内核文档（Address Space Layout Randomization）： Documentation for /proc/sys/kernel/ — The Linux Kernel documentationhttps://www.kernel.org/doc/Documentation/sysctl/kernel.txt3.15.1?Address Space Layout Randomization (oracle.com)
randomize_va_space
This option can be used to select the type of process address space randomization that is used in the system, for architectures that support this feature.
0Turn the process address space randomization off. This is the default for architectures that do not support this feature anyways, and kernels that are booted with the “norandmaps” parameter.1Make the addresses of mmap base, stack and VDSO page randomized. This, among other things, implies that shared libraries will be loaded to random addresses. Also for PIE-linked binaries, the location of code start is randomized. This is the default if the?CONFIG_COMPAT_BRK?option is enabled.2
Additionally enable heap randomization. This is the default if?CONFIG_COMPAT_BRK?is disabled.
There are a few legacy applications out there (such as some ancient versions of libc.so.5 from 1996) that assume that brk area starts just after the end of the code+bss. These applications break when start of the brk area is randomized. There are however no known non-legacy applications that would be broken this way, so for most systems it is safe to choose full randomization.
Systems with ancient and/or broken binaries should be configured with?CONFIG_COMPAT_BRK?enabled, which excludes the heap from process address space randomization.
地址空间布局随机化默认是开启的，开启了之后进程的虚拟地址空间布局就不再是默认布局，vm_area_struct链接成的结构大概就是这样的：
GNU Linux中修改ASLR的方法：
You can change the setting temporarily by writing a new value to?, for example:?/proc/sys/kernel/randomize_va_space
# echo value > /proc/sys/kernel/randomize_va_space
To change the value permanently, add the setting to?, for example:?/etc/sysctl.conf
kernel.randomize_va_space = value
and run the?sysctl -p?command.
If you change the value of?, you should test your application stack to ensure that it is compatible with the new setting.?randomize_va_便宜美国vpsspace
If necessary, you can disable ASLR for a specific program and its child processes by using the following command:
% setarch `uname -m` -R program [args …]
