When I rewrote tty ldisc code to use proper reference counts (commits
65b770468e and cbe9352fa0) in order to avoid a race with hangup, the
test-program that Eric Biederman used to trigger the original problem
seems to have exposed another long-standing bug: the hangup code did the
'tty_ldisc_halt()' to stop any buffer flushing activity, but unlike the
other call sites it never actually flushed any pending work.
As a result, if you get just the right timing, the pending work may be
just about to execute (ie the timer has already triggered and thus
cancel_delayed_work() was a no-op), when we then re-initialize the ldisc
from under it.
That, in turn, results in various random problems, usually seen as a
NULL pointer dereference in run_timer_softirq() or a BUG() in
worker_thread (but it can be almost anything).
Fix it by adding the required 'flush_scheduled_work()' after doing the
tty_ldisc_halt() (this also requires us to move the ldisc halt to before
taking the ldisc mutex in order to avoid a deadlock with the workqueue
executing do_tty_hangup, which requires the mutex).
The locking should be cleaned up one day (the requirement to do this
outside the ldisc_mutex is very annoying, and weakens the lock), but
that's a larger and separate undertaking.
Reported-by: Eric W. Biederman <ebiederm@xmission.com>
Tested-by: Xiaotian Feng <xtfeng@gmail.com>
Tested-by: Yanmin Zhang <yanmin_zhang@linux.intel.com>
Tested-by: Dave Young <hidave.darkstar@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
binutils prior to 2.17 can't deal with the currently possible
situation of a new segment following the per-CPU segment, but
that new segment being empty - objcopy misplaces the .bss (and
perhaps also the .brk) sections outside of any segment.
However, the current ordering of sections really just appears
to be the effect of cumulative unrelated changes; re-ordering
things allows to easily guarantee that the segment following
the per-CPU one is non-empty, and at once eliminates the need
for the bogus data.init2 segment.
Once touching this code, also use the various data section
helper macros from include/asm-generic/vmlinux.lds.h.
-v2: fix !SMP builds.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
Cc: <sam@ravnborg.org>
LKML-Reference: <4A94085D02000078000119A5@vpn.id2.novell.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
snd_interval_list() expected a sorted list but did not document this, so
there are drivers that give it an unsorted list. To fix this, change
the algorithm to work with any list.
This fixes the "Slave PCM not usable" error with USB devices that have
multiple alternate settings with sample rates in decreasing order, such
as the Philips Askey VC010 WebCam.
http://bugzilla.kernel.org/show_bug.cgi?id=14028
Reported-and-tested-by: Andrzej <adkadk@gmail.com>
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Cc: <stable@kernel.org>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reported by Stephen Rothwell, luckily it's harmless:
net/sched/sch_api.c: In function 'qdisc_watchdog':
net/sched/sch_api.c:460: warning: initialization from incompatible pointer type
net/sched/sch_cbq.c: In function 'cbq_undelay':
net/sched/sch_cbq.c:595: warning: initialization from incompatible pointer type
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 76db6d9500 (nfs41: add session setup
to the state manager) introduces an infinite loop possibility in the NFSv4
state manager. By first checking nfs4_has_session() before clearing the
NFS4CLNT_SESSION_SETUP flag, it allows for a situation where someone sets
that flag, but it never gets cleared, and so the state manager loops.
In fact commit c3fad1b1aa (nfs41: add session
reset to state manager) causes this to happen every time we get a network
partition error.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Tested-by: Daniel J Blueman <daniel.blueman@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2:
ocfs2/dlm: Wait on lockres instead of erroring cancel requests
ocfs2: Add missing lock name
ocfs2: Don't oops in ocfs2_kill_sb on a failed mount
ocfs2: release the buffer head in ocfs2_do_truncate.
ocfs2: Handle quota file corruption more gracefully
* 'fixes' of git://git.marvell.com/orion:
[ARM] Orion NAND: Make asm volatile avoid GCC pushing ldrd out of the loop
[ARM] Kirkwood: enable eSATA on QNAP TS-219P
[ARM] Kirkwood: __init requires linux/init.h
2.6.30's commit 8a0bdec194 removed
user_shm_lock() calls in hugetlb_file_setup() but left the
user_shm_unlock call in shm_destroy().
