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;
Subject: =?UTF-8?Q?Re:_cmpxchg.h:245:2:_error:_=e2=80=98asm=e2=80=99_operand?=
 =?UTF-8?Q?_has_impossible_constraints?=
To:     mroos@linux.ee
Cc:     tglx@linutronix.de, linux-kernel@vger.kernel.org,
        peterz@infradead.org, x86@kernel.org
References: <alpine.DEB.2.21.1808312122300.1349@nanos.tec.linutronix.de>
 <cfc3163c-40f2-ad5e-b303-bb8dc4288022@suse.com>
From:   Juergen Gross <jgross@suse.com>
Openpgp: preference=signencrypt
Autocrypt: addr=jgross@suse.com; prefer-encrypt=mutual; keydata=
 xsBNBFOMcBYBCACgGjqjoGvbEouQZw/ToiBg9W98AlM2QHV+iNHsEs7kxWhKMjrioyspZKOB
 ycWxw3ie3j9uvg9EOB3aN4xiTv4qbnGiTr3oJhkB1gsb6ToJQZ8uxGq2kaV2KL9650I1SJve
 dYm8Of8Zd621lSmoKOwlNClALZNew72NjJLEzTalU1OdT7/i1TXkH09XSSI8mEQ/ouNcMvIJ
 NwQpd369y9bfIhWUiVXEK7MlRgUG6MvIj6Y3Am/BBLUVbDa4+gmzDC9ezlZkTZG2t14zWPvx
 XP3FAp2pkW0xqG7/377qptDmrk42GlSKN4z76ELnLxussxc7I2hx18NUcbP8+uty4bMxABEB
 AAHNHkp1ZXJnZW4gR3Jvc3MgPGpncm9zc0BzdXNlLmRlPsLAeQQTAQIAIwUCU4xw6wIbAwcL
 CQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJELDendYovxMvi4UH/Ri+OXlObzqMANruTd4N
 zmVBAZgx1VW6jLc8JZjQuJPSsd/a+bNr3BZeLV6lu4Pf1Yl2Log129EX1KWYiFFvPbIiq5M5
 kOXTO8Eas4CaScCvAZ9jCMQCgK3pFqYgirwTgfwnPtxFxO/F3ZcS8jovza5khkSKL9JGq8Nk
 czDTruQ/oy0WUHdUr9uwEfiD9yPFOGqp4S6cISuzBMvaAiC5YGdUGXuPZKXLpnGSjkZswUzY
 d9BVSitRL5ldsQCg6GhDoEAeIhUC4SQnT9SOWkoDOSFRXZ+7+WIBGLiWMd+yKDdRG5RyP/8f
 3tgGiB6cyuYfPDRGsELGjUaTUq3H2xZgIPfOwE0EU4xwFgEIAMsx+gDjgzAY4H1hPVXgoLK8
 B93sTQFN9oC6tsb46VpxyLPfJ3T1A6Z6MVkLoCejKTJ3K9MUsBZhxIJ0hIyvzwI6aYJsnOew
 cCiCN7FeKJ/oA1RSUemPGUcIJwQuZlTOiY0OcQ5PFkV5YxMUX1F/aTYXROXgTmSaw0aC1Jpo
 w7Ss1mg4SIP/tR88/d1+HwkJDVW1RSxC1PWzGizwRv8eauImGdpNnseneO2BNWRXTJumAWDD
 pYxpGSsGHXuZXTPZqOOZpsHtInFyi5KRHSFyk2Xigzvh3b9WqhbgHHHE4PUVw0I5sIQt8hJq
 5nH5dPqz4ITtCL9zjiJsExHuHKN3NZsAEQEAAcLAXwQYAQIACQUCU4xwFgIbDAAKCRCw3p3W
 KL8TL0P4B/9YWver5uD/y/m0KScK2f3Z3mXJhME23vGBbMNlfwbr+meDMrJZ950CuWWnQ+d+
 Ahe0w1X7e3wuLVODzjcReQ/v7b4JD3wwHxe+88tgB9byc0NXzlPJWBaWV01yB2/uefVKryAf
 AHYEd0gCRhx7eESgNBe3+YqWAQawunMlycsqKa09dBDL1PFRosF708ic9346GLHRc6Vj5SRA
 UTHnQqLetIOXZm3a2eQ1gpQK9MmruO86Vo93p39bS1mqnLLspVrL4rhoyhsOyh0Hd28QCzpJ
 wKeHTd0MAWAirmewHXWPco8p1Wg+V+5xfZzuQY0f4tQxvOpXpt4gQ1817GQ5/Ed/wsDtBBgB
 CAAgFiEEhRJncuj2BJSl0Jf3sN6d1ii/Ey8FAlrd8NACGwIAgQkQsN6d1ii/Ey92IAQZFggA
 HRYhBFMtsHpB9jjzHji4HoBcYbtP2GO+BQJa3fDQAAoJEIBcYbtP2GO+TYsA/30H/0V6cr/W
