是的,mmap和mprotect是正确的功能。我不明白你当前的接受程度有什么问题,也就是说,你的意思是“我已经用mprotect()尝试过memalign()。但是从memalign中我可以得到什么,memalign从进程堆中分配内存“。
下面是一个例子如何创建一个写保护的存储区:
#include <fcntl.h>
#include <signal.h>
#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
static int alloc_size;
static char* memory;
void segv_handler (int signal_number) {
printf ("memory accessed!\n");
mprotect (memory, alloc_size, PROT_READ | PROT_WRITE);
}
int main() {
int fd;
struct sigaction sa;
/* Install segv_handler as the handler for SIGSEGV. */
memset (&sa, 0, sizeof (sa));
sa.sa_handler = &segv_handler;
sigaction (SIGSEGV, &sa, NULL);
/* Allocate one page of memory by mapping /dev/zero. Map the memory
as write-only, initially. */
alloc_size = getpagesize();
fd = open ("/dev/zero", O_RDONLY);
memory = mmap (NULL, alloc_size, PROT_WRITE, MAP_PRIVATE, fd, 0);
close (fd);
/* Write to the page to obtain a private copy. */
memory[0] = 0;
/* Make the memory unwritable. */
mprotect (memory, alloc_size, PROT_NONE);
/* Write to the allocated memory region. */
memory[0] = 1;
/* All done; unmap the memory. */
printf ("all done\n");
munmap (memory, alloc_size);
return 0;
}
我可以建议使用'MAP_ANONYMOUS'并避免整个'fopen()'e.t.c.怪事? – thkala
Minor nitpick:'printf'不是[异步安全](https://www.securecoding.cert.org/confluence/display/seccode/SIG30-C.+Call+only+asynchronous-safe+functions+within+信号+处理程序) – Flexo