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awilliam
GitHub Repository: awilliam/linux-vfio
 Path: blob/master/arch/frv/mm/elf-fdpic.c
10817 views
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/* 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 ([email protected])

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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/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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	unsigned long limit;

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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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	addr = PAGE_SIZE;

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	limit = (current->mm->start_stack - 0x00200000);

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	if (addr + len <= limit) {

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		limit -= len;

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		if (addr <= limit) {

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			vma = find_vma(current->mm, PAGE_SIZE);

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			for (; vma; vma = vma->vm_next) {

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				if (addr > limit)

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					break;

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				if (addr + len <= vma->vm_start)

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					goto success;

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				addr = vma->vm_end;

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			}

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		}

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	}

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	/* search from just above the WorkRAM area to the top of memory */

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	addr = PAGE_ALIGN(0x80000000);

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	limit = TASK_SIZE - len;

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	if (addr <= limit) {

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		vma = find_vma(current->mm, addr);

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		for (; vma; vma = vma->vm_next) {

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			if (addr > limit)

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				break;

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			if (addr + len <= vma->vm_start)

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				goto success;

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			addr = vma->vm_end;

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		}

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		if (!vma && addr <= limit)

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			goto success;

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	}

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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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