The check whether the IBSS is active and can be removed should be
performed before deinitializing the fields used for the check/search.
Otherwise, the configured BSS will not be found and removed properly.
To make it more clear for the future, rename sdata->u.ibss to the
local pointer ifibss which is used within the checks.
Dave Jones reported a bug with futex_lock_pi() that his trinity test
exposed. Sometime between queue_me() and taking the q.lock_ptr, the
lock_ptr became NULL, resulting in a crash.
While futex_wake() is careful to not call wake_futex() on futex_q's with
a pi_state or an rt_waiter (which are either waiting for a
futex_unlock_pi() or a PI futex_requeue()), futex_wake_op() and
futex_requeue() do not perform the same test.
Update futex_wake_op() and futex_requeue() to test for q.pi_state and
q.rt_waiter and abort with -EINVAL if detected. To ensure any future
breakage is caught, add a WARN() to wake_futex() if the same condition
is true.
This fix has seen 3 hours of testing with "trinity -c futex" on an
x86_64 VM with 4 CPUS.
[akpm@linux-foundation.org: tidy up the WARN()] Signed-off-by: Darren Hart <dvhart@linux.intel.com> Reported-by: Dave Jones <davej@redat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ingo Molnar <mingo@elte.hu> Cc: John Kacur <jkacur@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Request based dm attempts to re-run the request queue off the
request completion path. If used with a driver that potentially does
end_io from its request_fn, we could deadlock trying to recurse
back into request dispatch. Fix this by punting the request queue
run to kblockd.
Tested to fix a quickly reproducible deadlock in such a scenario.
On Thu, 2012-11-01 at 16:45 -0700, Michel Lespinasse wrote:
> Looking at the arch/parisc/kernel/sys_parisc.c implementation of
> get_shared_area(), I do have a concern though. The function basically
> ignores the pgoff argument, so that if one creates a shared mapping of
> pages 0-N of a file, and then a separate shared mapping of pages 1-N
> of that same file, both will have the same cache offset for their
> starting address.
>
> This looks like this would create obvious aliasing issues. Am I
> misreading this ? I can't understand how this could work good enough
> to be undetected, so there must be something I'm missing here ???
This turns out to be correct and we need to pay attention to the pgoff as
well as the address when creating the virtual address for the area.
Fortunately, the bug is rarely triggered as most applications which use pgoff
tend to use large values (git being the primary one, and it uses pgoff in
multiples of 16MB) which are larger than our cache coherency modulus, so the
problem isn't often seen in practise.
Reported-by: Michel Lespinasse <walken@google.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit 88a8516a2128 (ALSA: usbaudio: implement USB autosuspend) added
autosuspend code to all files making up the snd-usb-audio driver.
However, midi.c is part of snd-usb-lib and is also used by other
drivers, not all of which support autosuspend. Thus, calls to
usb_autopm_get_interface() could fail, and this unexpected error would
result in the MIDI output being completely unusable.
Make it work by ignoring the error that is expected with drivers that do
not support autosuspend.
Reported-by: Colin Fletcher <colin.m.fletcher@googlemail.com> Reported-by: Devin Venable <venable.devin@gmail.com> Reported-by: Dr Nick Bailey <nicholas.bailey@glasgow.ac.uk> Reported-by: Jannis Achstetter <jannis_achstetter@web.de> Reported-by: Rui Nuno Capela <rncbc@rncbc.org> Cc: Oliver Neukum <oliver@neukum.org> Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
SATA MICROCODE DOWNALOAD fails on isci driver. After receiving Register
Device to Host (FIS 0x34) frame Initiator resets phy.
In the frame handler routine response (FIS 0x34) was copied into wrong
buffer and upper layer did not receive any answer which resulted in
timeout and reset.
This patch corrects this bug.
Signed-off-by: Maciej Patelczyk <maciej.patelczyk@intel.com> Signed-off-by: Lukasz Dorau <lukasz.dorau@intel.com> Signed-off-by: James Bottomley <JBottomley@Parallels.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This is an ISY IWL 2000. Probably a clone of Belkin F7D1102 050d:1102.
Its FCC ID is the same.
Signed-off-by: Albert Pool <albertpool@solcon.nl> Acked-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In 32 bit the stack address provided by kernel_stack_pointer() may
point to an invalid range causing NULL pointer access or page faults
while in NMI (see trace below). This happens if called in softirq
context and if the stack is empty. The address at ®s->sp is then
out of range.
