31 static int parent_f(int sock, unsigned long *smap, int child)  in parent_f()  argument
38 	*smap = 0x22222BAD;  in parent_f()
39 	ret = msync(smap, MMAP_SZ, MS_SYNC);  in parent_f()
51 static int child_f(int sock, unsigned long *smap, int fd)  in child_f()  argument
55 	smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE,  in child_f()
57 	BUG_ON(smap == MAP_FAILED, "mmap()");  in child_f()
59 	BUG_ON(*smap != 0xdeadbabe, "MAP_PRIVATE | MAP_POPULATE changed file");  in child_f()
67 	BUG_ON(*smap == 0x22222BAD, "MAP_POPULATE didn't COW private page");  in child_f()
68 	BUG_ON(*smap != 0xdeadbabe, "mapping was corrupted");  in child_f()
77 	unsigned long *smap;  in main()  local
85 	smap = mmap(0, MMAP_SZ, PROT_READ | PROT_WRITE,  in main()
87 	BUG_ON(smap == MAP_FAILED, "mmap()");  in main()
89 	*smap = 0xdeadbabe;  in main()
91 	ret = msync(smap, MMAP_SZ, MS_SYNC);  in main()
104 		return parent_f(sock[1], smap, child);  in main()
110 	return child_f(sock[0], smap, fileno(ftmp));  in main()