kernel/arch/frv/mm/elf-fdpic.c

   1 /* elf-fdpic.c: ELF FDPIC memory layout management
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  */
  11
  12 #include <linux/sched.h>
  13 #include <linux/mm.h>
  14 #include <linux/fs.h>
  15 #include <linux/elf-fdpic.h>
  16 #include <asm/mman.h>
  17
  18 /*****************************************************************************/
  19 /*
  20  * lay out the userspace VM according to our grand design
  21  */
  22 #ifdef CONFIG_MMU
  23 void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params,
  24                                struct elf_fdpic_params *interp_params,
  25                                unsigned long *start_stack,
  26                                unsigned long *start_brk)
  27 {
  28         *start_stack = 0x02200000UL;
  29
  30         /* if the only executable is a shared object, assume that it is an interpreter rather than
  31          * a true executable, and map it such that "ld.so --list" comes out right
  32          */
  33         if (!(interp_params->flags & ELF_FDPIC_FLAG_PRESENT) &&
  34             exec_params->hdr.e_type != ET_EXEC
  35             ) {
  36                 exec_params->load_addr = PAGE_SIZE;
  37
  38                 *start_brk = 0x80000000UL;
  39         }
  40         else {
  41                 exec_params->load_addr = 0x02200000UL;
  42
  43                 if ((exec_params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
  44                     ELF_FDPIC_FLAG_INDEPENDENT
  45                     ) {
  46                         exec_params->flags &= ~ELF_FDPIC_FLAG_ARRANGEMENT;
  47                         exec_params->flags |= ELF_FDPIC_FLAG_CONSTDISP;
  48                 }
  49         }
  50
  51 } /* end elf_fdpic_arch_lay_out_mm() */
  52 #endif
  53
  54 /*****************************************************************************/
  55 /*
  56  * place non-fixed mmaps firstly in the bottom part of memory, working up, and then in the top part
  57  * of memory, working down
  58  */
  59 unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
  60                                      unsigned long pgoff, unsigned long flags)
  61 {
  62         struct vm_area_struct *vma;
  63         struct vm_unmapped_area_info info;
  64
  65         if (len > TASK_SIZE)
  66                 return -ENOMEM;
  67
  68         /* handle MAP_FIXED */
  69         if (flags & MAP_FIXED)
  70                 return addr;
  71
  72         /* only honour a hint if we're not going to clobber something doing so */
  73         if (addr) {
  74                 addr = PAGE_ALIGN(addr);
  75                 vma = find_vma(current->mm, addr);
  76                 if (TASK_SIZE - len >= addr &&
  77                     (!vma || addr + len <= vma->vm_start))
  78                         goto success;
  79         }
  80
  81         /* search between the bottom of user VM and the stack grow area */
  82         info.flags = 0;
  83         info.length = len;
  84         info.low_limit = PAGE_SIZE;
  85         info.high_limit = (current->mm->start_stack - 0x00200000);
  86         info.align_mask = 0;
  87         info.align_offset = 0;
  88         addr = vm_unmapped_area(&info);
  89         if (!(addr & ~PAGE_MASK))
  90                 goto success;
  91         VM_BUG_ON(addr != -ENOMEM);
  92
  93         /* search from just above the WorkRAM area to the top of memory */
  94         info.low_limit = PAGE_ALIGN(0x80000000);
  95         info.high_limit = TASK_SIZE;
  96         addr = vm_unmapped_area(&info);
  97         if (!(addr & ~PAGE_MASK))
  98                 goto success;
  99         VM_BUG_ON(addr != -ENOMEM);
 100
 101 #if 0
 102         printk("[area] l=%lx (ENOMEM) f='%s'\n",
 103                len, filp ? filp->f_path.dentry->d_name.name : "");
 104 #endif
 105         return -ENOMEM;
 106
 107  success:
 108 #if 0
 109         printk("[area] l=%lx ad=%lx f='%s'\n",
 110                len, addr, filp ? filp->f_path.dentry->d_name.name : "");
 111 #endif
 112         return addr;
 113 } /* end arch_get_unmapped_area() */