In detail:
Assume that can_do_hugetlb_shm() returns true and hence user_shm_lock()
is not called in hugetlb_file_setup(). However, user_shm_unlock() is
called in any case in shm_destroy() and in the following
atomic_dec_and_lock(&up->__count) in free_uid() is executed and if
up->__count gets zero, also cleanup_user_struct() is scheduled.
Note that sched_destroy_user() is empty if CONFIG_USER_SCHED is not set.
However, the ref counter up->__count gets unexpectedly non-positive and
the corresponding structs are freed even though there are live
references to them, resulting in a kernel oops after a lots of
shmget(SHM_HUGETLB)/shmctl(IPC_RMID) cycles and CONFIG_USER_SCHED set.
Hugh changed Stefan's suggested patch: can_do_hugetlb_shm() at the
time of shm_destroy() may give a different answer from at the time
of hugetlb_file_setup(). And fixed newseg()'s no_id error path,
which has missed user_shm_unlock() ever since it came in 2.6.9.
Reported-by: Stefan Huber <shuber2@gmail.com>
Signed-off-by: Hugh Dickins <hugh.dickins@tiscali.co.uk>
Tested-by: Stefan Huber <shuber2@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
smc91x: let smc91x work well under netpoll
pxaficp-ir: remove incorrect net_device_ops
NET: llc, zero sockaddr_llc struct
drivers/net: fixed drivers that support netpoll use ndo_start_xmit()
netpoll: warning for ndo_start_xmit returns with interrupts enabled
net: Fix Micrel KSZ8842 Kconfig description
netfilter: xt_quota: fix wrong return value (error case)
ipv6: Fix commit 63d9950b08 (ipv6: Make v4-mapped bindings consistent with IPv4)
E100: fix interaction with swiotlb on X86.
pkt_sched: Convert CBQ to tasklet_hrtimer.
pkt_sched: Convert qdisc_watchdog to tasklet_hrtimer
rtl8187: always set MSR_LINK_ENEDCA flag with RTL8187B
ibm_newemac: emac_close() needs to call netif_carrier_off()
net: fix ks8851 build errors
net: Rename MAC platform driver for w90p910 platform
yellowfin: Fix buffer underrun after dev_alloc_skb() failure
orinoco: correct key bounds check in orinoco_hw_get_tkip_iv
mac80211: fix todo lock
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6:
ima: hashing large files bug fix
kernel_read: redefine offset type
This line looks suspicious, because if this is true, then the
'flags' parameter of function reserve_bootmem_generic() will be
unused when !CONFIG_NUMA. I don't think this is what we want.
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: akpm@linux-foundation.org
LKML-Reference: <20090821083709.5098.52505.sendpatchset@localhost.localdomain>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
GCC 4.3.3 and 4.4.1 happily moves the dword load instruction out of the
loop in orion_nand_read_buf. This patch makes the instruction volatile
to avoid the issue. I've discussed this at gcc-help, refer to the thread
at
http://gcc.gnu.org/ml/gcc-help/2009-08/msg00187.html
The early clobber is added to avoid the destination registers and the
source register overlapping.
Signed-off-by: Simon Kagstrom <simon.kagstrom@netinsight.net>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Initialize PCI/PCIe on the QNAP TS-119, TS-219 and TS-219P hardware
allowing the use of the discrete eSATA controller connected to the PCIe
bus in the TS-219P.
Signed-off-by: John Holland <john.holland@cellent-fs.de>
Tested-by: Thomas Reitmayr <treitmayr@devbase.at>
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Include linux/init.h for __init to fix this error:
CC [M] drivers/net/wireless/wl12xx/boot.o
In file included from arch/arm/mach-kirkwood/include/mach/gpio.h:13,
from arch/arm/include/asm/gpio.h:5,
from include/linux/gpio.h:7,
from drivers/net/wireless/wl12xx/boot.c:24:
arch/arm/plat-orion/include/plat/gpio.h:32: error: expected ‘=’, ‘,’, ‘;’, ‘asm’ or ‘__attribute__’ before ‘orion_gpio_init’
make[6]: *** [drivers/net/wireless/wl12xx/boot.o] Error 1
make[5]: *** [drivers/net/wireless/wl12xx] Error 2
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Signed-off-by: Nicolas Pitre <nico@marvell.com>
This patch makes the error message about changing journaling mode on remount
more descriptive. Some people are going to hit this error now due to commit
bbae8bcc49 if they configure a kernel to default
to data=writeback mode. The problem happens if they have data=ordered set for
the root filesystem in /etc/fstab but not in the kernel command line (and they
don't use initrd). Their filesystem then gets mounted as data=writeback by
kernel but then their boot fails because init scripts won't be able to remount
the filesystem rw. Better error message will hopefully make it easier for them
to find the error in their setup and bother us less with error reports :).
