3.10.0-123.el7.x86 64 - System hangs during rmmod

dalewesson

SYSTEM: Linux version 3.10.0-123.el7.x86_64.debug-PC



Overview: Our driver supports configuration, management, and user level access to/from up to 6 32bit pci-comunications cards. We have made the necessary changes to our originally 2.6.X based kernel module to allow it to be loaded(insmod) and perform properly under 3.10.0-123.el7.



Problem: The 3.10.0-123.el7 system hangs when we attempt to remove the driver(rmmod).

I've included our "module_exit" (included below) with embedded printk's. When "rmmod iphwae" is executed the following output is seen, then the system hangs:

Mar 19 14:16:19 lab-247 kernel:

iphwae: Entering iph_module_cleanup...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Entering pci_unregister_driver()...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Exiting pci_unregister_driver()...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Entering unregister_chrdev()...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Exiting unregister_chrdev()...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Entering remove_proc_entry()...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Exiting remove_proc_entry()...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Entering cleanup trace buffer and MUTEX...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Exiting cleanup trace buffer and MUTEX...

Mar 19 14:16:19 lab-247 kernel:

iphwae: Exiting iph_module_cleanup()...

The printk's show that the kernal modules exit routine is completed successfully...





Any help with this problem would be GREATLY APPRECIATED

 

static void iph_module_cleanup(void)

{

int iError = 0;

void *pTraceHead;

printk("\niphwae: Entering iph_module_cleanup...\n");//(DAW)

msleep(5);//(DAW)

printk("\niphwae: Entering pci_unregister_driver()...\n");//(DAW)

msleep(5);//(DAW)

/* Deregister the driver from the pci module list */

pci_unregister_driver(&gIphwanDriver);

printk("\niphwae: Exiting pci_unregister_driver()...\n");//(DAW)

msleep(5);//(DAW)

/* Remove entry points and characteristics from the char module list */

#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)<br />
iError = unregister_chrdev(giMajor, DRIVER_NAME);

#else

printk("\niphwae: Entering unregister_chrdev()...\n");//(DAW)

msleep(5);//(DAW)

unregister_chrdev(giMajor, DRIVER_NAME);

printk("\niphwae: Exiting unregister_chrdev()...\n");//(DAW)

msleep(5);//(DAW)

#endif

printk("\niphwae: Entering remove_proc_entry()...\n");//(DAW)

msleep(5);//(DAW)

/* remove the /proc/iphxxx file */

remove_proc_entry(DRIVER_NAME, 0);

printk("\niphwae: Exiting remove_proc_entry()...\n");//(DAW)

msleep(5);//(DAW)

if (iError == 0)

{

printk("\niphwae: Entering cleanup trace buffer and MUTEX...\n");//(DAW)

msleep(5);//(DAW)

/* if the trace are active, we must destroy the mutex and release */

/* the trace buffer */

if (iph_gpucTrace != (byte *)0)

{

MUTEX_DESTROY(&iph_gTraceMutex);

pTraceHead = (void *)iph_gpucTrace;

iph_gpucTrace = NULL;

TMP_FREE(pTraceHead);

}

printk("\niphwae: Exiting cleanup trace buffer and MUTEX...\n");//(DAW)

msleep(5);//(DAW)

}

else

{

printk("\niphwae: failed to unregister the char device...\n");//(DAW)

msleep(5);//(DAW)

iph_TRACEK(TRCLVL_0, "[cleanup_module]: failed to unregister the char device");

}

printk("\niphwae: Exiting iph_module_cleanup()...\n");//(DAW)

msleep(5);//(DAW)

}

/*

* These two macros below are used to declare the two entry point of

* the driver. All loadable module must use theirs.

*/

module_init(iph_module_init);

module_exit(iph_module_cleanup);