Re: [PATCH] debugfs: Check return value of debugfs_real_fops() for NULL

From: Matthias Kaehlcke
Date: Wed Mar 28 2018 - 14:15:04 EST


El Wed, Mar 28, 2018 at 08:05:56PM +0200 Greg Kroah-Hartman ha dit:

>
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?
>
> A: No.
> Q: Should I include quotations after my reply?
>
> http://daringfireball.net/2007/07/on_top
>
> On Wed, Mar 28, 2018 at 07:47:53AM -0700, Manoj Gupta wrote:
> > Please note that there is nothing wrong in the generated code, just
> > that it confuses objtool.
>
> Then fix the tool, the C code is correct :)
>
> > Clang has simply omitted the statement where NULL is returned since
> > the pointer was always dereferenced post inlining.
>
> Then tell clang not to do that, like we tell gcc not to do that as that
> is a foolish thing for a compiler to do when building the kernel.

Thanks all for your input, we'll try to get
-fno-delete-null-pointer-checks or a similar flag to be added to
clang.