introduced a potential NULL dereference to some drivers. In
particular, when the device is used as a console, incoming bytes can
kill the box. This is caused by removed checks for TTY against NULL.
It happened because it was unclear to me why the checks were there. I
assumed them superfluous because the interrupts were unbound or
otherwise stopped. But this is not the case for consoles for these
drivers, as was pointed out by David Miller.
Now, this patch re-introduces the checks (at this point we check
port->state, not the tty proper, as we do not care about tty pointers
anymore). For both of the drivers, we place the check below the
handling of break signal so that sysrq can actually work. (One needs
to issue a break and then sysrq key within the following 5 seconds.)
We do not change sc26xx, sunhv, and sunsu here because they behave the
same as before. People having that hardware should fix the driver
eventually, however. They always could unconditionally dereference tty
in receive_chars, port->state in uart_handle_dcd_change, and
up->port.state->port.tty.
There is perhaps more to fix in all those drivers, but they are at
least in a state they were before.
Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: "David S. Miller" <davem@davemloft.net> Cc: Grant Likely <grant.likely@secretlab.ca> Cc: Rob Herring <rob.herring@calxeda.com> Cc: sparclinux@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:45 +0000 (16:44 -0400)]
tty: Fix recursive deadlock in tty_perform_flush()
tty_perform_flush() can deadlock when called while holding
a line discipline reference. By definition, all ldisc drivers
hold a ldisc reference, so calls originating from ldisc drivers
must not block for a ldisc reference.
The deadlock can occur when:
CPU 0 | CPU 1
|
tty_ldisc_ref(tty) |
.... | <line discipline halted>
tty_ldisc_ref_wait(tty) |
|
CPU 0 cannot progess because it cannot obtain an ldisc reference
with the line discipline has been halted (thus no new references
are granted).
CPU 1 cannot progress because an outstanding ldisc reference
has not been released.
An in-tree call-tree audit of tty_perform_flush() [1] shows 5
ldisc drivers calling tty_perform_flush() indirectly via
n_tty_ioctl_helper() and 2 ldisc drivers calling directly.
A single tty driver safely uses the function.
[1]
Recursive usage:
/* These functions are line discipline ioctls and thus
* recursive wrt line discipline references */
tty_perform_flush() - drivers/tty/tty_ioctl.c
ipw_ioctl(TCFLSH) - drivers/tty/ipwireless/tty.c
/* This function is a tty i/o ioctl method, which
* is invoked by tty_ioctl() */
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:40 +0000 (16:44 -0400)]
tty: Separate release semantics of ldisc reference
tty_ldisc_ref()/tty_ldisc_unref() have usage semantics
equivalent to down_read_trylock()/up_read(). Only
callers of tty_ldisc_put() are performing the additional
operations necessary for proper ldisc teardown, and then only
after ensuring no outstanding 'read lock' remains.
Thus, tty_ldisc_unref() should never be the last reference;
WARN if it is. Conversely, tty_ldisc_put() should never be
destructing if the use count != 1.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:35 +0000 (16:44 -0400)]
tty: Make core responsible for synchronizing its work
The tty core relies on the ldisc layer for synchronizing destruction
of the tty. Instead, the final tty release must wait for any pending tty
work to complete prior to tty destruction.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:34 +0000 (16:44 -0400)]
tty: Complete ownership transfer of flip buffers
Waiting for buffer work to complete is not required for safely
performing changes to the line discipline, once the line discipline
is halted. The buffer work routine, flush_to_ldisc(), will be
unable to acquire an ldisc ref and all existing references were
waited until released (so it can't already have one).
Ensure running buffer work which may reference the soon-to-be-gone
tty completes and any buffer work running after this point retrieves
a NULL tty.
Also, ensure all buffer work is cancelled on port destruction.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:33 +0000 (16:44 -0400)]
tty: Don't reenable already enabled ldisc
tty_ldisc_hangup() guarantees the ldisc is enabled (or that there
is no ldisc). Since __tty_hangup() was the only user, re-define
tty_ldisc_enable() in file-scope.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:32 +0000 (16:44 -0400)]
n_tty: Fully initialize ldisc before restarting buffer work
Buffer work may already be pending when the n_tty ldisc is re-opened,
eg., when setting the ldisc (via TIOCSETD ioctl) and when hanging up
the tty. Since n_tty_set_room() may restart buffer work, first ensure
the ldisc is completely initialized.
Factor n_tty_set_room() out of reset_buffer_flags() (only 2 callers)
and reorganize n_tty_open() to set termios last; buffer work will
be restarted there if necessary, after the char_map is properly
initialized.
