From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f72.google.com (mail-lf0-f72.google.com [209.85.215.72]) by kanga.kvack.org (Postfix) with ESMTP id D082A6B0260 for ; Wed, 11 Oct 2017 19:42:55 -0400 (EDT) Received: by mail-lf0-f72.google.com with SMTP id n69so66680lfn.18 for ; Wed, 11 Oct 2017 16:42:55 -0700 (PDT) Received: from mail-sor-f65.google.com (mail-sor-f65.google.com. [209.85.220.65]) by mx.google.com with SMTPS id t4sor5520158wrb.18.2017.10.11.16.42.53 for (Google Transport Security); Wed, 11 Oct 2017 16:42:54 -0700 (PDT) Subject: Re: [PATCH 01/11] Initialize the mapping of KASan shadow memory References: <20171011082227.20546-1-liuwenliang@huawei.com> <20171011082227.20546-2-liuwenliang@huawei.com> From: Dmitry Osipenko Message-ID: <31b16c9d-48c7-bc0a-51d1-cc6cf892329b@gmail.com> Date: Thu, 12 Oct 2017 02:42:49 +0300 MIME-Version: 1.0 In-Reply-To: <20171011082227.20546-2-liuwenliang@huawei.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Abbott Liu , linux@armlinux.org.uk, aryabinin@virtuozzo.com, afzal.mohd.ma@gmail.com, f.fainelli@gmail.com, labbott@redhat.com, kirill.shutemov@linux.intel.com, mhocko@suse.com, cdall@linaro.org, marc.zyngier@arm.com, catalin.marinas@arm.com, akpm@linux-foundation.org, mawilcox@microsoft.com, tglx@linutronix.de, thgarnie@google.com, keescook@chromium.org, arnd@arndb.de, vladimir.murzin@arm.com, tixy@linaro.org, ard.biesheuvel@linaro.org, robin.murphy@arm.com, mingo@kernel.org, grygorii.strashko@linaro.org Cc: glider@google.com, dvyukov@google.com, opendmb@gmail.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, jiazhenghua@huawei.com, dylix.dailei@huawei.com, zengweilin@huawei.com, heshaoliang@huawei.com On 11.10.2017 11:22, Abbott Liu wrote: > From: Andrey Ryabinin > > This patch initializes KASan shadow region's page table and memory. > There are two stage for KASan initializing: > 1. At early boot stage the whole shadow region is mapped to just > one physical page (kasan_zero_page). It's finished by the function > kasan_early_init which is called by __mmap_switched(arch/arm/kernel/ > head-common.S) > > 2. After the calling of paging_init, we use kasan_zero_page as zero > shadow for some memory that KASan don't need to track, and we alloc > new shadow space for the other memory that KASan need to track. These > issues are finished by the function kasan_init which is call by setup_arch. > > Cc: Andrey Ryabinin > Signed-off-by: Abbott Liu > --- > arch/arm/include/asm/kasan.h | 20 +++ > arch/arm/include/asm/pgalloc.h | 5 +- > arch/arm/include/asm/pgtable.h | 1 + > arch/arm/include/asm/proc-fns.h | 33 +++++ > arch/arm/include/asm/thread_info.h | 4 + > arch/arm/kernel/head-common.S | 4 + > arch/arm/kernel/setup.c | 2 + > arch/arm/mm/Makefile | 5 + > arch/arm/mm/kasan_init.c | 257 +++++++++++++++++++++++++++++++++++++ > mm/kasan/kasan.c | 2 +- > 10 files changed, 331 insertions(+), 2 deletions(-) > create mode 100644 arch/arm/include/asm/kasan.h > create mode 100644 arch/arm/mm/kasan_init.c > > diff --git a/arch/arm/include/asm/kasan.h b/arch/arm/include/asm/kasan.h > new file mode 100644 > index 0000000..90ee60c > --- /dev/null > +++ b/arch/arm/include/asm/kasan.h > @@ -0,0 +1,20 @@ > +#ifndef __ASM_KASAN_H > +#define __ASM_KASAN_H > + > +#ifdef CONFIG_KASAN > + > +#include > +/* > + * Compiler uses shadow offset assuming that addresses start > + * from 0. Kernel addresses don't start from 0, so shadow > + * for kernel really starts from 'compiler's shadow offset' + > + * ('kernel address space start' >> KASAN_SHADOW_SCALE_SHIFT) > + */ > + > +extern void kasan_init(void); > + > +#else > +static inline void kasan_init(void) { } > +#endif > + > +#endif > diff --git a/arch/arm/include/asm/pgalloc.h b/arch/arm/include/asm/pgalloc.h > index b2902a5..10cee6a 100644 > --- a/arch/arm/include/asm/pgalloc.h > +++ b/arch/arm/include/asm/pgalloc.h > @@ -50,8 +50,11 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) > */ > #define pmd_alloc_one(mm,addr) ({ BUG(); ((pmd_t *)2); }) > #define pmd_free(mm, pmd) do { } while (0) > +#ifndef CONFIG_KASAN > #define pud_populate(mm,pmd,pte) BUG() > - > +#else > +#define pud_populate(mm,pmd,pte) do { } while (0) > +#endif > #endif /* CONFIG_ARM_LPAE */ > > extern pgd_t *pgd_alloc(struct mm_struct *mm); > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index 1c46238..fdf343f 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -97,6 +97,7 @@ extern pgprot_t pgprot_s2_device; > #define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN) > #define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY) > #define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN) > +#define PAGE_KERNEL_RO _MOD_PROT(pgprot_kernel, L_PTE_XN | L_PTE_RDONLY) > #define PAGE_KERNEL_EXEC pgprot_kernel > #define PAGE_HYP _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_XN) > #define PAGE_HYP_EXEC _MOD_PROT(pgprot_kernel, L_PTE_HYP | L_PTE_RDONLY) > diff --git a/arch/arm/include/asm/proc-fns.h b/arch/arm/include/asm/proc-fns.h > index f2e1af4..6e26714 100644 > --- a/arch/arm/include/asm/proc-fns.h > +++ b/arch/arm/include/asm/proc-fns.h > @@ -131,6 +131,15 @@ extern void cpu_resume(void); > pg &= ~(PTRS_PER_PGD*sizeof(pgd_t)-1); \ > (pgd_t *)phys_to_virt(pg); \ > }) > + > +#define cpu_set_ttbr0(val) \ > + do { \ > + u64 ttbr = val; \ > + __asm__("mcrr p15, 0, %Q0, %R0, c2" \ > + : : "r" (ttbr)); \ > + } while (0) > + > + > #else > #define cpu_get_pgd() \ > ({ \ > @@ -140,6 +149,30 @@ extern void cpu_resume(void); > pg &= ~0x3fff; \ > (pgd_t *)phys_to_virt(pg); \ > }) > + > +#define cpu_set_ttbr(nr, val) \ > + do { \ > + u64 ttbr = val; \ > + __asm__("mcr p15, 0, %0, c2, c0, 0" \ > + : : "r" (ttbr)); \ > + } while (0) > + > +#define cpu_get_ttbr(nr) \ > + ({ \ > + unsigned long ttbr; \ > + __asm__("mrc p15, 0, %0, c2, c0, 0" \ > + : "=r" (ttbr)); \ > + ttbr; \ > + }) > + > +#define cpu_set_ttbr0(val) \ > + do { \ > + u64 ttbr = val; \ > + __asm__("mcr p15, 0, %0, c2, c0, 0" \ > + : : "r" (ttbr)); \ > + } while (0) > + > + > #endif > > #else /*!CONFIG_MMU */ > diff --git a/arch/arm/include/asm/thread_info.h b/arch/arm/include/asm/thread_info.h > index 1d468b5..52c4858 100644 > --- a/arch/arm/include/asm/thread_info.h > +++ b/arch/arm/include/asm/thread_info.h > @@ -16,7 +16,11 @@ > #include > #include > > +#ifdef CONFIG_KASAN > +#define THREAD_SIZE_ORDER 2 > +#else > #define THREAD_SIZE_ORDER 1 > +#endif > #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) > #define THREAD_START_SP (THREAD_SIZE - 8) > > diff --git a/arch/arm/kernel/head-common.S b/arch/arm/kernel/head-common.S > index 8733012..c17f4a2 