【发布时间】：2019-08-13 17:55:03
【问题描述】：
这个问题来自What does SEGMENT_START("text-segment", 0x400000) represent?
从提到的问题中，我了解到内存映射中提到的用于构建可执行文件的地址是指虚拟地址，而不是物理地址。
我一直在使用这两个在线资源来了解可执行文件的内存布局：
https://www.geeksforgeeks.org/memory-layout-of-c-program/
https://www.embeddedrelated.com/showarticle/900.php
两者都暗示可执行文件的“开始”是它的文本段。如果这是真的，并且可执行文件的内存映射引用虚拟地址，为什么我的内存映射中的text-segment 不引用0x0？我的理解是，当加载可执行文件时，操作系统会给它一个虚拟地址范围——从0x00 开始。那么什么占用了0x00 - 0x3FFFFF的虚拟地址范围呢？
什么是/如何确定可执行文件的虚拟地址范围的结束地址？
> uname -a && ld --verbose
Linux LinuxBox 4.20.3-200.fc29.x86_64 #1 SMP Thu Jan 17 15:19:35 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
GNU ld version 2.31.1-15.fc29
Supported emulations:
elf_x86_64
elf32_x86_64
elf_i386
elf_iamcu
elf_l1om
elf_k1om
i386pep
i386pe
using internal linker script:
==================================================
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Copying and distribution of this script, with or without modification,
are permitted in any medium without royalty provided the copyright
notice and this notice are preserved. */
OUTPUT_FORMAT("elf64-x86-64", "elf64-x86-64",
"elf64-x86-64")
OUTPUT_ARCH(i386:x86-64)
ENTRY(_start)
SEARCH_DIR("=/usr/x86_64-redhat-linux/lib64"); SEARCH_DIR("=/usr/lib64"); SEARCH_DIR("=/usr/local/lib64"); SEARCH_DIR("=/lib64"); SEARCH_DIR("=/usr/x86_64-redhat-linux/lib"); SEARCH_DIR("=/usr/local/lib"); SEARCH_DIR("=/lib"); SEARCH_DIR("=/usr/lib");
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==================================================
【问题讨论】：
标签： linker binaryfiles ld binutils memory-layout