From: JuanJo C. <jjo...@me...> - 2007-01-24 16:00:30
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Hi! Since 2.6.18 FC5 kernels updates and _all_ FC6 kernels, my uml-2.6.17 fails with same problem reported before @this list: stops responding after "VFS: Mounted root (ext3 filesystem) readonly." I tracked back and narrowed the kernel versions where the problem started to show: OK: kernel-smp-2.6.17-1.2187_FC5 (last FC5 upd. kernel known to run ok) BAD: kernel-smp-2.6.18-1.2239.fc5 (IIRC 1st non-working FC5 kernel) BAD: kernel-2.6.19-1.2895.fc6 (current FC6 kernel) Note: this is a FC6 uptodate distro, booted with these 3 diff. kernels. FYI those FC5 kernels have same selinux policyversion , so FC6 "environment" runs ok, I suggest to those wanting to run UML on FC6 to try booting with kernel-smp-2.6.17-1.2187_FC5 as a workaround. To see at least if the command gets "enough" CPU to halt the UML, I tried: ./linux init=/sbin/halt -f It didn't, "ps lx" on the host shows: $ ps lx 0 240 4284 4152 15 0 33000 11000 - R+ pts/1 3:31 ./linux (Jj9kkn) [/sbin/halt] 1 240 4293 4284 25 0 33000 11000 - S+ pts/1 0:00 ./linux (Jj9kkn) [/sbin/halt] 1 240 4294 4284 24 0 33000 11000 - S+ pts/1 0:00 ./linux (Jj9kkn) [/sbin/halt] 1 240 4295 4284 15 0 33000 11000 - S+ pts/1 0:00 ./linux (Jj9kkn) [/sbin/halt] 1 240 4296 4284 15 0 60 56 - R+ pts/1 2:42 [linux] , where cpu time for those "R+" procs almost equals wall time; strace'ing repeats eternally these lines: $ strace -p 4284 -- SIGCHLD (Child exited) @ 0 (0) --- waitpid(4296, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGSEGV}], WSTOPPED) = 4296 ptrace(PTRACE_GETREGS, 4296, 0, 0xa06ab82c) = 0 ptrace(PTRACE_GETFPXREGS, 4296, 0, 0xa06ab8dc) = 0 ptrace(PTRACE_CONT, 4296, 0, SIGSEGV) = 0 : : Hope this reports helps to put light on this UML/FC6 bug. Regards! -- --Juanjo # Juan Jose Ciarlante (JuanJo) jjo ;at; mendoza.gov.ar # # GnuPG Public Key: gpg --keyserver wwwkeys.eu.pgp.net --recv-key 66727177 # # Key fingerprint: 0D2F 3E5D 8B5C 729E 0560 F453 A3F7 E249 6672 7177 # |
From: Antoine M. <an...@na...> - 2007-01-24 16:11:07
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Hi, thanks for that, it should help figure out which release/patch caused the problem. Could you try the same test using plain kernel.org kernels? (2.6.17 and 2.6.18 for a start) That should tell us if it is was a redhat patch that introduced the problem. Antoine JuanJo Ciarlante wrote: > Hi! > Since 2.6.18 FC5 kernels updates and _all_ FC6 kernels, my uml-2.6.17 > fails with same problem reported before @this list: stops responding > after "VFS: Mounted root (ext3 filesystem) readonly." > > I tracked back and narrowed the kernel versions where the problem > started to show: > OK: kernel-smp-2.6.17-1.2187_FC5 (last FC5 upd. kernel known to run ok) > BAD: kernel-smp-2.6.18-1.2239.fc5 (IIRC 1st non-working FC5 kernel) > BAD: kernel-2.6.19-1.2895.fc6 (current FC6 kernel) > > Note: this is a FC6 uptodate distro, booted with these 3 diff. > kernels. > FYI those FC5 kernels have same selinux policyversion , so FC6 > "environment" runs ok, I suggest to those wanting to run UML on FC6 > to try booting with kernel-smp-2.6.17-1.2187_FC5 as a workaround. > > To see at least if the command gets "enough" CPU to halt the UML, I tried: > ./linux init=/sbin/halt -f > > It didn't, "ps lx" on the host shows: > $ ps lx > 0 240 4284 4152 15 0 33000 11000 - R+ pts/1 3:31 ./linux (Jj9kkn) [/sbin/halt] > 1 240 4293 4284 25 0 33000 11000 - S+ pts/1 0:00 ./linux (Jj9kkn) [/sbin/halt] > 1 240 4294 4284 24 0 33000 11000 - S+ pts/1 0:00 ./linux (Jj9kkn) [/sbin/halt] > 1 240 4295 4284 15 0 33000 11000 - S+ pts/1 0:00 ./linux (Jj9kkn) [/sbin/halt] > 1 240 4296 4284 15 0 60 56 - R+ pts/1 2:42 [linux] > , where cpu time for those "R+" procs almost equals wall time; > > strace'ing repeats eternally these lines: > $ strace -p 4284 > -- SIGCHLD (Child exited) @ 0 (0) --- > waitpid(4296, [{WIFSTOPPED(s) && WSTOPSIG(s) == SIGSEGV}], WSTOPPED) = 4296 > ptrace(PTRACE_GETREGS, 4296, 0, 0xa06ab82c) = 0 > ptrace(PTRACE_GETFPXREGS, 4296, 0, 0xa06ab8dc) = 0 > ptrace(PTRACE_CONT, 4296, 0, SIGSEGV) = 0 > : > : > > Hope this reports helps to put light on this UML/FC6 bug. > > Regards! > |
