Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261786AbVE0PCU (ORCPT ); Fri, 27 May 2005 11:02:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261790AbVE0PCU (ORCPT ); Fri, 27 May 2005 11:02:20 -0400 Received: from os.inf.tu-dresden.de ([141.76.48.99]:25272 "EHLO os.inf.tu-dresden.de") by vger.kernel.org with ESMTP id S261786AbVE0PCH (ORCPT ); Fri, 27 May 2005 11:02:07 -0400 Date: Fri, 27 May 2005 17:02:09 +0200 From: "Udo A. Steinberg" To: Linux Kernel Mailing List Cc: Roland McGrath Subject: [OOPS] 2.6.12-rc3 ptrace bug? Message-ID: <20050527170209.59355a59@laptop.hypervisor.org> X-GPG-Fingerprint: CE1F 5FDD 3C01 BE51 2106 292E 9E14 735D 233B 9D29 X-Mailer: X-Mailer 5.0 Gold Mime-Version: 1.0 Content-Type: multipart/signed; boundary="Signature_Fri__27_May_2005_17_02_09_+0200_AYPgGyDH/iLeIjm3"; protocol="application/pgp-signature"; micalg=pgp-sha1 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3770 Lines: 90 --Signature_Fri__27_May_2005_17_02_09_+0200_AYPgGyDH/iLeIjm3 Content-Type: multipart/mixed; boundary="Multipart_Fri__27_May_2005_17_02_09_+0200_Ydd=3EvFvhxDwzEL" --Multipart_Fri__27_May_2005_17_02_09_+0200_Ydd=3EvFvhxDwzEL Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable Content-Disposition: inline The attached (radically shortened) program to measure pipe performance oops= es the Linux-2.6.12-rc3 kernel when traced using "strace -f". The problem no l= onger occurs in -rc4 or -rc5. It would be good to know whether the bug causing the problem is known and has been fixed or simply went away due to other change= s. I have been unable to find a Changelog detailing the patches that went into -rc4. The bug is reproducible on all -rc3 kernels I've tried. Unable to handle kernel NULL pointer dereference at virtual address 00000000 printing eip: 00000000 *pde =3D 00000000 Oops: 0000 [#1] PREEMPT=20 Modules linked in: CPU: 0 EIP: 0060:[<00000000>] Not tainted VLI EFLAGS: 00010286 (2.6.12-rc3)=20 EIP is at 0x0 eax: db052000 ebx: 01200011 ecx: 00000000 edx: 00000000 esi: df605060 edi: 00000000 ebp: db052000 esp: db052fc4 ds: 007b es: 007b ss: 0068 Process pipe (pid: 778, threadinfo=3Ddb052000 task=3Ddf605060) Stack: 01202011 00000000 00000000 00000000 b7ea0708 bf9da748 00000000 00000= 07b=20 c010007b 00000078 b7f290a5 00000073 00000282 bf9da6e0 0000007b=20 Call Trace: Code: Bad EIP value. Best regards, -Udo. --Multipart_Fri__27_May_2005_17_02_09_+0200_Ydd=3EvFvhxDwzEL Content-Type: application/octet-stream; name=pipe.c Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename=pipe.c CiNpbmNsdWRlIDxzdGRpby5oPgojaW5jbHVkZSA8c3RkbGliLmg+CiNpbmNsdWRlIDx1bmlzdGQu aD4KCnVuc2lnbmVkIGl0ZXJhdGlvbnMgPSAxMDAwOwppbnQgcGluZ1syXSwgcG9uZ1syXTsKcGlk X3QgcGlkOwoKdm9pZCBkb19waW5nICh2b2lkKQp7CiAgICBjaGFyIGJ1ZmZlcjsKICAgIHVuc2ln bmVkIGk7CiAgICAKICAgIGZvciAoaSA9IDA7IGkgPCBpdGVyYXRpb25zOyBpKyspIHsKICAgICAg ICBpZiAod3JpdGUgKHBpbmdbMV0sICJFIiwgMSkgIT0gMSkKICAgICAgICAgICAgYnJlYWs7CiAg ICAgICAgaWYgKHJlYWQgKHBvbmdbMF0sICZidWZmZXIsIDEpICE9IDEpCiAgICAgICAgICAgIGJy ZWFrOwogICAgfQoKICAgIGNsb3NlIChwaW5nWzFdKTsKICAgIGNsb3NlIChwb25nWzBdKTsKCiAg ICB3YWl0cGlkIChwaWQsICZpLCAwKTsKfQoKdm9pZCBkb19lY2hvICh2b2lkKQp7CiAgICBjaGFy IGJ1ZmZlcjsKCiAgICBmb3IgKDs7KSB7CiAgICAgICAgaWYgKHJlYWQgKHBpbmdbMF0sICZidWZm ZXIsIDEpICE9IDEpCiAgICAgICAgICAgIGJyZWFrOwogICAgICAgIGlmICh3cml0ZSAocG9uZ1sx XSwgIlIiLCAxKSAhPSAxKQogICAgICAgICAgICBicmVhazsKICAgIH0KfQoKaW50IG1haW4gKGlu dCBhcmdjLCBjaGFyICoqYXJndikKewogICAgaWYgKHBpcGUgKHBpbmcpID09IC0xIHx8IHBpcGUg KHBvbmcpID09IC0xKQogICAgICAgIHJldHVybiAtMTsKICAgIAogICAgc3dpdGNoIChwaWQgPSBm b3JrKCkpIHsKCiAgICAgICAgY2FzZSAtMToKICAgICAgICAgICAgcmV0dXJuIC0xOwoKICAgICAg ICBjYXNlIDA6CiAgICAgICAgICAgIGNsb3NlIChwaW5nWzFdKTsKICAgICAgICAgICAgY2xvc2Ug KHBvbmdbMF0pOwogICAgICAgICAgICBkb19lY2hvKCk7CiAgICAgICAgICAgIHJldHVybiAwOwoK ICAgICAgICBkZWZhdWx0OgogICAgICAgICAgICBjbG9zZSAocGluZ1swXSk7CiAgICAgICAgICAg IGNsb3NlIChwb25nWzFdKTsKICAgICAgICAgICAgZG9fcGluZygpOyAgICAgICAgCiAgICB9Cgog ICAgcmV0dXJuIDA7Cn0K --Multipart_Fri__27_May_2005_17_02_09_+0200_Ydd=3EvFvhxDwzEL-- --Signature_Fri__27_May_2005_17_02_09_+0200_AYPgGyDH/iLeIjm3 Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.7 (GNU/Linux) iD8DBQFClzZznhRzXSM7nSkRAiOvAJ4lpqWTDeQdwJ78tElMS+T1XMKPLwCdFeDb //4eswCEPxMWq+YMnTiajME= =6vSE -----END PGP SIGNATURE----- --Signature_Fri__27_May_2005_17_02_09_+0200_AYPgGyDH/iLeIjm3-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/