Use 'atomic_dec_and_lock()' to make sure that we always hold the
tty_ldisc_lock when the ldisc count goes to zero. That way we can never
race against 'tty_ldisc_try()' increasing the count again.
Reported-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
By using the user count for the actual lifetime rules, we can get rid of
the silly "wait_for_idle" logic, because any busy ldisc will
automatically stay around until the last user releases it. This avoids
a host of odd issues, and simplifies the code.
So now, when the last ldisc reference is dropped, we just release the
ldisc operations struct reference, and free the ldisc.
It looks obvious enough, and it does work for me, but the counting
_could_ be off. It probably isn't (bad counting in the new version would
generally imply that the old code did something really bad, like free an
ldisc with a non-zero count), but it does need some testing, and
preferably somebody looking at it.
With this change, both 'tty_ldisc_put()' and 'tty_ldisc_deref()' are
just aliases for the new ref-counting 'put_ldisc()'. Both of them
decrement the ldisc user count and free it if it goes down to zero.
They're identical functions, in other words.
But the reason they still exist as sepate functions is that one of them
was exported (tty_ldisc_deref) and had a stupid name (so I don't want to
use it as the main name), and the other one was used in multiple places
(and I didn't want to make the patch larger just to rename the users).
In addition to the refcounting, I did do some minimal cleanup. For
example, now "tty_ldisc_try()" actually returns the ldisc it got under
the lock, rather than returning true/false and then the caller would
look up the ldisc again (now without the protection of the lock).
That said, there's tons of dubious use of 'tty->ldisc' without obviously
proper locking or refcounting left. I expressly did _not_ want to try to
fix it all, keeping the patch minimal. There may or may not be bugs in
that kind of code, but they wouldn't be _new_ bugs.
That said, even if the bugs aren't new, the timing and lifetime will
change. For example, some silly code may depend on the 'tty->ldisc'
pointer not changing because they hold a refcount on the 'ldisc'. And
that's no longer true - if you hold a ref on the ldisc, the 'ldisc'
itself is safe, but tty->ldisc may change.
So the proper locking (remains) to hold tty->ldisc_mutex if you expect
tty->ldisc to be stable. That's not really a _new_ rule, but it's an
example of something that the old code might have unintentionally
depended on and hidden bugs.
Whatever. The patch _looks_ sensible to me. The only users of
ldisc->users are:
- get_ldisc() - atomically increment the count
- put_ldisc() - atomically decrements the count and releases if zero
- tty_ldisc_try_get() - creates the ldisc, and sets the count to 1.
The ldisc should then either be released, or be attached to a tty.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This is pure preparation of changing the ldisc reference counting to be
a true refcount that defines the lifetime of the ldisc. But this is a
purely syntactic change for now to make the next steps easier.
This patch should make no semantic changes at all. But I wanted to make
the ldisc refcount be an atomic (I will be touching it without locks
soon enough), and I wanted to rename it so that there isn't quite as
much confusion between 'ldo->refcount' (ldisk operations refcount) and
'ld->refcount' (ldisc refcount itself) in the same file.
So it's now an atomic 'ld->users' count. It still starts at zero,
despite having a reference from 'tty->ldisc', but that will change once
we turn it into a _real_ refcount.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Tested-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Tested-by: Sergey Senozhatsky <sergey.senozhatsky@mail.by>
Acked-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Make Block Layer SG support v4 the default, since recent udev versions
depend on this to access serial numbers and other low level info properly.
This should be backported to older kernels as well, since most distros have
enabled this for a long time.
Signed-off-by: John Stoffel <john@stoffel.org>
Cc: stable@kernel.org
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
This patch fixes the napi list handling when an ehea interface is shut
down to avoid corruption of the napi list.
Signed-off-by: Hannes Hering <hering2@de.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The VF driver was not correctly recognizing that it did not correctly set
it's mac address. As a result the VF driver was unable to receive network
traffic until being unloaded and reloaded. The issue was root caused to
the fact that the CTS bit was not taken into account when checking for the
request being NAKed.
Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The suspend code runs with interrupts disabled, and the powerpc workaround we
do in the cpufreq suspend hook calls the drivers ->get method.
powernow-k8's ->get does an smp_call_function_single
which needs interrupts enabled
cpufreq's suspend/resume code was added in 42d4dc3f4e to work around
a hardware problem on ppc powerbooks. If we make all this code
conditional on powerpc, we avoid the issue above.