 V+J/FCayg6uNtm3MJLo4rE+o4sdpjjsGAQCooqffpgA+luTT13YZNV62hAnCLKXH9n3+ZAgJ
 RtAyDWk1B/0SMDVs1wxufMkKC3Q/1D3BYIvBlrTVKdBYXPxngcRoqV2J77lscEvkLNUGsu/z
 W2pf7+P3mWWlrPMJdlbax00vevyBeqtqNKjHstHatgMZ2W0CFC4hJ3YEetuRBURYPiGzuJXU
 pAd7a7BdsqWC4o+GTm5tnGrCyD+4gfDSpkOT53S/GNO07YkPkm/8J4OBoFfgSaCnQ1izwgJQ
 jIpcG2fPCI2/hxf2oqXPYbKr1v4Z1wthmoyUgGN0LPTIm+B5vdY82wI5qe9uN6UOGyTH2B3p
 hRQUWqCwu2sqkI3LLbTdrnyDZaixT2T0f4tyF5Lfs+Ha8xVMhIyzNb1byDI5FKCb
Message-ID: <1c8dc5d4-e97c-274f-e6a4-a4e930ffa74f@suse.com>
Date:   Thu, 6 Sep 2018 16:43:37 +0200
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <cfc3163c-40f2-ad5e-b303-bb8dc4288022@suse.com>
Content-Type: text/plain; charset=utf-8
Content-Language: de-DE
Content-Transfer-Encoding: 8bit
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On 06/09/18 15:54, Juergen Gross wrote:
> Hey Meelis,
> 
> On Mon, 27 Aug 2018, Meelis Roos wrote:
> 
>> While trying to compile v4.18-13105-gaba16dc5cf93 with gcc 5.3.1 on a
>> 32-bit x86 configured for AMD K6
>>   CC      mm/slub.o
>> In file included from ./arch/x86/include/asm/atomic.h:8:0,
>>                  from ./include/linux/atomic.h:7,
>>                  from ./arch/x86/include/asm/thread_info.h:54,
>>                  from ./include/linux/thread_info.h:38,
>>                  from ./arch/x86/include/asm/preempt.h:7,
>>                  from ./include/linux/preempt.h:81,
>>                  from ./include/linux/spinlock.h:51,
>>                  from ./include/linux/mmzone.h:8,
>>                  from ./include/linux/gfp.h:6,
>>                  from ./include/linux/mm.h:10,
>>                  from mm/slub.c:13:
>> mm/slub.c: In function ‘__slab_free’:
>> ./arch/x86/include/asm/cmpxchg.h:245:2: error: ‘asm’ operand has
> impossible constraints
>>   asm volatile(pfx "cmpxchg%c4b %2; sete %0"   \
> 
> Could you give the attched patch a try? I've been hit by this issue
> via kbuild robot complaining about one of my patches which didn't
> touch the asm stuff above.
> 
> I suspect the "=a" contraint of the outputs and "a" of the inputs
> are the culprit. You could save me from having to search through
> all the debian repos for a gcc showing that issue...

You don't to test. I've installed a debian VM and could reproduce the
issue locally.

My patch changes the picture: instead of a build error gcc loops
forever.


Juergen