Strange process hangs on 2.6.0

Strange process hangs on 2.6.0

[Łukasz Osipiuk]

Hello Everyone,

I am getting strange process hangs on 2.6.0 (stable). The same problem
also occurred on many of test kernels (all that i checked out).

Problem occurs when i run text-mode emacs using a wrapper script:

runemacs.sh:
#!/bin/sh
emacs -q -nw $*

it happens only if i login to my ordinary user, then switch user to root by
calling:
# su -

and then execute ./runemacs.sh anyfile

emacs draws himself in the terminal but is not responding.
Only SIGKILL manages to terminate it.

The problem magically does not happen if:
1. i directly call emacs -q -nw anyfile (without wrapper script)
2. i precede the command line in wrapper script with exec
3. if i change the root shell from bash to zsh
4. after running emacs without wrapper script the wrapper works fine
   too (but only in the same terminal)
5. i call strace ./runemacs.sh anyfile ;)
6. probably many others

I'm not sure if it is really a bug in kernel but it did not happen
when i used 2.4 line.

I'm running PLD linux with home-compiled kernel from www.kernel.org
without any additional patches.

Here follows the info about such hung emacs from /proc:

# cat cmdline
emacs
# cat wchan
finish_stop

# cat status
Name:	emacs
State:	T (stopped)
SleepAVG:	70%
Tgid:	23542
Pid:	23542
PPid:	23541
TracerPid:	0
Uid:	0	0	0	0
Gid:	0	0	0	0
FDSize:	256
Groups:	0 1 2 3 4 6 10 
VmSize:	   11484 kB
VmLck:	       0 kB
VmRSS:	    5372 kB
VmData:	     424 kB
VmStk:	     192 kB
VmExe:	    1304 kB
VmLib:	    4092 kB
Threads:	1
SigPnd:	0000000000000000
ShdPnd:	0000000000000000
SigBlk:	0000000008000000
SigIgn:	8000000000000000
SigCgt:	0000000059816eff
CapInh:	0000000000000000
CapPrm:	00000000fffffeff
CapEff:	00000000fffffeff

# cat stat
23542 (emacs) T 23541 23542 23453 1027 23541 256 1542 0 1265 0 9 2 0 0 18 0 1 0 1591106 11759616 1343 4294967295 134512640 135846344 3221222704 3221218524 1077556839 0 134217728 0 1501654783 3222426827 0 0 17 0 0 0

