Gentoo Forums
Gentoo Forums
Gentoo Forums
Quick Search: in
[SOLVED] CTRL-C no longer working
View unanswered posts
View posts from last 24 hours

 
Reply to topic    Gentoo Forums Forum Index Networking & Security
View previous topic :: View next topic  
Author Message
Anarcho
Advocate
Advocate


Joined: 06 Jun 2004
Posts: 2967
Location: Germany

PostPosted: Mon Nov 23, 2015 2:50 pm    Post subject: [SOLVED] CTRL-C no longer working Reply with quote

Hi all,

since at least 2 weeks I have a strange problem on one of my servers. CTRL-C is not working on the shell. I couldn't test local but the problem exists via SSH and I also tested via telnet.

Every other CTRL-Key-Combination I tried is still working (e.g. CTRL-D, CTRL-Z).

I checked what I have emerged in the last weeks:

Code:
Mon Oct 26 12:32:55 2015 >>> sys-libs/glibc-2.21-r1
Mon Oct 26 12:32:59 2015 >>> virtual/libintl-0-r2
Mon Oct 26 12:33:38 2015 >>> dev-libs/gmp-6.0.0a
Mon Oct 26 12:33:51 2015 >>> media-libs/libpng-1.6.18
Mon Oct 26 12:34:09 2015 >>> dev-libs/mpfr-3.1.3_p4
Mon Oct 26 12:54:34 2015 >>> sys-devel/gcc-4.9.3
Mon Oct 26 12:54:56 2015 >>> dev-libs/elfutils-0.163
Mon Oct 26 12:55:50 2015 >>> dev-libs/nettle-3.1.1
Mon Oct 26 12:56:21 2015 >>> sys-apps/util-linux-2.26.2
Mon Oct 26 12:57:32 2015 >>> x11-libs/pixman-0.32.8
Mon Oct 26 13:01:00 2015 >>> dev-lang/python-2.7.10
Mon Oct 26 13:03:05 2015 >>> dev-lang/python-3.4.3
Mon Oct 26 13:03:18 2015 >>> dev-python/pyasn1-0.1.8
Mon Oct 26 13:03:26 2015 >>> dev-python/ply-3.6-r1
Mon Oct 26 13:03:35 2015 >>> dev-python/pycparser-2.14
Mon Oct 26 13:03:51 2015 >>> dev-python/cffi-1.2.1
Mon Oct 26 13:05:12 2015 >>> dev-python/cryptography-1.0.2
Mon Oct 26 13:05:41 2015 >>> sys-fs/lvm2-2.02.116
Mon Oct 26 13:35:29 2015 >>> net-libs/gnutls-3.3.17.1
Fri Nov  6 21:42:01 2015 >>> dev-python/packaging-15.3-r2
Fri Nov  6 21:43:43 2015 >>> app-crypt/mit-krb5-1.13.2-r2
Fri Nov  6 21:44:00 2015 >>> sys-process/procps-3.3.10-r1
Fri Nov  6 21:44:14 2015 >>> sys-apps/kmod-21
Fri Nov  6 21:46:14 2015 >>> dev-util/cmake-3.3.1-r1
Fri Nov  6 21:46:49 2015 >>> net-misc/openssh-7.1_p1-r2
Fri Nov  6 21:46:56 2015 >>> net-nds/rpcbind-0.2.3-r1
Fri Nov  6 21:47:10 2015 >>> dev-python/setuptools-18.4
Fri Nov  6 21:47:16 2015 >>> dev-python/certifi-2015.9.6.2
Fri Nov  6 21:47:23 2015 >>> dev-python/pypax-0.9.2
Fri Nov  6 21:47:30 2015 >>> dev-python/six-1.10.0
Fri Nov  6 21:47:38 2015 >>> dev-python/pytest-2.8.2
Fri Nov  6 21:47:46 2015 >>> sys-apps/elfix-0.9.2
Mon Nov 16 12:25:36 2015 >>> media-libs/libpng-1.6.19
Mon Nov 16 12:25:46 2015 >>> sys-apps/less-481
Mon Nov 16 12:25:52 2015 >>> dev-perl/IO-Socket-SSL-2.12.0
Mon Nov 16 12:26:22 2015 >>> dev-libs/libxml2-2.9.2-r4
Mon Nov 16 12:26:42 2015 >>> dev-libs/libxslt-1.1.28-r5
Mon Nov 16 12:31:44 2015 >>> dev-libs/glib-2.44.1-r1


Another strange thing is that I can't quit from screen anymore. Screens hangs after CTRL-D. When this happens I can see ^C chars in the shell, so the key code itself seems to go through.