Signed-off-by: Jan Kara <jack@suse.cz>
The old description for this configuration option was perhaps not
completely balanced in terms of describing the tradeoffs of using a
default of data=writeback vs. data=ordered. Despite the fact that old
description very strongly recomended disabling this feature, all of
the major distributions have elected to preserve the existing 'legacy'
default, which is a strong hint that it perhaps wasn't telling the
whole story.
This revised description has been vetted by a number of ext3
developers as being better at informing the user about the tradeoffs
of enabling or disabling this configuration feature.
Cc: linux-ext4@vger.kernel.org
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Jan Kara <jack@suse.cz>
Fix a logic error in the range check of the input level control that
would prevent setting any volume less than the maximum.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
The NETPOLL requires that interrupts remain disabled in its callbacks.
Using *_irq_save()/irq_restore() to replace *_irq_disable()/irq_enable()
functions in NETPOLL's callbacks of smc91x, so that it doesn't enable
interrupts when already disabled, and kgdboe/netconsole would work
properly over smc91x.
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes broken pxaficp-ir. The problem was in incorrect
net_device_ops being specified which prevented the driver from
operating. The symptoms were:
- failing ifconfig for IrLAN, resulting in
SIOCSIFFLAGS: Cannot assign requested address
- irattach working for IrCOMM, but the port stayed disabled
Moreover this patch corrects missing sysfs device link.
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
sllc_arphrd member of sockaddr_llc might not be changed. Zero sllc
before copying to the above layer's structure.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Hashing files larger than INT_MAX causes process to loop.
Dependent on redefining kernel_read() offset type to loff_t.
(http://bugzilla.kernel.org/show_bug.cgi?id=13909)
Cc: stable@kernel.org
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
vfs_read() offset is defined as loff_t, but kernel_read()
offset is only defined as unsigned long. Redefine
kernel_read() offset as loff_t.
Cc: stable@kernel.org
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
The NETPOLL API requires that interrupts remain disabled in
netpoll_send_skb(). The use of "A functions set" in the NETPOLL API
callbacks causes the interrupts to get enabled and can lead to kernel
instability.
The solution is to use "B functions set" to prevent the irqs from
getting enabled while in netpoll_send_skb().
A functions set:
local_irq_disable()/local_irq_enable()
spin_lock_irq()/spin_unlock_irq()
spin_trylock_irq()/spin_unlock_irq()
B functions set:
local_irq_save()/local_irq_restore()
spin_lock_irqsave()/spin_unlock_irqrestore()
spin_trylock_irqsave()/spin_unlock_irqrestore()
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
WARN_ONCE for ndo_start_xmit() enable interrupts in netpoll_send_skb(),
because the NETPOLL API requires that interrupts remain disabled in
netpoll_send_skb().
Signed-off-by: Dongdong Deng <dongdong.deng@windriver.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Andreas Mohr <andi@lisas.de>
Acked-by: Richard Röjfors <richard.rojfors.ext@mocean-labs.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Success was indicated on a memory allocation failure, thereby causing
a crash due to a later NULL deref.
(Affects v2.6.30-rc1 up to here.)
Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Commit 63d9950b08
(ipv6: Make v4-mapped bindings consistent with IPv4)
changes behavior of inet6_bind() for v4-mapped addresses so it should
behave the same way as inet_bind().