# cat statm
2871 1343 2717 1069 0 1802 0

# cat maps
08048000-0818e000 r-xp 00000000 03:06 114203     /usr/bin/emacs
0818e000-08475000 rw-p 00145000 03:06 114203     /usr/bin/emacs
08475000-084d2000 rwxp 00000000 00:00 0 
40000000-40013000 r-xp 00000000 03:06 88133      /lib/ld-2.3.2.so
40013000-40014000 rw-p 00012000 03:06 88133      /lib/ld-2.3.2.so
40014000-40015000 rw-p 00000000 00:00 0 
40015000-40057000 r-xp 00000000 03:06 88533      /usr/X11R6/lib/libXaw3d.so.7.0
40057000-4005d000 rw-p 00042000 03:06 88533      /usr/X11R6/lib/libXaw3d.so.7.0
4005d000-4005f000 rw-p 00000000 00:00 0 
4005f000-40074000 r-xp 00000000 03:06 750692     /usr/X11R6/lib/libXmu.so.6.2
40074000-40075000 rw-p 00014000 03:06 750692     /usr/X11R6/lib/libXmu.so.6.2
40075000-400c1000 r-xp 00000000 03:06 750696     /usr/X11R6/lib/libXt.so.6.0
400c1000-400c4000 rw-p 0004c000 03:06 750696     /usr/X11R6/lib/libXt.so.6.0
400c4000-400c5000 rw-p 00000000 00:00 0 
400c5000-400cd000 r-xp 00000000 03:06 750686     /usr/X11R6/lib/libSM.so.6.0
400cd000-400ce000 rw-p 00007000 03:06 750686     /usr/X11R6/lib/libSM.so.6.0
400ce000-400cf000 rw-p 00000000 00:00 0 
400cf000-400e3000 r-xp 00000000 03:06 71487      /usr/X11R6/lib/libICE.so.6.3
400e3000-400e4000 rw-p 00014000 03:06 71487      /usr/X11R6/lib/libICE.so.6.3
400e4000-400e6000 rw-p 00000000 00:00 0 
400e6000-400f3000 r-xp 00000000 03:06 498959     /usr/X11R6/lib/libXext.so.6.4
400f3000-400f4000 rw-p 0000c000 03:06 498959     /usr/X11R6/lib/libXext.so.6.4
40109000-40152000 r-xp 00000000 03:06 414438     /usr/lib/libtiff.so.3.6.0
40152000-40154000 rw-p 00048000 03:06 414438     /usr/lib/libtiff.so.3.6.0
40154000-40171000 r-xp 00000000 03:06 555124     /usr/lib/libjpeg.so.62.0.0
40171000-40172000 rw-p 0001c000 03:06 555124     /usr/lib/libjpeg.so.62.0.0
40172000-401a5000 r-xp 00000000 03:06 38644      /usr/lib/libpng12.so.0.1.2.6beta2
401a5000-401a6000 rw-p 00033000 03:06 38644      /usr/lib/libpng12.so.0.1.2.6beta2
401a6000-401b5000 r-xp 00000000 03:06 72425      /lib/libz.so.1.2.1
401b5000-401b6000 rw-p 0000f000 03:06 72425      /lib/libz.so.1.2.1
401b6000-401b7000 rw-p 00000000 00:00 0 
401b7000-401d8000 r-xp 00000000 03:06 124395     /lib/libm-2.3.2.so
401d8000-401d9000 rw-p 00020000 03:06 124395     /lib/libm-2.3.2.so
401d9000-401e0000 r-xp 00000000 03:06 37627      /usr/lib/libungif.so.4.1.0
401e0000-401e1000 rw-p 00006000 03:06 37627      /usr/lib/libungif.so.4.1.0
401e1000-401ef000 r-xp 00000000 03:06 704272     /usr/X11R6/lib/libXpm.so.4.11
401ef000-401f0000 rw-p 0000d000 03:06 704272     /usr/X11R6/lib/libXpm.so.4.11
401f0000-402b4000 r-xp 00000000 03:06 750687     /usr/X11R6/lib/libX11.so.6.2
402b4000-402b8000 rw-p 000c3000 03:06 750687     /usr/X11R6/lib/libX11.so.6.2
402b8000-402d2000 r-xp 00000000 03:06 485182     /lib/libncurses.so.5.3
402d2000-402d3000 rw-p 00019000 03:06 485182     /lib/libncurses.so.5.3
402d3000-4040d000 r-xp 00000000 03:06 111554     /lib/libc-2.3.2.so
4040d000-40425000 rw-p 0013a000 03:06 111554     /lib/libc-2.3.2.so
40425000-40428000 rw-p 00000000 00:00 0 
40428000-40447000 r-xp 00000000 03:06 485356     /lib/libtinfo.so.5.3
40447000-4044f000 rw-p 0001e000 03:06 485356     /lib/libtinfo.so.5.3
4044f000-40450000 rw-p 00000000 00:00 0 
40450000-40452000 r-xp 00000000 03:06 124334     /lib/libdl-2.3.2.so
40452000-40453000 rw-p 00001000 03:06 124334     /lib/libdl-2.3.2.so
40453000-40454000 rw-p 00000000 00:00 0 
40454000-40654000 r--p 00000000 03:06 103087     /usr/lib/locale/locale-archive
40654000-40681000 r--p 0043d000 03:06 103087     /usr/lib/locale/locale-archive
40681000-40688000 r--p 00487000 03:06 103087     /usr/lib/locale/locale-archive
4069d000-406a6000 r-xp 00000000 03:06 374158     /lib/libnss_files-2.3.2.so
406a6000-406a7000 rw-p 00008000 03:06 374158     /lib/libnss_files-2.3.2.so
bffd0000-c0000000 rwxp fffd1000 00:00 0 



And here is some system info:

# cat /proc/cpuinfo
processor       : 0
vendor_id       : AuthenticAMD
cpu family      : 6
model           : 10
model name      : AMD Athlon(tm) XP 2500+
stepping        : 0
cpu MHz         : 1830.418
cache size      : 512 KB
fdiv_bug        : no
hlt_bug         : no
f00f_bug        : no
coma_bug        : no
fpu             : yes
fpu_exception   : yes
cpuid level     : 1
wp              : yes
flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow
bogomips        : 3620.86

# uname -a
Linux lucash 2.6.0 #8 Thu Dec 25 12:12:27 CET 2003 i686 AMD_Athlon(tm)_XP_2500+ unknown PLD Linux


-- 
Pozdrawiam Lucash
mailto: l.osipiuk@zodiac.mimuw.edu.pl
http://www.sourceforge.net/projects/subconv

 LocalWords:  everyone

Re: Strange process hangs on 2.6.0

[Lawrence Bowie]

Can you please share an strace of executing this as root?

Thanks,

LDB

?ukasz Osipiuk wrote:

>Hello Everyone,
>
>I am getting strange process hangs on 2.6.0 (stable). The same problem
>also occurred on many of test kernels (all that i checked out).
>
>Problem occurs when i run text-mode emacs using a wrapper script:
>
>runemacs.sh:
>#!/bin/sh
>emacs -q -nw $*
>
>it happens only if i login to my ordinary user, then switch user to root by
>calling:
># su -
>
>and then execute ./runemacs.sh anyfile
>
>emacs draws himself in the terminal but is not responding.
>Only SIGKILL manages to terminate it.
>
>The problem magically does not happen if:
>1. i directly call emacs -q -nw anyfile (without wrapper script)
>2. i precede the command line in wrapper script with exec
>3. if i change the root shell from bash to zsh
>4. after running emacs without wrapper script the wrapper works fine
>   too (but only in the same terminal)
>5. i call strace ./runemacs.sh anyfile ;)
>6. probably many others
>
>I'm not sure if it is really a bug in kernel but it did not happen
>when i used 2.4 line.
>
>I'm running PLD linux with home-compiled kernel from www.kernel.org
>without any additional patches.
>
>Here follows the info about such hung emacs from /proc:
>
># cat cmdline
>emacs
># cat wchan
>finish_stop
>
># cat status
>Name:	emacs
>State:	T (stopped)
>SleepAVG:	70%
>Tgid:	23542
>Pid:	23542
>PPid:	23541
>TracerPid:	0
>Uid:	0	0	0	0
>Gid:	0	0	0	0
>FDSize:	256
>Groups:	0 1 2 3 4 6 10 
>VmSize:	   11484 kB
>VmLck:	       0 kB
>VmRSS:	    5372 kB
>VmData:	     424 kB
>VmStk:	     192 kB
>VmExe:	    1304 kB
>VmLib:	    4092 kB
>Threads:	1
>SigPnd:	0000000000000000
>ShdPnd:	0000000000000000
>SigBlk:	0000000008000000
>SigIgn:	8000000000000000
>SigCgt:	0000000059816eff
>CapInh:	0000000000000000
>CapPrm:	00000000fffffeff
>CapEff:	00000000fffffeff
>
># cat stat
>23542 (emacs) T 23541 23542 23453 1027 23541 256 1542 0 1265 0 9 2 0 0 18 0 1 0 1591106 11759616 1343 4294967295 134512640 135846344 3221222704 3221218524 1077556839 0 134217728 0 1501654783 3222426827 0 0 17 0 0 0
>
># cat statm
>2871 1343 2717 1069 0 1802 0
>
># cat maps
>08048000-0818e000 r-xp 00000000 03:06 114203     /usr/bin/emacs
>0818e000-08475000 rw-p 00145000 03:06 114203     /usr/bin/emacs
>08475000-084d2000 rwxp 00000000 00:00 0 
>40000000-40013000 r-xp 00000000 03:06 88133      /lib/ld-2.3.2.so
>40013000-40014000 rw-p 00012000 03:06 88133      /lib/ld-2.3.2.so
>40014000-40015000 rw-p 00000000 00:00 0 
>40015000-40057000 r-xp 00000000 03:06 88533      /usr/X11R6/lib/libXaw3d.so.7.0
>40057000-4005d000 rw-p 00042000 03:06 88533      /usr/X11R6/lib/libXaw3d.so.7.0
>4005d000-4005f000 rw-p 00000000 00:00 0 
>4005f000-40074000 r-xp 00000000 03:06 750692     /usr/X11R6/lib/libXmu.so.6.2
>40074000-40075000 rw-p 00014000 03:06 750692     /usr/X11R6/lib/libXmu.so.6.2
>40075000-400c1000 r-xp 00000000 03:06 750696     /usr/X11R6/lib/libXt.so.6.0
>400c1000-400c4000 rw-p 0004c000 03:06 750696     /usr/X11R6/lib/libXt.so.6.0