I installed zsh and in zsh CTRL-C is working, but bash is broken (I already re-emerged bash and readline).

Does anyone have an idea? Do you need some more information?

Greets,

Matthias

EDIT: ksh is also working, but emerging gettext hangs on "checking for working sleep..." (if I kill the conftest process, it continues). So there seems to be a little more broken.
_________________
...it's only Rock'n'Roll, but I like it!


Last edited by Anarcho on Thu Nov 26, 2015 7:37 am; edited 1 time in total
Back to top
View user's profile Send private message
khayyam
Watchman
Watchman


Joined: 07 Jun 2012
Posts: 6228
Location: Room 101

PostPosted: Mon Nov 23, 2015 3:39 pm    Post subject: Reply with quote

Matthias ... within and without screen what is the interupt key?

Code:
$ awk -F";" '/intr/{print $1}' <(stty -a)

Also, what TERM is set, again, both within and without screen.

It might also be worth providing 'emerge --info'.

Anarcho wrote:
EDIT: ksh is also working, but emerging gettext hangs on "checking for working sleep..." (if I kill the conftest process, it continues). So there seems to be a little more broken.

The fact that zsh and ksh work suggests its not a deeper issue, the above may not be related ... btw, zsh doesn't use readline.

best ... khay


Last edited by khayyam on Mon Nov 23, 2015 3:48 pm; edited 1 time in total
Back to top
View user's profile Send private message
Anarcho
Advocate
Advocate


Joined: 06 Jun 2004
Posts: 2967
Location: Germany

PostPosted: Mon Nov 23, 2015 3:47 pm    Post subject: Reply with quote

Hi,

without screen:
Code:
maz@server ~ $ awk -F";" '/intr/{print $1}' <(stty -a)
intr = ^C
maz@server ~ $ echo $TERM
xterm


In screen only TERM changes to screen. But in screen CTRL-C is also non-working. The same settings are set in ksh/zsh where is is working.

And emerge --info:

Code:
maz@server ~ $ emerge --info
Portage 2.2.20.1 (python 2.7.10-final-0, hardened/linux/amd64, gcc-4.8.4, glibc-2.20-r2, 4.1.6-hardened x86_64)
=================================================================
System uname: Linux-4.1.6-hardened-x86_64-Intel-R-_Xeon-R-_CPU_E3-1241_v3_@_3.50GHz-with-gentoo-2.2
KiB Mem:    32864184 total,   1092528 free
KiB Swap:   31250424 total,  29703144 free
Timestamp of repository gentoo: Mon, 23 Nov 2015 02:00:01 +0000
sh bash 4.3_p42
ld GNU ld (Gentoo 2.25.1 p1.1) 2.25.1
app-shells/bash:          4.3_p42::gentoo
dev-java/java-config:     2.2.0::gentoo
dev-lang/perl:            5.20.2::gentoo
dev-lang/python:          2.7.10::gentoo, 3.3.5-r1::gentoo, 3.4.3::gentoo
dev-util/cmake:           3.3.1-r1::gentoo
dev-util/pkgconfig:       0.28-r2::gentoo
sys-apps/baselayout:      2.2::gentoo
sys-apps/openrc:          0.17::gentoo
sys-apps/sandbox:         2.6-r1::gentoo
sys-devel/autoconf:       2.69::gentoo
sys-devel/automake:       1.13.4::gentoo, 1.14.1::gentoo, 1.15::gentoo
sys-devel/binutils:       2.25.1-r1::gentoo
sys-devel/gcc:            4.8.4::gentoo, 4.9.3::gentoo
sys-devel/gcc-config:     1.7.3::gentoo
sys-devel/libtool:        2.4.6::gentoo
sys-devel/make:           4.1-r1::gentoo
sys-kernel/linux-headers: 3.18::gentoo (virtual/os-headers)
sys-libs/glibc:           2.20-r2::gentoo
Repositories:

gentoo
    location: /usr/portage
    sync-type: rsync
    sync-uri: rsync://rsync.gentoo.org/gentoo-portage
    priority: -1000

dfreise
    location: /var/lib/layman/dfreise
    masters: gentoo
    priority: 0

x-portage
    location: /usr/local/portage
    masters: gentoo
    priority: 1

gt-overlay
    location: /var/lib/layman/gt-overlay
    masters: gentoo
    priority: 2

ACCEPT_KEYWORDS="amd64"
ACCEPT_LICENSE="* -@EULA"
CBUILD="x86_64-pc-linux-gnu"
CFLAGS="-march=native -O2 -pipe"
CHOST="x86_64-pc-linux-gnu"
CONFIG_PROTECT="/etc /usr/lib64/fax /usr/share/gnupg/qualified.txt /var/spool/fax/etc"
CONFIG_PROTECT_MASK="/etc/ca-certificates.conf /etc/env.d /etc/fonts/fonts.conf /etc/gconf /etc/gentoo-release /etc/php/apache2-php5.6/ext-active/ /etc/php/cgi-php5.6/ext-active/ /etc/php/cli-php5.6/ext-active/ /etc/revdep-rebuild /etc/sandbox.d /etc/terminfo"
CXXFLAGS="-march=native -O2 -pipe"
DISTDIR="/usr/portage/distfiles"
FCFLAGS="-O2 -pipe"
FEATURES="assume-digests binpkg-logs config-protect-if-modified distlocks ebuild-locks fixlafiles merge-sync news parallel-fetch preserve-libs protect-owned sandbox sfperms strict unknown-features-warn unmerge-logs unmerge-orphans userfetch userpriv usersandbox usersync xattr"
FFLAGS="-O2 -pipe"
GENTOO_MIRRORS="http://distfiles.gentoo.org"
LANG="de_DE.utf8"
LDFLAGS="-Wl,-O1 -Wl,--as-needed"
MAKEOPTS="-j8"
PKGDIR="/usr/portage/packages"
PORTAGE_CONFIGROOT="/"
PORTAGE_RSYNC_OPTS="--recursive --links --safe-links --perms --times --omit-dir-times --compress --force --whole-file --delete --stats --human-readable --timeout=180 --exclude=/distfiles --exclude=/local --exclude=/packages"
PORTAGE_TMPDIR="/var/tmp"
USE="acl amd64 avx avx2 berkdb bindist bzip2 cli cracklib crypt cxx dnssec dri gdbm hardened iconv iproute2 ipv6 jpeg justify lxc mmx mmxext modules multilib mysql ncurses nls nptl openmp pam pax_kernel pcre pie png postgres readline seccomp session sse sse2 sse4_1 sse4_2 ssl ssp ssse3 tcpd threads tiff unicode urandom xattr xtpax zlib" ABI_X86="64" ALSA_CARDS="ali5451 als4000 atiixp atiixp-modem bt87x ca0106 cmipci emu10k1x ens1370 ens1371 es1938 es1968 fm801 hda-intel intel8x0 intel8x0m maestro3 trident usb-audio via82xx via82xx-modem ymfpci" APACHE2_MODULES="proxy proxy_http actions alias auth_basic authn_alias authn_anon authn_core authn_dbm authn_file authz_core authz_dbm authz_groupfile authz_host authz_owner authz_user autoindex cache cgi cgid dav dav_fs dav_lock deflate dir env expires ext_filter file_cache filter headers include info log_config logio mime mime_magic negotiation rewrite setenvif socache_shmcb speling status unique_id unixd userdir usertrack vhost_alias" CALLIGRA_FEATURES="kexi words flow plan sheets stage tables krita karbon braindump author" CAMERAS="ptp2" COLLECTD_PLUGINS="df interface irq load memory rrdtool swap syslog" CPU_FLAGS_X86="mmx mmxext avx ssse3 avx2 sse sse2 sse3 sse4_1 sse4_2" ELIBC="glibc" FRITZCAPI_CARDS="fcpci" GPSD_PROTOCOLS="ashtech aivdm earthmate evermore fv18 garmin garmintxt gpsclock itrax mtk3301 nmea ntrip navcom oceanserver oldstyle oncore rtcm104v2 rtcm104v3 sirf superstar2 timing tsip tripmate tnt ublox ubx" INPUT_DEVICES="keyboard mouse evdev" KERNEL="linux" LCD_DEVICES="bayrad cfontz cfontz633 glk hd44780 lb216 lcdm001 mtxorb ncurses text" LIBREOFFICE_EXTENSIONS="presenter-console presenter-minimizer" LINGUAS="de" OFFICE_IMPLEMENTATION="libreoffice" PHP_TARGETS="php5-6" PYTHON_SINGLE_TARGET="python2_7" PYTHON_TARGETS="python2_7 python3_4 python3_3" QEMU_SOFTMMU_TARGETS="i386 x86_64" QEMU_USER_TARGETS="i386 x86_64" RUBY_TARGETS="ruby20 ruby21" USERLAND="GNU" VIDEO_CARDS="fbdev glint intel mach64 mga nouveau nv r128 radeon savage sis tdfx trident vesa via vmware dummy v4l" XTABLES_ADDONS="quota2 psd pknock lscan length2 ipv4options ipset ipp2p iface geoip fuzzy condition tee tarpit sysrq steal rawnat logmark ipmark dhcpmac delude chaos account"
Unset:  CC, CPPFLAGS, CTARGET, CXX, EMERGE_DEFAULT_OPTS, INSTALL_MASK, LC_ALL, PORTAGE_BUNZIP2_COMMAND, PORTAGE_COMPRESS, PORTAGE_COMPRESS_FLAGS, PORTAGE_RSYNC_EXTRA_OPTS, USE_PYTHON


