Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 20 May 2019 12:08:47 -0400
From:   Steven Rostedt <rostedt@goodmis.org>
To:     Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc:     LKML <linux-kernel@vger.kernel.org>,
        Peter Zijlstra <peterz@infradead.org>,
        Linus Torvalds <torvalds@linux-foundation.org>,
        Jiri Kosina <jkosina@suse.cz>,
        Josh Poimboeuf <jpoimboe@redhat.com>,
        Andy Lutomirski <luto@amacapital.net>,
        Jeff Dike <jdike@addtoit.com>,
        Richard Weinberger <richard@nod.at>,
        linux-um@lists.infradead.org
Subject: Re: [PATCH] x86: Hide the int3_emulate_call/jmp functions from UML
Message-ID: <20190520120847.2ca3eac1@gandalf.local.home>
In-Reply-To: <41bc0b7b-9f51-6a10-6182-811163aa0890@cambridgegreys.com>
References: <20190511083954.23a60052@gandalf.local.home>
        <41bc0b7b-9f51-6a10-6182-811163aa0890@cambridgegreys.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, 20 May 2019 09:08:01 +0100
Anton Ivanov <anton.ivanov@cambridgegreys.com> wrote:

> On 11/05/2019 13:39, Steven Rostedt wrote:
> > 
> > From: "Steven Rostedt (VMware)" <rostedt@goodmis.org>
> > 
> > User Mode Linux does not have access to the ip or sp fields of the
> > pt_regs, and accessing them causes UML to fail to build. Hide the
> > int3_emulate_jmp() and int3_emulate_call() instructions from UML, as it
> > doesn't need them anyway.
> > 
> > Reported-by: kbuild test robot <lkp@intel.com>
> > Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
> > ---
> > 
> > [ I added this to my queue to test too ]

Looks like when I added this text, claws-mail, decided to line wrap the
patch :-p


> > 
> >   arch/x86/include/asm/text-patching.h | 4 +++-
> >   1 file changed, 3 insertions(+), 1 deletion(-)
> > 
> > diff --git a/arch/x86/include/asm/text-patching.h
> > b/arch/x86/include/asm/text-patching.h index 05861cc08787..0bbb07eaed6b
> > 100644 --- a/arch/x86/include/asm/text-patching.h
> > +++ b/arch/x86/include/asm/text-patching.h
> > @@ -39,6 +39,7 @@ extern int poke_int3_handler(struct pt_regs *regs);
> >   extern void *text_poke_bp(void *addr, const void *opcode, size_t len,
> > void *handler); extern int after_bootmem;
> >   
> > +#ifndef CONFIG_UML_X86
> >   static inline void int3_emulate_jmp(struct pt_regs *regs, unsigned
> > long ip) {
> >   	regs->ip = ip;
> > @@ -65,6 +66,7 @@ static inline void int3_emulate_call(struct pt_regs
> > *regs, unsigned long func) int3_emulate_push(regs, regs->ip -
> > INT3_INSN_SIZE + CALL_INSN_SIZE); int3_emulate_jmp(regs, func);
> >   }
> > -#endif
> > +#endif /* CONFIG_X86_64 */
> > +#endif /* !CONFIG_UML_X86 */
> >   
> >   #endif /* _ASM_X86_TEXT_PATCHING_H */
> >   
> The patch has been garbled by an auto-wrap. Can you resend it please.
> 

Anyway, it's already in Linus's tree. It was required to keep UML
compiling with other changes that needed to get into the merge window.

-- Steve