>400c4000-400c5000 rw-p 00000000 00:00 0 
>400c5000-400cd000 r-xp 00000000 03:06 750686     /usr/X11R6/lib/libSM.so.6.0
>400cd000-400ce000 rw-p 00007000 03:06 750686     /usr/X11R6/lib/libSM.so.6.0
>400ce000-400cf000 rw-p 00000000 00:00 0 
>400cf000-400e3000 r-xp 00000000 03:06 71487      /usr/X11R6/lib/libICE.so.6.3
>400e3000-400e4000 rw-p 00014000 03:06 71487      /usr/X11R6/lib/libICE.so.6.3
>400e4000-400e6000 rw-p 00000000 00:00 0 
>400e6000-400f3000 r-xp 00000000 03:06 498959     /usr/X11R6/lib/libXext.so.6.4
>400f3000-400f4000 rw-p 0000c000 03:06 498959     /usr/X11R6/lib/libXext.so.6.4
>40109000-40152000 r-xp 00000000 03:06 414438     /usr/lib/libtiff.so.3.6.0
>40152000-40154000 rw-p 00048000 03:06 414438     /usr/lib/libtiff.so.3.6.0
>40154000-40171000 r-xp 00000000 03:06 555124     /usr/lib/libjpeg.so.62.0.0
>40171000-40172000 rw-p 0001c000 03:06 555124     /usr/lib/libjpeg.so.62.0.0
>40172000-401a5000 r-xp 00000000 03:06 38644      /usr/lib/libpng12.so.0.1.2.6beta2
>401a5000-401a6000 rw-p 00033000 03:06 38644      /usr/lib/libpng12.so.0.1.2.6beta2
>401a6000-401b5000 r-xp 00000000 03:06 72425      /lib/libz.so.1.2.1
>401b5000-401b6000 rw-p 0000f000 03:06 72425      /lib/libz.so.1.2.1
>401b6000-401b7000 rw-p 00000000 00:00 0 
>401b7000-401d8000 r-xp 00000000 03:06 124395     /lib/libm-2.3.2.so
>401d8000-401d9000 rw-p 00020000 03:06 124395     /lib/libm-2.3.2.so
>401d9000-401e0000 r-xp 00000000 03:06 37627      /usr/lib/libungif.so.4.1.0
>401e0000-401e1000 rw-p 00006000 03:06 37627      /usr/lib/libungif.so.4.1.0
>401e1000-401ef000 r-xp 00000000 03:06 704272     /usr/X11R6/lib/libXpm.so.4.11
>401ef000-401f0000 rw-p 0000d000 03:06 704272     /usr/X11R6/lib/libXpm.so.4.11
>401f0000-402b4000 r-xp 00000000 03:06 750687     /usr/X11R6/lib/libX11.so.6.2
>402b4000-402b8000 rw-p 000c3000 03:06 750687     /usr/X11R6/lib/libX11.so.6.2
>402b8000-402d2000 r-xp 00000000 03:06 485182     /lib/libncurses.so.5.3
>402d2000-402d3000 rw-p 00019000 03:06 485182     /lib/libncurses.so.5.3
>402d3000-4040d000 r-xp 00000000 03:06 111554     /lib/libc-2.3.2.so
>4040d000-40425000 rw-p 0013a000 03:06 111554     /lib/libc-2.3.2.so
>40425000-40428000 rw-p 00000000 00:00 0 
>40428000-40447000 r-xp 00000000 03:06 485356     /lib/libtinfo.so.5.3
>40447000-4044f000 rw-p 0001e000 03:06 485356     /lib/libtinfo.so.5.3
>4044f000-40450000 rw-p 00000000 00:00 0 
>40450000-40452000 r-xp 00000000 03:06 124334     /lib/libdl-2.3.2.so
>40452000-40453000 rw-p 00001000 03:06 124334     /lib/libdl-2.3.2.so
>40453000-40454000 rw-p 00000000 00:00 0 
>40454000-40654000 r--p 00000000 03:06 103087     /usr/lib/locale/locale-archive
>40654000-40681000 r--p 0043d000 03:06 103087     /usr/lib/locale/locale-archive
>40681000-40688000 r--p 00487000 03:06 103087     /usr/lib/locale/locale-archive
>4069d000-406a6000 r-xp 00000000 03:06 374158     /lib/libnss_files-2.3.2.so
>406a6000-406a7000 rw-p 00008000 03:06 374158     /lib/libnss_files-2.3.2.so
>bffd0000-c0000000 rwxp fffd1000 00:00 0 
>
>
>
>And here is some system info:
>
># cat /proc/cpuinfo
>processor       : 0
>vendor_id       : AuthenticAMD
>cpu family      : 6
>model           : 10
>model name      : AMD Athlon(tm) XP 2500+
>stepping        : 0
>cpu MHz         : 1830.418
>cache size      : 512 KB
>fdiv_bug        : no
>hlt_bug         : no
>f00f_bug        : no
>coma_bug        : no
>fpu             : yes
>fpu_exception   : yes
>cpuid level     : 1
>wp              : yes
>flags           : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 mmx fxsr sse syscall mmxext 3dnowext 3dnow
>bogomips        : 3620.86
>
># uname -a
>Linux lucash 2.6.0 #8 Thu Dec 25 12:12:27 CET 2003 i686 AMD_Athlon(tm)_XP_2500+ unknown PLD Linux
>
>
>  
>

