From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from postfix1-c.free.fr (postfix1-c.free.fr [213.228.0.79]) by ozlabs.org (Postfix) with ESMTP id 380FE67A3F for ; Thu, 30 Mar 2006 05:43:05 +1100 (EST) Received: from smtp2-g19.free.fr (smtp2-g19.free.fr [212.27.42.28]) by postfix1-c.free.fr (Postfix) with ESMTP id 1E20F188EFFE for ; Wed, 29 Mar 2006 20:43:04 +0200 (CEST) Message-ID: <442AD531.2040702@vmfacility.fr> Date: Wed, 29 Mar 2006 20:42:57 +0200 From: Ivan Warren MIME-Version: 1.0 To: Olaf Hering Subject: Re: [OT] ppc64 serialization problem References: <1143597506.3075.53.camel@localhost.localdomain> <17450.2061.510951.479016@cargo.ozlabs.ibm.com> <1143656433.3075.108.camel@localhost.localdomain> <20060329183259.GA18514@suse.de> In-Reply-To: <20060329183259.GA18514@suse.de> Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg=sha1; boundary="------------ms030701090102010901090103" Cc: Greg Smith , linuxppc-dev@ozlabs.org, Paul Mackerras List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , This is a cryptographically signed message in MIME format. --------------ms030701090102010901090103 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Olaf Hering wrote: > On Wed, Mar 29, Greg Smith wrote: > > >> So it is clear between .A and .B -> value of b was read then written. If >> anything happens between .A and .B to ->b, then it is lost. >> > > Even gcc4.1 does it that way with -O0 Yeah.. Noticed that..gcc 3.3.3 and gcc 4.0.3 also do this Even declaring the field volatile has no effect.. Question : Is this *NORMAL* behavior ? I discussed this with some C folks and they seem to think (at least some of them) that it's broken per standards.. (volatile fields should be only read/written IFF read/written explicitly - pretty much what section 6.3.7 of the C std says). Anyway I can produce perfectly valid sample code (to my understanding anyway) that produces incorrect result.. YUCK ! This is also possibly a problem with the powerpc64 back end of gcc.. Anyway.. It's OT.. Sorry to have bothered you guys ! (And thanks Greg for pointing me here). --Ivan --------------ms030701090102010901090103 Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIJFzCC AuYwggJPoAMCAQICAw8zMzANBgkqhkiG9w0BAQQFADBiMQswCQYDVQQGEwJaQTElMCMGA1UE ChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNv bmFsIEZyZWVtYWlsIElzc3VpbmcgQ0EwHhcNMDUwNzI2MTQwODQ1WhcNMDYwNzI2MTQwODQ1 WjBZMQ8wDQYDVQQEEwZXYXJyZW4xDTALBgNVBCoTBEl2YW4xFDASBgNVBAMTC0l2YW4gV2Fy cmVuMSEwHwYJKoZIhvcNAQkBFhJpdmFuQHZtZmFjaWxpdHkuZnIwggEiMA0GCSqGSIb3DQEB AQUAA4IBDwAwggEKAoIBAQDRDxGyHQY7HSoR21Yt1gCrWIllQB75/gWzbtvkbVpfIEuW4qYe XW1g6N5EggRU+WVsozDi0iVSsGdRleqx4pE4hjvhXXYQ+f7j+7SZLoIbb46+brJVPy7okf9u XCjOcNixRwYaDoEOZSM7N5x+RZxLGb3XIs4w6AwZkewZk0Fn5vdBG6e248QqnveAWCcxsmgT nSZQ01tmyzwB8ke135oK83jZTeQ6Hk8VCa2t82ssbVC1Uue8C/ZtxP981vj3cMRwNm3JM+T2 0C5ianZItpBw9LwHXH1JWcFxjEuG1rzsI50ACXY813MKQM2LFZDFhnWLEQOGTdlCWul5F+X2 9xXlAgMBAAGjLzAtMB0GA1UdEQQWMBSBEml2YW5Adm1mYWNpbGl0eS5mcjAMBgNVHRMBAf8E AjAAMA0GCSqGSIb3DQEBBAUAA4GBAJoB4l6xIdaqXUZxsy0imAOZ3v10mMcJU905ny4cihcP HxeIgF4/qVuQSLBHxfH3l3vl3dTiX1HApIrNQR0ooZQdlAFTk1f55MYEUKVVPTZ1SyBdF7hF Kd6EA4vLLaw9y4tUFzbnPsQjJFpqfqrTOkn9gsj+zgsTCNMV2+ZeQxZrMIIC5jCCAk+gAwIB AgIDDzMzMA0GCSqGSIb3DQEBBAUAMGIxCzAJBgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUg Q29uc3VsdGluZyAoUHR5KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29uYWwgRnJlZW1h aWwgSXNzdWluZyBDQTAeFw0wNTA3MjYxNDA4NDVaFw0wNjA3MjYxNDA4NDVaMFkxDzANBgNV BAQTBldhcnJlbjENMAsGA1UEKhMESXZhbjEUMBIGA1UEAxMLSXZhbiBXYXJyZW4xITAfBgkq hkiG9w0BCQEWEml2YW5Adm1mYWNpbGl0eS5mcjCCASIwDQYJKoZIhvcNAQEBBQADggEPADCC AQoCggEBANEPEbIdBjsdKhHbVi3WAKtYiWVAHvn+BbNu2+RtWl8gS5biph5dbWDo3kSCBFT5 ZWyjMOLSJVKwZ1GV6rHikTiGO+FddhD5/uP7tJkughtvjr5uslU/LuiR/25cKM5w2LFHBhoO gQ5lIzs3nH5FnEsZvdcizjDoDBmR7BmTQWfm90Ebp7bjxCqe94BYJzGyaBOdJlDTW2bLPAHy R7XfmgrzeNlN5DoeTxUJra3zayxtULVS57wL9m3E/3zW+PdwxHA2bckz5PbQLmJqdki2kHD0 vAdcfUlZwXGMS4bWvOwjnQAJdjzXcwpAzYsVkMWGdYsRA4ZN2UJa6XkX5fb3FeUCAwEAAaMv MC0wHQYDVR0RBBYwFIESaXZhbkB2bWZhY2lsaXR5LmZyMAwGA1UdEwEB/wQCMAAwDQYJKoZI hvcNAQEEBQADgYEAmgHiXrEh1qpdRnGzLSKYA5ne/XSYxwlT3TmfLhyKFw8fF4iAXj+pW5BI sEfF8feXe+Xd1OJfUcCkis1BHSihlB2UAVOTV/nkxgRQpVU9NnVLIF0XuEUp3oQDi8strD3L i1QXNuc+xCMkWmp+qtM6Sf2CyP7OCxMI0xXb5l5DFmswggM/MIICqKADAgECAgENMA0GCSqG SIb3DQEBBQUAMIHRMQswCQYDVQQGEwJaQTEVMBMGA1UECBMMV2VzdGVybiBDYXBlMRIwEAYD VQQHEwlDYXBlIFRvd24xGjAYBgNVBAoTEVRoYXd0ZSBDb25zdWx0aW5nMSgwJgYDVQQLEx9D