From: "Srinivas Surabhi" <srinivas.surabhi@wipro.com>
To: linux-kernel@vger.kernel.org
Subject: parameters passing problem in driver module
Date: Tue, 20 Feb 2001 16:07:55 +0530 [thread overview]
Message-ID: <77452C3AEA9.AAA40DE@vindhya.mail.wipro.com> (raw)
In application program ,code for call to write system call is given
below...
#include<fcntl.h>
main()
{
int count,fd;
fd=open("/dev/pseudo",O_RDWR);
write(fd,buff,5);
}
In driver module code for getting the buffer and count
#include<all related header files...>
int psuedo_write(struct inode*in,struct file*fp,char *buf,int count)
{
kprintf("<1>pseudo_write routine called \n");
kprintf("<1>count=%d \n",count);
kprintf("<1>buffer=%s \n",buff);
return 0;
}
/******so here after inserting the module into the kernel using insmod
pseudo.o and executing the application cc -c pseudo_app.c, the o/p on
console is *****/
"pseudo_write routine called"
"count=9988345352" /*garbage*/
"buffer=@#%h" . /*garbage*/
/*** but neither the buffer is carried from user space to kernel space nor
the count, why?***/Please help me
out.
next reply other threads:[~2001-02-20 10:53 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2001-02-20 10:37 Srinivas Surabhi [this message]
2001-02-20 11:19 ` parameters passing problem in driver module Erik Mouw
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