Subject: Re: 3.11-rc7:BUG: soft lockup

From: Ding Tianhong <[email-masked]>
Date: Mon, 2 Sep 2013 17:04:12 +0800

On 2013/9/2 16:24, Baoquan He wrote:
> Hi Tianhong,
> 
> I applied your patch and execute below cmd. 
> Then keyboard inputting problems happened, 
> I can't enter user/password correctly, then reboot again, it's OK now.

Thanks for your work, I don't understand that the keyboard problem is the patch fault or your system problem, 
if it is not happen again, I think the problem is fixed.

> 
> The original bug still can't be reproduced.
> 
> make SUBDIRS=net/bridge/netfilter/
> cp /net/bridge/netfilter/ebtables.ko
> /lib/modules/3.11.0-rc7+/kernel/net/bridge/netfilter/ebtables.ko
> depmod
> modprobe ebtables.ko
> reboot
> 
> Baoquan
> Thanks
> 
>> please try this patch and give me the result, thanks.
>>
>> Return the correct value if mutex_lock_interruptible() failed, avoid
>> confusion with that the modules is not exist, and deal with the return
>> value in right way.
>>
>> if mutex_lock_interrupt() failed, sh
>>
>> Signed-off-by: root <[email-masked]>
>> ---
>>  net/bridge/netfilter/ebtables.c | 17 +++++++----------
>>  1 file changed, 7 insertions(+), 10 deletions(-)
>>
>> diff --git a/net/bridge/netfilter/ebtables.c b/net/bridge/netfilter/ebtables.c
>> index ac78024..e7fe9f8 100644
>> --- a/net/bridge/netfilter/ebtables.c
>> +++ b/net/bridge/netfilter/ebtables.c
>> @@ -322,17 +322,14 @@ static inline void *
>>  find_inlist_lock_noload(struct list_head *head, const char *name, int *error,
>>     struct mutex *mutex)
>>  {
>> -	struct {
>> -		struct list_head list;
>> -		char name[EBT_FUNCTION_MAXNAMELEN];
>> -	} *e;
>> +	struct ebt_table *e;
>>  
>>  	*error = mutex_lock_interruptible(mutex);
>>  	if (*error != 0)
>> -		return NULL;
>> +		return ERR_PTR(-EINTR);
>>  
>>  	list_for_each_entry(e, head, list) {
>> -		if (strcmp(e->name, name) == 0)
>> +		 if (strcmp(e->name, name) == 0 && try_module_get(e->me))
>>  			return e;
>>  	}
>>  	*error = -ENOENT;
>> @@ -1005,7 +1002,7 @@ static int do_replace_finish(struct net *net, struct ebt_replace *repl,
>>  		goto free_counterstmp;
>>  
>>  	t = find_table_lock(net, repl->name, &ret, &ebt_mutex);
>> -	if (!t) {
>> +	if (IS_ERR_OR_NULL(t)) {
>>  		ret = -ENOENT;
>>  		goto free_iterate;
>>  	}
>> @@ -1284,7 +1281,7 @@ static int do_update_counters(struct net *net, const char *name,
>>  		return -ENOMEM;
>>  
>>  	t = find_table_lock(net, name, &ret, &ebt_mutex);
>> -	if (!t)
>> +	if (IS_ERR_OR_NULL(t))
>>  		goto free_tmp;
>>  
>>  	if (num_counters != t->private->nentries) {
>> @@ -1504,7 +1501,7 @@ static int do_ebt_get_ctl(struct sock *sk, int cmd, void __user *user, int *len)
>>  		return -EFAULT;
>>  
>>  	t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
>> -	if (!t)
>> +	if (IS_ERR_OR_NULL(t))
>>  		return ret;
>>  
>>  	switch(cmd) {
>> @@ -2319,7 +2316,7 @@ static int compat_do_ebt_get_ctl(struct sock *sk, int cmd,
>>  		return -EFAULT;
>>  
>>  	t = find_table_lock(net, tmp.name, &ret, &ebt_mutex);
>> -	if (!t)
>> +	if (IS_ERR_OR_NULL(t))
>>  		return ret;
>>  
>>  	xt_compat_lock(NFPROTO_BRIDGE);
> 
> 
> .
>