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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 | /* elf-fdpic.c: ELF FDPIC memory layout management * * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved. * Written by David Howells (dhowells@redhat.com) * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version * 2 of the License, or (at your option) any later version. */ #include <linux/sched.h> #include <linux/sched/mm.h> #include <linux/mm.h> #include <linux/fs.h> #include <linux/elf-fdpic.h> #include <asm/mman.h> /*****************************************************************************/ /* * lay out the userspace VM according to our grand design */ #ifdef CONFIG_MMU void elf_fdpic_arch_lay_out_mm(struct elf_fdpic_params *exec_params, struct elf_fdpic_params *interp_params, unsigned long *start_stack, unsigned long *start_brk) { *start_stack = 0x02200000UL; /* if the only executable is a shared object, assume that it is an interpreter rather than * a true executable, and map it such that "ld.so --list" comes out right */ if (!(interp_params->flags & ELF_FDPIC_FLAG_PRESENT) && exec_params->hdr.e_type != ET_EXEC ) { exec_params->load_addr = PAGE_SIZE; *start_brk = 0x80000000UL; } else { exec_params->load_addr = 0x02200000UL; if ((exec_params->flags & ELF_FDPIC_FLAG_ARRANGEMENT) == ELF_FDPIC_FLAG_INDEPENDENT ) { exec_params->flags &= ~ELF_FDPIC_FLAG_ARRANGEMENT; exec_params->flags |= ELF_FDPIC_FLAG_CONSTDISP; } } } /* end elf_fdpic_arch_lay_out_mm() */ #endif /*****************************************************************************/ /* * place non-fixed mmaps firstly in the bottom part of memory, working up, and then in the top part * of memory, working down */ unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, unsigned long len, unsigned long pgoff, unsigned long flags) { struct vm_area_struct *vma; struct vm_unmapped_area_info info; if (len > TASK_SIZE) return -ENOMEM; /* handle MAP_FIXED */ if (flags & MAP_FIXED) return addr; /* only honour a hint if we're not going to clobber something doing so */ if (addr) { addr = PAGE_ALIGN(addr); vma = find_vma(current->mm, addr); if (TASK_SIZE - len >= addr && (!vma || addr + len <= vm_start_gap(vma))) goto success; } /* search between the bottom of user VM and the stack grow area */ info.flags = 0; info.length = len; info.low_limit = PAGE_SIZE; info.high_limit = (current->mm->start_stack - 0x00200000); info.align_mask = 0; info.align_offset = 0; addr = vm_unmapped_area(&info); if (!(addr & ~PAGE_MASK)) goto success; VM_BUG_ON(addr != -ENOMEM); /* search from just above the WorkRAM area to the top of memory */ info.low_limit = PAGE_ALIGN(0x80000000); info.high_limit = TASK_SIZE; addr = vm_unmapped_area(&info); if (!(addr & ~PAGE_MASK)) goto success; VM_BUG_ON(addr != -ENOMEM); #if 0 printk("[area] l=%lx (ENOMEM) f='%s'\n", len, filp ? filp->f_path.dentry->d_name.name : ""); #endif return -ENOMEM; success: #if 0 printk("[area] l=%lx ad=%lx f='%s'\n", len, addr, filp ? filp->f_path.dentry->d_name.name : ""); #endif return addr; } /* end arch_get_unmapped_area() */ |