Peter Hurley [Mon, 11 Mar 2013 20:44:29 +0000 (16:44 -0400)]
tty: Halt both ldiscs concurrently
The pty driver does not obtain an ldisc reference to the linked
tty when writing. When the ldiscs are sequentially halted, it
is possible for one ldisc to be halted, and before the second
ldisc can be halted, a concurrent write schedules buffer work on
the first ldisc. This can lead to an access-after-free error when
the scheduled buffer work starts on the closed ldisc.
Prevent subsequent use after halt by performing each stage
of the halt on both ttys.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:28 +0000 (16:44 -0400)]
tty: Strengthen no-subsequent-use guarantee of tty_ldisc_halt()
In preparation for destructing and freeing the tty, the line discipline
must first be brought to an inactive state before it can be destructed.
This line discipline shutdown must:
- disallow new users of the ldisc
- wait for existing ldisc users to finish
- only then, cancel/flush their pending/running work
Factor tty_ldisc_wait_idle() from tty_set_ldisc() and tty_ldisc_kill()
to ensure this shutdown order.
Failure to provide this guarantee can result in scheduled work
running after the tty has already been freed, as indicated in the
following log message:
Peter Hurley [Mon, 11 Mar 2013 20:44:26 +0000 (16:44 -0400)]
tty: Fix ldisc halt sequence on hangup
Flip buffer work cannot be cancelled until all outstanding ldisc
references have been released. Convert the ldisc ref wait into
a full ldisc halt with buffer work cancellation.
Note that the legacy mutex is not held while cancelling.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:25 +0000 (16:44 -0400)]
tty: Remove unnecessary re-test of ldisc ref count
Since the tty->ldisc is prevented from being changed by tty_set_ldisc()
when a tty is being hung up, re-testing the ldisc user count is
unnecessary -- ie, it cannot be a different ldisc and the user count
cannot have increased (assuming the caller meets the precondition that
TTY_LDISC flag is cleared)
Removal of the 'early-out' locking optimization is necessary for
the subsequent patch 'tty: Fix ldisc halt sequence on hangup'.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Mon, 11 Mar 2013 20:44:23 +0000 (16:44 -0400)]
n_tty: Don't flush buffer when closing ldisc
A buffer flush is both undesirable and unnecessary when the ldisc
is closing. A buffer flush performs the following:
1. resets ldisc data fields to their initial state
2. resets tty->receive_room to indicate more data can be sent
3. schedules buffer work to receive more data
4. signals a buffer flush has happened to linked pty in packet mode
Since the ldisc has been halted and the tty may soon be destructed,
buffer work must not be scheduled as that work might access
an invalid tty and ldisc state. Also, the ldisc read buffer is about
to be freed, so that's pointless.
Resetting the ldisc data fields is pointless as well since that
structure is about to be freed.
Resetting tty->receive_room is unnecessary, as it will be properly
reset if a new ldisc is reopened. Besides, resetting the original
receive_room value would be wrong since the read buffer will be
gone.
Since the packet mode flush is observable from userspace, this
behavior has been preserved.
The test jig originally authored by Ilya Zykov <ilya@ilyx.ru> and
signed off by him is included below. The test jig prompts the
following warnings which this patch fixes.
/*
* pty_thrash.c
*
* Based on original test jig by Ilya Zykov <ilya@ilyx.ru>
*
* Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
* Signed-off-by: Ilya Zykov <ilya@ilyx.ru>
*/
child_id = fork();
if (child_id == -1)
error_exit("forking child");
if (parent) {
int err, id, status;
char buf[128];
int n;
n = read(fd, buf, sizeof(buf));
if (n < 0)
error_exit("master reading");
printf("%.*s\n", n-1, buf);
close(fd);
err = kill(child_id, SIGKILL);
if (err < 0)
error_exit("killing child");
id = waitpid(child_id, &status, 0);
if (id < 0 || id != child_id)
error_exit("waiting for child");
} else { /* Child */
close(fd);
printf("Test cycle on slave pty %s\n", pts_name);
fd = open(pts_name, O_RDWR);
if (fd < 0)
error_exit("opening pty slave");
while (1) {
char pattern[] = "test\n";
if (write(fd, pattern, strlen(pattern)) < 0)
error_exit("slave writing");
}
The ifx6x60 driver implements both legacy suspend/resume callbacks and
dev_pm_ops. The SPI core is going to ignore legacy suspend/resume
callbacks if a driver implements dev_pm_ops. Since the legacy suspend/resume
callbacks are empty in this case it is safe to just remove them.