ZXJ0aWZpY2F0aW9uIFNlcnZpY2VzIERpdmlzaW9uMSQwIgYDVQQDExtUaGF3dGUgUGVyc29u YWwgRnJlZW1haWwgQ0ExKzApBgkqhkiG9w0BCQEWHHBlcnNvbmFsLWZyZWVtYWlsQHRoYXd0 ZS5jb20wHhcNMDMwNzE3MDAwMDAwWhcNMTMwNzE2MjM1OTU5WjBiMQswCQYDVQQGEwJaQTEl MCMGA1UEChMcVGhhd3RlIENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3Rl IFBlcnNvbmFsIEZyZWVtYWlsIElzc3VpbmcgQ0EwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJ AoGBAMSmPFVzVftOucqZWh5owHUEcJ3f6f+jHuy9zfVb8hp2vX8MOmHyv1HOAdTlUAow1wJj WiyJFXCO3cnwK4Vaqj9xVsuvPAsH5/EfkTYkKhPPK9Xzgnc9A74r/rsYPge/QIACZNenpruf ZdHFKlSFD0gEf6e20TxhBEAeZBlyYLf7AgMBAAGjgZQwgZEwEgYDVR0TAQH/BAgwBgEB/wIB ADBDBgNVHR8EPDA6MDigNqA0hjJodHRwOi8vY3JsLnRoYXd0ZS5jb20vVGhhd3RlUGVyc29u YWxGcmVlbWFpbENBLmNybDALBgNVHQ8EBAMCAQYwKQYDVR0RBCIwIKQeMBwxGjAYBgNVBAMT EVByaXZhdGVMYWJlbDItMTM4MA0GCSqGSIb3DQEBBQUAA4GBAEiM0VCD6gsuzA2jZqxnD3+v rL7CF6FDlpSdf0whuPg2H6otnzYvwPQcUCCTcDz9reFhYsPZOhl+hLGZGwDFGguCdJ4lUJRi x9sncVcljd2pnDmOjCBPZV+V2vf3h9bGCE6u9uo05RAaWzVNd+NWIXiC3CEZNd4ksdMdRv9d X2VPMYIDOzCCAzcCAQEwaTBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3RlIENvbnN1 bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVtYWlsIElz c3VpbmcgQ0ECAw8zMzAJBgUrDgMCGgUAoIIBpzAYBgkqhkiG9w0BCQMxCwYJKoZIhvcNAQcB MBwGCSqGSIb3DQEJBTEPFw0wNjAzMjkxODQyNTdaMCMGCSqGSIb3DQEJBDEWBBQ+oUsk3qtm lC4LbHx5OvPqpl4sJjBSBgkqhkiG9w0BCQ8xRTBDMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMC AgIAgDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKDB4BgkrBgEEAYI3 EAQxazBpMGIxCzAJBgNVBAYTAlpBMSUwIwYDVQQKExxUaGF3dGUgQ29uc3VsdGluZyAoUHR5 KSBMdGQuMSwwKgYDVQQDEyNUaGF3dGUgUGVyc29uYWwgRnJlZW1haWwgSXNzdWluZyBDQQID DzMzMHoGCyqGSIb3DQEJEAILMWugaTBiMQswCQYDVQQGEwJaQTElMCMGA1UEChMcVGhhd3Rl IENvbnN1bHRpbmcgKFB0eSkgTHRkLjEsMCoGA1UEAxMjVGhhd3RlIFBlcnNvbmFsIEZyZWVt YWlsIElzc3VpbmcgQ0ECAw8zMzANBgkqhkiG9w0BAQEFAASCAQA76CEui4yYOeL6G7AFO43G 3+Hhv+X5cZyUnRUfLpVzafhQuyf1RZ+Rz2xC7V+sYnkbbmqkuoRgTH/vQ04Ryu6/oLb8jrVu /NUajr/pJK8T0lnnEDH/iKZjc8UgL8p424CDh/F6iqu2HYNGaciP0s8F4sA/or1k5xLZBviq Dl3Y8gCsjGa5A6XbKhs+Xk/ir6KIao2ptkxjl0eSGyTdvl+wLBwlxLokOaobyRACh1wRPQ+q ot5gXg3to7fysa13HZhsouxXngKiP387938k/pON6AChI+DA6NidbJWGPzdDRWOhqvs1ph41 9d2y994yMzy2YFemT7aip6PmGTlNr6GlAAAAAAAA --------------ms030701090102010901090103--