Change proc/<pid>/cmdline to 8k

[Navin P]

On Thu, Jun 4, 2015 at 10:47 AM, Greg KH <gregkh at linuxfoundation.org> wrote:
> On Thu, Jun 04, 2015 at 09:52:08AM +0530, Navin P wrote:
>> Hi,
>>
>>   I want to change the cmdline of a process to support 8096 . It works
>> well on ppc where the page size is 65k.
>>   But when i try to increase it on x86 (i686)
>>
>> http://lxr.free-electrons.com/source/fs/proc/base.c  by doing
>> 6*PAGE_SIZE, i get kernel panic after some time
>>
>> 199 static int proc_pid_cmdline(struct seq_file *m, struct pid_namespace *ns,
>> 200                             struct pid *pid, struct task_struct *task)
>> 201 {
>> 202         /*
>> 203          * Rely on struct seq_operations::show() being called once
>> 204          * per internal buffer allocation. See single_open(), traverse().
>> 205          */
>> 206         BUG_ON(m->size < PAGE_SIZE);
>> 207         m->count += get_cmdline(task, m->buf, 6*PAGE_SIZE);
>> 208         return 0;
>> 209 }
>> 210
>
> That shows you that this will not work, sorry.

Can you please help me and guide me into achieving this ?