Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Sun, 23 Jul 2023 10:27:33 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     <kabe@vega.pgw.jp>
Cc:     regressions@lists.linux.dev, bagasdotme@gmail.com,
        alexander.deucher@amd.com, christian.koenig@amd.com,
        Xinhui.Pan@amd.com, tglx@linutronix.de, mingo@redhat.com,
        bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com,
        linux-kernel@vger.kernel.org, amd-gfx@lists.freedesktop.org,
        kkabe@vega.pgw.jp
Subject: Re: radeon.ko/i586: BUG: kernel NULL pointer
 dereference,address:00000004
Message-ID: <20230723102733.70baeb1a@rorschach.local.home>
In-Reply-To: <230722113014.M0204460@vega.pgw.jp>
References: <230721083955.M0102626@vega.pgw.jp>
        <230722113014.M0204460@vega.pgw.jp>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Sat, 22 Jul 2023 11:30:14 +0900
<kabe@vega.pgw.jp> wrote:

> >> diff --git a/arch/x86/include/asm/ftrace.h b/arch/x86/include/asm/ftrace.h
> >> index 897cf02c20b1..801f4414da3e 100644
> >> --- a/arch/x86/include/asm/ftrace.h
> >> +++ b/arch/x86/include/asm/ftrace.h
> >> @@ -13,7 +13,7 @@
> >>  #ifdef CONFIG_HAVE_FENTRY
> >>  # include <asm/ibt.h>
> >>  /* Add offset for endbr64 if IBT enabled */
> >> -# define FTRACE_MCOUNT_MAX_OFFSET	ENDBR_INSN_SIZE
> >> +# define FTRACE_MCOUNT_MAX_OFFSET	(ENDBR_INSN_SIZE + MCOUNT_INSN_SIZE)
> >>  #endif
> >>  
> >>  #ifdef CONFIG_DYNAMIC_FTRACE
> >>   
> 
> Above patch didn't work, but
> Does it matter that I am compiling with "gcc -fcf-protection=none"
> to not emit endbr32 instructions for i586?

This patch is supposed to address the case when ENDBR_INSN_SIZE is
zero. So I would think that that wouldn't matter.

-- Steve