Insert KMSAN hooks that make the necessary bookkeeping changes: - poison page shadow and origins in alloc_pages()/free_page(); - clear page shadow and origins in clear_page(), copy_user_highpage(); - copy page metadata in copy_highpage(), wp_page_copy(); - handle vmap()/vunmap()/iounmap(); Signed-off-by: Alexander Potapenko <glider@xxxxxxxxxx> --- Link: https://linux-review.googlesource.com/id/I6d4f53a0e7eab46fa29f0348f3095d9f2e326850 --- arch/x86/include/asm/page_64.h | 13 +++++++++++++ arch/x86/mm/ioremap.c | 3 +++ include/linux/highmem.h | 3 +++ mm/memory.c | 2 ++ mm/page_alloc.c | 14 ++++++++++++++ mm/vmalloc.c | 20 ++++++++++++++++++-- 6 files changed, 53 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h index 4bde0dc66100c..c10547510f1f4 100644 --- a/arch/x86/include/asm/page_64.h +++ b/arch/x86/include/asm/page_64.h @@ -44,14 +44,27 @@ void clear_page_orig(void *page); void clear_page_rep(void *page); void clear_page_erms(void *page); +/* This is an assembly header, avoid including too much of kmsan.h */ +#ifdef CONFIG_KMSAN +void kmsan_unpoison_memory(const void *addr, size_t size); +#endif +__no_sanitize_memory static inline void clear_page(void *page) { +#ifdef CONFIG_KMSAN + /* alternative_call_2() changes @page. */ + void *page_copy = page; +#endif alternative_call_2(clear_page_orig, clear_page_rep, X86_FEATURE_REP_GOOD, clear_page_erms, X86_FEATURE_ERMS, "=D" (page), "0" (page) : "cc", "memory", "rax", "rcx"); +#ifdef CONFIG_KMSAN + /* Clear KMSAN shadow for the pages that have it. */ + kmsan_unpoison_memory(page_copy, PAGE_SIZE); +#endif } void copy_page(void *to, void *from); diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 026031b3b7829..4d0349ecc7cd7 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -17,6 +17,7 @@ #include <linux/cc_platform.h> #include <linux/efi.h> #include <linux/pgtable.h> +#include <linux/kmsan.h> #include <asm/set_memory.h> #include <asm/e820/api.h> @@ -474,6 +475,8 @@ void iounmap(volatile void __iomem *addr) return; } + kmsan_iounmap_page_range((unsigned long)addr, + (unsigned long)addr + get_vm_area_size(p)); memtype_free(p->phys_addr, p->phys_addr + get_vm_area_size(p)); /* Finally remove it */ diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 39bb9b47fa9cd..3e1898a44d7e3 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -6,6 +6,7 @@ #include <linux/kernel.h> #include <linux/bug.h> #include <linux/cacheflush.h> +#include <linux/kmsan.h> #include <linux/mm.h> #include <linux/uaccess.h> #include <linux/hardirq.h> @@ -277,6 +278,7 @@ static inline void copy_user_highpage(struct page *to, struct page *from, vfrom = kmap_local_page(from); vto = kmap_local_page(to); copy_user_page(vto, vfrom, vaddr, to); + kmsan_unpoison_memory(page_address(to), PAGE_SIZE); kunmap_local(vto); kunmap_local(vfrom); } @@ -292,6 +294,7 @@ static inline void copy_highpage(struct page *to, struct page *from) vfrom = kmap_local_page(from); vto = kmap_local_page(to); copy_page(vto, vfrom); + kmsan_copy_page_meta(to, from); kunmap_local(vto); kunmap_local(vfrom); } diff --git a/mm/memory.c b/mm/memory.c index 8f1de811a1dcb..ea9e48daadb15 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -51,6 +51,7 @@ #include <linux/highmem.h> #include <linux/pagemap.h> #include <linux/memremap.h> +#include <linux/kmsan.h> #include <linux/ksm.h> #include <linux/rmap.h> #include <linux/export.h> @@ -3003,6 +3004,7 @@ static vm_fault_t wp_page_copy(struct vm_fault *vmf) put_page(old_page); return 0; } + kmsan_copy_page_meta(new_page, old_page); } if (mem_cgroup_charge(page_folio(new_page), mm, GFP_KERNEL)) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index