From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: Faulting linear address?? Date: Mon, 11 Sep 2017 15:49:01 +0200 Message-ID: <1505137741.23667.2.camel@citrix.com> References: <1504856421.3847.1.camel@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7405321029750995071==" Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Minjun Hong Cc: xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org --===============7405321029750995071== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-MN7yY/4o9wldcFTLON7+" --=-MN7yY/4o9wldcFTLON7+ Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2017-09-11 at 02:00 +0900, Minjun Hong wrote: > I made the new Xen4.5 binary with 'debug=3Dy' option that I modified > and install it. > Then, there was a kernel panic caused by the debugging code triggered > by 'debug=3Dy' during booting process(of dom0): >=20 Once again, can you show us here what you are changing? > (XEN) ----[ Xen-4.5.0 =C2=A0x86_64 =C2=A0debug=3Dy =C2=A0Not tainted ]---= - > (XEN) CPU: =C2=A0 =C2=A07 > (XEN) RIP: =C2=A0 =C2=A0e008:[] vcpu_migrate+0x1bd/0x37= 4 > (XEN) RFLAGS: 0000000000010096 =C2=A0 CONTEXT: hypervisor > [...] > (XEN) Xen call trace: > (XEN) =C2=A0 =C2=A0[] vcpu_migrate+0x1bd/0x374 > (XEN) =C2=A0 =C2=A0[] vcpu_force_reschedule+0x9e/0xa7 > (XEN) =C2=A0 =C2=A0[] do_vcpu_op+0x2e7/0x69d > (XEN) =C2=A0 =C2=A0[] syscall_enter+0xeb/0x145 > (XEN) > (XEN) Pagetable walk from ffff82d081422020: > (XEN) =C2=A0L4[0x105] =3D 0000000086092063 ffffffffffffffff > (XEN) =C2=A0L3[0x142] =3D 000000008608f063 ffffffffffffffff > (XEN) =C2=A0L2[0x00a] =3D 0000000000000000 ffffffffffffffff > (XEN) > (XEN) **************************************** > (XEN) Panic on CPU 7: > (XEN) FATAL PAGE FAULT > (XEN) [error_code=3D0000] > (XEN) Faulting linear address: ffff82d081422020 > (XEN) **************************************** >=20 > Because I received a solution from my professor, I think it is a hard > work to change Xen version. > This makes it a bit harder for us to give effective advices, but if you really can't move forward, then fine, we still can at least try. > Anyway, even if I turned on the 'debug=3Dy' option, I could not get > accurate information like with 'debug=3Dn'; I get only linear > address(ffff82d081422020). > Well, the difference is that now, if Xen is compiled with frame pointers, we are (much more) sure that the stack trace is accurate, i.e., about where the problem is actually happening, and how you got there. > So, I want to use a dis-assembly utility like 'addr2line' or > 'objdump', which binaries can I use as input to the utility? > I'm using Ubuntu and previously I used '/boot/xen-syms-4.5.0' as > input to the utilities. > Yes, if that is the binary of the hypervisor you compiled (with debug=3Dy), that's what you should use. You should also have it, in the source tree, as xen/xen-syms. > But I could get wrong information, which told me a code line that is > never related this problem. >=20 The address you pass to addr2line is not the 'Faulting linear address'. It must be the address of the instruction that was being executing when the exception occurred. IOW, you shall use ffff82d08012ba6c, from here: (XEN)=C2=A0=C2=A0=C2=A0=C2=A0[] vcpu_migrate+0x1bd/0x374 Which, in fact, is the address present in the program counter register (RIP): (XEN) RIP:=C2=A0=C2=A0=C2=A0=C2=A0e008:[] vcpu_migrate+0= x1bd/0x374 > I know that a beginner in the Xen developer community like me might > be annoying you, but I ask you one more help. > You being a beginner is not a problem. :-) The biggest problem I have right now, while trying to help you, is that I can't see what you are doing, and how you're changing the code. Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-MN7yY/4o9wldcFTLON7+ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAABCAAGBQJZtpRPAAoJEBZCeImluHPuQrMP/RSfp3NVQuZXSP89tLaqPrAf NOsr7NfYSHlwK/vX6FTrDL6rsgzplLaw4AawFLsEwrbQ+51Cehun478Kv4G4Fynq ZFc8U7axdSTUv07as1r9HZ3ggqN9fgyOZBcPS2LuJpOtt597eM2XvsrFteVx4MCa nX/XXIqvZNMoL+V/eenNhqtP/OMOMG5Q7Tw2x7/rQkMNId3h7PTA4XWiiJBKDjKh ODVba4NyCphME/RzN5vCHWC1uhMpiKjTvBipWs17ri5ViidikXN7a1dtbWFIto3F 3McOrvelhFRnKGsnjVc7/HLWBN8P39qCvnL2eMbfZHts2+PE1qr/QvvlbfMf7F53 F+uFQVVCFN9F77A4Oaws2LOgHV86zMOYHBmAnN2QQj0B69QGiIMNjXtqfc3cjhpI Y6mOxv0tuFDKVRx4YVpoaqlePhmP5C2Qw/sJsuFJE53HBUGJ+nMELGAHieNegtT2 THl4WJZxqu0KP0D52bgerShk1g01P/F2hDCD3NMrh4bwUNPSNhsqlL53XuQvWY4F eueGwtQ9XCfG58vzFsgvAB3IK5JydIdMNqPx/bBqNvHVzA71RvghowsLPM9n3sls 042F+VZT6y1ghY06JnZnt2GrxLvqyuKRd98LuG6Eb0DNDYEOmNv9v1Fov4YYhJmP EPe4eQ8qtzSrEGIr7sJK =2BCF -----END PGP SIGNATURE----- --=-MN7yY/4o9wldcFTLON7+-- --===============7405321029750995071== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============7405321029750995071==--