Signed-off-by: Dave Jones <davej@redhat.com>
The first offline/online cycle is successful, the second not.
Doing:
echo 0 >cpu1/online
echo 1 >cpu1/online
echo 0 >cpu1/online
The last command will trigger:
Jul 22 14:39:50 linux kernel: [ 593.210125] ------------[ cut here ]------------
Jul 22 14:39:50 linux kernel: [ 593.210139] WARNING: at lib/kref.c:43 kref_get+0x23/0x2b()
Jul 22 14:39:50 linux kernel: [ 593.210144] Hardware name: To Be Filled By O.E.M.
Jul 22 14:39:50 linux kernel: [ 593.210148] Modules linked in: powernow_k8
Jul 22 14:39:50 linux kernel: [ 593.210158] Pid: 378, comm: kondemand/2 Tainted: G W 2.6.31-rc2 #38
Jul 22 14:39:50 linux kernel: [ 593.210163] Call Trace:
Jul 22 14:39:50 linux kernel: [ 593.210171] [<ffffffff812008e8>] ? kref_get+0x23/0x2b
Jul 22 14:39:50 linux kernel: [ 593.210181] [<ffffffff81041926>] warn_slowpath_common+0x77/0xa4
Jul 22 14:39:50 linux kernel: [ 593.210190] [<ffffffff81041962>] warn_slowpath_null+0xf/0x11
Jul 22 14:39:50 linux kernel: [ 593.210198] [<ffffffff812008e8>] kref_get+0x23/0x2b
Jul 22 14:39:50 linux kernel: [ 593.210206] [<ffffffff811ffa19>] kobject_get+0x1a/0x22
Jul 22 14:39:50 linux kernel: [ 593.210214] [<ffffffff813e815d>] cpufreq_cpu_get+0x8a/0xcb
Jul 22 14:39:50 linux kernel: [ 593.210222] [<ffffffff813e87d1>] __cpufreq_driver_getavg+0x1d/0x67
Jul 22 14:39:50 linux kernel: [ 593.210231] [<ffffffff813ea18f>] do_dbs_timer+0x158/0x27f
Jul 22 14:39:50 linux kernel: [ 593.210240] [<ffffffff810529ea>] worker_thread+0x200/0x313
...
The output continues on every do_dbs_timer ondemand freq checking poll.
This regression was introduced by git commit:
3f4a782b5c
The policy is released when the cpufreq device is removed in:
__cpufreq_remove_dev():
/* if this isn't the CPU which is the parent of the kobj, we
* only need to unlink, put and exit
*/
Not creating the symlink is not sever at all.
As long as:
sysfs_remove_link(&sys_dev->kobj, "cpufreq");
handles it gracefully that the symlink did not exist.
Possibly no error should be returned at all, because ondemand
governor would still provide the same functionality.
Userspace in userspace gov case might be confused if the link
is missing.
Resolves http://bugzilla.kernel.org/show_bug.cgi?id=13903
CC: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
CC: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
Suspend/Resume fails on multi socket, multi core systems because the cpufreq
code erroneously sets the per_cpu policy_cpu value when a logical cpu is
offline.
This most notably results in missing sysfs files that are used to set the
cpu frequencies of the various cpus.
Signed-off-by: Prarit Bhargava <prarit@redhat.com>
Signed-off-by: Dave Jones <davej@redhat.com>
Commit ee88415caf
introduced this regression when it removed enable bit in cpu_dbs_info_s.
That added a possibility of dbs_cpufreq_notifier getting called for a
CPU that is not yet managed by conservative governor. That will happen
as the transition notifier is set as soon as one CPU switches to
conservative governor and other CPUs can get a NULL pointer dereference
without the enable bit check. Add the enable bit back again.
Reported-by: Lermytte Christophe <Christophe.Lermytte@thomson.net>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Dave Jones <davej@redhat.com>
The TWL4030 IRQ handler has a bug which leads to spinlock lock-up. It is
calling the 'unmask' function in a process context. :The mask/unmask/ack
functions are only designed to be called from the IRQ handler code,
or the proper API interfaces found in linux/interrupt.h.
