From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <44A2491D.5040102@domain.hid> Date: Wed, 28 Jun 2006 11:17:17 +0200 From: Jan Kiszka MIME-Version: 1.0 Subject: Re: [Xenomai-core] [PATCH 2/6] Improve fault report References: <20060626172116.019532000@domain.hid> <20060626172118.347530000@domain.hid> <1151480559.5154.2.camel@domain.hid> <44A234F9.9010705@domain.hid> <1151481889.5154.14.camel@domain.hid> <44A23B66.7070202@domain.hid> <1151483788.5154.22.camel@domain.hid> <44A24308.70703@domain.hid> <1151485207.5154.28.camel@domain.hid> In-Reply-To: <1151485207.5154.28.camel@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig35FB6F728DF96B93A0BFAD71" Sender: jan.kiszka@domain.hid List-Id: "Xenomai life and development \(bug reports, patches, discussions\)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: rpm@xenomai.org Cc: xenomai@xenomai.org This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig35FB6F728DF96B93A0BFAD71 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Philippe Gerum wrote: > On Wed, 2006-06-28 at 10:51 +0200, Jan Kiszka wrote: >> Philippe Gerum wrote: >>> On Wed, 2006-06-28 at 10:18 +0200, Jan Kiszka wrote: >>>> Philippe Gerum wrote: >>>>> On Wed, 2006-06-28 at 09:51 +0200, Jan Kiszka wrote: >>>>>> Philippe Gerum wrote: >>>>>>> On Mon, 2006-06-26 at 19:21 +0200, jan.kiszka@domain.hid wrote: >>>>>>>> plain text document attachment (enhance-kernel-fault-report.patc= h) >>>>>>>> Introduce xnarch_fault_um() to test if a fault happened in user-= mode and applies the new feature to report core and driver crashes more v= erbosely.=20 >>>>>>>> if (xnpod_shadow_p()) { >>>>>>>> #ifdef CONFIG_XENO_OPT_DEBUG >>>>>>>> - if (xnarch_fault_notify(fltinfo)) /* Don't report debug traps= */ >>>>>>>> + if (!xnarch_fault_um(fltinfo)) { >>>>>>>> + xnarch_trace_panic_freeze(); >>>>>>> KGDB breakpoint issue? >>>>>> Sorry, please switch on verbose mode, didn't get yet what you mean= =2E >>>>> Oops, sorry. I meant: what if a KGDB breakpoint is hit from kernel = space >>>>> while running a shadow thread? The way I read the modified test seq= uence >>>>> above, such bp trap is going to trigger a panic, instead of being >>>>> silently passed to Linux. >>>> I would say: KGDB will not come along here with a breakpoint. It sho= uld >>>> already got involved in __ipipe_divert_exception(). >>> Ok, so the only problem that remains would be inlined asm("int 1/3") = in >>> kernel space not handled by KGDB (whether the KGDB patch is in or not= ). >>> I'm still scratching my head pondering if we can live with this or no= t. >> But this is perfectly one of the situations my patch tries to catch: a= >> fatal bug in the kernel! Such a hand-coded kernel breakpoint without a= >> debugger caring is a bug to me. >=20 > Not that sure: passive debug code may exist. Only the presence of the > debugger should activate it. >=20 =2E..but remains a bug for me /w RT code. We now complain about this exception happened. And there is no crash/BUG in this case, just a desirable warning with back-trace in the log. Jan PS: Other OSes show you a nice blue-screen when they ran on such orphaned breakpoints. --------------enig35FB6F728DF96B93A0BFAD71 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.2 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFEokkeniDOoMHTA+kRAj86AJ9ufp0MijEUFVYMszc63J4ARs5EbwCeKoOW b5nuEZOCHWME20VorXSAPoI= =43J8 -----END PGP SIGNATURE----- --------------enig35FB6F728DF96B93A0BFAD71--