Fixing this by checking if regs and ®s->sp are in the same stack
context. Otherwise return the previous stack pointer stored in struct
thread_info. If that address is invalid too, return address of regs.
V2:
* add comments to kernel_stack_pointer()
* always return a valid stack address by falling back to the address
of regs
Reported-by: Yang Wei <wei.yang@windriver.com> Signed-off-by: Robert Richter <robert.richter@amd.com> Link: http://lkml.kernel.org/r/20120912135059.GZ8285@erda.amd.com Signed-off-by: H. Peter Anvin <hpa@linux.intel.com> Cc: Jun Zhang <jun.zhang@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Documentation/networking/ifenslave.c: In function ‘if_getconfig’:
Documentation/networking/ifenslave.c:508:14: warning: variable ‘mtu’ set but not used [-Wunused-but-set-variable]
Documentation/networking/ifenslave.c:508:6: warning: variable ‘metric’ set but not used [-Wunused-but-set-variable]
The purpose of this function is to simply print out the values
it probes, so...
Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix several -Wuninitialized compiler warnings by changing the
order of getting modedb in riva_update_default_var() to set
first the fallback and then the prefered timing.
Set CommandMailbox with memset before use it. Fix for:
drivers/block/DAC960.c: In function ‘DAC960_V1_EnableMemoryMailboxInterface’:
arch/x86/include/asm/io.h:61:1: warning: ‘CommandMailbox.Bytes[12]’
may be used uninitialized in this function [-Wuninitialized]
drivers/block/DAC960.c:1175:30: note: ‘CommandMailbox.Bytes[12]’
was declared here
__find_resource() incorrectly returns a resource window which overlaps
an existing allocated window. This happens when the parent's
resource-window spans 0x00000000 to 0xffffffff and is entirely allocated
to all its children resource-windows.
__find_resource() looks for gaps in resource allocation among the
children resource windows. When it encounters the last child window it
blindly tries the range next to one allocated to the last child. Since
the last child's window ends at 0xffffffff the calculation overflows,
leading the algorithm to believe that any window in the range 0x0000000
to 0xfffffff is available for allocation. This leads to a conflicting
window allocation.
Michal Ludvig reported this issue seen on his platform. The following
patch fixes the problem and has been verified by Michal. I believe this
bug has been there for ages. It got exposed by git commit 2bbc6942273b
("PCI : ability to relocate assigned pci-resources")
Signed-off-by: Ram Pai <linuxram@us.ibm.com> Tested-by: Michal Ludvig <mludvig@logix.net.nz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently pci-bridges are allocated enough resources to satisfy their immediate
requirements. Any additional resource-requests fail if additional free space,
contiguous to the one already allocated, is not available. This behavior is not
reasonable since sufficient contiguous resources, that can satisfy the request,
are available at a different location.
This patch provides the ability to expand and relocate a allocated resource.
v2: Changelog: Fixed size calculation in pci_reassign_resource()
v3: Changelog : Split this patch. The resource.c changes are already
upstream. All the pci driver changes are in here.
Signed-off-by: Ram Pai <linuxram@us.ibm.com> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org> Cc: Andrew Worsley <amworsley@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch below does what Paul McKenney suggested in the previous thread.
Signed-off-by: Dave Jones <davej@redhat.com> Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calls into reiserfs journalling code and reiserfs_get_block() need to
be protected with write lock. We remove write lock around calls to high
level quota code in the next patch so these paths would suddently become
unprotected.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Calls into highlevel quota code cannot happen under the write lock. These
calls take dqio_mutex which ranks above write lock. So drop write lock
before calling back into quota code.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In reiserfs_quota_on() we do quite some work - for example unpacking
tail of a quota file. Thus we have to hold write lock until a moment
we call back into the quota code.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When remounting reiserfs dquot_suspend() or dquot_resume() can be called.
These functions take dqonoff_mutex which ranks above write lock so we have
to drop it before calling into quota code.
Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, we will schedule session recovery and then return to the
caller of nfs4_handle_exception. This works for most cases, but causes
a hang on the following test case:
Client Server
------ ------
Open file over NFS v4.1
Write to file
Expire client
Try to lock file
The server will return NFS4ERR_BADSESSION, prompting the client to
schedule recovery. However, the client will continue placing lock
attempts and the open recovery never seems to be scheduled. The
simplest solution is to wait for session recovery to run before retrying
the lock.