I tried to downgrade glibc but without success, that's why it's not the current version in emerge --info.
_________________
...it's only Rock'n'Roll, but I like it!
Back to top
View user's profile Send private message
khayyam
Watchman
Watchman


Joined: 07 Jun 2012
Posts: 6228
Location: Room 101

PostPosted: Mon Nov 23, 2015 4:22 pm    Post subject: Reply with quote

Anarcho wrote:
In screen only TERM changes to screen. But in screen CTRL-C is also non-working. The same settings are set in ksh/zsh where is is working.

Mathias ... as I said, zsh doesn't use readline (not sure about ksh, but it likely doesn't either ... at least there is no dependency on it). The fact that this is hardened makes it more difficult for me to debug, as I'm fairly unfamilar with it, nor how various components (and useflags) interact. So, I'm not sure what to suggest, or where you might look (other than perhaps your logs).

best ... khay
Back to top
View user's profile Send private message
Ant P.
Watchman
Watchman


Joined: 18 Apr 2009
Posts: 5589

PostPosted: Mon Nov 23, 2015 5:42 pm    Post subject: Reply with quote

I'd say it's related to the bash-completion bug, but you don't have that use flag enabled. May be the same root cause though.
Back to top
View user's profile Send private message
khayyam
Watchman
Watchman


Joined: 07 Jun 2012
Posts: 6228
Location: Room 101

PostPosted: Mon Nov 23, 2015 5:54 pm    Post subject: Reply with quote

Ant P. wrote:
I'd say it's related to the bash-completion bug, but you don't have that use flag enabled. May be the same root cause though.

Ant ... I was thinking the same after reading your post, and re-reading that thread.

@matthias ... you might try 'bash --noprofile' to disable the reading of /etc/profile and so test if anything set there, including profile.d/*.sh, are effecting tty.

best ... khay
Back to top
View user's profile Send private message
Anarcho
Advocate
Advocate


Joined: 06 Jun 2004
Posts: 2967
Location: Germany

PostPosted: Mon Nov 23, 2015 5:57 pm    Post subject: Reply with quote

Thanks khay and ant for your answers.

bash --noprofile doesn't make a change.

EDIT: OK, another strange thing that seems related: I can't kill e.g. watch using normal SIGTERM, I have to send SIGKILL. It seems like the SIGTERM is somehow broken? Maybe I need a restart...
_________________
...it's only Rock'n'Roll, but I like it!
Back to top
View user's profile Send private message
Hu
Moderator
Moderator


Joined: 06 Mar 2007
Posts: 13493

PostPosted: Tue Nov 24, 2015 2:36 am    Post subject: Reply with quote

What is the output of cat /proc/PID/status where PID is a process that survives a signal that should have killed it?
Back to top
View user's profile Send private message
Anarcho
Advocate
Advocate


Joined: 06 Jun 2004
Posts: 2967
Location: Germany

PostPosted: Wed Nov 25, 2015 7:11 pm    Post subject: Reply with quote

Hi Hu,

status is (watch in this example):

Code:
Name:   watch
State:   S (sleeping)
Tgid:   5240
Ngid:   0
Pid:   5240
PPid:   5196
TracerPid:   0
Uid:   1000   1000   1000   1000
Gid:   410   410   410   410
FDSize:   256
Groups:   10 16 248 410 1312 1313
NStgid:   5240
NSpid:   5240
NSpgid:   5240
NSsid:   5196
VmPeak:      10908 kB
VmSize:      10904 kB
VmLck:          0 kB
VmPin:          0 kB
VmHWM:       2996 kB
VmRSS:       2996 kB
VmData:        580 kB
VmStk:        132 kB
VmExe:         20 kB
VmLib:       2232 kB
VmPTE:         40 kB
VmPMD:         12 kB
VmSwap:          0 kB
Threads:   1
SigQ:   1/128211
SigPnd:   0000000000000000
ShdPnd:   0000000000000000
SigBlk:   fffffffe3bfae207
SigIgn:   0000000001000000
SigCgt:   0000000008084003
CapInh:   0000000000000000
CapPrm:   0000000000000000
CapEff:   0000000000000000
CapBnd:   0000003fffffffff
Seccomp:   0
Cpus_allowed:   ff
Cpus_allowed_list:   0-7
Mems_allowed:   1
Mems_allowed_list:   0
voluntary_ctxt_switches:   34
nonvoluntary_ctxt_switches:   2

_________________
...it's only Rock'n'Roll, but I like it!
Back to top
View user's profile Send private message
Hu
Moderator
Moderator


Joined: 06 Mar 2007
Posts: 13493

PostPosted: Wed Nov 25, 2015 11:54 pm    Post subject: Reply with quote

Your watch has many signals blocked that should not be blocked. From the low end, you have SIGHUP, SIGINT, SIGQUIT, SIGUSR1 blocked. I suggest you examine the status of the parent of watch to see if it has those signals blocked. If yes, examine the parent of that process. Repeat until you find the eldest process in the tree with those signals blocked, then show us the /proc/PID/status for that process.
Back to top
View user's profile Send private message
Anarcho
Advocate
Advocate


Joined: 06 Jun 2004
Posts: 2967
Location: Germany

PostPosted: Thu Nov 26, 2015 7:37 am    Post subject: Reply with quote

Thank you Hu for pointing me to the correct direction!

SSHD was the evil process with the signal block mask.

I tried to start a second SSHD (from the ssh-session) with another Port which was attached to the init-process but still has the same signal mask. I then startet the second SSHD using a cronjob, because the crond has a correct signal mask. This sshd was working as expected. I could then restart the first sshd from the second one and had a working sshd again.

Thanks again all of you for your fast help!

Greetings,

Matthias
_________________
...it's only Rock'n'Roll, but I like it!
Back to top
View user's profile Send private message
Display posts from previous:   
Reply to topic    Gentoo Forums Forum Index Networking & Security All times are GMT
Page 1 of 1

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum