linux-toradex.git/drivers/tty/n_gsm.c, branch v3.0.91

n_gsm: memory leak in uplink error path

2012-10-07T15:27:26+00:00

commit 88ed2a60610974443335c924d7cb8e5dcf9dbdc1 upstream.

Uplink (TX) network data will go through gsm_dlci_data_output_framed
there is a bug where if memory allocation fails, the skb which
has already been pulled off the list will be lost.

In addition TX skbs were being processed in LIFO order

Fixed the memory leak, and changed to FIFO order processing

Signed-off-by: Russ Gorby 
Tested-by: Kappel, LaurentX 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

n_gsm: added interlocking for gsm_data_lock for certain code paths

2012-10-07T15:27:25+00:00

commit 5e44708f75b0f8712da715d6babb0c21089b2317 upstream.

There were some locking holes in the management of the MUX's
message queue for 2 code paths:
1) gsmld_write_wakeup
2) receipt of CMD_FCON flow-control message
In both cases gsm_data_kick is called w/o locking so it can collide
with other other instances of gsm_data_kick (pulling messages tx_tail)
or potentially other instances of __gsm_data_queu (adding messages to tx_head)

Changed to take the tx_lock in these 2 cases

Signed-off-by: Russ Gorby 
Tested-by: Yin, Fengwei 
Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman

n_gsm: fix the wrong FCS handling

2011-08-05T04:58:40+00:00

commit f086ced17191fa0c5712539d2b680eae3dc972a1 upstream.

FCS could be GSM0_SOF, so will break state machine...

[This byte isn't quoted in any way so a SOF here doesn't imply an error
 occurred.]

Signed-off-by: Alek Du 
Signed-off-by: Alan Cox 
[Trivial but best backported once its in 3.1rc I think]
Signed-off-by: Greg Kroah-Hartman

tty: n_gsm: improper skb_pull() use was leaking framed data

2011-06-16T19:00:15+00:00

gsm_dlci_data_output_framed() was doing:
memcpy(dp, skb_pull(dlci->skb, len), len);

The problem is skb_pull() returns the post-increment data ptr
so the first chunk of dlci->skb->data is leaked.

Signed-off-by: Russ Gorby 
Signed-off-by: Greg Kroah-Hartman

tty: n_gsm: Fixed logic to decode break signal from modem status

2011-06-16T19:00:15+00:00

The modem status can be one or 2 octets and contains the V.24 signals
and in the 2 octet case also the break signal.
We were improperly decoding the break signal from the modem in the
2 octet case.

Signed-off-by: Russ Gorby 
Signed-off-by: Greg Kroah-Hartman

Revert "tty: make receive_buf() return the amout of bytes received"

2011-06-03T21:33:24+00:00

This reverts commit b1c43f82c5aa265442f82dba31ce985ebb7aa71c.

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 a5660b41af6a: "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 a5660b41af6a.

Milton Miller pointed out the 'unsigned int' issue.

Reported-by: Benjamin Herrenschmidt 
Reported-by: Milton Miller 
Cc: Stefan Bigler 
Cc: Toby Gray 
Cc: Felipe Balbi 
Cc: Greg Kroah-Hartman 
Cc: Alan Cox 
Signed-off-by: Linus Torvalds

Merge branch 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6

2011-05-23T19:23:20+00:00

* 'tty-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty-2.6: (48 commits)
  serial: 8250_pci: add support for Cronyx Omega PCI multiserial board.
  tty/serial: Fix break handling for PORT_TEGRA
  tty/serial: Add explicit PORT_TEGRA type
  n_tracerouter and n_tracesink ldisc additions.
  Intel PTI implementaiton of MIPI 1149.7.
  Kernel documentation for the PTI feature.
  export kernel call get_task_comm().
  tty: Remove to support serial for S5P6442
  pch_phub: Support new device ML7223
  8250_pci: Add support for the Digi/IBM PCIe 2-port Adapter
  ASoC: Update cx20442 for TTY API change
  pch_uart: Support new device ML7223 IOH
  parport: Use request_muxed_region for IT87 probe and lock
  tty/serial: add support for Xilinx PS UART
  n_gsm: Use print_hex_dump_bytes
  drivers/tty/moxa.c: Put correct tty value
  TTY: tty_io, annotate locking functions
  TTY: serial_core, remove superfluous set_task_state
  TTY: serial_core, remove invalid test
  Char: moxa, fix locking in moxa_write
  ...

Fix up trivial conflicts in drivers/bluetooth/hci_ldisc.c and
drivers/tty/serial/Makefile.

I did the hci_ldisc thing as an evil merge, cleaning things up.

treewide: fix a few typos in comments

2011-05-10T08:16:21+00:00

- kenrel -> kernel
- whetehr -> whether
- ttt -> tt
- sss -> ss

Signed-off-by: Justin P. Mattock 
Signed-off-by: Jiri Kosina

n_gsm: Use print_hex_dump_bytes

2011-04-29T21:17:46+00:00

Use the standard mechanism to print a hex buffer
to eliminate empty printf warning.

A couple % smaller text and data too.

$ size drivers/tty/n_gsm.o*
   text	   data	    bss	    dec	    hex	filename
  23543	    312	   6376	  30231	   7617	drivers/tty/n_gsm.o.new
  24051	    408	   6496	  30955	   78eb	drivers/tty/n_gsm.o.old

Signed-off-by: Joe Perches 
Acked-by: Randy Dunlap 
Signed-off-by: Greg Kroah-Hartman

tty: make receive_buf() return the amout of bytes received

2011-04-23T00:31:53+00:00

it makes it simpler to keep track of the amount of
bytes received and simplifies how flush_to_ldisc counts
the remaining bytes. It also fixes a bug of lost bytes
on n_tty when flushing too many bytes via the USB
serial gadget driver.

Tested-by: Stefan Bigler 
Tested-by: Toby Gray 
Signed-off-by: Felipe Balbi 
Signed-off-by: Greg Kroah-Hartman