c5952749ad40b..fa8029b714a81 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -26,6 +26,7 @@ #include <linux/compiler.h> #include <linux/kernel.h> #include <linux/kasan.h> +#include <linux/kmsan.h> #include <linux/module.h> #include <linux/suspend.h> #include <linux/pagevec.h> @@ -1288,6 +1289,7 @@ static __always_inline bool free_pages_prepare(struct page *page, VM_BUG_ON_PAGE(PageTail(page), page); trace_mm_page_free(page, order); + kmsan_free_page(page, order); if (unlikely(PageHWPoison(page)) && !order) { /* @@ -1734,6 +1736,9 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn, { if (early_page_uninitialised(pfn)) return; + if (!kmsan_memblock_free_pages(page, order)) + /* KMSAN will take care of these pages. */ + return; __free_pages_core(page, order); } @@ -3663,6 +3668,14 @@ static struct page *rmqueue_pcplist(struct zone *preferred_zone, /* * Allocate a page from the given zone. Use pcplists for order-0 allocations. */ + +/* + * Do not instrument rmqueue() with KMSAN. This function may call + * __msan_poison_alloca() through a call to set_pfnblock_flags_mask(). + * If __msan_poison_alloca() attempts to allocate pages for the stack depot, it + * may call rmqueue() again, which will result in a deadlock. + */ +__no_sanitize_memory static inline struct page *rmqueue(struct zone *preferred_zone, struct zone *zone, unsigned int order, @@ -5389,6 +5402,7 @@ struct page *__alloc_pages(gfp_t gfp, unsigned int order, int preferred_nid, } trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype); + kmsan_alloc_page(page, order, alloc_gfp); return page; } diff --git a/mm/vmalloc.c b/mm/vmalloc.c index d2a00ad4e1dd1..333de26b3c56e 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -319,6 +319,9 @@ int ioremap_page_range(unsigned long addr, unsigned long end, err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), ioremap_max_page_shift); flush_cache_vmap(addr, end); + if (!err) + kmsan_ioremap_page_range(addr, end, phys_addr, prot, + ioremap_max_page_shift); return err; } @@ -418,7 +421,7 @@ static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, * * This is an internal function only. Do not use outside mm/. */ -void vunmap_range_noflush(unsigned long start, unsigned long end) +void __vunmap_range_noflush(unsigned long start, unsigned long end) { unsigned long next; pgd_t *pgd; @@ -440,6 +443,12 @@ void vunmap_range_noflush(unsigned long start, unsigned long end) arch_sync_kernel_mappings(start, end); } +void vunmap_range_noflush(unsigned long start, unsigned long end) +{ + kmsan_vunmap_range_noflush(start, end); + __vunmap_range_noflush(start, end); +} + /** * vunmap_range - unmap kernel virtual addresses * @addr: start of the VM area to unmap @@ -574,7 +583,7 @@ static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, * * This is an internal function only. Do not use outside mm/. */ -int vmap_pages_range_noflush(unsigned long addr, unsigned long end, +int __vmap_pages_range_noflush(unsigned long addr, unsigned long end, pgprot_t prot, struct page **pages, unsigned int page_shift) { unsigned int i, nr = (end - addr) >> PAGE_SHIFT; @@ -600,6 +609,13 @@ int vmap_pages_range_noflush(unsigned long addr, unsigned long end, return 0; } +int vmap_pages_range_noflush(unsigned long addr, unsigned long end, + pgprot_t prot, struct page **pages, unsigned int page_shift) +{ + kmsan_vmap_pages_range_noflush(addr, end, prot, pages, page_shift); + return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift); +} + /** * vmap_pages_range - map pages to a kernel virtual address * @addr: start of the VM area to map -- 2.34.1.173.g76aa8bc2d0-goog
