Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753208AbcDVXRR (ORCPT ); Fri, 22 Apr 2016 19:17:17 -0400 Received: from mail-bn1on0116.outbound.protection.outlook.com ([157.56.110.116]:61549 "EHLO na01-bn1-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751995AbcDVXRP (ORCPT ); Fri, 22 Apr 2016 19:17:15 -0400 From: Quinn Tran To: Josh Poimboeuf , James Bottomley , "Martin K. Petersen" CC: linux-scsi , linux-kernel , Denys Vlasenko , "Thomas Graf" , Peter Zijlstra , David Rientjes , Andrew Morton , "Arnd Bergmann" , "jamborm@gcc.gnu.org" , "Ingo Molnar" , Himanshu Madhani , Dept-Eng QLA2xxx Upstream Subject: Re: [PATCH] scsi: fc: force inlining of wwn conversion functions Thread-Topic: [PATCH] scsi: fc: force inlining of wwn conversion functions Thread-Index: AQHRmkOPF0R0OUUoC0+gtaTaccjq25+WME2A Date: Fri, 22 Apr 2016 23:17:08 +0000 Message-ID: <5B57167E-EF1A-4739-BAD3-758AE3991846@qlogic.com> References: <20160419085221.GA29087@gmail.com> <80200c53ae54f6cb34bd6fb51e9da65fdcc03004.1461073602.git.jpoimboe@redhat.com> In-Reply-To: <80200c53ae54f6cb34bd6fb51e9da65fdcc03004.1461073602.git.jpoimboe@redhat.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: user-agent: Microsoft-MacOutlook/0.0.0.160212 authentication-results: redhat.com; dkim=none (message not signed) header.d=none;redhat.com; dmarc=none action=none header.from=qlogic.com; x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [198.186.0.2] x-ld-processed: 0d68a1f9-1490-4d0e-8767-a87dab3ef2ba,ExtAddr,ExtAddr x-ms-office365-filtering-correlation-id: c3189abd-6125-4eb5-7823-08d36b043a22 x-microsoft-exchange-diagnostics: 1;SN1PR11MB0654;5:kKJsWLsqmQ+dtcktpCBLp3Hb4vEilc2vY8JFglwdwljj3PCJuqO5r6I/jldPIfzIVj8riFmSN07QyVNCTGB4VZToe9lwQDcgKYc/GbAtUhF/Zu8rhMiegE7YCRogvNLbTIF4EzUqUzvNnzyIM+K8wP9rW7UcGhzHZKwQ7aRBGiRcsH4YJND6mffATyzuzG7L;24:DvYnpKGqZZtX0ksT0mIEbENc/BcX4A1hiunbOrpyXlhFTH9B9N9jYJShC0AyodJD4valU4Q2YO5J+6oBhDUxSvWU3Vajq/LHSOWzwGbqfN4=;7:jGQeyA/JNUF+2j3MfUcRGTJezq93rt0yBCNypWN1DGgXS5Vj0Tqc5mG8ppXuBiLZr2lItjFhuS5bBZqfAcB+xrYhp9KAbPWuYxwpI4hbMHvMrCTqQU9t977U4Mtcu+9+gtZuL+baZcD0GIKeJ9Q4UlyQswhrsT0NckGTmJn0UDY3M+oRzi4xe5o4lY7xesFT+P9efQ7zp6GsfAMXJLvOs543EsFrArAAQA2Hq1eOT54=;20:EsFFjYRB/2GYo+4y2+G6/NQps+/lwyNIofuzrnWYpGKRXRhDT+RSBiP3cxjkvJUmspxYu31j4cPr6mrITJRfklvFx7GVnnsS+oe0/G8ZZX9ePLfypuHzvc/T66Ns9Gg6Q+SBRJMX2/vPGob/UP+lXiIeNq9bBLN+reoJzQ21ONg= x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:SN1PR11MB0654; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:; x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(9101521026)(601004)(2401047)(5005006)(8121501046)(10201501046)(3002001);SRVR:SN1PR11MB0654;BCL:0;PCL:0;RULEID:;SRVR:SN1PR11MB0654; x-forefront-prvs: 0920602B08 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(13464003)(377454003)(377424004)(15975445007)(5008740100001)(6116002)(3846002)(102836003)(76176999)(4001430100002)(50986999)(106116001)(2950100001)(122556002)(3280700002)(3660700001)(81166005)(77096005)(2900100001)(5002640100001)(19580405001)(19580395003)(33656002)(66066001)(1096002)(36756003)(10400500002)(2906002)(4326007)(82746002)(5004730100002)(99286002)(83716003)(586003)(87936001)(54356999)(1220700001)(5001770100001)(86362001)(107886002)(92566002)(4001350100001)(189998001);DIR:OUT;SFP:1102;SCL:1;SRVR:SN1PR11MB0654;H:SN1PR11MB0655.namprd11.prod.outlook.com;FPR:;SPF:None;MLV:sfv;LANG:en; spamdiagnosticoutput: 1:23 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-OriginatorOrg: qlogic.com X-MS-Exchange-CrossTenant-originalarrivaltime: 22 Apr 2016 23:17:08.7188 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 0d68a1f9-1490-4d0e-8767-a87dab3ef2ba X-MS-Exchange-Transport-CrossTenantHeadersStamped: SN1PR11MB0654 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u3MNHM1F020470 Content-Length: 7064 Lines: 152 Current kernel (4.6.0-rc4+) + GCC 5.3.0 definitely truncated qla2x00_get_host_fabric_name() routine. Just like Josh indicated, we’re dropping down to the next routine. root@mars:/sys/class/fc_host/host3 2016-04-22 16:07:30 > cat fabric_name Killed —— static void qla2x00_get_host_fabric_name(struct Scsi_Host *shost) { 32d0: e8 00 00 00 00 callq 32d5 32d5: 55 push %rbp 32d6: 48 89 e5 mov %rsp,%rbp 32d9: 0f 1f 80 00 00 00 00 nopl 0x0(%rax) 00000000000032e0 : qla2x00_get_starget_node_name(): /root/qt/linux.git/drivers/scsi/qla2xxx/qla_attr.c:1756 fc_host_port_type(shost) = port_type; } ---- Apr 22 16:07:50 mars kernel: BUG: unable to handle kernel NULL pointer dereference at 0000000000000058 Apr 22 16:07:50 mars kernel: IP: [] scsi_is_host_device+0x7/0x20 Apr 22 16:07:50 mars kernel: PGD 7fe1c8067 PUD 7f5c72067 PMD 0 Apr 22 16:07:50 mars kernel: Oops: 0000 [#1] SMP Apr 22 16:07:50 mars kernel: Modules linked in: qla2xxx scsi_transport_fc ebtable_nat ebtables ipt_MASQUERADE nf_nat_masquerade_ipv4 iptable_nat nf_nat_ipv4 ... dm_mirror(E) dm_region_hash(E) dm_log(E) dm_mod(E) [last unloaded: qla2xxx] Apr 22 16:07:50 mars kernel: CPU: 8 PID: 10452 Comm: cat Tainted: G E 4.6.0-rc4+ #2 Apr 22 16:07:50 mars kernel: Hardware name: HP ProLiant DL380 G7, BIOS P67 05/05/2011 Apr 22 16:07:50 mars kernel: task: ffff8807fcd1a880 ti: ffff8807ff128000 task.ti: ffff8807ff128000 Apr 22 16:07:50 mars kernel: RIP: 0010:[] [] scsi_is_host_device+0x7/0x20 Apr 22 16:07:50 mars kernel: RSP: 0018:ffff8807ff12bcf0 EFLAGS: 00010246 Apr 22 16:07:50 mars kernel: RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff880ffe8ade88 Apr 22 16:07:50 mars kernel: RDX: ffff8807f5db9000 RSI: ffff880ffed43340 RDI: 0000000000000000 Apr 22 16:07:50 mars kernel: RBP: ffff8807ff12bd08 R08: ffff88101f45ac38 R09: ffff8807fccef280 Apr 22 16:07:50 mars kernel: R10: 0000000000000000 R11: 0000000000000000 R12: ffff88101b7e6000 Apr 22 16:07:50 mars kernel: R13: ffff8807fdaf1f00 R14: ffff8800dad379c0 R15: 0000000000000001 Apr 22 16:07:50 mars kernel: FS: 00007fd569512700(0000) GS:ffff88081fc80000(0000) knlGS:0000000000000000 Apr 22 16:07:50 mars kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Apr 22 16:07:50 mars kernel: CR2: 0000000000000058 CR3: 00000007f23f4000 CR4: 00000000000006e0 Apr 22 16:07:50 mars kernel: Stack: Apr 22 16:07:50 mars kernel: ffffffffa0759db5 ffff88101b7e6000 ffff8807f5db9000 ffff8807ff12bd10 Apr 22 16:07:50 mars kernel: ffff8807ff12bd30 ffffffffa065b1bb ffff880ffed43340 ffffffff8166d950 Apr 22 16:07:50 mars kernel: ffff8807ff12bd50 ffffffff813c9e30 ffffffff815ccfb2 ffff8800dad379c0 Apr 22 16:07:50 mars kernel: Call Trace: Apr 22 16:07:50 mars kernel: [] ? qla2x00_get_starget_node_name+0x25/0x90 [qla2xxx] Apr 22 16:07:50 mars kernel: [] ? show_fc_host_fabric_name+0x4b/0x80 [scsi_transport_fc] Apr 22 16:07:50 mars kernel: [] ? dev_attr_show+0x20/0x50 Regards, Quinn Tran -----Original Message----- From: on behalf of Josh Poimboeuf Date: Tuesday, April 19, 2016 at 6:56 AM To: James Bottomley , "Martin K. Petersen" Cc: linux-scsi , linux-kernel , Denys Vlasenko , Thomas Graf , Peter Zijlstra , David Rientjes , Andrew Morton , Arnd Bergmann , "jamborm@gcc.gnu.org" , Ingo Molnar , Himanshu Madhani , Dept-Eng QLA2xxx Upstream Subject: [PATCH] scsi: fc: force inlining of wwn conversion functions >objtool reports [1] the following warning: > > drivers/scsi/qla2xxx/qla_attr.o: warning: objtool: qla2x00_get_host_fabric_name() falls through to next function qla2x00_get_starget_port_name() > >This warning is due to a gcc bug [2] which causes corrupt code: > > 0000000000002f53 : > 2f53: 55 push %rbp > 2f54: 48 89 e5 mov %rsp,%rbp > > 0000000000002f57 : > 2f57: 55 push %rbp > 2f58: b9 e8 00 00 00 mov $0xe8,%ecx > 2f5d: 48 89 e5 mov %rsp,%rbp > ... > >Note that qla2x00_get_host_fabric_name() is inexplicably truncated after >setting up the frame pointer. It falls through to the next function, >which is very bad. > >It occurs with the combination of the following two recent commits: > > bc27fb68aaad ("include/uapi/linux/byteorder, swab: force inlining of some byteswap operations") > ef3fb2422ffe ("scsi: fc: use get/put_unaligned64 for wwn access") > >The call chain which appears to trigger the problem is: > > qla2x00_get_host_fabric_name() > wwn_to_u64() > get_unaligned_be64() > be64_to_cpup() > __be64_to_cpup() > >The bug requires very specific conditions to trigger. According to Martin >Jambor (from the gcc bugzilla): > > "This bug can occur when an inlineable function containing a call to > __builtin_constant_p, which checks a parameter or a value it > references and a (possibly indirect) caller of the function actually > passes a constant, but stores it using a type of a different size." > >There's no reliable way to avoid (or even detect) the bug. Until it >gets fixed in released versions of gcc, the least intrusive workaround >for this particular issue is to force the wwn conversion functions to be >inlined. > >[1] https://lists.01.org/pipermail/kbuild-all/2016-April/019579.html >[2] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70646 > >Reported-by: kbuild test robot >Signed-off-by: Josh Poimboeuf >--- > include/scsi/scsi_transport_fc.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > >diff --git a/include/scsi/scsi_transport_fc.h b/include/scsi/scsi_transport_fc.h >index bf66ea6..1919cd4 100644 >--- a/include/scsi/scsi_transport_fc.h >+++ b/include/scsi/scsi_transport_fc.h >@@ -796,12 +796,12 @@ fc_remote_port_chkready(struct fc_rport *rport) > return result; > } > >-static inline u64 wwn_to_u64(u8 *wwn) >+static __always_inline u64 wwn_to_u64(u8 *wwn) > { > return get_unaligned_be64(wwn); > } > >-static inline void u64_to_wwn(u64 inm, u8 *wwn) >+static __always_inline void u64_to_wwn(u64 inm, u8 *wwn) > { > put_unaligned_be64(inm, wwn); > } >-- >2.4.11 > >-- >To unsubscribe from this list: send the line "unsubscribe linux-scsi" in >the body of a message to majordomo@vger.kernel.org >More majordomo info at http://vger.kernel.org/majordomo-info.html