内核模块无法链接-找不到符号Mutex_lock_nested [英] kernel module won't link - symbol mutex_lock_nested not found

问题描述

我正在尝试在x64上为Linux 3.10.45构建内核模块(用于硬件的压力测试工具). 到目前为止，在添加互斥锁之前，它似乎还可以正常工作.

I am trying to build a kernel module (stress-test tool for a hardware) for a Linux 3.10.45 on x64. So far it seemed to work fine, until adding a mutex.

我添加了互斥锁，并使用了互斥锁，函数互斥锁，互斥锁和互斥锁.

I added mutex using and the functions mutex_init, mutex_lock, mutex_unlock and mutex_destroy.

构建模块不会产生任何错误或警告，但是在加载'insmod'时，dmesg中会显示错误消息:

Building the module yielded no errors or warnings, but when loading with 'insmod', there are error messages in dmesg:

[76603.744551] tryBlk: Unknown symbol mutex_lock_nested (err 0)
[76603.744574] tryBlk: Unknown symbol mutex_destroy (err 0)

我发现一个提示，即未知符号"有时会有助于添加MODULE_LICENSE("GPL v2")行.

I found a hint that with 'Unknown symbol', it sometimes helps to add the MODULE_LICENSE("GPL v2") line.

没有区别.

看着linux/mutex.h，我发现只有定义了符号CONFIG_DEBUG_LOCK_ALLOC时，mutex_lock才会定义为Mutex_lock_nested.检查一下，它似乎是在我的.config文件中定义的. (不记得碰它.它基本上只是kernel.org的内核，已构建).

Looking at linux/mutex.h, I found that the mutex_lock will only define to mutex_lock_nested if the symbol CONFIG_DEBUG_LOCK_ALLOC is defined. Checking this, it seems to be defined in my .config . (Cannot remember touching it. It is basically just a kernel from kernel.org, built).

这有问题吗?我是否需要手动向模块添加其他内容以使其具有此调试功能?

Is there a problem with this? Do I need to manually add something else to my module to make it build with this debug-feature?

试图更改包含文件和顺序.没什么.

Tried to change include files and sequence. No difference.

系统正在运行Debian-7'Wheezy'x64，内核更改为3.10.45.

System is running Debian-7 'Wheezy' x64, with kernel changed to a 3.10.45 .

使用互斥锁的文件:

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/mutex.h>
#include <linux/vmalloc.h>
#include <linux/uaccess.h>
#include "ring.h"




struct RingBuf
{
    unsigned char *buffer;
    unsigned int size;
    unsigned int inp,outp;
    struct mutex mtx;
};



static int _bytesavail(struct RingBuf *self);
static int _spaceavail(struct RingBuf *self);


struct RingBuf *RingBuf_init(unsigned int size)
{
  struct RingBuf *self;
    if( size<16 )size=16;
    if( size>0x10000000u )return 0;
    if( size & (size-1) )
    {
      unsigned int ns;
        // is not a power of 2.
        size = size<<1;
        while(1)
        {
            ns=size&(size-1);
            if(!ns)break;
            size=ns;
        }
    }
    self = (struct RingBuf*)vmalloc(sizeof(*self)+size);
    memset( self , 0 , sizeof(*self) );
    self->buffer = (unsigned char*)(self+1);
    self->size = size;
    self->inp = 0;
    self->outp = 0;
    mutex_init( &(self->mtx) );
    return self;
}

void RingBuf_uninit(struct RingBuf *self)
{
    if(!self)return;
    mutex_lock( &(self->mtx) );
    mutex_destroy( &(self->mtx) );
    memset( self , 0xFE , sizeof(*self) );
    vfree(self);
}

