linux-kernel - Re: [PATCH] x86: livepatch: Treat R_X86_64_PLT32 as R_X86_64

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] [day] [month] [year] [list]

Date:   Mon, 18 Feb 2019 12:47:49 +0100
From:   "gregkh@...uxfoundation.org" <gregkh@...uxfoundation.org>
To:     "chenzefeng (A)" <chenzefeng2@...wei.com>
Cc:     "hjl.tools@...il.com" <hjl.tools@...il.com>,
        "jpoimboe@...hat.com" <jpoimboe@...hat.com>,
        "sjenning@...hat.com" <sjenning@...hat.com>,
        "jikos@...nel.org" <jikos@...nel.org>,
        "vojtech@...e.com" <vojtech@...e.com>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "mingo@...hat.com" <mingo@...hat.com>,
        "hpa@...or.com" <hpa@...or.com>, "x86@...nel.org" <x86@...nel.org>,
        "live-patching@...r.kernel.org" <live-patching@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "chengjian (D)" <cj.chengjian@...wei.com>
Subject: Re: [PATCH] x86: livepatch: Treat R_X86_64_PLT32 as R_X86_64_PC32

On Fri, Feb 15, 2019 at 02:01:31AM +0000, chenzefeng (A) wrote:
> On x86-64, for 32-bit PC-relacive branches, we can generate PLT32 relocation, instead of PC32 relocation. and R_X86_64_PLT32 can be treated the same as R_X86_64_PC32 since linux kernel doesn't use PLT.
> 
> In linux 4.4 commit b21ebf2fb4cd ("x86: Treat R_X86_64_PLT32 as R_X86_64_PC32") been fixed for the module loading, but not fixed for livepatch relocation, which will fail to load livepatch with the error message as follow:
> relocation failed for symbol <symbol name> at <symbol address>
> 
> Signed-off-by: chenzefeng <chenzefeng2@...wei.com>
> ---
>  arch/x86/kernel/livepatch.c | 1 +
>  1 file changed, 1 insertion(+)

<formletter>

This is not the correct way to submit patches for inclusion in the
stable kernel tree.  Please read:
    https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html
for how to do this properly.

</formletter>