linux-kernel - Re: [PATCH] ARM: don't export unused return

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Wed, 13 Nov 2019 17:00:58 +0000
From:   Russell King - ARM Linux admin <linux@...linux.org.uk>
To:     Geert Uytterhoeven <geert@...ux-m68k.org>
Cc:     Masahiro Yamada <yamada.masahiro@...ionext.com>,
        Arnd Bergmann <arnd@...db.de>,
        Thomas Gleixner <tglx@...utronix.de>,
        Enrico Weigelt <info@...ux.net>,
        Linux ARM <linux-arm-kernel@...ts.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] ARM: don't export unused return_address()

On Wed, Nov 13, 2019 at 02:15:00PM +0100, Geert Uytterhoeven wrote:
> Hi Russell,
> 
> On Wed, Nov 13, 2019 at 12:45 PM Russell King - ARM Linux admin
> <linux@...linux.org.uk> wrote:
> > On Wed, Nov 13, 2019 at 08:40:39PM +0900, Masahiro Yamada wrote:
> > > On Tue, Oct 1, 2019 at 11:31 PM Geert Uytterhoeven <geert@...ux-m68k.org> wrote:
> > > > On Fri, Sep 6, 2019 at 5:47 PM Arnd Bergmann <arnd@...db.de> wrote:
> > > > > Without the frame pointer enabled, return_address() is an inline
> > > > > function and does not need to be exported, as shown by this warning:
> > > > >
> > > > > WARNING: "return_address" [vmlinux] is a static EXPORT_SYMBOL_GPL
> > > > >
> > > > > Move the EXPORT_SYMBOL_GPL() into the #ifdef as well.
> > > > >
> > > > > Signed-off-by: Arnd Bergmann <arnd@...db.de>
> > > >
> > > > Thanks for your patch!
> > > >
> > > > Tested-by: Geert Uytterhoeven <geert+renesas@...der.be>
> > > >
> > > > > --- a/arch/arm/kernel/return_address.c
> > > > > +++ b/arch/arm/kernel/return_address.c
> > > > > @@ -53,6 +53,7 @@ void *return_address(unsigned int level)
> > > > >                 return NULL;
> > > > >  }
> > > > >
> > > >
> > > > Checkpatch doesn't like the empty line above:
> > > >
> > > > WARNING: EXPORT_SYMBOL(foo); should immediately follow its function/variable
> > > >
> > > > > +EXPORT_SYMBOL_GPL(return_address);
> > > > > +
> > > > >  #endif /* if defined(CONFIG_FRAME_POINTER) && !defined(CONFIG_ARM_UNWIND) */
> > > > >
> > > > > -EXPORT_SYMBOL_GPL(return_address);
> 
> > > What has happened to this patch?
> > >
> > > I still see this warning.
> >
> > Simple - it got merged, it caused build regressions, it got dropped.
> > A new version is pending me doing another round of patch merging.
> 
> I believe that was not Arnd's patch, but Ben Dooks' alternative solution[*]?

I don't keep track of who did what, sorry.

> 
> [*] Commit 0b0617e5a610fe12 ("ARM: 8918/1: only build return_address() if
>     needed"), which I discovered in next-20191031 when checking if Arnd's
>     patch was applied....
-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up