我了解到每个进程的默认堆栈大小限制在8MB以内,mmap_base是根据堆栈大小( rlimit和随机值)计算的。下面的代码是x86(linux/include/uapi/asm-generic/resource.h).中计算mmap_base地址的mmap_base函数
static unsigned long mmap_base(unsigned long rnd)
{
unsigned long gap = rlimit(RLIMIT_STACK);
if (gap < MIN_GAP)
gap = MIN_GAP;
else if (ga
我正在阅读戈朗的内存映射文件的实现之一。首先,他描述了几种访问模式:
// RDONLY maps the memory read-only.
// Attempts to write to the MMap object will result in undefined behavior.
RDONLY = 0
// RDWR maps the memory as read-write. Writes to the MMap object will update the
// underlying file.
RDWR = 1 << iota
// COPY maps the m
我在维基百科上读到了关于mmap的内容,并尝试了这个示例。我和gcc一起编译了这个程序,并在上面运行了valgrind。
下面是valgrind的输出:
# valgrind a.out
==7018== Memcheck, a memory error detector
==7018== Copyright (C) 2002-2011, and GNU GPL'd, by Julian Seward et al.
==7018== Using Valgrind-3.7.0 and LibVEX; rerun with -h for copyright info
==7018== C