Cc: Bi Chao <chao.bi@intel.com> Cc: Chen Jun <jun.d.chen@intel.com> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Johan Hovold [Thu, 7 Mar 2013 14:55:53 +0000 (15:55 +0100)]
TTY: fix close of uninitialised ports
Make sure we do not make tty-driver callbacks or wait for port to drain
on uninitialised ports (e.g. when open failed) in
tty_port_close_start().
No callback, such as flush_buffer or wait_until_sent, needs to be made
on a port that has never been opened. Neither does it make much sense to
add drain delay for an uninitialised port.
Currently a drain delay of up to two seconds could be added when a tty
fails to open.
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Johan Hovold [Thu, 7 Mar 2013 14:55:51 +0000 (15:55 +0100)]
TTY: fix DTR not being dropped on hang up
Move HUPCL handling to port shutdown so that DTR is dropped also on hang
up (tty_port_close is a noop for hung-up ports).
Also do not try to drop DTR for uninitialised ports where it has never
been raised (e.g. after a failed open).
Note that this is also the current behaviour of serial-core.
Nine drivers currently call tty_port_close_start directly (rather than
through tty_port_close) and seven of them lower DTR as part of their
close (if the port has been initialised). Fixup the remaining two
drivers so that it continues to be lowered also on normal (non-HUP)
close. [ Note that most of those other seven drivers did not expect DTR
to have been dropped by tty_port_close_start in the first place. ]
Signed-off-by: Johan Hovold <jhovold@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Jiri Slaby [Thu, 7 Mar 2013 12:12:36 +0000 (13:12 +0100)]
crisv10: use flags from tty_port
First, remove STD_FLAGS as the value, or its subvalues
(ASYNC_BOOT_AUTOCONF | ASYNC_SKIP_TEST) is not tested anywhere --
there is no point to initialize flags to that. Second, use flags
member from tty_port when we have it now. So that we do not waste
space.
Jiri Slaby [Thu, 7 Mar 2013 12:12:34 +0000 (13:12 +0100)]
TTY: cleanup tty->hw_stopped uses
tty->hw_stopped is set only by drivers to remember HW state. If it is
never set to 1 in a particular driver, there is no need to check it in
the driver at all. Remove such checks.
Jiri Slaby [Thu, 7 Mar 2013 12:12:32 +0000 (13:12 +0100)]
TTY: serial/bfin_uart, unbreak build with KGDB enabled
There are no (and never were any) kgdb fields in uart_ops. Setting
them produces a build error:
drivers/tty/serial/bfin_uart.c:1054:2: error: unknown field 'kgdboc_port_startup' specified in initializer
drivers/tty/serial/bfin_uart.c:1054:2: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/bfin_uart.c:1054:2: warning: (near initialization for 'bfin_serial_pops.ioctl') [enabled by default]
drivers/tty/serial/bfin_uart.c:1055:2: error: unknown field 'kgdboc_port_shutdown' specified in initializer
drivers/tty/serial/bfin_uart.c:1055:2: warning: initialization from incompatible pointer type [enabled by default]
drivers/tty/serial/bfin_uart.c:1055:2: warning: (near initialization for 'bfin_serial_pops.poll_init') [enabled by default]
Jiri Slaby [Thu, 7 Mar 2013 12:12:30 +0000 (13:12 +0100)]
TTY: add tty_port_tty_hangup helper
It allows for cleaning up on a considerable amount of places. They did
port_get, hangup, kref_put. Now the only thing needed is to call
tty_port_tty_hangup which does exactly that. And they can also decide
whether to consider CLOCAL or completely ignore that.
Jiri Slaby [Thu, 7 Mar 2013 12:12:31 +0000 (13:12 +0100)]
TTY: quatech2, remove unneeded is_open
tty->ops->break_ctl cannot be called outside the gap between open and
close. So there is no need to check whether the port is open in
break_ctl in quatech2. Remove the check and also that member
completely.
Jiri Slaby [Thu, 7 Mar 2013 12:12:29 +0000 (13:12 +0100)]
TTY: add tty_port_tty_wakeup helper
It allows for cleaning up on a considerable amount of places. They did
port_get, wakeup, kref_put. Now the only thing needed is to call
tty_port_tty_wakeup which does exactly that.
One exception is ifx6x60 where tty_wakeup was open-coded. We now call
tty_wakeup properly there.
