From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <4A618239.90506@domain.hid> Date: Sat, 18 Jul 2009 10:05:13 +0200 From: Jan Kiszka MIME-Version: 1.0 References: <1247750127.306081.22356.nullmailer@domain.hid> <1247754601.4228.73.camel@domain.hid> <1247829470.829653.30773.nullmailer@domain.hid> <1247832340.4228.132.camel@domain.hid> <1247837534.904271.19070.nullmailer@domain.hid> <1247838733.4228.139.camel@domain.hid> <1247845909.586479.22758.nullmailer@domain.hid> In-Reply-To: <1247845909.586479.22758.nullmailer@domain.hid> Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="------------enig2F1E7A333A0A6AF1086BAD57" Sender: jan.kiszka@domain.hid Subject: Re: [Xenomai-help] rt_task_shadow returns always -EFAULT List-Id: Help regarding installation and common use of Xenomai List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Petr Cervenka Cc: xenomai-help This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig2F1E7A333A0A6AF1086BAD57 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Petr Cervenka wrote: >>>> Try instrumenting ksrc/skins/native/syscall.c, __rt_task_create(), t= o >>>> identify which spot returns -EFAULT. I can't reproduce this issue on= a >>>> ppc target; I may try over x86 later, but this would speed up things= if >>>> you could spot the failing test before I'm able to switch to this. >>>> >>> Meanwhile I tried to mess little bit with rt_task_shadow() function t= o see, where is the source of -EFAULT. I planned to continue to follow it= inside syscall etc. >>> But most attempts to confirm, that the value is returned by line: >>> err =3D XENOMAI_SKINCALL2(__native_muxid, __native_task_create, &bul= k, >>> NULL); >> This branches to __rt_task_create in kernel space. >> >=20 > The bulk variable is totally wrong in kernel space: > for example (2, 0, 0, 0, 0, 134217728), perhaps always same values. Val= ue 2 could be number of arguments of the skincall. > It fails on following line (syscall.c:aprox. 193): > if (__xn_safe_copy_to_user((void __user *)bulk.a1, &ph, sizeof(ph))) {= >=20 >>> where suprisingly followed by correct behavior. For example following= (nothing doing) change in the attached patch solves the whole thing: >>> --- /usr/src/xenomai/src/skins/native/task2.c 2009-04-13 19:20:18.0= 00000000 +0200 >>> +++ /usr/src/xenomai/src/skins/native/task.c 2009-07-17 15:06:20.0= 00000000 +0200 >>> @@ -241,6 +241,7 @@ >>> pthread_setspecific(__native_tskey, NULL); >>> free(self); >>> #endif /* !HAVE___THREAD */ >>> + rt_task_set_mode(0, 0, NULL); >>> return err; >>> } >>> >>> objdumps of original and changed rt_task_shadow() is in attachment >>> >>> I will continue in research, but I'm really not good in dissasembling= nor the register knowledge. >>> >> Try rebuilding the user-space libs passing --without-__thread to the >> configure script. >> >=20 > After rebuilding with "./configure --enable-smp --without-__thread" it = works without any problems. > Do you already know, where the problem is? What does the "--without-__t= hread" argument mean? It's reproducible, will try to understand it. It's either a compiler bug (your kubuntu version is fairly old and also unsupported due to security flaws), or we actually still have a problems around TLS variables (Thread Local Storage, that's what --without-__thread disables). Jan --------------enig2F1E7A333A0A6AF1086BAD57 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iEYEARECAAYFAkphgjkACgkQniDOoMHTA+mhYwCbBYTMZsAfz+bOoSGyJVAS5ff9 v6MAnRHTWP5eqsy+7SvbLSmFoB2SXpgJ =KR1f -----END PGP SIGNATURE----- --------------enig2F1E7A333A0A6AF1086BAD57--