1. 04 6月, 2011 1 次提交
    • L
      Revert "tty: make receive_buf() return the amout of bytes received" · 55db4c64
      Linus Torvalds 提交于
      This reverts commit b1c43f82.
      
      It was broken in so many ways, and results in random odd pty issues.
      
      It re-introduced the buggy schedule_work() in flush_to_ldisc() that can
      cause endless work-loops (see commit a5660b41: "tty: fix endless
      work loop when the buffer fills up").
      
      It also used an "unsigned int" return value fo the ->receive_buf()
      function, but then made multiple functions return a negative error code,
      and didn't actually check for the error in the caller.
      
      And it didn't actually work at all.  BenH bisected down odd tty behavior
      to it:
        "It looks like the patch is causing some major malfunctions of the X
         server for me, possibly related to PTYs.  For example, cat'ing a
         large file in a gnome terminal hangs the kernel for -minutes- in a
         loop of what looks like flush_to_ldisc/workqueue code, (some ftrace
         data in the quoted bits further down).
      
         ...
      
         Some more data: It -looks- like what happens is that the
         flush_to_ldisc work queue entry constantly re-queues itself (because
         the PTY is full ?) and the workqueue thread will basically loop
         forver calling it without ever scheduling, thus starving the consumer
         process that could have emptied the PTY."
      
      which is pretty much exactly the problem we fixed in a5660b41.
      
      Milton Miller pointed out the 'unsigned int' issue.
      Reported-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      Reported-by: NMilton Miller <miltonm@bga.com>
      Cc: Stefan Bigler <stefan.bigler@keymile.com>
      Cc: Toby Gray <toby.gray@realvnc.com>
      Cc: Felipe Balbi <balbi@ti.com>
      Cc: Greg Kroah-Hartman <gregkh@suse.de>
      Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      55db4c64
  2. 23 4月, 2011 1 次提交
  3. 20 4月, 2011 1 次提交
  4. 02 3月, 2011 1 次提交
  5. 26 1月, 2011 1 次提交
    • T
      console: rename acquire/release_console_sem() to console_lock/unlock() · ac751efa
      Torben Hohn 提交于
      The -rt patches change the console_semaphore to console_mutex.  As a
      result, a quite large chunk of the patches changes all
      acquire/release_console_sem() to acquire/release_console_mutex()
      
      This commit makes things use more neutral function names which dont make
      implications about the underlying lock.
      
      The only real change is the return value of console_trylock which is
      inverted from try_acquire_console_sem()
      
      This patch also paves the way to switching console_sem from a semaphore to
      a mutex.
      
      [akpm@linux-foundation.org: coding-style fixes]
      [akpm@linux-foundation.org: make console_trylock return 1 on success, per Geert]
      Signed-off-by: NTorben Hohn <torbenh@gmx.de>
      Cc: Thomas Gleixner <tglx@tglx.de>
      Cc: Greg KH <gregkh@suse.de>
      Cc: Ingo Molnar <mingo@elte.hu>
      Cc: Geert Uytterhoeven <geert@linux-m68k.org>
      Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      ac751efa
  6. 05 11月, 2010 1 次提交
  7. 11 8月, 2010 4 次提交
  8. 11 6月, 2009 1 次提交
    • A
      tty: rewrite the ldisc locking · c65c9bc3
      Alan Cox 提交于
      There are several pretty much unfixable races in the old ldisc code, especially
      with respect to pty behaviour and also to hangup. It's easier to rewrite the
      code than simply try and patch it up.
      
      This patch
      - splits the ldisc from the tty (so we will be able to refcount it more cleanly
        later)
      - introduces a mutex lock for ldisc changing on an active device
      - fixes the complete mess that hangup caused
      - implements hopefully correct setldisc/close/hangup locking
      
      There are still some problems around pty pairs that have always been there but
      at least it is now possible to understand the code and fix further problems.
      
      This fixes the following known bugs
      - hang up can leak ldisc references
      - hang up may not call open/close on ldisc in a matched way
      - pty/tty pairs can deadlock during an ldisc change
      - reading the ldisc proc files can cause every ldisc to be loaded
      
      and probably a few other of the mysterious ldisc race reports.
      
      I'm sure it also adds the odd new one.
      Signed-off-by: NAlan Cox <alan@linux.intel.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      c65c9bc3
  9. 01 2月, 2009 1 次提交
    • M
      Fix memory corruption in console selection · 878b8619
      Mikulas Patocka 提交于
      Fix an off-by-two memory error in console selection.
      
      The loop below goes from sel_start to sel_end (inclusive), so it writes
      one more character.  This one more character was added to the allocated
      size (+1), but it was not multiplied by an UTF-8 multiplier.
      
      This patch fixes a memory corruption when UTF-8 console is used and the
      user selects a few characters, all of them 3-byte in UTF-8 (for example
      a frame line).
      
      When memory redzones are enabled, a redzone corruption is reported.
      When they are not enabled, trashing of random memory occurs.
      Signed-off-by: NMikulas Patocka <mpatocka@redhat.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      878b8619
  10. 03 1月, 2009 1 次提交
  11. 21 7月, 2008 1 次提交
    • A
      tty: Ldisc revamp · a352def2
      Alan Cox 提交于
      Move the line disciplines towards a conventional ->ops arrangement.  For
      the moment the actual 'tty_ldisc' struct in the tty is kept as part of
      the tty struct but this can then be changed if it turns out that when it
      all settles down we want to refcount ldiscs separately to the tty.
      
      Pull the ldisc code out of /proc and put it with our ldisc code.
      Signed-off-by: NAlan Cox <alan@redhat.com>
      Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      a352def2
  12. 17 7月, 2007 1 次提交
  13. 09 5月, 2007 1 次提交
  14. 30 9月, 2006 1 次提交
    • A
      [PATCH] tty locking on resize · ca9bda00
      Alan Cox 提交于
      The current kernel serializes console resizes but does not serialize the
      resize against the tty structure updates.  This means that while two
      parallel resizes cannot mess up the console you can get incorrect results
      reported.
      
      Secondly while doing this I added vc_lock_resize() to lock and resize the
      console.  This leaves all knowledge of the console_sem in the vt/console
      driver and kicks it out of the tty layer, which is good
      
      Thirdly while doing this I decided I couldn't stand "disallocate" any
      longer so I switched it to "deallocate".
      Signed-off-by: NAlan Cox <alan@redhat.com>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      ca9bda00
  15. 11 1月, 2006 1 次提交
    • A
      [PATCH] TTY layer buffering revamp · 33f0f88f
      Alan Cox 提交于
      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: NAlan Cox <alan@redhat.com>
      Cc: Paul Fulghum <paulkf@microgate.com>
      Signed-off-by: NHirokazu Takata <takata@linux-m32r.org>
      Signed-off-by: NSerge Hallyn <serue@us.ibm.com>
      Signed-off-by: NJeff Dike <jdike@addtoit.com>
      Signed-off-by: NJohn Hawkes <hawkes@sgi.com>
      Signed-off-by: NMartin Schwidefsky <schwidefsky@de.ibm.com>
      Signed-off-by: NAdrian Bunk <bunk@stusta.de>
      Signed-off-by: NAndrew Morton <akpm@osdl.org>
      Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      33f0f88f
  16. 07 11月, 2005 1 次提交
  17. 17 4月, 2005 1 次提交
    • L
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds 提交于
      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