linux-kernel - Re: [v3 PATCH 05/10] x86/insn-kernel: Add support to resolve 16-bit addressing encodings (fwd)

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Date:   Thu, 26 Jan 2017 19:35:20 -0800
From:   Ricardo Neri <ricardo.neri-calderon@...ux.intel.com>
To:     Julia Lawall <julia.lawall@...6.fr>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Brian Gerst <brgerst@...il.com>,
        Chris Metcalf <cmetcalf@...lanox.com>,
        Dave Hansen <dave.hansen@...ux.intel.com>,
        Paolo Bonzini <pbonzini@...hat.com>,
        Liang Z Li <liang.z.li@...el.com>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Huang Rui <ray.huang@....com>, Jiri Slaby <jslaby@...e.cz>,
        Jonathan Corbet <corbet@....net>,
        "Michael S. Tsirkin" <mst@...hat.com>,
        Paul Gortmaker <paul.gortmaker@...driver.com>,
        Vlastimil Babka <vbabka@...e.cz>,
        Chen Yucong <slaoub@...il.com>,
        Alexandre Julliard <julliard@...ehq.org>,
        Fenghua Yu <fenghua.yu@...el.com>, Stas Sergeev <stsp@...t.ru>,
        "Ravi V. Shankar" <ravi.v.shankar@...el.com>,
        Shuah Khan <shuah@...nel.org>, linux-kernel@...r.kernel.org,
        x86@...nel.org, linux-msdos@...r.kernel.org, wine-devel@...ehq.org,
        Adam Buchbinder <adam.buchbinder@...il.com>,
        Colin Ian King <colin.king@...onical.com>,
        Lorenzo Stoakes <lstoakes@...il.com>,
        Qiaowei Ren <qiaowei.ren@...el.com>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Adrian Hunter <adrian.hunter@...el.com>,
        Kees Cook <keescook@...omium.org>,
        Thomas Garnier <thgarnie@...gle.com>,
        Dmitry Vyukov <dvyukov@...gle.com>,
        Ingo Molnar <mingo@...hat.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        "H. Peter Anvin" <hpa@...or.com>,
        Andy Lutomirski <luto@...nel.org>,
        Borislav Petkov <bp@...e.de>, kbuild-all@...org
Subject: Re: [v3 PATCH 05/10] x86/insn-kernel: Add support to resolve 16-bit
 addressing encodings (fwd)

On Wed, 2017-01-25 at 22:49 +0100, Julia Lawall wrote:
> Check the type of seg on line 267.

Ah! I missed that. It makes sense. I will fix this issue.

Thanks and BR,
Ricardo
> 
> julia
> 
> ---------- Forwarded message ----------
> Date: Thu, 26 Jan 2017 05:24:40 +0800
> From: kbuild test robot <fengguang.wu@...el.com>
> To: kbuild@...org
> Cc: Julia Lawall <julia.lawall@...6.fr>
> Subject: Re: [v3 PATCH 05/10] x86/insn-kernel: Add support to resolve 16-bit
>     addressing encodings
> 
> In-Reply-To: <20170125202353.101059-6-ricardo.neri-calderon@...ux.intel.com>
> 
> Hi Ricardo,
> 
> [auto build test WARNING on tip/auto-latest]
> [also build test WARNING on v4.10-rc5 next-20170125]
> [cannot apply to tip/x86/core]
> [if your patch is applied to the wrong git tree, please drop us a note to help improve the system]
> 
> url:    https://github.com/0day-ci/linux/commits/Ricardo-Neri/x86-Enable-User-Mode-Instruction-Prevention/20170126-043345
> :::::: branch date: 51 minutes ago
> :::::: commit date: 51 minutes ago
> 
> >> arch/x86/lib/insn-kernel.c:267:6-9: WARNING: Unsigned expression compared with zero: seg < 0
> 
> git remote add linux-review https://github.com/0day-ci/linux
> git remote update linux-review
> git checkout 574de0de238ef30c816985006f02f7a1dbba92aa
> vim +267 arch/x86/lib/insn-kernel.c
> 
> 574de0de Ricardo Neri 2017-01-25  251  		addr = (seg << 4) + regs_get_register(regs, addr_offset1);
> 574de0de Ricardo Neri 2017-01-25  252  	} else {
> 574de0de Ricardo Neri 2017-01-25  253  		ret = get_reg_offset_16(insn, regs, &addr_offset1,
> 574de0de Ricardo Neri 2017-01-25  254  					&addr_offset2);
> 574de0de Ricardo Neri 2017-01-25  255  		if (ret < 0)
> 574de0de Ricardo Neri 2017-01-25  256  			goto out_err;
> 574de0de Ricardo Neri 2017-01-25  257  		/*
> 574de0de Ricardo Neri 2017-01-25  258  		 * Don't fail on invalid offset values. They might be invalid
> 574de0de Ricardo Neri 2017-01-25  259  		 * because they are not supported. Instead, use them in the
> 574de0de Ricardo Neri 2017-01-25  260  		 * calculation only if they contain a valid value.
> 574de0de Ricardo Neri 2017-01-25  261  		 */
> 574de0de Ricardo Neri 2017-01-25  262  		if (addr_offset1 >= 0)
> 574de0de Ricardo Neri 2017-01-25  263  			addr1 = regs_get_register(regs, addr_offset1);
> 574de0de Ricardo Neri 2017-01-25  264  		if (addr_offset2 >= 0)
> 574de0de Ricardo Neri 2017-01-25  265  			addr2 = regs_get_register(regs, addr_offset2);
> 574de0de Ricardo Neri 2017-01-25  266  		seg = __get_segment_selector_16(regs, insn, addr_offset1);
> 574de0de Ricardo Neri 2017-01-25 @267  		if (seg < 0)
> 574de0de Ricardo Neri 2017-01-25  268  			goto out_err;
> 574de0de Ricardo Neri 2017-01-25  269  		addr =  (seg << 4) + addr1 + addr2;
> 574de0de Ricardo Neri 2017-01-25  270  	}
> 574de0de Ricardo Neri 2017-01-25  271  	addr += insn->displacement.value;
> 574de0de Ricardo Neri 2017-01-25  272
> 574de0de Ricardo Neri 2017-01-25  273  	return (void __user *)addr;
> 574de0de Ricardo Neri 2017-01-25  274  out_err:
> 574de0de Ricardo Neri 2017-01-25  275  	return (void __user *)-1;
> 
> ---
> 0-DAY kernel test infrastructure                Open Source Technology Center
> https://lists.01.org/pipermail/kbuild-all                   Intel Corporation