Re: kref refcounting breakage in mainline
From: Mike Galbraith
Date: Thu Mar 15 2007 - 03:53:49 EST
On Wed, 2007-03-14 at 22:27 -0700, Greg KH wrote:
> But can you try this version instead?
It exploded in strcmp(). Unfortunately, the full oops didn't make it to
either console or serial console.
[ 30.783048] ipmi message handler version 39.1
[ 30.787632] ipmi device interface
[ 30.791166] IPMI System Interface driver.
[ 30.816961] BUG: unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 30.832700] printing eip:
[ 30.842383] c02d4098
[ 30.851458] *pde = 00000000
[ 30.861089] Oops: 0000 [#1]
[ 30.870585] PREEMPT SMP
[ 30.879724] Modules linked in:
[ 30.889288] CPU: 1
[ 30.889290] EIP: 0060:[<c02d4098>] Not tainted VLI
[ 30.889292] EFLAGS: 00010282 (2.6.21-rc3-smp #81)
I did this...
--- kernel/module.c.org 2007-03-15 07:20:15.000000000 +0100
+++ kernel/module.c 2007-03-15 08:13:36.000000000 +0100
@@ -2419,15 +2419,19 @@ void module_remove_driver(struct device_
if (drv->owner && drv->owner->mkobj.drivers_dir)
mk = &drv->owner->mkobj;
- else {
+ else if (drv->mod_name) {
/* Lookup built-in module entry in /sys/modules */
mkobj = kset_find_obj(&module_subsys.kset, drv->mod_name);
if (!mkobj)
- return;
+ goto out_free;
mk = container_of(mkobj, struct module_kobject, kobj);
+ } else {
+ WARN_ON(1);
+ goto out_free;
}
sysfs_remove_link(mk->drivers_dir, driver_name);
kobject_put(mkobj);
+out_free:
kfree(driver_name);
}
EXPORT_SYMBOL(module_remove_driver);
...and it booted.
[ 24.670410] ipmi message handler version 39.1
[ 24.675000] ipmi device interface
[ 24.678542] IPMI System Interface driver.
[ 24.703956] BUG: at kernel/module.c:2429 module_remove_driver()
[ 24.716837] [<c0105086>] show_trace_log_lvl+0x1a/0x30
[ 24.728909] [<c01057b2>] show_trace+0x12/0x14
[ 24.740239] [<c0105856>] dump_stack+0x16/0x18
[ 24.751469] [<c01441ce>] module_remove_driver+0xa5/0xa7
[ 24.763584] [<c035a014>] bus_remove_driver+0x6d/0x82
[ 24.775390] [<c035a978>] driver_unregister+0xb/0x18
[ 24.787019] [<c034c8c2>] init_ipmi_si+0x7a9/0x7c1
[ 24.798450] [<c06705bc>] init+0x144/0x26c
[ 24.809129] [<c0104cfb>] kernel_thread_helper+0x7/0x1c
[ 24.820916] =======================
[ 24.830926] ipmi_si: Unable to find any System Interface(s)
[ 24.842952] IPMI Watchdog: driver initialized
24.853749] Copyright (C) 2004 MontaVista Software - IPMI Powerdown via sys_reboot.
-Mike
-
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