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129 lines
3.4 KiB
129 lines
3.4 KiB
/* |
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* This file is subject to the terms and conditions of the GNU General Public |
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* License. See the file "COPYING" in the main directory of this archive |
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* for more details. |
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* |
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* Copyright (C) 2011 Wind River Systems, |
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* written by Ralf Baechle <[email protected]> |
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*/ |
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#include <linux/compiler.h> |
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#include <linux/elf-randomize.h> |
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#include <linux/errno.h> |
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#include <linux/mm.h> |
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#include <linux/mman.h> |
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#include <linux/export.h> |
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#include <linux/personality.h> |
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#include <linux/random.h> |
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#include <linux/sched/signal.h> |
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#include <linux/sched/mm.h> |
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unsigned long shm_align_mask = PAGE_SIZE - 1; /* Sane caches */ |
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EXPORT_SYMBOL(shm_align_mask); |
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#define COLOUR_ALIGN(addr, pgoff) \ |
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((((addr) + shm_align_mask) & ~shm_align_mask) + \ |
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(((pgoff) << PAGE_SHIFT) & shm_align_mask)) |
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enum mmap_allocation_direction {UP, DOWN}; |
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static unsigned long arch_get_unmapped_area_common(struct file *filp, |
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unsigned long addr0, unsigned long len, unsigned long pgoff, |
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unsigned long flags, enum mmap_allocation_direction dir) |
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{ |
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struct mm_struct *mm = current->mm; |
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struct vm_area_struct *vma; |
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unsigned long addr = addr0; |
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int do_color_align; |
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struct vm_unmapped_area_info info; |
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if (unlikely(len > TASK_SIZE)) |
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return -ENOMEM; |
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if (flags & MAP_FIXED) { |
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/* Even MAP_FIXED mappings must reside within TASK_SIZE */ |
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if (TASK_SIZE - len < addr) |
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return -EINVAL; |
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/* |
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* We do not accept a shared mapping if it would violate |
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* cache aliasing constraints. |
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*/ |
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if ((flags & MAP_SHARED) && |
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((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask)) |
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return -EINVAL; |
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return addr; |
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} |
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do_color_align = 0; |
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if (filp || (flags & MAP_SHARED)) |
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do_color_align = 1; |
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/* requesting a specific address */ |
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if (addr) { |
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if (do_color_align) |
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addr = COLOUR_ALIGN(addr, pgoff); |
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else |
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addr = PAGE_ALIGN(addr); |
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vma = find_vma(mm, addr); |
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if (TASK_SIZE - len >= addr && |
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(!vma || addr + len <= vm_start_gap(vma))) |
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return addr; |
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} |
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info.length = len; |
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info.align_mask = do_color_align ? (PAGE_MASK & shm_align_mask) : 0; |
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info.align_offset = pgoff << PAGE_SHIFT; |
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if (dir == DOWN) { |
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info.flags = VM_UNMAPPED_AREA_TOPDOWN; |
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info.low_limit = PAGE_SIZE; |
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info.high_limit = mm->mmap_base; |
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addr = vm_unmapped_area(&info); |
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if (!(addr & ~PAGE_MASK)) |
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return addr; |
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/* |
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* A failed mmap() very likely causes application failure, |
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* so fall back to the bottom-up function here. This scenario |
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* can happen with large stack limits and large mmap() |
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* allocations. |
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*/ |
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} |
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info.flags = 0; |
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info.low_limit = mm->mmap_base; |
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info.high_limit = TASK_SIZE; |
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return vm_unmapped_area(&info); |
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} |
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unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr0, |
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unsigned long len, unsigned long pgoff, unsigned long flags) |
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{ |
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return arch_get_unmapped_area_common(filp, |
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addr0, len, pgoff, flags, UP); |
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} |
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/* |
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* There is no need to export this but sched.h declares the function as |
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* extern so making it static here results in an error. |
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*/ |
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unsigned long arch_get_unmapped_area_topdown(struct file *filp, |
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unsigned long addr0, unsigned long len, unsigned long pgoff, |
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unsigned long flags) |
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{ |
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return arch_get_unmapped_area_common(filp, |
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addr0, len, pgoff, flags, DOWN); |
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} |
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bool __virt_addr_valid(const volatile void *kaddr) |
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{ |
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unsigned long vaddr = (unsigned long)kaddr; |
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if ((vaddr < PAGE_OFFSET) || (vaddr >= MAP_BASE)) |
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return false; |
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return pfn_valid(PFN_DOWN(virt_to_phys(kaddr))); |
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} |
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EXPORT_SYMBOL_GPL(__virt_addr_valid);
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