Re: [PATCH v2 1/5] exec: Only compute current once in flush_old_exec

[Bernd Edlinger]

On 3/9/20 6:56 PM, Bernd Edlinger wrote:
> On 3/9/20 6:34 PM, Eric W. Biederman wrote:
>> Bernd Edlinger <bernd.edlinger@xxxxxxxxxx> writes:
>>
>>> On 3/8/20 10:35 PM, Eric W. Biederman wrote:
>>>>
>>>> Make it clear that current only needs to be computed once in
>>>> flush_old_exec.  This may have some efficiency improvements and it
>>>> makes the code easier to change.
>>>>
>>>> Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
>>>> ---
>>>>  fs/exec.c | 9 +++++----
>>>>  1 file changed, 5 insertions(+), 4 deletions(-)
>>>>
>>>> diff --git a/fs/exec.c b/fs/exec.c
>>>> index db17be51b112..c3f34791f2f0 100644
>>>> --- a/fs/exec.c
>>>> +++ b/fs/exec.c
>>>> @@ -1260,13 +1260,14 @@ void __set_task_comm(struct task_struct *tsk, const char *buf, bool exec)
>>>>   */
>>>>  int flush_old_exec(struct linux_binprm * bprm)
>>>>  {
>>>> +	struct task_struct *me = current;
>>>>  	int retval;
>>>>  
>>>>  	/*
>>>>  	 * Make sure we have a private signal table and that
>>>>  	 * we are unassociated from the previous thread group.
>>>>  	 */
>>>> -	retval = de_thread(current);
>>>> +	retval = de_thread(me);
>>>>  	if (retval)
>>>>  		goto out;
>>>>  
>>>> @@ -1294,10 +1295,10 @@ int flush_old_exec(struct linux_binprm * bprm)
>>>>  	bprm->mm = NULL;
>>>>  
>>>>  	set_fs(USER_DS);
>>>> -	current->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
>>>> +	me->flags &= ~(PF_RANDOMIZE | PF_FORKNOEXEC | PF_KTHREAD |
>>>>  					PF_NOFREEZE | PF_NO_SETAFFINITY);
>>>
>>> I wonder if this line should be aligned with the previous?
>>
>> In this case I don't think so.  The style used for second line is indent
>> with tabs as much as possible to the right.  I haven't changed that.
>>
>> Further mixing a change in indentation style with just a variable rename
>> will make the patch confusing to read because two things have to be
>> verified at the same time.
>>
>> So while I see why you ask I think this bit needs to stay as is.
>>
> 
> Ah, okay, I see.
> Thanks for explaining this rule, I was not aware of it,
> but I am still new here :)
> 

Reviewed-by: Bernd Edlinger <bernd.edlinger@xxxxxxxxxx>


Bernd.