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[root@CENTOS 03-CharDevice]# make make -C /lib/modules/2.6.18-53.el5/build M=/usr/src/src/ldd3src/03-CharDevice modules make[1]: Entering directory `/usr/src/kernels/2.6.18-53.el5-i686' CC [M] /usr/src/src/ldd3src/03-CharDevice/chardev.o In file included from /usr/src/src/ldd3src/03-CharDevice/chardev.c:5: include/linux/config.h:6:2: warning: #warning Including config.h is deprecated. Building modules, stage 2. MODPOST CC /usr/src/src/ldd3src/03-CharDevice/chardev.mod.o LD [M] /usr/src/src/ldd3src/03-CharDevice/chardev.ko make[1]: Leaving directory `/usr/src/kernels/2.6.18-53.el5-i686' [root@CENTOS 03-CharDevice]# ls -l total 292 -rw-r--r-- 1 root root 5709 Apr 24 04:52 chardev.c -rw-r--r-- 1 root root 110674 Apr 24 04:52 chardev.ko -rw-r--r-- 1 root root 1043 Apr 24 04:52 chardev.mod.c -rw-r--r-- 1 root root 42824 Apr 24 04:52 chardev.mod.o -rw-r--r-- 1 root root 69008 Apr 24 04:52 chardev.o -rw-r--r-- 1 root root 886 Jan 24 13:05 Makefile -rw-r--r-- 1 root root 0 Apr 23 11:01 Module.symvers -rwxr-xr-x 1 root root 496 Apr 24 04:52 simple_load -rwxr-xr-x 1 root root 172 Apr 24 04:52 simple_unload [root@CENTOS 03-CharDevice]# less simple_load [root@CENTOS 03-CharDevice]# ./simple_load [root@CENTOS 03-CharDevice]# cat /dev/chardevr I already told you 0 times Hello world! [root@CENTOS 03-CharDevice]# cat /dev/chardevn -bash: /dev/chardevn: No such device or address [root@CENTOS 03-CharDevice]# strace cat /dev/chardevr execve("/bin/cat", ["cat", "/dev/chardevr"], [/* 22 vars */]) = 0 brk(0) = 0x8ac8000 access("/etc/ld.so.preload", R_OK) = -1 ENOENT (No such file or directory) open("/etc/ld.so.cache", O_RDONLY) = 3 fstat64(3, {st_mode=S_IFREG|0644, st_size=34759, ...}) = 0 mmap2(NULL, 34759, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7fce000 close(3) = 0 open("/lib/libc.so.6", O_RDONLY) = 3 read(3, "\177ELF\1\1\1\0\0\0\0\0\0\0\0\0\3\0\3\0\1\0\0\0000\277\272\0004\0\0\0"..., 512) = 512 fstat64(3, {st_mode=S_IFREG|0755, st_size=1585788, ...}) = 0 mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7fcd000 mmap2(0xb96000, 1308068, PROT_READ|PROT_EXEC, MAP_PRIVATE|MAP_DENYWRITE, 3, 0) = 0xb96000 mmap2(0xcd0000, 12288, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_DENYWRITE, 3, 0x139) = 0xcd0000 mmap2(0xcd3000, 9636, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_FIXED|MAP_ANONYMOUS, -1, 0) = 0xcd3000 close(3) = 0 mmap2(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0xb7fcc000 set_thread_area({entry_number:-1 -> 6, base_addr:0xb7fcc6c0, limit:1048575, seg_32bit:1, contents:0, read_exec_only:0, limit_in_pages:1, seg_not_present:0, useable:1}) = 0 mprotect(0xcd0000, 8192, PROT_READ) = 0 mprotect(0xb8d000, 4096, PROT_READ) = 0 munmap(0xb7fce000, 34759) = 0 brk(0) = 0x8ac8000 brk(0x8ae9000) = 0x8ae9000 open("/usr/lib/locale/locale-archive", O_RDONLY|O_LARGEFILE) = 3 fstat64(3, {st_mode=S_IFREG|0644, st_size=56418032, ...}) = 0 mmap2(NULL, 2097152, PROT_READ, MAP_PRIVATE, 3, 0) = 0xb7dcc000 close(3) = 0 fstat64(1, {st_mode=S_IFCHR|0620, st_rdev=makedev(136, 0), ...}) = 0 open("/dev/chardevr", O_RDONLY|O_LARGEFILE) = 3 fstat64(3, {st_mode=S_IFCHR|0644, st_rdev=makedev(253, 0), ...}) = 0 read(3, "I already told you 2 times Hello"..., 4096) = 40 write(1, "I already told you 2 times Hello"..., 40I already told you 2 times Hello world! ) = 40 read(3, "", 4096) = 0 close(3) = 0 close(1) = 0 exit_group(0) = ?