Re: [Patch V2] proc: check error pointer returned by m_start()

[Cong Wang <amwang@redhat.com>]

于 2011年03月28日 13:46, Anca Emanuel 写道:
> On Mon, Mar 28, 2011 at 8:26 AM, Amerigo Wang<amwang@redhat.com>  wrote:
>> From: WANG Cong<xiyou.wangcong@gmail.com>
>>
>> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
>> index 7c708a4..8e59169 100644
>> --- a/fs/proc/task_mmu.c
>> +++ b/fs/proc/task_mmu.c
>> @@ -124,8 +124,10 @@ static void *m_start(struct seq_file *m, loff_t *pos)
>>                 return ERR_PTR(-ESRCH);
>>
>>         mm = mm_for_maps(priv->task);
>> -       if (!mm || IS_ERR(mm))
>> +       if (IS_ERR_OR_NULL(mm)) {
>> +               put_task_struct(priv->task);
>>                 return mm;
>> +       }
>>         down_read(&mm->mmap_sem);
>>
>>         tail_vma = get_gate_vma(priv->task->mm);
>> @@ -182,6 +184,8 @@ static void m_stop(struct seq_file *m, void *v)
>>         struct proc_maps_private *priv = m->private;
>>         struct vm_area_struct *vma = v;
>>
>> +       if (IS_ERR_OR_NULL(v))
>> +               return;
>
> Note: this is not functional equivalent with the previous patch.
>

I moved that put_task_struct() into m_start() itself.

>
> I din't test the above patch.
>
> Linus already have the fix in his tree.

Yes, I really should pull before I made a patch. :-/

Anyway, thanks for reporting and testing.