDLE(PG_idle, "idle" ) \ -IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) +IF_HAVE_PG_ARCH_2(PG_arch_2, "arch_2" ) \ +IF_HAVE_PG_SKIP_KASAN_POISON(PG_skip_kasan_poison, "skip_kasan_poison") #define show_page_flags(flags) \ (flags) ? __print_flags(flags, "|", \ diff --git a/mm/kasan/common.c b/mm/kasan/common.c index 6bb87f2acd4e..0ecd293af344 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -97,7 +97,7 @@ slab_flags_t __kasan_never_merge(void) return 0; } -void __kasan_alloc_pages(struct page *page, unsigned int order, bool init) +void __kasan_unpoison_pages(struct page *page, unsigned int order, bool init) { u8 tag; unsigned long i; @@ -111,7 +111,7 @@ void __kasan_alloc_pages(struct page *page, unsigned int order, bool init) kasan_unpoison(page_address(page), PAGE_SIZE << order, init); } -void __kasan_free_pages(struct page *page, unsigned int order, bool init) +void __kasan_poison_pages(struct page *page, unsigned int order, bool init) { if (likely(!PageHighMem(page))) kasan_poison(page_address(page), PAGE_SIZE << order, diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c index 4004388b4e4b..ed5e5b833d61 100644 --- a/mm/kasan/hw_tags.c +++ b/mm/kasan/hw_tags.c @@ -238,6 +238,38 @@ struct kasan_track *kasan_get_free_track(struct kmem_cache *cache, return &alloc_meta->free_track[0]; } +void kasan_alloc_pages(struct page *page, unsigned int order, gfp_t flags) +{ + /* + * This condition should match the one in post_alloc_hook() in + * page_alloc.c. + */ + bool init = !want_init_on_free() && want_init_on_alloc(flags); + + if (flags & __GFP_SKIP_KASAN_POISON) + SetPageSkipKASanPoison(page); + + if (flags & __GFP_ZEROTAGS) { + int i; + + for (i = 0; i != 1 << order; ++i) + tag_clear_highpage(page + i); + } else { + kasan_unpoison_pages(page, order, init); + } +} + +void kasan_free_pages(struct page *page, unsigned int order) +{ + /* + * This condition should match the one in free_pages_prepare() in + * page_alloc.c. + */ + bool init = want_init_on_free(); + + kasan_poison_pages(page, order, init); +} + #if IS_ENABLED(CONFIG_KASAN_KUNIT_TEST) void kasan_set_tagging_report_once(bool state) diff --git a/mm/mempool.c b/mm/mempool.c index a258cf4de575..0b8afbec3e35 100644 --- a/mm/mempool.c +++ b/mm/mempool.c @@ -106,7 +106,8 @@ static __always_inline void kasan_poison_element(mempool_t *pool, void *element) if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) kasan_slab_free_mempool(element); else if (pool->alloc == mempool_alloc_pages) - kasan_free_pages(element, (unsigned long)pool->pool_data, false); + kasan_poison_pages(element, (unsigned long)pool->pool_data, + false); } static void kasan_unpoison_element(mempool_t *pool, void *element) @@ -114,7 +115,8 @@ static void kasan_unpoison_element(mempool_t *pool, void *element) if (pool->alloc == mempool_alloc_slab || pool->alloc == mempool_kmalloc) kasan_unpoison_range(element, __ksize(element)); else if (pool->alloc == mempool_alloc_pages) - kasan_alloc_pages(element, (unsigned long)pool->pool_data, false); + kasan_unpoison_pages(element, (unsigned long)pool->pool_data, + false); } static __always_inline void add_element(mempool_t *pool, void *element) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index aaa1655cf682..5ad76e540a22 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -382,7 +382,7 @@ int page_group_by_mobility_disabled __read_mostly; static DEFINE_STATIC_KEY_TRUE(deferred_pages); /* - * Calling kasan_free_pages() only after deferred memory initialization + * Calling kasan_poison_pages() only after deferred memory initialization * has completed. Poisoning pages during deferred memory init will greatly * lengthen the process and cause problem in large memory systems as the * deferred pages initialization is done with interrupt disabled. @@ -394,15 +394,12 @@ static