调试信息过多造成dmesg无法完全显示怎么办？

#ifndef __KERNEL__

#define __KERNEL__

#endif

#ifndef MODULE

#define MODULE

#endif

#if defined(MODVERSIONS) && !defined(__GENKSYMS__)

#include

#endif

#ifdef DBGPRT_OUTVER

#include "dbgprint.ver" /* redefine "dbgprint" to include CRC */

#endif

#ifndef EXPORT_SYMTAB

#define EXPORT_SYMTAB

#endif

#include

#include

#include

#include

#include

//#include

#include

#include

#include "dbgprint.h"

EXPORT_SYMBOL(DbgPrint);

#ifndef DBGPRT_VER

#define DBGPRT_VER "0.90"

#endif

int dbgprt_major=65; //the major device number

char dbgprt_dev_name[]={"ALIDbg"}; //the name in /dev

char dbgprt_ver[]={DBGPRT_VER};

//module paramaters and infos

MODULE_AUTHOR("ALI_SHA");

MODULE_DESCRIPTION("Ali M3321 DEBUGER PRINT.");

MODULE_PARM(dbgprt_ver,"s");

MODULE_PARM_DESC(dbgprt_ver,DBGPRT_VER);

MODULE_PARM(dbgprt_major,"i");

MODULE_PARM_DESC(dbgprt_major,"65");

MODULE_PARM(dbgprt_dev_name,"s");

MODULE_PARM_DESC(dbgprt_dev_name,"ALIDbg");

wait_queue_head_t pSleep;

//used to manager the buffer

char chrgMessage[4096]; //the last 1024 don't use for overflow

char* pchEnd;

char* pchStart;

char fTurn; //pchEnd littl than pchStart

char* pchMessageEnd; //the end pointer of array

int nOverLen;

struct file_operations ALIDbgOps =

{

THIS_MODULE,

NULL,

DbgRead,

NULL, //ali_write,

NULL,

NULL,

DbgIoCtl,

NULL,

DbgOpen,

NULL,

DbgClose,

NULL,

NULL,

NULL,

NULL,

NULL

};

int init_module(void)

{

int nResult;

nResult = register_chrdev(dbgprt_major,dbgprt_dev_name,&ALIDbgOps);

if(nResult<0)

{

printk("can't register this device!\n");

return -1;

}

pchStart=chrgMessage;

pchEnd=chrgMessage;

pchMessageEnd=chrgMessage+3072;

fTurn=0;

init_waitqueue_head(&pSleep);

return 0;

}

int cleanup_module()

{

unregister_chrdev(dbgprt_major,dbgprt_dev_name);

return 0;

}

int DbgOpen(struct inode* i,struct file *f)

{

MOD_INC_USE_COUNT;

return 0;

}

int DbgClose(struct inode* i,struct file *f)

{

wake_up_interruptible(&pSleep);

MOD_DEC_USE_COUNT;

return 0;

}

ssize_t DbgRead (struct file* fileDbg, char* pchMsg, size_t nLen, loff_t* pOff)

{

int nMsgLen;

if(!fTurn && (pchStart==pchEnd) )

{

interruptible_sleep_on(&pSleep);

}

if(!fTurn)

{

nMsgLen=pchEnd-pchStart;

if(nLen {

copy_to_user(pchMsg,pchStart,nLen);

pchStart+=nLen;

return nLen;

}

copy_to_user(pchMsg,pchStart,nMsgLen);

}

else

{

if(nLen {

copy_to_user(pchMsg,pchStart,nLen);

pchStart+=nLen;

return nLen;

}

copy_to_user(pchMsg,pchStart,nOverLen);

fTurn=0;

nMsgLen=pchEnd-chrgMessage;

if( (nLen-nOverLen) {

copy_to_user(pchMsg+nOverLen,chrgMessage,nLen-nOverLen);

pchStart=chrgMessage+nLen-nOverLen;

return nLen;

}

copy_to_user(pchMsg+nOverLen,chrgMessage,nMsgLen);

nMsgLen+=nOverLen;

}

pchStart=chrgMessage;

pchEnd=chrgMessage;

return nMsgLen;

}

int DbgIoCtl(struct inode* i,struct file *f,unsigned int cmd,unsigned long arg)

{

switch(cmd)

{

case DBGPRT_IO_CANCLE:

wake_up_interruptible(&pSleep);

break;

default:

return -1;

}

return 0;

}

int DbgPrint(const char *fmt, ...)

{

va_list args;

int nMessageLen;

va_start(args, fmt);

nMessageLen=vsprintf(pchEnd,fmt,args);

va_end(args);

pchEnd+=nMessageLen;

if(pchEnd>=pchMessageEnd)

//the message overflowed

{

nOverLen=pchEnd-pchMessageEnd;

pchEnd=chrgMessage;

fTurn=1;

}

else

{

//the end pointer exceed the start pointor from back

if(fTurn && (pchEnd>pchStart))

{

pchStart=pchEnd;

*pchStart=255; //add a alarmer

}

}

wake_up_interruptible(&pSleep);

return nMessageLen;

}

我所说的版本问题已经解决了.

可以用ioctl来cancle掉被挂起的read.

#ifndef _DBGPRT_H_

#define _DBGPRT_H_

#define DBGPRT_IO_CANCLE 1

int DbgOpen(struct inode* i,struct file *f);

int DbgClose(struct inode* i,struct file *f);

ssize_t DbgRead (struct file* fileDbg, char* pchMsg, size_t nLen, loff_t* pOff);

int DbgIoCtl(struct inode* i,struct file *f,unsigned int cmd,unsigned long arg);

int DbgPrint(const char *fmt, ...);

#endif//_DBGPRT_H_

posted on 2009-12-30 14:06 alexhappy 阅读(208) 评论(0)  编辑 收藏 引用 所属分类: 调试技巧