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

Bernd Edlinger
2020-03-09T17:56:50Z

On 3/9/20 6:34 PM, Eric W. Biederman wrote:
> Bernd Edlinger <bernd.edlinger@hotmail.de> 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@xmission.com>
>>> ---
>>> 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 :)

Thanks
Bernd.