linux-toradex.git/drivers/char, branch v2.6.32.51

tty: icount changeover for other main devices

2011-11-26T17:10:38+00:00

commit 0587102cf9f427c185bfdeb2cef41e13ee0264b1 upstream

Again basically cut and paste

Convert the main driver set to use the hooks for GICOUNT

Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Dan Carpenter

tty: Make tiocgicount a handler

2011-11-26T17:10:38+00:00

commit d281da7ff6f70efca0553c288bb883e8605b3862 upstream

Dan Rosenberg noted that various drivers return the struct with uncleared
fields. Instead of spending forever trying to stomp all the drivers that
get it wrong (and every new driver) do the job in one place.

This first patch adds the needed operations and hooks them up, including
the needed USB midlayer and serial core plumbing.

Signed-off-by: Alan Cox 
Signed-off-by: Greg Kroah-Hartman 
Signed-off-by: Dan Carpenter

TPM: Zero buffer after copying to userspace

2011-11-07T20:32:06+00:00

commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 upstream.

Since the buffer might contain security related data it might be a good idea to
zero the buffer after we have copied it to userspace.

This got assigned CVE-2011-1162.

Signed-off-by: Rajiv Andrade 
Signed-off-by: James Morris 
Signed-off-by: Greg Kroah-Hartman

TPM: Call tpm_transmit with correct size

2011-11-07T20:32:05+00:00

commit 6b07d30aca7e52f2881b8c8c20c8a2cd28e8b3d3 upstream.

This patch changes the call of tpm_transmit by supplying the size of the
userspace buffer instead of TPM_BUFSIZE.

This got assigned CVE-2011-1161.

[The first hunk didn't make sense given one could expect
 way less data than TPM_BUFSIZE, so added tpm_transmit boundary
 check over bufsiz instead
 The last parameter of tpm_transmit() reflects the amount
 of data expected from the device, and not the buffer size
 being supplied to it. It isn't ideal to parse it directly,
 so we just set it to the maximum the input buffer can handle
 and let the userspace API to do such job.]

Signed-off-by: Rajiv Andrade 
Signed-off-by: James Morris 
Signed-off-by: Greg Kroah-Hartman

hvc_console: Improve tty/console put_chars handling

2011-11-07T20:32:04+00:00

commit 8c2381af0d3ef62a681dac5a141b6dabb27bf2e1 upstream.

Currently, the hvc_console_print() function drops console output if the
hvc backend's put_chars() returns 0.  This patch changes this behavior
to allow a retry through returning -EAGAIN.

This change also affects the hvc_push() function.  Both functions are
changed to handle -EAGAIN and to retry the put_chars() operation.

If a hvc backend returns -EAGAIN, the retry handling differs:

  - hvc_console_print() spins to write the complete console output.
  - hvc_push() behaves the same way as for returning 0.

Now hvc backends can indirectly control the way how console output is
handled through the hvc console layer.

Signed-off-by: Hendrik Brueckner 
Acked-by: Anton Blanchard 
Signed-off-by: Benjamin Herrenschmidt 
Signed-off-by: Greg Kroah-Hartman

net: Compute protocol sequence numbers and fragment IDs using MD5.

2011-08-16T01:57:20+00:00

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.

Reported-by: Dan Kaminsky 
Tested-by: Willy Tarreau 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

TTY: ldisc, do not close until there are readers

2011-07-13T03:29:23+00:00

commit 92f6fa09bd453ffe3351fa1f1377a1b7cfa911e6 upstream.

We restored tty_ldisc_wait_idle in 100eeae2c5c (TTY: restore
tty_ldisc_wait_idle). We used it in the ldisc changing path to fix the
case where there are tasks in n_tty_read waiting for data and somebody
tries to change ldisc.

Similar to the case above, there may be also tasks waiting in
n_tty_read while hangup is performed. As 65b770468e98 (tty-ldisc: turn
ldisc user count into a proper refcount) removed the wait-until-idle
from all paths, hangup path won't wait for them to disappear either
now. So add it back even to the hangup path.

There is a difference, we need uninterruptible sleep as there is
obviously HUP signal pending. So tty_ldisc_wait_idle now sleeps
without possibility to be interrupted. This is what original
tty_ldisc_wait_idle did. After the wait idle reintroduction
(100eeae2c5c), we have had interruptible sleeps for the ldisc changing
path. But as there is a 5s timeout anyway, we don't allow it to be
interrupted from now on. It's not worth the added complexity of
deciding what kind of sleep we want.

