Re: [PATCH] mm: remove the newlines, which are added for unknown reasons and interfere with bug analysis

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Oct 07, 2024 at 03:53:07PM +0900, Jeongjun Park wrote:
> Looking at the source code links for mm/memory.c in the sample reports 
> in the syzbot report links [1].
> 
> it looks like the line numbers are designated as lines that have been 
> increased by 1. This may seem like a problem with syzkaller or the 
> addr2line program that assigns the line numbers, but there is no problem 
> with either of them.
> 
> In the previous commit d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC"), 
> when modifying mm/memory.c, an unknown line break is added to the very first 
> line of the file. However, the git.kernel.org site displays the source code 
> with the added line break removed, so even though addr2line has assigned 
> the correct line number, it looks like the line number has increased by 1.
> 
> This may seem like a trivial thing, but I think it would be appropriate 
> to remove all the newline characters added to the upstream and stable 
> versions, as they are not only incorrect in terms of code style but also 
> hinder bug analysis.
> 
> [1]
> 
> https://syzkaller.appspot.com/bug?extid=4145b11cdf925264bff4
> https://syzkaller.appspot.com/bug?extid=fa43f1b63e3aa6f66329
> https://syzkaller.appspot.com/bug?extid=890a1df7294175947697
> 
> Fixes: d61ea1cb0095 ("userfaultfd: UFFD_FEATURE_WP_ASYNC")
> Cc: stable@vger.kernel.org
> Signed-off-by: Jeongjun Park <aha310510@gmail.com>
> ---
>  mm/memory.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/mm/memory.c b/mm/memory.c
> index 2366578015ad..7dffe8749014 100644
> --- a/mm/memory.c
> +++ b/mm/memory.c
> @@ -1,4 +1,3 @@
> -

This sounds like you have broken tools that can not handle an empty line
in a file.

Why not fix those?

Also, your changelog text has trailing whitespace, ironic for a patch
that does a whitespace cleanup :)

thanks,

greg k-h