int RingBuf_add(struct RingBuf *self,const void *data,int num)
{
  int cpy;
    if(num<=0)return 0;
    mutex_lock( &(self->mtx) );
    // check amount to copy
    cpy = _spaceavail(self);
    if(cpy>num)cpy=num;
    // one part or split
    if( self->inp+cpy <= self->size )
    {
        // one chunk
        memcpy( self->buffer+self->inp , data , cpy );
    }else{
      int p1 = (self->size-self->inp);
        // wrapped
        memcpy( self->buffer+self->inp , data , p1 );
        memcpy( self->buffer , ((const unsigned char*)data)+p1 , cpy-p1 );
    }
    self->inp = (self->inp+cpy) & (self->size-1) ;
    mutex_unlock( &(self->mtx) );
    return cpy;
}

int RingBuf_get(struct RingBuf *self,void *data,int num)
{
  int cpy;
    if(num<=0)return 0;
    mutex_lock( &(self->mtx) );
    // check amount to copy
    cpy = _bytesavail(self);
    if(cpy>num)cpy=num;
    // one part or split
    if( self->outp+cpy <= self->size )
    {
        // one chunk
        memcpy( data , self->buffer+self->outp , cpy );
    }else{
      int p1 = (self->size-self->outp);
        // wrapped
        memcpy( data , self->buffer+self->outp , p1 );
        memcpy( ((unsigned char*)data)+p1 , self->buffer , cpy-p1 );
    }
    self->outp = (self->outp+cpy) & (self->size-1) ;
    mutex_unlock( &(self->mtx) );
    return cpy;
}

int RingBuf_get_user(struct RingBuf *self,void __user *data,int num)
{
  int cpy;
  int ret;
    if(num<=0)return 0;
    mutex_lock( &(self->mtx) );
    // check amount to copy
    cpy = _bytesavail(self);
    if(cpy>num)cpy=num;
    // one part or split
    if( self->outp+cpy <= self->size )
    {
        // one chunk
        ret = copy_to_user( data , self->buffer+self->outp , cpy );
    }else{
      int p1 = (self->size-self->outp);
        // wrapped
        ret = copy_to_user( data , self->buffer+self->outp , p1 );
        if(!ret)
            ret = copy_to_user( ((unsigned char*)data)+p1 , self->buffer , cpy-p1 );
    }
    if(ret)return -1;
    self->outp = (self->outp+cpy) & (self->size-1) ;
    mutex_unlock( &(self->mtx) );
    return cpy;
}

int RingBuf_numBytes(struct RingBuf *self)
{
  int result;
    mutex_lock( &(self->mtx) );
    result = _bytesavail(self);
    mutex_unlock( &(self->mtx) );
    return result;
}

static int _bytesavail(struct RingBuf *self)
{
    return (self->inp-self->outp)&(self->size-1);
}

static int _spaceavail(struct RingBuf *self)
{
    return (self->outp-self->inp-1)&(self->size-1);
}

推荐答案

我刚刚发现它在某种程度上取决于我如何构建模块.

I just found that it somehow depends on how I am building the module.

互斥锁的内容位于另一个源文件(上面列出的文件)中.当我将其剪切/粘贴到模块的第一个主源中时，它就可以工作.

The mutex stuff is in another source-file (the one listed above). When I cut/paste it into the first main-source of the module, it works.

因此，如何创建一个跨多个源文件的模块是一个问题.

So it is a problem of how to create a module spanning several source files.

我的(不正确地工作)Makefile是:

My (NOT CORRECTLY WORKING) Makefile is:

obj-m += tryBlk.o
tryBlk-objs := ring.o

它的构建没有警告，但是没有正确找到'ring.o'文件中的内核符号.

It builds without warnings, but the kernel-symbols in the 'ring.o' file are not correctly found.

================================================

===============================================

我现在也解决了另一个问题.要共享，makefile不好.

I also solved the other problem now. To share, the makefile was bad.

这是更好的makefile:

Here the better makefile:

obj-m := tryBlk.o
tryBlk-objs := tryBlk_main.o ring.o

我还需要将主体部分从"tryBlk.c"重命名为"tryBlk_main.c"

I also needed to rename the main part from 'tryBlk.c' to 'tryBlk_main.c'

这篇关于内核模块无法链接-找不到符号Mutex_lock_nested的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！