Jiri Slaby [Thu, 7 Mar 2013 12:12:25 +0000 (13:12 +0100)]
TTY: jsm, remove superfluous check
data_len in jsm_input cannot be zero as we would jump out early in the
function. It also cannot be negative because it is an int and we do
bitwise and with 8192. So remove the check.
Peter Hurley [Wed, 6 Mar 2013 13:38:20 +0000 (08:38 -0500)]
n_tty: Lock access to tty->pgrp for POSIX job control
Concurrent access to tty->pgrp must be protected with tty->ctrl_lock.
Also, as noted in the comments, reading current->signal->tty is
safe because either,
1) current->signal->tty is assigned by current, or
2) current->signal->tty is set to NULL.
NB: for reference, tty_check_change() implements a similar POSIX
check for the ioctls corresponding to tcflush(), tcdrain(),
tcsetattr(), tcsetpgrp(), tcflow() and tcsendbreak().
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Wed, 6 Mar 2013 13:38:19 +0000 (08:38 -0500)]
n_tty: Fix unsafe driver-side signals
An ldisc reference is insufficient guarantee the foreground process
group is not in the process of being signalled from a hangup.
1) Reads of tty->pgrp must be locked with ctrl_lock
2) The group pid must be referenced for the duration of signalling.
Because the driver-side is not process-context, a pid reference
must be acquired.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Wed, 6 Mar 2013 13:20:53 +0000 (08:20 -0500)]
n_tty: Fix stuck throttled driver
As noted in the following comment:
/* FIXME: there is a tiny race here if the receive room check runs
before the other work executes and empties the buffer (upping
the receiving room and unthrottling. We then throttle and get
stuck. This has been observed and traced down by Vincent Pillet/
We need to address this when we sort out out the rx path locking */
Use new safe throttle/unthrottle functions to re-evaluate conditions
if interrupted by the complement flow control function.
Reported-by: Vincent Pillet <vincentx.pillet@intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Peter Hurley [Wed, 6 Mar 2013 13:20:52 +0000 (08:20 -0500)]
tty: Add safe tty throttle/unthrottle functions
The tty driver can become stuck throttled due to race conditions
between throttle and unthrottle, when the decision to throttle
or unthrottle is conditional. The following example helps to
illustrate the race:
CPU 0 | CPU 1
|
if (condition A) |
| <processing such that A not true>
| if (!condition A)
| unthrottle()
throttle() |
|
Note the converse is also possible; ie.,
CPU 0 | CPU 1
|
| if (!condition A)
<processing such that A true> |
if (condition A) |
throttle() |
| unthrottle()
|
Add new throttle/unthrottle functions based on the familiar model
of task state and schedule/wake. For example,
while (1) {
tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
if (!condition)
break;
if (!tty_throttle_safe(tty))
break;
}
__tty_set_flow_change(tty, 0);
In this example, if an unthrottle occurs after the condition is
evaluated but before tty_throttle_safe(), then tty_throttle_safe()
will return non-zero, looping and forcing the re-evaluation of
condition.
Reported-by: Vincent Pillet <vincentx.pillet@intel.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
David Rientjes [Sun, 17 Mar 2013 22:49:10 +0000 (15:49 -0700)]
perf,x86: fix link failure for non-Intel configs
Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") introduces a link failure since
perf_restore_debug_store() is only defined for CONFIG_CPU_SUP_INTEL:
arch/x86/power/built-in.o: In function `restore_processor_state':
(.text+0x45c): undefined reference to `perf_restore_debug_store'
Fix it by defining the dummy function appropriately.
Signed-off-by: David Rientjes <rientjes@google.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Sun, 17 Mar 2013 22:44:43 +0000 (15:44 -0700)]
perf,x86: fix wrmsr_on_cpu() warning on suspend/resume
Commit 1d9d8639c063 ("perf,x86: fix kernel crash with PEBS/BTS after
suspend/resume") fixed a crash when doing PEBS performance profiling
after resuming, but in using init_debug_store_on_cpu() to restore the
DS_AREA mtrr it also resulted in a new WARN_ON() triggering.
init_debug_store_on_cpu() uses "wrmsr_on_cpu()", which in turn uses CPU
cross-calls to do the MSR update. Which is not really valid at the
early resume stage, and the warning is quite reasonable. Now, it all
happens to _work_, for the simple reason that smp_call_function_single()
ends up just doing the call directly on the CPU when the CPU number
matches, but we really should just do the wrmsr() directly instead.
This duplicates the wrmsr() logic, but hopefully we can just remove the
wrmsr_on_cpu() version eventually.
Linus Torvalds [Sun, 17 Mar 2013 18:04:14 +0000 (11:04 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
"Eric's rcu barrier patch fixes a long standing problem with our
unmount code hanging on to devices in workqueue helpers. Liu Bo
nailed down a difficult assertion for in-memory extent mappings."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix warning of free_extent_map
Btrfs: fix warning when creating snapshots
Btrfs: return as soon as possible when edquot happens
Btrfs: return EIO if we have extent tree corruption
btrfs: use rcu_barrier() to wait for bdev puts at unmount
Btrfs: remove btrfs_try_spin_lock
Btrfs: get better concurrency for snapshot-aware defrag work
Liu Bo [Fri, 15 Mar 2013 14:46:39 +0000 (08:46 -0600)]
Btrfs: fix warning of free_extent_map
Users report that an extent map's list is still linked when it's actually
going to be freed from cache.
The story is that
a) when we're going to drop an extent map and may split this large one into
smaller ems, and if this large one is flagged as EXTENT_FLAG_LOGGING which means
that it's on the list to be logged, then the smaller ems split from it will also
be flagged as EXTENT_FLAG_LOGGING, and this is _not_ expected.
b) we'll keep ems from unlinking the list and freeing when they are flagged with
EXTENT_FLAG_LOGGING, because the log code holds one reference.
The end result is the warning, but the truth is that we set the flag
EXTENT_FLAG_LOGGING only during fsync.
So clear flag EXTENT_FLAG_LOGGING for extent maps split from a large one.
Reported-by: Johannes Hirte <johannes.hirte@fem.tu-ilmenau.de> Reported-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Linus Torvalds [Sat, 16 Mar 2013 01:06:55 +0000 (18:06 -0700)]
Merge branch 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild
Pull kbuild fix from Michal Marek:
"One fix for for make headers_install/headers_check to not require make
3.81. The requirement has been accidentally introduced in 3.7."
* 'kbuild' of git://git.kernel.org/pub/scm/linux/kernel/git/mmarek/kbuild:
kbuild: fix make headers_check with make 3.80
Linus Torvalds [Sat, 16 Mar 2013 01:05:37 +0000 (18:05 -0700)]
Merge tag 'for-3.9-rc3' of git://openrisc.net/jonas/linux
Pull OpenRISC bug fixes from Jonas Bonn:
- The GPIO descriptor work has exposed how broken the non-GPIOLIB bits
for OpenRISC were. We now require GPIOLIB as this is the preferred
way forward.
- The system.h split introduced a bug in llist.h for arches using
asm-generic/cmpxchg.h directly, which is currently only OpenRISC.
The patch here moves two defines from asm-generic/atomic.h to
asm-generic/cmpxchg.h to make things work as they should.
- The VIRT_TO_BUS selector was added for OpenRISC, but OpenRISC does
not have the virt_to_bus methods, so there's a patch to remove it
again.
* tag 'for-3.9-rc3' of git://openrisc.net/jonas/linux:
openrisc: remove HAVE_VIRT_TO_BUS
asm-generic: move cmpxchg*_local defs to cmpxchg.h
openrisc: require gpiolib
Linus Torvalds [Sat, 16 Mar 2013 01:04:38 +0000 (18:04 -0700)]
Merge tag 'char-misc-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc fixes from Greg Kroah-Hartman:
"Here are some tiny fixes for the w1 drivers and the final removal
patch for getting rid of CONFIG_EXPERIMENTAL (all users of it are now
gone from your tree, this just drops the Kconfig item itself.)
All have been in the linux-next tree for a while"
* tag 'char-misc-3.9-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
final removal of CONFIG_EXPERIMENTAL
w1: fix oops when w1_search is called from netlink connector
w1-gpio: fix unused variable warning
w1-gpio: remove erroneous __exit and __exit_p()
ARM: w1-gpio: fix erroneous gpio requests
Linus Torvalds [Sat, 16 Mar 2013 00:35:49 +0000 (17:35 -0700)]
Merge tag 'sound-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"A collection of small fixes, as expected for the middle rc:
- A couple of fixes for potential NULL dereferences and out-of-range
array accesses revealed by static code parsers
- A fix for the wrong error handling detected by trinity
- A regression fix for missing audio on some MacBooks
- CA0132 DSP loader fixes
- Fix for EAPD control of IDT codecs on machines w/o speaker
- Fix a regression in the HD-audio widget list parser code
- Workaround for the NuForce UDH-100 USB audio"
* tag 'sound-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda - Fix missing EAPD/GPIO setup for Cirrus codecs
sound: sequencer: cap array index in seq_chn_common_event()
ALSA: hda/ca0132 - Remove extra setting of dsp_state.
ALSA: hda/ca0132 - Check download state of DSP.
ALSA: hda/ca0132 - Check if dspload_image succeeded.
ALSA: hda - Disable IDT eapd_switch if there are no internal speakers
ALSA: hda - Fix snd_hda_get_num_raw_conns() to return a correct value
ALSA: usb-audio: add a workaround for the NuForce UDH-100
ALSA: asihpi - fix potential NULL pointer dereference
ALSA: seq: Fix missing error handling in snd_seq_timer_open()
Linus Torvalds [Sat, 16 Mar 2013 00:35:03 +0000 (17:35 -0700)]
Merge branch 'fixes-for-3.9' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping
Pull DMA-mapping fix from Marek Szyprowski:
"An important fix for all ARM architectures which use ZONE_DMA.
Without it dma_alloc_* calls with GFP_ATOMIC flag might have allocated
buffers outsize DMA zone."
* 'fixes-for-3.9' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping:
ARM: DMA-mapping: add missing GFP_DMA flag for atomic buffer allocation
Linus Torvalds [Sat, 16 Mar 2013 00:34:01 +0000 (17:34 -0700)]
Merge tag 'mfd-fixes-3.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-fixes
Pull MFD fixes from Samuel Ortiz:
"This is the first batch of MFD fixes for 3.9.
With this one we have:
- An ab8500 build failure fix.
- An ab8500 device tree parsing fix.
- A fix for twl4030_madc remove routine to work properly (when
built-in).
- A fix for properly registering palmas interrupt handler.
- A fix for omap-usb init routine to actually write into the
hostconfig register.
- A couple of warning fixes for ab8500-gpadc and tps65912"
* tag 'mfd-fixes-3.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/sameo/mfd-fixes:
mfd: twl4030-madc: Remove __exit_p annotation
mfd: ab8500: Kill "reg" property from binding
mfd: ab8500-gpadc: Complain if we fail to enable vtvout LDO
mfd: wm831x: Don't forward declare enum wm831x_auxadc
mfd: twl4030-audio: Fix argument type for twl4030_audio_disable_resource()
mfd: tps65912: Declare and use tps65912_irq_exit()
mfd: palmas: Provide irq flags through DT/platform data
mfd: Make AB8500_CORE select POWER_SUPPLY to fix build error
mfd: omap-usb-host: Actually update hostconfig
Linus Torvalds [Sat, 16 Mar 2013 00:33:13 +0000 (17:33 -0700)]
Merge tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging
Pull hwmon fixes from Guenter Roeck:
"Bug fixes for pmbus, ltc2978, and lineage-pem drivers
Added specific maintainer for some hwmon drivers"
* tag 'hwmon-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
hwmon: (pmbus/ltc2978) Fix temperature reporting
hwmon: (pmbus) Fix krealloc() misuse in pmbus_add_attribute()
hwmon: (lineage-pem) Add missing terminating entry for pem_[input|fan]_attributes
MAINTAINERS: Add maintainer for MAX6697, INA209, and INA2XX drivers
Peter Hurley [Wed, 6 Mar 2013 12:20:57 +0000 (07:20 -0500)]
tty: Signal SIGHUP before hanging up ldisc
An exiting session leader can hang if a foreground process is
blocking for line discipline i/o, eg. in n_tty_read(). This happens
because the blocking reader is holding an ldisc reference (indicating
the line discipline is in-use) which prevents __tty_hangup() from
recycling the line discipline. Although waiters are woken before
attempting to gain exclusive access for changing the ldisc, the
blocking reader in this case will not exit the i/o loop since it
has not yet received SIGHUP (because it has not been sent).
Instead, perform signalling first, then recycle the line discipline.
Peter Hurley [Wed, 6 Mar 2013 12:20:56 +0000 (07:20 -0500)]
tty: Signal foreground group processes in hangup
When the session leader is exiting, signal the foreground group
processes as part of the hangup sequence, instead of after the
hangup is complete. This prepares for hanging up the
line discipline _after_ signalling processes which
may be blocking on ldisc i/o.
Parameterize __tty_hangup() to distinguish between when the
session leader is exiting and all other hangups; signal the
foreground group after signalling the session leader and its
process group, which preserves the original signal order.
Peter Hurley [Wed, 6 Mar 2013 12:20:55 +0000 (07:20 -0500)]
tty: Use spin_lock() inside existing critical region
The interrupt state does not need to be saved, disabled and
restored here; interrupts are already off because this lock
is bracketed by spin_lock_irq/spin_unlock_irq.
Peter Hurley [Wed, 6 Mar 2013 12:20:54 +0000 (07:20 -0500)]
tty: Fix spinlock flavor in non-atomic __tty_hangup()
__tty_hangup() and tty_vhangup() cannot be called from atomic context,
so locks do not need to preserve the interrupt state (although,
still disable interrupts).
Stephane Eranian [Fri, 15 Mar 2013 13:26:07 +0000 (14:26 +0100)]
perf,x86: fix kernel crash with PEBS/BTS after suspend/resume
This patch fixes a kernel crash when using precise sampling (PEBS)
after a suspend/resume. Turns out the CPU notifier code is not invoked
on CPU0 (BP). Therefore, the DS_AREA (used by PEBS) is not restored properly
by the kernel and keeps it power-on/resume value of 0 causing any PEBS
measurement to crash when running on CPU0.
The workaround is to add a hook in the actual resume code to restore
the DS Area MSR value. It is invoked for all CPUS. So for all but CPU0,
the DS_AREA will be restored twice but this is harmless.
Takashi Iwai [Fri, 15 Mar 2013 13:23:32 +0000 (14:23 +0100)]
ALSA: hda - Fix missing EAPD/GPIO setup for Cirrus codecs
During the transition to the generic parser, the hook to the codec
specific automute function was forgotten. This resulted in the silent
output on some MacBooks.
Dan Carpenter [Fri, 15 Mar 2013 06:14:22 +0000 (09:14 +0300)]
sound: sequencer: cap array index in seq_chn_common_event()
"chn" here is a number between 0 and 255, but ->chn_info[] only has
16 elements so there is a potential write beyond the end of the
array.
If the seq_mode isn't SEQ_2 then we let the individual drivers
(either opl3.c or midi_synth.c) handle it. Those functions all
do a bounds check on "chn" so I haven't changed anything here.
The opl3.c driver has up to 18 channels and not 16.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
Arnd Bergmann [Thu, 14 Mar 2013 21:56:38 +0000 (22:56 +0100)]
mfd: twl4030-madc: Remove __exit_p annotation
4740f73fe5 "mfd: remove use of __devexit" removed the __devexit annotation
on the twl4030_madc_remove function, but left an __exit_p() present on the
pointer to this function. Using __exit_p was as wrong with the devexit in
place as it is now, but now we get a gcc warning about an unused function.
In order for the twl4030_madc_remove to work correctly in built-in code, we
have to remove the __exit_p.
Cc: Bill Pemberton <wfp5p@virginia.edu> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Dylan Reid [Fri, 15 Mar 2013 00:27:45 +0000 (17:27 -0700)]
ALSA: hda/ca0132 - Check download state of DSP.
Instead of using the dspload_is_loaded() function, check the dsp_state
that is kept in the spec. The dspload_is_loaded() function returns
true if the DSP transfer was never started. This false-positive leads
to multiple second delays when ca0132_setup_efaults() times out on
each write.
Dylan Reid [Fri, 15 Mar 2013 00:27:44 +0000 (17:27 -0700)]
ALSA: hda/ca0132 - Check if dspload_image succeeded.
If dspload_image() fails, it was ignored and dspload_wait_loaded() was
still called. dsp_loaded should never be set to true in this case,
skip it. The check in dspload_wait_loaded() return true if the DSP is
loaded or if it never started.
The vm_flags introduced in 6d7825b10dbe ("mm/fremap.c: fix oops on error
path") is supposed to avoid a compiler warning about unitialized
vm_flags without changing the generated code.
However I am concerned that this is going to be very brittle, and fail
with some compiler versions. The failure could be either of:
- compiler could actually load vma->vm_flags before checking for the
!vma condition, thus reintroducing the oops
- compiler could optimize out the !vma check, since the pointer just got
dereferenced shortly before (so the compiler knows it can't be NULL!)
I propose reversing this part of the change and initializing vm_flags to 0
just to avoid the bogus uninitialized use warning.
Signed-off-by: Michel Lespinasse <walken@google.com> Cc: Tommi Rantala <tt.rantala@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Linus Torvalds [Thu, 14 Mar 2013 21:53:07 +0000 (14:53 -0700)]
Merge branch 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull fix for hlist_entry_safe() regression from Paul McKenney:
"This contains a single commit that fixes a regression in
hlist_entry_safe(). This macro references its argument twice, which
can cause NULL-pointer errors. This commit applies a gcc statement
expression, creating a temporary variable to avoid the double
reference. This has been posted to LKML at
https://lkml.org/lkml/2013/3/9/75.
Kudos to CAI Qian, whose testing uncovered this, to Eric Dumazet, who
spotted root cause, and to Li Zefan, who tested this commit."
* 'rcu/urgent' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
list: Fix double fetch of pointer in hlist_entry_safe()
list: Fix double fetch of pointer in hlist_entry_safe()
The current version of hlist_entry_safe() fetches the pointer twice,
once to test for NULL and the other to compute the offset back to the
enclosing structure. This is OK for normal lock-based use because in
that case, the pointer cannot change. However, when the pointer is
protected by RCU (as in "rcu_dereference(p)"), then the pointer can
change at any time. This use case can result in the following sequence
of events:
1. CPU 0 invokes hlist_entry_safe(), fetches the RCU-protected
pointer as sees that it is non-NULL.
2. CPU 1 invokes hlist_del_rcu(), deleting the entry that CPU 0
just fetched a pointer to. Because this is the last entry
in the list, the pointer fetched by CPU 0 is now NULL.
3. CPU 0 refetches the pointer, obtains NULL, and then gets a
NULL-pointer crash.
This commit therefore applies gcc's "({ })" statement expression to
create a temporary variable so that the specified pointer is fetched
only once, avoiding the above sequence of events. Please note that
it is the caller's responsibility to use rcu_dereference() as needed.
This allows RCU-protected uses to work correctly without imposing
any additional overhead on the non-RCU case.
Many thanks to Eric Dumazet for spotting root cause!
Reported-by: CAI Qian <caiqian@redhat.com> Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by: Li Zefan <lizefan@huawei.com>
Linus Torvalds [Thu, 14 Mar 2013 19:11:28 +0000 (12:11 -0700)]
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs
Pull ext2, ext3, reiserfs, quota fixes from Jan Kara:
"A fix for regression in ext2, and a format string issue in ext3. The
rest isn't too serious."
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs:
ext2: Fix BUG_ON in evict() on inode deletion
reiserfs: Use kstrdup instead of kmalloc/strcpy
ext3: Fix format string issues
quota: add missing use of dq_data_lock in __dquot_initialize
Liu Bo [Wed, 13 Mar 2013 13:43:03 +0000 (07:43 -0600)]
Btrfs: fix warning when creating snapshots
Creating snapshot passes extent_root to commit its transaction,
but it can lead to the warning of checking root for quota in
the __btrfs_end_transaction() when someone else is committing
the current transaction. Since we've recorded the needed root
in trans_handle, just use it to get rid of the warning.
Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Wang Shilong [Wed, 6 Mar 2013 11:51:47 +0000 (11:51 +0000)]
Btrfs: return as soon as possible when edquot happens
If one of qgroup fails to reserve firstly, we should return immediately,
it is unnecessary to continue check.
Signed-off-by: Wang Shilong <wangsl-fnst@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Josef Bacik [Fri, 8 Mar 2013 20:41:02 +0000 (15:41 -0500)]
Btrfs: return EIO if we have extent tree corruption
The callers of lookup_inline_extent_info all handle getting an error back
properly, so return an error if we have corruption instead of being a jerk and
panicing. Still WARN_ON() since this is kind of crucial and I've been seeing it
a bit too much recently for my taste, I think we're doing something wrong
somewhere. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
Eric Sandeen [Sat, 9 Mar 2013 15:18:39 +0000 (15:18 +0000)]
btrfs: use rcu_barrier() to wait for bdev puts at unmount
Doing this would reliably fail with -EBUSY for me:
# mount /dev/sdb2 /mnt/scratch; umount /mnt/scratch; mkfs.btrfs -f /dev/sdb2
...
unable to open /dev/sdb2: Device or resource busy
because mkfs.btrfs tries to open the device O_EXCL, and somebody still has it.
Using systemtap to track bdev gets & puts shows a kworker thread doing a
blkdev put after mkfs attempts a get; this is left over from the unmount
path:
so unmount might complete before __free_device fires & does its blkdev_put.
Adding an rcu_barrier() to btrfs_close_devices() causes unmount to wait
until all blkdev_put()s are done, and the device is truly free once
unmount completes.
Cc: stable@vger.kernel.org Signed-off-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
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