From: JuanJo C. <jjo...@me...> - 2007-01-31 14:30:45
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On Wed, Jan 24, 2007 at 04:00:27PM +0000, Antoine Martin wrote: BTW ... please avoid top-posting. > JuanJo Ciarlante wrote: > >Hi! > >Since 2.6.18 FC5 kernels updates and _all_ FC6 kernels, my uml-2.6.17 > >fails with same problem reported before @this list: stops responding > >after "VFS: Mounted root (ext3 filesystem) readonly." > > > >I tracked back and narrowed the kernel versions where the problem > >started to show: > > OK: kernel-smp-2.6.17-1.2187_FC5 (last FC5 upd. kernel known to run ok) > > BAD: kernel-smp-2.6.18-1.2239.fc5 (IIRC 1st non-working FC5 kernel) > > BAD: kernel-2.6.19-1.2895.fc6 (current FC6 kernel) > > > > Note: this is a FC6 uptodate distro, booted with these 3 diff. > > kernels. > > FYI those FC5 kernels have same selinux policyversion , so FC6 > > "environment" runs ok, I suggest to those wanting to run UML on FC6 > > to try booting with kernel-smp-2.6.17-1.2187_FC5 as a workaround. > > > > <SNIP> > > > thanks for that, it should help figure out which release/patch caused > the problem. > Could you try the same test using plain kernel.org kernels? > (2.6.17 and 2.6.18 for a start) > That should tell us if it is was a redhat patch that introduced the problem. Indeed I did the following tests, based on released utrace patch (OK means UML runs w/no problem, BAD means UML stops after VFS root mounting ) #1 2.6.18.6 vanilla: OK #2 2.6.18.6+utrace,CONFIG_{UP}TRACE=y : BAD (same behaviour as FC6 stock kernel) #3 2.6.18.6+utrace,CONFIG_{UP}TRACE unset: BAD (idem) Curiously, #3 did the very same as #2 (even wrt strace process disposition and strace "behaviour"), I'd expected #3 to simply fail at boot with EINVAL or alike (given that no ptrace support was compiled in). Regards -- --Juanjo # Juan Jose Ciarlante (JuanJo) jjo ;at; mendoza.gov.ar # # GnuPG Public Key: gpg --keyserver wwwkeys.eu.pgp.net --recv-key 66727177 # # Key fingerprint: 0D2F 3E5D 8B5C 729E 0560 F453 A3F7 E249 6672 7177 # |
From: Jeff D. <jd...@ad...> - 2007-01-31 15:38:29
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On Wed, Jan 31, 2007 at 11:30:17AM -0300, JuanJo Ciarlante wrote: > Indeed I did the following tests, based on released utrace patch (OK > means UML runs w/no problem, BAD means UML stops after VFS root mounting ) > #1 2.6.18.6 vanilla: OK > #2 2.6.18.6+utrace,CONFIG_{UP}TRACE=y : BAD (same behaviour as FC6 stock kernel) > #3 2.6.18.6+utrace,CONFIG_{UP}TRACE unset: BAD (idem) > > Curiously, #3 did the very same as #2 (even wrt strace process disposition > and strace "behaviour"), I'd expected #3 to simply fail at boot with > EINVAL or alike (given that no ptrace support was compiled in). So, it looks like utrace is buggy. BTW, you can't compile out ptrace (unless the utrace patch actually removes ptrace and replaces it with its own conditionally compiled emulation). Jeff -- Work email - jdike at linux dot intel dot com |
From: JuanJo C. <jjo...@me...> - 2007-01-31 15:48:16
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On Wed, Jan 31, 2007 at 10:30:46AM -0500, Jeff Dike wrote: > > So, it looks like utrace is buggy. > > BTW, you can't compile out ptrace (unless the utrace patch actually > removes ptrace and replaces it with its own conditionally compiled > emulation). mhh indeed..., anyway I saw some heavy changes even for the "remaining" lines when CONFIG_UTRACE is unset, ie: AFAICS utrace patch does *NOT*: #ifdef CONFIG_UTRACE : new utrace,ptrace implementation #else : same "old" code (stock ptrace impl.) #endif ... as one would expect. Regards, -- --Juanjo # Juan Jose Ciarlante (JuanJo) jjo ;at; mendoza.gov.ar # # GnuPG Public Key: gpg --keyserver wwwkeys.eu.pgp.net --recv-key 66727177 # # Key fingerprint: 0D2F 3E5D 8B5C 729E 0560 F453 A3F7 E249 6672 7177 # |