During this change setting of err to -EADDRNOTAVAIL got lost:
af_inet.c:469 inet_bind()
err = -EADDRNOTAVAIL;
if (!sysctl_ip_nonlocal_bind &&
!(inet->freebind || inet->transparent) &&
addr->sin_addr.s_addr != htonl(INADDR_ANY) &&
chk_addr_ret != RTN_LOCAL &&
chk_addr_ret != RTN_MULTICAST &&
chk_addr_ret != RTN_BROADCAST)
goto out;
af_inet6.c:463 inet6_bind()
if (addr_type == IPV6_ADDR_MAPPED) {
int chk_addr_ret;
/* Binding to v4-mapped address on a v6-only socket
* makes no sense
*/
if (np->ipv6only) {
err = -EINVAL;
goto out;
}
/* Reproduce AF_INET checks to make the bindings consitant */
v4addr = addr->sin6_addr.s6_addr32[3];
chk_addr_ret = inet_addr_type(net, v4addr);
if (!sysctl_ip_nonlocal_bind &&
!(inet->freebind || inet->transparent) &&
v4addr != htonl(INADDR_ANY) &&
chk_addr_ret != RTN_LOCAL &&
chk_addr_ret != RTN_MULTICAST &&
chk_addr_ret != RTN_BROADCAST)
goto out;
} else {
Signed-off-by Bruno Prémont <bonbons@linux-vserver.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
E100 places it's RX packet descriptors inside skb->data and uses them
with bidirectional streaming DMA mapping. Data in descriptors is
accessed simultaneously by the chip (writing status and size when
a packet is received) and CPU (reading to check if the packet was
received). This isn't a valid usage of PCI DMA API, which requires use
of the coherent (consistent) memory for such purpose. Unfortunately e100
chips working in "simplified" RX mode have to store received data
directly after the descriptor. Fixing the driver to conform to the API
would require using unsupported "flexible" RX mode or receiving data
into a coherent memory and using CPU to copy it to network buffers.
This patch, while not yet making the driver conform to the PCI DMA API,
allows it to work correctly on X86 with swiotlb (while not breaking
other architectures).
Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
This code expects to run in softirq context, and bare hrtimers
run in hw IRQ context.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Modify loops in such way that the register value is checked also after
the timeout condition, just in case the heavy interrupt load etc. caused
the thread to sleep for the time period exceeding the timeout value.
While at it remove an extra ALI_STIMER read from snd_ali_stimer_ready().
Reported-by: Jack Byer <ojbyer@usa.net>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
setup_arch() unconditionally sets the preferred console to ttyS.
This breaks the use of 3270 devices as the console. Provide a new
function to set the default preferred console for s390. The preferred
console depends on the conmode parameter that is used to switch
between 3270 and 3215 terminal/console mode.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the NULL test on block is needed, it should be before the dereference of
the base field.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r@
expression E1,E2;
identifier fld;
statement S1,S2;
@@
E1 = E2->fld;
(
if (E1 == NULL) S1 else S2
|
*if (E2 == NULL) S1 else S2
)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If io_subchannel_initialize_dev fails it will release the only
reference to the ccw device therefore the caller should not
kfree this device since this is done in the release function.
Signed-off-by: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
None of this stuff should execute in hw IRQ context, therefore
use a tasklet_hrtimer so that it runs in softirq context.
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-rc-fixes-2.6:
[SCSI] mpt2sas: fix config request and diag reset deadlock
[SCSI] mpt2sas: Bump driver version 01.100.04.00
[SCSI] mpt2sas: fix oops because drv data points to NULL on resume from hibernate
[SCSI] mpt2sas: fix crash due to Watchdog is active while OS in standby mode
[SCSI] mpt2sas: fix infinite loop inside config request
[SCSI] mpt2sas: Excessive log info causes sas iounit page time out
[SCSI] mpt2sas: Raid 10 Value is showing as Raid 1E in /va/log/messages
[SCSI] mpt2sas: Expander fix oops saying "Already part of another port"
[SCSI] mpt2sas: Introduced check for enclosure_handle to avoid crash
In commit a8e7d49aa7 ("Fix race in
create_empty_buffers() vs __set_page_dirty_buffers()"), I removed a test
for a NULL page mapping unintentionally when some of the code inside
__set_page_dirty() was moved to the callers.
That removal generally didn't matter, since a filesystem would serialize
truncation (which clears the page mapping) against writing (which marks
the buffer dirty), so locking at a higher level (either per-page or an
inode at a time) should mean that the buffer page would be stable. And
indeed, nothing bad seemed to happen.