DEFINE_STATIC_KEY_TRUE(deferred_pages); * on-demand allocation and then freed again before the deferred pages * initialization is done, but this is not likely to happen. */ -static inline void kasan_free_nondeferred_pages(struct page *page, int order, - bool init, fpi_t fpi_flags) +static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) { - if (static_branch_unlikely(&deferred_pages)) - return; - if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && - (fpi_flags & FPI_SKIP_KASAN_POISON)) - return; - kasan_free_pages(page, order, init); + return static_branch_unlikely(&deferred_pages) || + (!IS_ENABLED(CONFIG_KASAN_GENERIC) && + (fpi_flags & FPI_SKIP_KASAN_POISON)) || + PageSkipKASanPoison(page); } /* Returns true if the struct page for the pfn is uninitialised */ @@ -453,13 +450,11 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn) return false; } #else -static inline void kasan_free_nondeferred_pages(struct page *page, int order, - bool init, fpi_t fpi_flags) +static inline bool should_skip_kasan_poison(struct page *page, fpi_t fpi_flags) { - if (!IS_ENABLED(CONFIG_KASAN_GENERIC) && - (fpi_flags & FPI_SKIP_KASAN_POISON)) - return; - kasan_free_pages(page, order, init); + return (!IS_ENABLED(CONFIG_KASAN_GENERIC) && + (fpi_flags & FPI_SKIP_KASAN_POISON)) || + PageSkipKASanPoison(page); } static inline bool early_page_uninitialised(unsigned long pfn) @@ -1226,10 +1221,16 @@ out: return ret; } -static void kernel_init_free_pages(struct page *page, int numpages) +static void kernel_init_free_pages(struct page *page, int numpages, bool zero_tags) { int i; + if (zero_tags) { + for (i = 0; i < numpages; i++) + tag_clear_highpage(page + i); + return; + } + /* s390's use of memset() could override KASAN redzones. */ kasan_disable_current(); for (i = 0; i < numpages; i++) { @@ -1245,7 +1246,7 @@ static __always_inline bool free_pages_prepare(struct page *page, unsigned int order, bool check_free, fpi_t fpi_flags) { int bad = 0; - bool init; + bool skip_kasan_poison = should_skip_kasan_poison(page, fpi_flags); VM_BUG_ON_PAGE(PageTail(page), page); @@ -1314,10 +1315,17 @@ static __always_inline bool free_pages_prepare(struct page *page, * With hardware tag-based KASAN, memory tags must be set before the * page becomes unavailable via debug_pagealloc or arch_free_page. */ - init = want_init_on_free(); - if (init && !kasan_has_integrated_init()) - kernel_init_free_pages(page, 1 << order); - kasan_free_nondeferred_pages(page, order, init, fpi_flags); + if (kasan_has_integrated_init()) { + if (!skip_kasan_poison) + kasan_free_pages(page, order); + } else { + bool init = want_init_on_free(); + + if (init) + kernel_init_free_pages(page, 1 << order, false); + if (!skip_kasan_poison) + kasan_poison_pages(page, order, init); + } /* * arch_free_page() can make the page's contents inaccessible. s390 @@ -2324,8 +2332,6 @@ static bool check_new_pages(struct page *page, unsigned int order) inline void post_alloc_hook(struct page *page, unsigned int order, gfp_t gfp_flags) { - bool init; - set_page_private(page, 0); set_page_refcounted(page); @@ -2344,10 +2350,16 @@ inline void post_alloc_hook(struct page *page, unsigned int order, * kasan_alloc_pages and kernel_init_free_pages must be * kept together to avoid discrepancies in behavior. */ - init = !want_init_on_free() && want_init_on_alloc(gfp_flags); - kasan_alloc_pages(page, order, init); - if (init && !kasan_has_integrated_init()) - kernel_init_free_pages(page, 1 << order); + if (kasan_has_integrated_init()) { + kasan_alloc_pages(page, order, gfp_flags); + } else { + bool init = !want_init_on_free() && want_init_on_alloc(gfp_flags); + + kasan_unpoison_pages(page, order, init); + if (init) + kernel_init_free_pages(page, 1 << order, + gfp_flags & __GFP_ZEROTAGS); + } set_page_owner(page, order, gfp_flags); } |