Konsole (and some other virtual terminals) not working correctly.

Avenger · 2013-08-15 08:19:42

When starting Konsole I just get a blank black window. I can see in the log that it's because it cannot open a pseudo terminal:

KPty::open: Can't open a pseudo teletype

I tried to open urxvt and got this message:

urxvt: can't initialize pseudo-tty

My permissions are as follows:

drwxr-xr-x  2 root root             0 Aug 15 09:28 /dev/pts
crw-rw-rw-  1 root tty 5,           2 Aug 15 10:14 /dev/ptmx
c---------  1 root root 5,          2 Aug 15 09:28 /dev/pts/ptmx

On the other hand xterm works, but it creates pts's with the wrong group permissions, it creates it as my user-group. And looking at strace I can see that urxvt fails because it cannot chown the created pts to the tty group.
So, I added my self to the tty group and now everything works, but looking at my other computers, my user is not a member of the tty group there and have no issues with the pseudo terminals.

Does anyone know what it could be?

I can add: I'm running testing on this computer.

Last edited by Avenger (2013-08-15 08:22:58)

Scimmia · 2013-08-15 08:31:16

is /dev/pts mounted?

Avenger · 2013-08-15 09:19:59

Yes, it's mounted but it seems the mount parameters were wrong. I noticed this email on the mailing list just now:

https://mailman.archlinux.org/pipermail … 33999.html

I had an old devpts mount line in fstab that I have now removed.

balta2ar · 2013-08-15 18:00:08

Same problem. Removing /dev/pts line helped indeed. Can anybody explain why did glibc break it? And why there're no notifications about this on the archlinux.org?

karol · 2013-08-15 18:03:04

balta2ar wrote:

Same problem. Removing /dev/pts line helped indeed. Can anybody explain why did glibc break it? And why there're no notifications about this on the archlinux.org?

Why did you have /dev/pts in your fstab?

balta2ar · 2013-08-15 18:05:37

karol wrote:

balta2ar wrote:
Same problem. Removing /dev/pts line helped indeed. Can anybody explain why did glibc break it? And why there're no notifications about this on the archlinux.org?
Why did you have /dev/pts in your fstab?

I don't know. I only ever changed lines with my own partitions, never changed any of system's lines. It was there for ages.

Thaodan · 2013-08-15 18:12:39

its present in my /etc/mtab this is ok or not?

karol · 2013-08-15 18:13:39

Thaodan wrote:

its present in my /etc/mtab this is ok or not?

It's OK.

Last edited by karol (2013-08-15 18:13:54)

johni · 2013-08-15 19:24:43

I don't have /dev/pts in my /etc/fstab file and I am suffering from the same problem after glibc-2.18 update.

Any idea how I can fix it? I may have to rollback glibc for now , which I really don't want to do

johni · 2013-08-15 19:46:25

Some more info from running konsole with strace:

1402  open("/dev/ptmx", O_RDWR)         = 9
1402  statfs("/dev/pts", {f_type="DEVPTS_SUPER_MAGIC", f_bsize=4096, f_blocks=0, f_bfree=0, f_bavail=0, f_files=0, f_ffree=0, f_fsid={0, 0}, f_namelen=255, f_frsize=4096}) = 0
1402  ioctl(9, SNDCTL_TMR_TIMEBASE or SNDRV_TIMER_IOCTL_NEXT_DEVICE or TCGETS, {B38400 opost isig icanon echo ...}) = 0
1402  ioctl(9, TIOCGPTN, [1])           = 0
1402  stat("/dev/pts/1", {st_mode=S_IFCHR|0600, st_rdev=makedev(136, 1), ...}) = 0
1402  getuid()                          = 518
1402  socket(PF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 10
1402  connect(10, {sa_family=AF_LOCAL, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
1402  close(10)                         = 0
1402  socket(PF_LOCAL, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0) = 10
1402  connect(10, {sa_family=AF_LOCAL, sun_path="/var/run/nscd/socket"}, 110) = -1 ENOENT (No such file or directory)
1402  close(10)                         = 0
1402  open("/etc/group", O_RDONLY|O_CLOEXEC) = 10
1402  fstat(10, {st_mode=S_IFREG|0644, st_size=807, ...}) = 0
1402  mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) = 0x7f5fb6a4c000
1402  read(10, "root:x:0:root\nbin:x:1:root,bin,d"..., 4096) = 807
1402  close(10)                         = 0
1402  munmap(0x7f5fb6a4c000, 4096)      = 0
1402  chown("/dev/pts/1", 518, 5)       = -1 EPERM (Operation not permitted)

Looks like it opens /dev/ptmx to get the new tty, /dev/pts/1, and then tried to chown /dev/pts/1 to my user id, which fails with EPERM.

johni · 2013-08-15 20:24:33

Nevermind on my problem. I figured it out.

I was indeed mounting /dev/pts manually because of a custom initcpio boot hook based on the dropbear_initrd_encrypt from aur. It mounts devpts so dropbear can work during boot to allow me to enter decryption key remotely. However after continuing my hook forgot to unmount /dev/pts. I fixed my hook, and now it works.

Note: This should not effect normal users of dropbear_initrd_encrypt because it correctly umounts /dev/pts. I am using a customized hook based on this because I am using loopAES for root encryption rather than luks.

FYI, the difference beween the default devpts mount, and the one you should have for glibc-2.18:

old:

devpts on /dev/pts type devpts (rw,relatime,mode=600,ptmxmode=000)

new:

devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000)

Thanks to Avenger for pointing to the mailing list entry on /etc/fstab that led me to search my boot hook.

irrlicht · 2013-08-15 20:43:36

nvm, i figured it out.

Last edited by irrlicht (2013-08-15 20:51:40)

Arch Linux

#1 2013-08-15 08:19:42

Konsole (and some other virtual terminals) not working correctly.

#2 2013-08-15 08:31:16

Re: Konsole (and some other virtual terminals) not working correctly.

#3 2013-08-15 09:19:59

Re: Konsole (and some other virtual terminals) not working correctly.

#4 2013-08-15 18:00:08

Re: Konsole (and some other virtual terminals) not working correctly.

#5 2013-08-15 18:03:04

Re: Konsole (and some other virtual terminals) not working correctly.

#6 2013-08-15 18:05:37

Re: Konsole (and some other virtual terminals) not working correctly.

#7 2013-08-15 18:12:39

Re: Konsole (and some other virtual terminals) not working correctly.

#8 2013-08-15 18:13:39

Re: Konsole (and some other virtual terminals) not working correctly.

#9 2013-08-15 19:24:43

Re: Konsole (and some other virtual terminals) not working correctly.

#10 2013-08-15 19:46:25

Re: Konsole (and some other virtual terminals) not working correctly.

#11 2013-08-15 20:24:33

Re: Konsole (and some other virtual terminals) not working correctly.

#12 2013-08-15 20:43:36

Re: Konsole (and some other virtual terminals) not working correctly.

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