From 072b1b62a6436b71ab951faae4500db2fbed63de Mon Sep 17 00:00:00 2001 From: Steve Capper Date: Thu, 2 May 2013 16:25:42 +0100 Subject: ARM64: mm: Make PAGE_NONE pages read only and no-execute. If we consider the following code sequence: my_pte = pte_modify(entry, myprot); x = pte_write(my_pte); y = pte_exec(my_pte); If myprot comes from a PROT_NONE page, then x and y will both be true which is undesireable behaviour. This patch sets the no-execute and read-only bits for PAGE_NONE such that the code above will return false for both x and y. Signed-off-by: Steve Capper Acked-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/arm64/include/asm/pgtable.h') diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index e333a243bfcc..77b09d6fee23 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -66,7 +66,7 @@ extern pgprot_t pgprot_default; #define _MOD_PROT(p, b) __pgprot_modify(p, 0, b) -#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE) +#define PAGE_NONE __pgprot_modify(pgprot_default, PTE_TYPE_MASK, PTE_PROT_NONE | PTE_RDONLY | PTE_PXN | PTE_UXN) #define PAGE_SHARED _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN) #define PAGE_SHARED_EXEC _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN) #define PAGE_COPY _MOD_PROT(pgprot_default, PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY) @@ -76,7 +76,7 @@ extern pgprot_t pgprot_default; #define PAGE_KERNEL _MOD_PROT(pgprot_default, PTE_PXN | PTE_UXN | PTE_DIRTY) #define PAGE_KERNEL_EXEC _MOD_PROT(pgprot_default, PTE_UXN | PTE_DIRTY) -#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE) +#define __PAGE_NONE __pgprot(((_PAGE_DEFAULT) & ~PTE_TYPE_MASK) | PTE_PROT_NONE | PTE_RDONLY | PTE_PXN | PTE_UXN) #define __PAGE_SHARED __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN) #define __PAGE_SHARED_EXEC __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN) #define __PAGE_COPY __pgprot(_PAGE_DEFAULT | PTE_USER | PTE_NG | PTE_PXN | PTE_UXN | PTE_RDONLY) -- cgit v1.2.3 From 59911ca4325dc7bd95e05c988fef3593b694e62c Mon Sep 17 00:00:00 2001 From: Steve Capper Date: Tue, 28 May 2013 13:35:51 +0100 Subject: ARM64: mm: Move PTE_PROT_NONE bit. Under ARM64, PTEs can be broadly categorised as follows: - Present and valid: Bit #0 is set. The PTE is valid and memory access to the region may fault. - Present and invalid: Bit #0 is clear and bit #1 is set. Represents present memory with PROT_NONE protection. The PTE is an invalid entry, and the user fault handler will raise a SIGSEGV. - Not present (file or swap): Bits #0 and #1 are clear. Memory represented has been paged out. The PTE is an invalid entry, and the fault handler will try and re-populate the memory where necessary. Huge PTEs are block descriptors that have bit #1 clear. If we wish to represent PROT_NONE huge PTEs we then run into a problem as there is no way to distinguish between regular and huge PTEs if we set bit #1. To resolve this ambiguity this patch moves PTE_PROT_NONE from bit #1 to bit #2 and moves PTE_FILE from bit #2 to bit #3. The number of swap/file bits is reduced by 1 as a consequence, leaving 60 bits for file and swap entries. Signed-off-by: Steve Capper Acked-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) (limited to 'arch/arm64/include/asm/pgtable.h') diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 77b09d6fee23..2291de0258ed 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -25,8 +25,8 @@ * Software defined PTE bits definition. */ #define PTE_VALID (_AT(pteval_t, 1) << 0) -#define PTE_PROT_NONE (_AT(pteval_t, 1) << 1) /* only when !PTE_VALID */ -#define PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !pte_present() */ +#define PTE_PROT_NONE (_AT(pteval_t, 1) << 2) /* only when !PTE_VALID */ +#define PTE_FILE (_AT(pteval_t, 1) << 3) /* only when !pte_present() */ #define PTE_DIRTY (_AT(pteval_t, 1) << 55) #define PTE_SPECIAL (_AT(pteval_t, 1) << 56) @@ -281,12 +281,12 @@ extern pgd_t idmap_pg_dir[PTRS_PER_PGD]; /* * Encode and decode a swap entry: - * bits 0-1: present (must be zero) - * bit 2: PTE_FILE - * bits 3-8: swap type + * bits 0, 2: present (must both be zero) + * bit 3: PTE_FILE + * bits 4-8: swap type * bits 9-63: swap offset */ -#define __SWP_TYPE_SHIFT 3 +#define __SWP_TYPE_SHIFT 4 #define __SWP_TYPE_BITS 6 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) @@ -306,15 +306,15 @@ extern pgd_t idmap_pg_dir[PTRS_PER_PGD]; /* * Encode and decode a file entry: - * bits 0-1: present (must be zero) - * bit 2: PTE_FILE - * bits 3-63: file offset / PAGE_SIZE + * bits 0, 2: present (must both be zero) + * bit 3: PTE_FILE + * bits 4-63: file offset / PAGE_SIZE */ #define pte_file(pte) (pte_val(pte) & PTE_FILE) -#define pte_to_pgoff(x) (pte_val(x) >> 3) -#define pgoff_to_pte(x) __pte(((x) << 3) | PTE_FILE) +#define pte_to_pgoff(x) (pte_val(x) >> 4) +#define pgoff_to_pte(x) __pte(((x) << 4) | PTE_FILE) -#define PTE_FILE_MAX_BITS 61 +#define PTE_FILE_MAX_BITS 60 extern int kern_addr_valid(unsigned long addr); -- cgit v1.2.3 From 084bd29810a5689e423d2f085255a3200a03a06e Mon Sep 17 00:00:00 2001 From: Steve Capper Date: Wed, 10 Apr 2013 13:48:00 +0100 Subject: ARM64: mm: HugeTLB support. Add huge page support to ARM64, different huge page sizes are supported depending on the size of normal pages: PAGE_SIZE is 4KB: 2MB - (pmds) these can be allocated at any time. 1024MB - (puds) usually allocated on bootup with the command line with something like: hugepagesz=1G hugepages=6 PAGE_SIZE is 64KB: 512MB - (pmds) usually allocated on bootup via command line. Signed-off-by: Steve Capper Acked-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) (limited to 'arch/arm64/include/asm/pgtable.h') diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 2291de0258ed..21771330f809 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -173,8 +173,17 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, /* * Huge pte definitions. */ -#define pte_huge(pte) ((pte_val(pte) & PTE_TYPE_MASK) == PTE_TYPE_HUGEPAGE) -#define pte_mkhuge(pte) (__pte((pte_val(pte) & ~PTE_TYPE_MASK) | PTE_TYPE_HUGEPAGE)) +#define pte_huge(pte) (!(pte_val(pte) & PTE_TABLE_BIT)) +#define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT)) + +/* + * Hugetlb definitions. + */ +#define HUGE_MAX_HSTATE 2 +#define HPAGE_SHIFT PMD_SHIFT +#define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT) +#define HPAGE_MASK (~(HPAGE_SIZE - 1)) +#define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) #define __HAVE_ARCH_PTE_SPECIAL -- cgit v1.2.3 From af07484863e0c20796081e57093886c22dc16705 Mon Sep 17 00:00:00 2001 From: Steve Capper Date: Fri, 19 Apr 2013 16:23:57 +0100 Subject: ARM64: mm: THP support. Bring Transparent HugePage support to ARM. The size of a transparent huge page depends on the normal page size. A transparent huge page is always represented as a pmd. If PAGE_SIZE is 4KB, THPs are 2MB. If PAGE_SIZE is 64KB, THPs are 512MB. Signed-off-by: Steve Capper Acked-by: Catalin Marinas --- arch/arm64/include/asm/pgtable.h | 55 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 55 insertions(+) (limited to 'arch/arm64/include/asm/pgtable.h') diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h index 21771330f809..720fc4a2be49 100644 --- a/arch/arm64/include/asm/pgtable.h +++ b/arch/arm64/include/asm/pgtable.h @@ -187,6 +187,61 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, #define __HAVE_ARCH_PTE_SPECIAL +/* + * Software PMD bits for THP + */ + +#define PMD_SECT_DIRTY (_AT(pmdval_t, 1) << 55) +#define PMD_SECT_SPLITTING (_AT(pmdval_t, 1) << 57) + +/* + * THP definitions. + */ +#define pmd_young(pmd) (pmd_val(pmd) & PMD_SECT_AF) + +#define __HAVE_ARCH_PMD_WRITE +#define pmd_write(pmd) (!(pmd_val(pmd) & PMD_SECT_RDONLY)) + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +#define pmd_trans_huge(pmd) (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT)) +#define pmd_trans_splitting(pmd) (pmd_val(pmd) & PMD_SECT_SPLITTING) +#endif + +#define PMD_BIT_FUNC(fn,op) \ +static inline pmd_t pmd_##fn(pmd_t pmd) { pmd_val(pmd) op; return pmd; } + +PMD_BIT_FUNC(wrprotect, |= PMD_SECT_RDONLY); +PMD_BIT_FUNC(mkold, &= ~PMD_SECT_AF); +PMD_BIT_FUNC(mksplitting, |= PMD_SECT_SPLITTING); +PMD_BIT_FUNC(mkwrite, &= ~PMD_SECT_RDONLY); +PMD_BIT_FUNC(mkdirty, |= PMD_SECT_DIRTY); +PMD_BIT_FUNC(mkyoung, |= PMD_SECT_AF); +PMD_BIT_FUNC(mknotpresent, &= ~PMD_TYPE_MASK); + +#define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) + +#define pmd_pfn(pmd) (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT) +#define pfn_pmd(pfn,prot) (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot))) +#define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) + +#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK)) + +static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) +{ + const pmdval_t mask = PMD_SECT_USER | PMD_SECT_PXN | PMD_SECT_UXN | + PMD_SECT_RDONLY | PMD_SECT_PROT_NONE | + PMD_SECT_VALID; + pmd_val(pmd) = (pmd_val(pmd) & ~mask) | (pgprot_val(newprot) & mask); + return pmd; +} + +#define set_pmd_at(mm, addr, pmdp, pmd) set_pmd(pmdp, pmd) + +static inline int has_transparent_hugepage(void) +{ + return 1; +} + /* * Mark the prot value as uncacheable and unbufferable. */ -- cgit v1.2.3