Except it turns out that apparently reiserfs does something odd when
under load and writing out the journal, and we have a number of bugzilla
entries that look similar:
http://bugzilla.kernel.org/show_bug.cgi?id=13556http://bugzilla.kernel.org/show_bug.cgi?id=13756http://bugzilla.kernel.org/show_bug.cgi?id=13876
and it looks like reiserfs depended on that check (the common theme
seems to be "data=journal", and a journal writeback during a truncate).
I suspect reiserfs should have some additional locking, but in the
meantime this should get us back to the pre-2.6.29 behavior.
Pattern-pointed-out-by: Roland Kletzing <devzero@web.de>
Cc: stable@kernel.org (2.6.29 and 2.6.30)
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Nick Piggin <npiggin@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
drm/radeon: add GET_PARAM/INFO support for Z pipes
drm/radeon/kms: add r100/r200 OQ support.
drm: Fix sysfs device confusion.
drm/radeon/kms: implement the bo busy ioctl properly.
As noted in 83d349f35e ("x86: don't send
an IPI to the empty set of CPU's"), some APIC's will be very unhappy
with an empty destination mask. That commit added a WARN_ON() for that
case, and avoided the resulting problem, but didn't fix the underlying
reason for why those empty mask cases happened.
This fixes that, by checking the result of 'cpumask_andnot()' of the
current CPU actually has any other CPU's left in the set of CPU's to be
sent a TLB flush, and not calling down to the IPI code if the mask is
empty.
The reason this started happening at all is that we started passing just
the CPU mask pointers around in commit 4595f9620 ("x86: change
flush_tlb_others to take a const struct cpumask"), and when we did that,
the cpumask was no longer thread-local.
Before that commit, flush_tlb_mm() used to create it's own copy of
'mm->cpu_vm_mask' and pass that copy down to the low-level flush
routines after having tested that it was not empty. But after changing
it to just pass down the CPU mask pointer, the lower level TLB flush
routines would now get a pointer to that 'mm->cpu_vm_mask', and that
could still change - and become empty - after the test due to other
CPU's having flushed their own TLB's.
See
http://bugzilla.kernel.org/show_bug.cgi?id=13933
for details.
Tested-by: Thomas Björnell <thomas.bjornell@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
RTL8187B always needs MSR_LINK_ENEDCA flag to be set even when it is in
no link mode, otherwise it'll not be able to associate when this flag is
not set after the change "mac80211: fix managed mode BSSID handling".
By accident, setting BSSID of AP before association makes 8187B to
successfuly associate even when ENEDCA flag isn't set, which was the
case before the mac80211 change. But now the BSSID of AP we are trying
to associate is only available after association is successful, and
any attempt to associate without the needed flag doesn't work.
Signed-off-by: Herton Ronaldo Krzesinski <herton@mandriva.com.br>
Tested-by: Larry Finger <Larry.Finger@lwfinger.net>
Acked-by: Hin-Tak Leung <htl10@users.sourceforge.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
When 'and'ing two bitmasks (where 'andnot' is a variation on it), some
cases want to know whether the result is the empty set or not. In
particular, the TLB IPI sending code wants to do cpumask operations and
determine if there are any CPU's left in the final set.
So this just makes the bitmask (and cpumask) functions return a boolean
for whether the result has any bits set.
Cc: stable@kernel.org (2.6.30, needed by TLB shootdown fix)
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The default_send_IPI_mask_logical() function uses the "flat" APIC mode
to send an IPI to a set of CPU's at once, but if that set happens to be
empty, some older local APIC's will apparently be rather unhappy. So
just warn if a caller gives us an empty mask, and ignore it.
This fixes a regression in 2.6.30.x, due to commit 4595f9620 ("x86:
change flush_tlb_others to take a const struct cpumask"), documented
here:
http://bugzilla.kernel.org/show_bug.cgi?id=13933
which causes a silent lock-up. It only seems to happen on PPro, P2, P3
and Athlon XP cores. Most developers sadly (or not so sadly, if you're
a developer..) have more modern CPU's. Also, on x86-64 we don't use the
flat APIC mode, so it would never trigger there even if the APIC didn't
like sending an empty IPI mask.
Reported-by: Pavel Vilim <wylda@volny.cz>
Reported-and-tested-by: Thomas Björnell <thomas.bjornell@gmail.com>
Reported-and-tested-by: Martin Rogge <marogge@onlinehome.de>
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
