Messages in this thread Patch in this message | | | From | Shile Zhang <> | Subject | [PATCH] mm/hugetlb: Implement ASLR and topdown for hugetlb mappings | Date | Fri, 3 Nov 2017 17:19:17 +0800 |
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merge from arch/x86
Signed-off-by: Shile Zhang <shile.zhang@nokia-sbell.com> --- arch/arm/include/asm/page.h | 1 + arch/arm/mm/hugetlbpage.c | 85 +++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 86 insertions(+)
diff --git a/arch/arm/include/asm/page.h b/arch/arm/include/asm/page.h index 4355f0e..994630f 100644 --- a/arch/arm/include/asm/page.h +++ b/arch/arm/include/asm/page.h @@ -144,6 +144,7 @@ extern void copy_page(void *to, const void *from); #ifdef CONFIG_KUSER_HELPERS #define __HAVE_ARCH_GATE_AREA 1 +#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA #endif #ifdef CONFIG_ARM_LPAE diff --git a/arch/arm/mm/hugetlbpage.c b/arch/arm/mm/hugetlbpage.c index fcafb52..46ed0c8 100644 --- a/arch/arm/mm/hugetlbpage.c +++ b/arch/arm/mm/hugetlbpage.c @@ -45,3 +45,88 @@ int pmd_huge(pmd_t pmd) { return pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT); } + +#ifdef CONFIG_HUGETLB_PAGE +static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *file, + unsigned long addr, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + struct hstate *h = hstate_file(file); + struct vm_unmapped_area_info info; + + info.flags = 0; + info.length = len; + info.low_limit = current->mm->mmap_legacy_base; + info.high_limit = TASK_SIZE; + info.align_mask = PAGE_MASK & ~huge_page_mask(h); + info.align_offset = 0; + return vm_unmapped_area(&info); +} + +static unsigned long hugetlb_get_unmapped_area_topdown(struct file *file, + unsigned long addr0, unsigned long len, + unsigned long pgoff, unsigned long flags) +{ + struct hstate *h = hstate_file(file); + struct vm_unmapped_area_info info; + unsigned long addr; + + info.flags = VM_UNMAPPED_AREA_TOPDOWN; + info.length = len; + info.low_limit = PAGE_SIZE; + info.high_limit = current->mm->mmap_base; + info.align_mask = PAGE_MASK & ~huge_page_mask(h); + info.align_offset = 0; + addr = vm_unmapped_area(&info); + + /* + * A failed mmap() very likely causes application failure, + * so fall back to the bottom-up function here. This scenario + * can happen with large stack limits and large mmap() + * allocations. + */ + if (addr & ~PAGE_MASK) { + VM_BUG_ON(addr != -ENOMEM); + info.flags = 0; + info.low_limit = TASK_UNMAPPED_BASE; + info.high_limit = TASK_SIZE; + addr = vm_unmapped_area(&info); + } + + return addr; +} + +unsigned long +hugetlb_get_unmapped_area(struct file *file, unsigned long addr, + unsigned long len, unsigned long pgoff, unsigned long flags) +{ + struct hstate *h = hstate_file(file); + struct mm_struct *mm = current->mm; + struct vm_area_struct *vma; + + if (len & ~huge_page_mask(h)) + return -EINVAL; + if (len > TASK_SIZE) + return -ENOMEM; + + if (flags & MAP_FIXED) { + if (prepare_hugepage_range(file, addr, len)) + return -EINVAL; + return addr; + } + + if (addr) { + addr = ALIGN(addr, huge_page_size(h)); + vma = find_vma(mm, addr); + if (TASK_SIZE - len >= addr && + (!vma || addr + len <= vma->vm_start)) + return addr; + } + if (mm->get_unmapped_area == arch_get_unmapped_area) + return hugetlb_get_unmapped_area_bottomup(file, addr, len, + pgoff, flags); + else + return hugetlb_get_unmapped_area_topdown(file, addr, len, + pgoff, flags); +} +#endif /* CONFIG_HUGETLB_PAGE */ -- 2.6.2
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