Also there is no need to have IRQ chaining mechanism. The right way to
handle this is to claim the parent interrupt as a standard interrupt
and arrange for handle_twl4030_pih to take care of the rest of the devices.
Mail thread on this issue can be found at:
http://marc.info/?l=linux-arm-kernel&m=124629940123396&w=2
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Tested-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
If user has already enabled profiling support in the kernel
(for oprofile, old-style profiling of ftrace) then offer up
perfcounters with a y default in interactive kconfig sessions.
Still keep it off by default otherwise.
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The following fix was initially inspired by David Howells fix
few days back:
http://lkml.org/lkml/2009/7/9/109
However, Ingo disapproves such fixes as it's dangerous (it can
hide future, relevant warnings) - in something as
performance-uncritical.
So, initialize 'err' to '0' to work around a GCC false positive
warning:
http://lkml.org/lkml/2009/7/18/89
Signed-off-by: Subrata Modak<subrata@linux.vnet.ibm.com>
Cc: Sachin P Sant <sachinp@linux.vnet.ibm.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Balbir Singh <balbir@linux.vnet.ibm.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
LKML-Reference: <20090721023226.31855.67236.sendpatchset@subratamodak.linux.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
In uv_setup_irq(), the call to create_irq() initially assigns
IRQ vectors to cpu 0. The subsequent call to
assign_irq_vector() in arch_enable_uv_irq() migrates the IRQ to
another cpu and frees the cpu 0 vector - at least it will be
freed as soon as the "IRQ move" completes.
arch_enable_uv_irq() needs to send a cleanup IPI to complete
the IRQ move. Otherwise, assignment of GRU interrupts on large
systems (>200 cpus) will exhaust the cpu 0 interrupt vectors
and initialization of the GRU driver will fail.
Signed-off-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20090720142840.GA8885@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
With VMALLOC_END included in the calculation of MAXMEM (as of
2.6.28) it is no longer correct to also bump __VMALLOC_RESERVE
in reserve_top_address(). Doing so results in needlessly small
lowmem.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
LKML-Reference: <4A71DD2A020000780000D482@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Change SGI UV default apicid mode to "physical". This is
required to match settings in the UV hub chip.
Signed-off-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20090727143856.GA8905@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The UV chipset automatically supplies the upper bits on nodes
being referenced by MMR accesses. These bit can be deleted from
the hub addressing macros.
Signed-off-by: Jack Steiner <steiner@sgi.com>
LKML-Reference: <20090727143808.GA8076@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The UV BIOS has added additional MMR ranges that are mapped via
EFI virtual mode mappings. These ranges should be deleted from
ranges mapped by uv_system_init().
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
LKML-Reference: <20090727143656.GA7698@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
UV blades may not have any blade-local memory. Add a field
(nid) to the UV blade structure to indicates whether the node
has local memory. This is needed by the GRU driver (pushed
separately).
Signed-off-by: Jack Steiner <steiner@sgi.com>
Cc: linux-mm@kvack.org
LKML-Reference: <20090727143507.GA7006@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Check whether index is within bounds before testing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: a.p.zijlstra@chello.nl
Cc: Andrew Morton <akpm@linux-foundation.org>
LKML-Reference: <4A757BCF.40101@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Prevent calling do_nanosleep() with clockid
CLOCK_MONOTONIC_RAW, it may cause oops, such as NULL pointer
dereference.
Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: <stable@kernel.org>
LKML-Reference: <4A764FF3.50607@ct.jp.nec.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Fix the following build failure with gcc 3.2:
CC [M] drivers/net/3c59x.o
drivers/net/3c59x.c:2726:1: directives may not be used inside a macro argument
drivers/net/3c59x.c:2725:59: unterminated argument list invoking macro "pr_err"
drivers/net/3c59x.c: In function `dump_tx_ring':
drivers/net/3c59x.c:2727: implicit declaration of function `pr_err'
drivers/net/3c59x.c:2731: syntax error before ')' token
Apparently gcc 3.2 doesn't like #if interleaved with a macro call.
Signed-off-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Check whether index is within bounds before grabbing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Check whether index is within bounds before grabbing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
If there are multiple simultaneous waiters for the same buffer object,
a temporary reference to its sync object may be leaked.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
On some architectures the comparison may cause a compilation failure.
