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googlers / maze / linux / 268f3be177ce93791da38facc34126b5038cd851 / . / arch / frv / mm / elf-fdpic.c
blob: f5a653033fe0da2966de0112ca4b8a1e1e651f20 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -0700[diff] [blame]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
17/*****************************************************************************/
18/*
19 * lay out the userspace VM according to our grand design
20 */
21#ifdef CONFIG_MMU
22void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params,
23 struct elf_fdpic_params *interp_params,
24 unsigned long *start_stack,
25 unsigned long *start_brk)
26{
27 *start_stack = 0x02200000UL;
28
29 /* if the only executable is a shared object, assume that it is an interpreter rather than
30 * a true executable, and map it such that "ld.so --list" comes out right
31 */
32 if (!(interp_params->flags & ELF_FDPIC_FLAG_PRESENT) &&
33 exec_params->hdr.e_type != ET_EXEC
34 ) {
35 exec_params->load_addr = PAGE_SIZE;
36
37 *start_brk = 0x80000000UL;
38 }
39 else {
40 exec_params->load_addr = 0x02200000UL;
41
42 if ((exec_params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) ==
43 ELF_FDPIC_FLAG_INDEPENDENT
44 ) {
45 exec_params->flags &= ~ELF_FDPIC_FLAG_ARRANGEMENT;
46 exec_params->flags |= ELF_FDPIC_FLAG_CONSTDISP;
47 }
48 }
49
50} /* end elf_fdpic_arch_lay_out_mm() */
51#endif
52
53/*****************************************************************************/
54/*
55 * place non-fixed mmaps firstly in the bottom part of memory, working up, and then in the top part
56 * of memory, working down
57 */
58unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len,
59 unsigned long pgoff, unsigned long flags)
60{
61 struct vm_area_struct *vma;
62 unsigned long limit;
63
64 if (len > TASK_SIZE)
65 return -ENOMEM;
66
67 /* only honour a hint if we're not going to clobber something doing so */
68 if (addr) {
69 addr = PAGE_ALIGN(addr);
70 vma = find_vma(current->mm, addr);
71 if (TASK_SIZE - len >= addr &&
72 (!vma || addr + len <= vma->vm_start))
73 goto success;
74 }
75
76 /* search between the bottom of user VM and the stack grow area */
77 addr = PAGE_SIZE;
78 limit = (current->mm->start_stack - 0x00200000);
79 if (addr + len <= limit) {
80 limit -= len;
81
82 if (addr <= limit) {
83 vma = find_vma(current->mm, PAGE_SIZE);
84 for (; vma; vma = vma->vm_next) {
85 if (addr > limit)
86 break;
87 if (addr + len <= vma->vm_start)
88 goto success;
89 addr = vma->vm_end;
90 }
91 }
92 }
93
94 /* search from just above the WorkRAM area to the top of memory */
95 addr = PAGE_ALIGN(0x80000000);
96 limit = TASK_SIZE - len;
97 if (addr <= limit) {
98 vma = find_vma(current->mm, addr);
99 for (; vma; vma = vma->vm_next) {
100 if (addr > limit)
101 break;
102 if (addr + len <= vma->vm_start)
103 goto success;
104 addr = vma->vm_end;
105 }
106
107 if (!vma && addr <= limit)
108 goto success;
109 }
110
111#if 0
112 printk("[area] l=%lx (ENOMEM) f='%s'\n",
113 len, filp ? filp->f_dentry->d_name.name : "");
114#endif
115 return -ENOMEM;
116
117 success:
118#if 0
119 printk("[area] l=%lx ad=%lx f='%s'\n",
120 len, addr, filp ? filp->f_dentry->d_name.name : "");
121#endif
122 return addr;
123} /* end arch_get_unmapped_area() */