1. 30 Apr, 2008 1 commit
  2. 30 Mar, 2008 1 commit
  3. 08 Feb, 2008 1 commit
  4. 06 Feb, 2008 2 commits
    • Joe Peterson's avatar
      Fix IXANY and restart after signal (e.g. ctrl-C) in n_tty line discipline · 54d2a37e
      Joe Peterson authored
      Fix two N_TTY line discipline issues related to resuming a stopped TTY
      (typically done with ctrl-S):
      
      1) Fix handling of character that resumes a stopped TTY (with IXANY)
      
      With "stty ixany", the TTY line discipline would lose the first character
      after the stop, so typing, for example, "hi^Sthere" resulted in "hihere"
      (the 't' would cause the resume after ^S, but it would then be thrown away
      rather than processed as an input character).  This was inconsistent with
      the behavior of other Unix systems.
      
      2) Fix interrupt signal (e.g. ctrl-C) behavior in stopped TTYs
      
      With "stty -ixany" (often the default), interrupt signals were ignored
      in a stopped TTY until the TTY was resumed with the start char (typically
      ctrl-Q), which was inconsistent with the behavior of other Unix systems.
      Signed-off-by: default avatarJoe Peterson <joe@skyrush.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      54d2a37e
    • Joe Peterson's avatar
      tty: enable the echoing of ^C in the N_TTY discipline · ec5b1157
      Joe Peterson authored
      Turn on INTR/QUIT/SUSP echoing in the N_TTY line discipline (e.g.  ctrl-C
      will appear as "^C" if stty echoctl is set and ctrl-C is set as INTR).
      
      Linux seems to be the only unix-like OS (recently I've verified this on
      Solaris, BSD, and Mac OS X) that does *not* behave this way, and I really
      miss this as a good visual confirmation of the interrupt of a program in
      the console or xterm.  I remember this fondly from many Unixs I've used
      over the years as well.  Bringing this to Linux also seems like a good way
      to make it yet more compliant with standard unix-like behavior.
      
      [akpm@linux-foundation.org: coding-style fixes]
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      ec5b1157
  5. 19 Oct, 2007 1 commit
  6. 16 Jul, 2007 2 commits
    • Miloslav Trmac's avatar
      Audit: add TTY input auditing · 522ed776
      Miloslav Trmac authored
      Add TTY input auditing, used to audit system administrator's actions.  This is
      required by various security standards such as DCID 6/3 and PCI to provide
      non-repudiation of administrator's actions and to allow a review of past
      actions if the administrator seems to overstep their duties or if the system
      becomes misconfigured for unknown reasons.  These requirements do not make it
      necessary to audit TTY output as well.
      
      Compared to an user-space keylogger, this approach records TTY input using the
      audit subsystem, correlated with other audit events, and it is completely
      transparent to the user-space application (e.g.  the console ioctls still
      work).
      
      TTY input auditing works on a higher level than auditing all system calls
      within the session, which would produce an overwhelming amount of mostly
      useless audit events.
      
      Add an "audit_tty" attribute, inherited across fork ().  Data read from TTYs
      by process with the attribute is sent to the audit subsystem by the kernel.
      The audit netlink interface is extended to allow modifying the audit_tty
      attribute, and to allow sending explanatory audit events from user-space (for
      example, a shell might send an event containing the final command, after the
      interactive command-line editing and history expansion is performed, which
      might be difficult to decipher from the TTY input alone).
      
      Because the "audit_tty" attribute is inherited across fork (), it would be set
      e.g.  for sshd restarted within an audited session.  To prevent this, the
      audit_tty attribute is cleared when a process with no open TTY file
      descriptors (e.g.  after daemon startup) opens a TTY.
      
      See https://www.redhat.com/archives/linux-audit/2007-June/msg00000.html for a
      more detailed rationale document for an older version of this patch.
      
      [akpm@linux-foundation.org: build fix]
      Signed-off-by: default avatarMiloslav Trmac <mitr@redhat.com>
      Cc: Al Viro <viro@zeniv.linux.org.uk>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Cc: Casey Schaufler <casey@schaufler-ca.com>
      Cc: Steve Grubb <sgrubb@redhat.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      522ed776
    • Alan Cox's avatar
      Prevent an O_NDELAY writer from blocking when a tty write is blocked by the tty atomic writer mutex · 9c1729db
      Alan Cox authored
      Without this a tty write could block if a previous blocking tty write was
      in progress on the same tty and blocked by a line discipline or hardware
      event.  Originally found and reported by Dave Johnson.
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Acked-by: default avatarDave Johnson <djohnson+linux-kernel@sw.starentnetworks.com>
      Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      9c1729db
  7. 01 Jun, 2007 1 commit
  8. 11 May, 2007 1 commit
  9. 12 Feb, 2007 2 commits
  10. 13 Dec, 2006 1 commit
  11. 08 Dec, 2006 1 commit
    • Alan Cox's avatar
      [PATCH] tty: switch to ktermios · 606d099c
      Alan Cox authored
      This is the grungy swap all the occurrences in the right places patch that
      goes with the updates.  At this point we have the same functionality as
      before (except that sgttyb() returns speeds not zero) and are ready to
      begin turning new stuff on providing nobody reports lots of bugs
      
      If you are a tty driver author converting an out of tree driver the only
      impact should be termios->ktermios name changes for the speed/property
      setting functions from your upper layers.
      
      If you are implementing your own TCGETS function before then your driver
      was broken already and its about to get a whole lot more painful for you so
      please fix it 8)
      
      Also fill in c_ispeed/ospeed on init for most devices, although the current
      code will do this for you anyway but I'd like eventually to lose that extra
      paranoia
      
      [akpm@osdl.org: bluetooth fix]
      [mp3@de.ibm.com: sclp fix]
      [mp3@de.ibm.com: warning fix for tty3270]
      [hugh@veritas.com: fix tty_ioctl powerpc build]
      [jdike@addtoit.com: uml: fix ->set_termios declaration]
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Signed-off-by: default avatarMartin Peschke <mp3@de.ibm.com>
      Acked-by: default avatarPeter Oberparleiter <oberpar@de.ibm.com>
      Cc: Cornelia Huck <cornelia.huck@de.ibm.com>
      Signed-off-by: default avatarHugh Dickins <hugh@veritas.com>
      Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
      Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      606d099c
  12. 28 Jun, 2006 1 commit
    • Paul Fulghum's avatar
      [PATCH] remove TTY_DONT_FLIP · 817d6d3b
      Paul Fulghum authored
      Remove TTY_DONT_FLIP tty flag.  This flag was introduced in 2.1.X kernels
      to prevent the N_TTY line discipline functions read_chan() and
      n_tty_receive_buf() from running at the same time.  2.2.15 introduced
      tty->read_lock to protect access to the N_TTY read buffer, which is the
      only state requiring protection between these two functions.
      
      The current TTY_DONT_FLIP implementation is broken for SMP, and is not
      universally honored by drivers that send data directly to the line
      discipline receive_buf function.
      
      Because TTY_DONT_FLIP is not necessary, is broken in implementation, and is
      not universally honored, it is removed.
      Signed-off-by: default avatarPaul Fulghum <paulkf@microgate.com>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Cc: Theodore Ts'o <tytso@mit.edu>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      817d6d3b
  13. 11 Jun, 2006 1 commit
    • Paul Mackerras's avatar
      [PATCH] Fix for the PPTP hangs that have been reported · 289a1e99
      Paul Mackerras authored
      People have been reporting that PPP connections over ptys, such as
      used with PPTP, will hang randomly when transferring large amounts of
      data, for instance in http://bugzilla.kernel.org/show_bug.cgi?id=6530.
      I have managed to reproduce the problem, and the patch below fixes the
      actual cause.
      
      The problem is not in fact in ppp_async.c but in n_tty.c.  What
      happens is that when pptp reads from the pty, we call read_chan() in
      drivers/char/n_tty.c on the master side of the pty.  That copies all
      the characters out of its buffer to userspace and then calls
      check_unthrottle(), which calls the pty unthrottle routine, which
      calls tty_wakeup on the slave side, which calls ppp_asynctty_wakeup,
      which calls tasklet_schedule.  So far so good.  Since we are in
      process context, the tasklet runs immediately and calls
      ppp_async_process(), which calls ppp_async_push, which calls the
      tty->driver->write function to send some more output.
      
      However, tty->driver->write() returns zero, because the master
      tty->receive_room is still zero.  We haven't returned from
      check_unthrottle() yet, and read_chan() only updates tty->receive_room
      _after_ calling check_unthrottle.  That means that the driver->write
      call in ppp_async_process() returns 0.  That would be fine if we were
      going to get a subsequent wakeup call, but we aren't (we just had it,
      and the buffer is now empty).
      
      The solution is for n_tty.c to update tty->receive_room _before_
      calling the driver unthrottle routine.  The patch below does this.
      With this patch I was able to transfer a 900MB file over a PPTP
      connection (taking about 25 minutes), whereas without the patch the
      connection would always stall in under a minute.
      Signed-off-by: default avatarPaul Mackerras <paulus@samba.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      289a1e99
  14. 23 Mar, 2006 1 commit
  15. 10 Jan, 2006 1 commit
    • Alan Cox's avatar
      [PATCH] TTY layer buffering revamp · 33f0f88f
      Alan Cox authored
      The API and code have been through various bits of initial review by
      serial driver people but they definitely need to live somewhere for a
      while so the unconverted drivers can get knocked into shape, existing
      drivers that have been updated can be better tuned and bugs whacked out.
      
      This replaces the tty flip buffers with kmalloc objects in rings. In the
      normal situation for an IRQ driven serial port at typical speeds the
      behaviour is pretty much the same, two buffers end up allocated and the
      kernel cycles between them as before.
      
      When there are delays or at high speed we now behave far better as the
      buffer pool can grow a bit rather than lose characters. This also means
      that we can operate at higher speeds reliably.
      
      For drivers that receive characters in blocks (DMA based, USB and
      especially virtualisation) the layer allows a lot of driver specific
      code that works around the tty layer with private secondary queues to be
      removed. The IBM folks need this sort of layer, the smart serial port
      people do, the virtualisers do (because a virtualised tty typically
      operates at infinite speed rather than emulating 9600 baud).
      
      Finally many drivers had invalid and unsafe attempts to avoid buffer
      overflows by directly invoking tty methods extracted out of the innards
      of work queue structs. These are no longer needed and all go away. That
      fixes various random hangs with serial ports on overflow.
      
      The other change in here is to optimise the receive_room path that is
      used by some callers. It turns out that only one ldisc uses receive room
      except asa constant and it updates it far far less than the value is
      read. We thus make it a variable not a function call.
      
      I expect the code to contain bugs due to the size alone but I'll be
      watching and squashing them and feeding out new patches as it goes.
      
      Because the buffers now dynamically expand you should only run out of
      buffering when the kernel runs out of memory for real.  That means a lot of
      the horrible hacks high performance drivers used to do just aren't needed any
      more.
      
      Description:
      
      tty_insert_flip_char is an old API and continues to work as before, as does
      tty_flip_buffer_push() [this is why many drivers dont need modification].  It
      does now also return the number of chars inserted
      
      There are also
      
      tty_buffer_request_room(tty, len)
      
      which asks for a buffer block of the length requested and returns the space
      found.  This improves efficiency with hardware that knows how much to
      transfer.
      
      and tty_insert_flip_string_flags(tty, str, flags, len)
      
      to insert a string of characters and flags
      
      For a smart interface the usual code is
      
          len = tty_request_buffer_room(tty, amount_hardware_says);
          tty_insert_flip_string(tty, buffer_from_card, len);
      
      More description!
      
      At the moment tty buffers are attached directly to the tty.  This is causing a
      lot of the problems related to tty layer locking, also problems at high speed
      and also with bursty data (such as occurs in virtualised environments)
      
      I'm working on ripping out the flip buffers and replacing them with a pool of
      dynamically allocated buffers.  This allows both for old style "byte I/O"
      devices and also helps virtualisation and smart devices where large blocks of
      data suddenely materialise and need storing.
      
      So far so good.  Lots of drivers reference tty->flip.*.  Several of them also
      call directly and unsafely into function pointers it provides.  This will all
      break.  Most drivers can use tty_insert_flip_char which can be kept as an API
      but others need more.
      
      At the moment I've added the following interfaces, if people think more will
      be needed now is a good time to say
      
       int tty_buffer_request_room(tty, size)
      
      Try and ensure at least size bytes are available, returns actual room (may be
      zero).  At the moment it just uses the flipbuf space but that will change.
      Repeated calls without characters being added are not cumulative.  (ie if you
      call it with 1, 1, 1, and then 4 you'll have four characters of space.  The
      other functions will also try and grow buffers in future but this will be a
      more efficient way when you know block sizes.
      
       int tty_insert_flip_char(tty, ch, flag)
      
      As before insert a character if there is room.  Now returns 1 for success, 0
      for failure.
      
       int tty_insert_flip_string(tty, str, len)
      
      Insert a block of non error characters.  Returns the number inserted.
      
       int tty_prepare_flip_string(tty, strptr, len)
      
      Adjust the buffer to allow len characters to be added.  Returns a buffer
      pointer in strptr and the length available.  This allows for hardware that
      needs to use functions like insl or mencpy_fromio.
      Signed-off-by: default avatarAlan Cox <alan@redhat.com>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Signed-off-by: default avatarHirokazu Takata <takata@linux-m32r.org>
      Signed-off-by: default avatarSerge Hallyn <serue@us.ibm.com>
      Signed-off-by: default avatarJeff Dike <jdike@addtoit.com>
      Signed-off-by: default avatarJohn Hawkes <hawkes@sgi.com>
      Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: default avatarAdrian Bunk <bunk@stusta.de>
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      33f0f88f
  16. 28 Oct, 2005 1 commit
  17. 10 Sep, 2005 1 commit
  18. 07 Jul, 2005 1 commit
    • Roman Zippel's avatar
      [PATCH] tty output lossage fix · d6afe27b
      Roman Zippel authored
      The patch fixes a few corner cases around tty line editing with
      very long input lines:
      
      - n_tty_receive_char(): don't simply drop eol characters,
        otherwise canon_data isn't increased and the reader isn't woken
        up.
      
      - n_tty_receive_room(): If there is no newline pending and the
        edit buffer is full, allow only a single character to be written
        (until eol is found and the line is flushed), so characters from
        the next line aren't dropped.
      
      - write_chan(): if an incomplete line was written, continue
        writing until write() returns 0, otherwise it might not write
        the eol character to flush the line and the writer goes to sleep
        without ever being woken up.
      
      BTW the core problem is that part of this should be handled in the
      receive_buf path, but for this it has to return the number of
      written characters, as the amount of written characters may not be
      the same as the amount of characters going into the write buffer,
      so the receive_room() usage in pty_write() is not really reliable.
      
      Alan said:
      
      The problem looks valid. The behaviour of 'traditional unix' appears to
      be the following
      
      	If you exceed the line limit then beep and drop the character
      	Always allow EOL to complete a canonical line input
      	Always do signal/control processing if enabled
      Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
      Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
      d6afe27b
  19. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4