Original partial fix Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Pekka Paalanen <pq@iki.fi>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This was caught by Weiss. Also added some comments to the
fb_changed and mode_changed variables to explain what they do.
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Tested-by: Thomas White <taw@bitwiz.org.uk>
Signed-off-by: Dave Airlie <airlied@redhat.com>
Match the logic to the comments in the debug message
Signed-off-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This patch supersedes my previous patch "sky2: Avoid transmitting
during sky2_restart".
I have reworked the patch to avoid crashes during both sky2_restart()
and sky2_set_ringparam().
Without this patch, the sky2 driver can be crashed by doing:
# pktgen eth1 & (transmit many packets on eth1)
# ethtool -G eth1 tx 510
I am aware you object to storing extra state, but I can't see a way
around this. Without remembering that we're restarting,
netif_wake_queue() is called in the ISR from sky2_tx_complete(), and
netif_tx_lock() is used in sky2_tx_done(). If anybody can see a way
around this, please let me know.
Signed-off-by: Mike McCormack <mikem@ring3k.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
From Gabe Black in bugzilla 13888:
native_save_fl is implemented as follows:
11static inline unsigned long native_save_fl(void)
12{
13 unsigned long flags;
14
15 asm volatile("# __raw_save_flags\n\t"
16 "pushf ; pop %0"
17 : "=g" (flags)
18 : /* no input */
19 : "memory");
20
21 return flags;
22}
If gcc chooses to put flags on the stack, for instance because this is
inlined into a larger function with more register pressure, the offset
of the flags variable from the stack pointer will change when the
pushf is performed. gcc doesn't attempt to understand that fact, and
address used for pop will still be the same. It will write to
somewhere near flags on the stack but not actually into it and
overwrite some other value.
I saw this happen in the ide_device_add_all function when running in a
simulator I work on. I'm assuming that some quirk of how the simulated
hardware is set up caused the code path this is on to be executed when
it normally wouldn't.
A simple fix might be to change "=g" to "=r".
Reported-by: Gabe Black <spamforgabe@umich.edu>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Cc: Stable Team <stable@kernel.org>
Make rdmsr_on_cpus/wrmsr_on_cpus execute on the current CPU only if it
is in the supplied bitmask.
Signed-off-by: Borislav Petkov <borislav.petkov@amd.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Older versions of binutils did not accept the naked "ASSERT" syntax;
it is considered an expression whose value needs to be assigned to
something.
Reported-tested-and-fixed-by: Jean Delvare <khali@linux-fr.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Check whether index is within bounds before testing the element.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Since forceuid is the default, we now need to show when it's disabled.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
The latest Apple MacBook (MacBook5,2) doesn't reboot successfully
under Linux; neither the EFI reboot method nor the default method
using the keyboard controller works (the system just hangs and doesn't
reset). However, the method using the "PCI reset register" at 0xcf9
does work.
This adds a quirk to detect this machine via DMI and force the
reboot_type to BOOT_CF9. With this it reboots successfully without
requiring a command-line option. Note that the EFI code forces
reboot_type to BOOT_EFI when the machine is booted via EFI, but this
overrides that since the core_initcall runs after the EFI
initialization code.
Signed-off-by: Paul Mackerras <paulus@samba.org>
LKML-Reference: <19062.56420.501516.316181@cargo.ozlabs.ibm.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Do all key clearing except sending sommands to device when rfkill
enabled. When rfkill enabled the interface is brought down and will
be brought back up correctly after rfkill is enabled again.
Same change is not needed for iwl3945 as it ignores return code when
sending key clearing command to device.
This fixes http://bugzilla.kernel.org/show_bug.cgi?id=13742
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Tested-by: Frans Pop <elendil@planet.nl>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Check whether index is within bounds before testing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Error handling code following a kzalloc should free the allocated data.
The semantic match that finds the problem is as follows:
(http://www.emn.fr/x-info/coccinelle/)
// <smpl>
@r exists@
local idexpression x;
statement S;
expression E;
identifier f,f1,l;
position p1,p2;
expression *ptr != NULL;
@@
x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...);
...
if (x == NULL) S
<... when != x
when != if (...) { <+...x...+> }
(
x->f1 = E
|
(x->f1 == NULL || ...)
|
f(...,x->f1,...)
)
...>
(
return \(0\|<+...x...+>\|ptr\);
|
return@p2 ...;
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