Before 65b770468e98 tty_ldisc_release was called also from
tty_ldisc_release. It is called from tty_release, so I don't think we
need to restore that one.

This is nicely reproducible after constifying the timing when
drivers/tty/n_tty.c is patched as follows ("TTY: ntty, add one more
sanity check" patch is needed to actually see it explode):
%% -1548,6 +1549,7 @@ static int n_tty_open(struct tty_struct *tty)

        /* These are ugly. Currently a malloc failure here can panic */
        if (!tty->read_buf) {
+               msleep(100);
                tty->read_buf = kzalloc(N_TTY_BUF_SIZE, GFP_KERNEL);
                if (!tty->read_buf)
                        return -ENOMEM;
%% -1785,6 +1788,7 @@ do_it_again:
                                break;
                        }
                        timeout = schedule_timeout(timeout);
+                       msleep(20);
                        continue;
                }
                __set_current_state(TASK_RUNNING);
===== With a process: =====
    while (1) {
        int fd = open(argv[1], O_RDWR);
        read(fd, buf, sizeof(buf));
        close(fd);
    }
===== and its child: =====
        setsid();
        while (1) {
                int fd = open(tty, O_RDWR|O_NOCTTY);
                ioctl(fd, TIOCSCTTY, 1);
                vhangup();
                close(fd);
                usleep(100 * (10 + random() % 1000));
        }
===== EOF =====

References: https://bugzilla.novell.com/show_bug.cgi?id=693374
References: https://bugzilla.novell.com/show_bug.cgi?id=694509
Signed-off-by: Jiri Slaby 
Cc: Alan Cox 
Cc: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

i8k: Avoid lahf in 64-bit code

2011-06-23T22:24:04+00:00

commit bc1f419c76a2d6450413ce4349f4e4a07be011d5 upstream.

i8k uses lahf to read the flag register in 64-bit code; early x86-64
CPUs, however, lack this instruction and we get an invalid opcode
exception at runtime.
Use pushf to load the flag register into the stack instead.

Signed-off-by: Luca Tettamanti 
Reported-by: Jeff Rickman 
Tested-by: Jeff Rickman 
Tested-by: Harry G McGavran Jr 
Cc: Massimo Dal Zotto 
Signed-off-by: Jean Delvare 
Signed-off-by: Greg Kroah-Hartman

Fix gcc 4.5.1 miscompiling drivers/char/i8k.c (again)

2011-05-09T22:54:59+00:00

commit 22d3243de86bc92d874abb7c5b185d5c47aba323 upstream.

The fix in commit 6b4e81db2552 ("i8k: Tell gcc that *regs gets
clobbered") to work around the gcc miscompiling i8k.c to add "+m
(*regs)" caused register pressure problems and a build failure.

Changing the 'asm' statement to 'asm volatile' instead should prevent
that and works around the gcc bug as well, so we can remove the "+m".

[ Background on the gcc bug: a memory clobber fails to mark the function
  the asm resides in as non-pure (aka "__attribute__((const))"), so if
  the function does nothing else that triggers the non-pure logic, gcc
  will think that that function has no side effects at all. As a result,
  callers will be mis-compiled.

  Adding the "+m" made gcc see that it's not a pure function, and so
  does "asm volatile". The problem was never really the need to mark
  "*regs" as changed, since the memory clobber did that part - the
  problem was just a bug in the gcc "pure" function analysis  - Linus ]

Signed-off-by: Jim Bos 
Acked-by: Jakub Jelinek 
Cc: Andi Kleen 
Cc: Andreas Schwab 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

i8k: Tell gcc that *regs gets clobbered

2011-05-09T22:54:59+00:00

commit 6b4e81db2552bad04100e7d5ddeed7e848f53b48 upstream.

More recent GCC caused the i8k driver to stop working, on Slackware
compiler was upgraded from gcc-4.4.4 to gcc-4.5.1 after which it didn't
work anymore, meaning the driver didn't load or gave total nonsensical
output.

As it turned out the asm(..) statement forgot to mention it modifies the
*regs variable.

Credits to Andi Kleen and Andreas Schwab for providing the fix.

Signed-off-by: Jim Bos 
Cc: Andi Kleen 
Cc: Andreas Schwab 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman