115 lines
3.2 KiB
C
115 lines
3.2 KiB
C
/* elf-fdpic.c: ELF FDPIC memory layout management
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*
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* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
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* Written by David Howells (dhowells@redhat.com)
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation; either version
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* 2 of the License, or (at your option) any later version.
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*/
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#include <linux/sched.h>
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#include <linux/sched/mm.h>
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#include <linux/mm.h>
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#include <linux/fs.h>
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#include <linux/elf-fdpic.h>
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#include <asm/mman.h>
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/*****************************************************************************/
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/*
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* lay out the userspace VM according to our grand design
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*/
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#ifdef CONFIG_MMU
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void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params,
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struct elf_fdpic_params *interp_params,
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unsigned long *start_stack,
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unsigned long *start_brk)
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{
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*start_stack = 0x02200000UL;
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/* if the only executable is a shared object, assume that it is an interpreter rather than
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* a true executable, and map it such that "ld.so --list" comes out right
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*/
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if (!(interp_params->flags & ELF_FDPIC_FLAG_PRESENT) &&
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exec_params->hdr.e_type != ET_EXEC
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) {
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exec_params->load_addr = PAGE_SIZE;
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*start_brk = 0x80000000UL;
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}
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else {
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exec_params->load_addr = 0x02200000UL;
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if ((exec_params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
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ELF_FDPIC_FLAG_INDEPENDENT
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) {
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exec_params->flags &= ~ELF_FDPIC_FLAG_ARRANGEMENT;
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exec_params->flags |= ELF_FDPIC_FLAG_CONSTDISP;
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}
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}
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} /* end elf_fdpic_arch_lay_out_mm() */
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#endif
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/*****************************************************************************/
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/*
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* place non-fixed mmaps firstly in the bottom part of memory, working up, and then in the top part
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* of memory, working down
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*/
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unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
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unsigned long pgoff, unsigned long flags)
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{
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struct vm_area_struct *vma;
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struct vm_unmapped_area_info info;
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if (len > TASK_SIZE)
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return -ENOMEM;
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/* handle MAP_FIXED */
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if (flags & MAP_FIXED)
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return addr;
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/* only honour a hint if we're not going to clobber something doing so */
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if (addr) {
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addr = PAGE_ALIGN(addr);
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vma = find_vma(current->mm, addr);
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if (TASK_SIZE - len >= addr &&
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(!vma || addr + len <= vma->vm_start))
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goto success;
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}
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/* search between the bottom of user VM and the stack grow area */
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info.flags = 0;
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info.length = len;
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info.low_limit = PAGE_SIZE;
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info.high_limit = (current->mm->start_stack - 0x00200000);
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info.align_mask = 0;
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info.align_offset = 0;
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addr = vm_unmapped_area(&info);
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if (!(addr & ~PAGE_MASK))
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goto success;
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VM_BUG_ON(addr != -ENOMEM);
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/* search from just above the WorkRAM area to the top of memory */
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info.low_limit = PAGE_ALIGN(0x80000000);
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info.high_limit = TASK_SIZE;
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addr = vm_unmapped_area(&info);
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if (!(addr & ~PAGE_MASK))
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goto success;
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VM_BUG_ON(addr != -ENOMEM);
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#if 0
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printk("[area] l=%lx (ENOMEM) f='%s'\n",
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len, filp ? filp->f_path.dentry->d_name.name : "");
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#endif
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return -ENOMEM;
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success:
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#if 0
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printk("[area] l=%lx ad=%lx f='%s'\n",
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len, addr, filp ? filp->f_path.dentry->d_name.name : "");
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#endif
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return addr;
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} /* end arch_get_unmapped_area() */
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