diff options
author | Will Deacon <will@kernel.org> | 2021-06-24 14:05:25 +0100 |
---|---|---|
committer | Will Deacon <will@kernel.org> | 2021-06-24 14:05:25 +0100 |
commit | fdceddb06a5ff5ad3894cf9e8124d5af38ac5793 (patch) | |
tree | 1c0e225ad623ec5d6d02c42f400b2202f4567dc0 /arch | |
parent | 81ad4bb1fe91d28d793d801e462a284c7f82cc40 (diff) | |
parent | c275c5c6d50a0518cdb0584e85905d10e7cefc6e (diff) | |
download | linux-fdceddb06a5ff5ad3894cf9e8124d5af38ac5793.tar.bz2 |
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
Diffstat (limited to 'arch')
-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 |
11 files changed, 146 insertions, 47 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)) |