Re: Strange process hangs on 2.6.0

[Linus Torvalds]

On Thu, 25 Dec 2003, [iso-8859-2] ?ukasz Osipiuk wrote:
> 
> I am getting strange process hangs on 2.6.0 (stable). The same problem
> also occurred on many of test kernels (all that i checked out).

Sounds like the bash bug that is long-time (and that is just a lot harder 
to trigger on 2.4.x).

The problem is a timing issue in the bash pipeline setup, and if the 
child reads from stdin runs before the parent has fully set up the 
tty process group, the command will get stuck in stopped state.

Fedora core 1 is reported to have a fixed bash, so if you are RH-based, 
the easiest fix should be to just upgrade to that.

> emacs draws himself in the terminal but is not responding.
> Only SIGKILL manages to terminate it.

SIGCONT will fix it, but yeah, it's not something you want happening.

		Linus

Re: Strange process hangs on 2.6.0

[Łukasz Osipiuk]

Dnia Thu, Dec 25, 2003 at 08:23:33PM -0500, Lawrence Bowie napisał(a):
> Can you please share an strace of executing this as root?

I'd love to but as I've written when i call this script with strace
i dont get any hung at all :(.

-- 
Lucash
mailto: l.osipiuk@zodiac.mimuw.edu.pl

Re: Strange process hangs on 2.6.0

[Łukasz Osipiuk]

Thu, Des 25, 2003 at 06:12:13PM -0800, Linus Torvalds wrote:
> 
> 
> On Thu, 25 Dec 2003, [iso-8859-2] ?ukasz Osipiuk wrote:

> Fedora core 1 is reported to have a fixed bash, so if you are RH-based, 
> the easiest fix should be to just upgrade to that.

You are right, thanks. If I install the package from Fedora it seems
that everything works fine. I'm working on finding out which patch
does the job.

> > emacs draws himself in the terminal but is not responding.
> > Only SIGKILL manages to terminate it.
> 
> SIGCONT will fix it, but yeah, it's not something you want happening.

Nope. SIGCONT did not have any effect.

-- 
Lucash
mailto: l.osipiuk@zodiac.mimuw.edu.pl