100644 > --- a/arch/arm/kernel/head-common.S > +++ b/arch/arm/kernel/head-common.S > @@ -101,7 +101,11 @@ __mmap_switched: > str r2, [r6] @ Save atags pointer > cmp r7, #0 > strne r0, [r7] @ Save control register values > +#ifdef CONFIG_KASAN > + b kasan_early_init > +#else > b start_kernel > +#endif > ENDPROC(__mmap_switched) > > .align 2 > diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c > index 8e9a3e4..985d9a3 100644 > --- a/arch/arm/kernel/setup.c > +++ b/arch/arm/kernel/setup.c > @@ -62,6 +62,7 @@ > #include > #include > #include > +#include > > #include "atags.h" > > @@ -1108,6 +1109,7 @@ void __init setup_arch(char **cmdline_p) > early_ioremap_reset(); > > paging_init(mdesc); > + kasan_init(); > request_standard_resources(mdesc); > > if (mdesc->restart) > diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile > index 950d19b..498c316 100644 > --- a/arch/arm/mm/Makefile > +++ b/arch/arm/mm/Makefile > @@ -106,4 +106,9 @@ obj-$(CONFIG_CACHE_L2X0) += cache-l2x0.o l2c-l2x0-resume.o > obj-$(CONFIG_CACHE_L2X0_PMU) += cache-l2x0-pmu.o > obj-$(CONFIG_CACHE_XSC3L2) += cache-xsc3l2.o > obj-$(CONFIG_CACHE_TAUROS2) += cache-tauros2.o > + > +KASAN_SANITIZE_kasan_init.o := n > +obj-$(CONFIG_KASAN) += kasan_init.o > + > + > obj-$(CONFIG_CACHE_UNIPHIER) += cache-uniphier.o > diff --git a/arch/arm/mm/kasan_init.c b/arch/arm/mm/kasan_init.c > new file mode 100644 > index 0000000..2bf0782 > --- /dev/null > +++ b/arch/arm/mm/kasan_init.c > @@ -0,0 +1,257 @@ > +#include > +#include > +#include > +#include > +#include > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#include "mm.h" > + > +static pgd_t tmp_page_table[PTRS_PER_PGD] __initdata __aligned(1ULL << 14); > + > +pmd_t tmp_pmd_table[PTRS_PER_PMD] __page_aligned_bss; > + > +static __init void *kasan_alloc_block(size_t size, int node) > +{ > + return memblock_virt_alloc_try_nid(size, size, __pa(MAX_DMA_ADDRESS), > + BOOTMEM_ALLOC_ACCESSIBLE, node); > +} > + > +static void __init kasan_early_pmd_populate(unsigned long start, unsigned long end, pud_t *pud) > +{ > + unsigned long addr; > + unsigned long next; > + pmd_t *pmd; > + > + pmd = pmd_offset(pud, start); > + for (addr = start; addr < end;) { > + pmd_populate_kernel(&init_mm, pmd, kasan_zero_pte); > + next = pmd_addr_end(addr, end); > + addr = next; > + flush_pmd_entry(pmd); > + pmd++; > + } > +} > + > +static void __init kasan_early_pud_populate(unsigned long start, unsigned long end, pgd_t *pgd) > +{ > + unsigned long addr; > + unsigned long next; > + pud_t *pud; > + > + pud = pud_offset(pgd, start); > + for (addr = start; addr < end;) { > + next = pud_addr_end(addr, end); > + kasan_early_pmd_populate(addr, next, pud); > + addr = next; > + pud++; > + } > +} > + > +void __init kasan_map_early_shadow(pgd_t *pgdp) > +{ > + int i; > + unsigned long start = KASAN_SHADOW_START; > + unsigned long end = KASAN_SHADOW_END; > + unsigned long addr; > + unsigned long next; > + pgd_t *pgd; > + > + for (i = 0; i < PTRS_PER_PTE; i++) > + set_pte_at(&init_mm, KASAN_SHADOW_START + i*PAGE_SIZE, > + &kasan_zero_pte[i], pfn_pte( > + virt_to_pfn(kasan_zero_page), > + __pgprot(_L_PTE_DEFAULT | L_PTE_DIRTY | L_PTE_XN))); Shouldn't all __pgprot's contain L_PTE_MT_WRITETHROUGH ? [...] -- Dmitry -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org