The overlay on the i830M has a peculiar failure mode: It works the
first time around after boot-up, but consistenly hangs the second time
it's used.
Chris Wilson has dug out a nice errata:
"1.5.12 Clock Gating Disable for Display Register
Address Offset: 06200h–06203h
"Bit 3
Ovrunit Clock Gating Disable.
0 = Clock gating controlled by unit enabling logic
1 = Disable clock gating function
DevALM Errata ALM049: Overlay Clock Gating Must be Disabled: Overlay
& L2 Cache clock gating must be disabled in order to prevent device
hangs when turning off overlay.SW must turn off Ovrunit clock gating
(6200h) and L2 Cache clock gating (C8h)."
Now I've nowhere found that 0xc8 register and hence couldn't apply the
l2 cache workaround. But I've remembered that part of the magic that
the OVERLAY_ON/OFF commands are supposed to do is to rearrange cache
allocations so that the overlay scaler has some scratch space.
And while pondering how that could explain the hang the 2nd time we
enable the overlay, I've remembered that the old ums overlay code did
_not_ issue the OVERLAY_OFF cmd.
And indeed, disabling the OFF cmd results in the overlay working
flawlessly, so I guess we can workaround the lack of the above
workaround by simply never disabling the overlay engine once it's
enabled.
Note that we have the first part of the above w/a already implemented
in i830_init_clock_gating - leave that as-is to avoid surprises.
v2: Add a comment in the code.
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=47827 Tested-by: Rhys <rhyspuk@gmail.com> Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
[bwh: Backported to 3.2:
- Adjust context
- s/intel_ring_emit(ring, /OUT_RING(/] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mirko Lindner <mlindner@marvell.com> Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The issue occurs when eCryptfs is mounted with a cipher supported by
the crypto subsystem but not by eCryptfs. The mount succeeds and an
error does not occur until a write. This change checks for eCryptfs
cipher support at mount time.
Resolves Launchpad issue #338914, reported by Tyler Hicks in 03/2009.
https://bugs.launchpad.net/ecryptfs/+bug/338914
Signed-off-by: Tim Sally <tsally@atomicpeace.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the eCryptfs mount options do not include '-o acl', but the lower
filesystem's mount options do include 'acl', the MS_POSIXACL flag is not
flipped on in the eCryptfs super block flags. This flag is what the VFS
checks in do_last() when deciding if the current umask should be applied
to a newly created inode's mode or not. When a default POSIX ACL mask is
set on a directory, the current umask is incorrectly applied to new
inodes created in the directory. This patch ignores the MS_POSIXACL flag
passed into ecryptfs_mount() and sets the flag on the eCryptfs super
block depending on the flag's presence on the lower super block.
Additionally, it is incorrect to allow a writeable eCryptfs mount on top
of a read-only lower mount. This missing check did not allow writes to
the read-only lower mount because permissions checks are still performed
on the lower filesystem's objects but it is best to simply not allow a
rw mount on top of ro mount. However, a ro eCryptfs mount on top of a rw
mount is valid and still allowed.
The use of kfree(serial) in error cases of usb_serial_probe
was invalid - usb_serial structure allocated in create_serial()
gets reference of usb_device that needs to be put, so we need
to use usb_serial_put() instead of simple kfree().
Signed-off-by: Jan Safrata <jan.nikitenko@gmail.com> Acked-by: Johan Hovold <jhovold@gmail.com> Cc: Richard Retanubun <richardretanubun@ruggedcom.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ICMP tuples have id in src and type/code in dst.
So comparing src.u.all with dst.u.all will always fail here
and ip_xfrm_me_harder() is called for every ICMP packet,
even if there was no NAT.
The correct syntax for gcc -x is "gcc -x assembler", not
"gcc -xassembler". Even though the latter happens to work, the former
is what is documented in the manual page and thus what gcc wrappers
such as icecream do expect.
This isn't a cosmetic change. The missing space prevents icecream from
recognizing compilation tasks it can't handle, leading to silent kernel
miscompilations.
Besides me, credits go to Michael Matz and Dirk Mueller for
investigating the miscompilation issue and tracking it down to this
incorrect -x parameter syntax.
Signed-off-by: Jean Delvare <jdelvare@suse.de> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Bernhard Walle <bernhard@bwalle.de> Cc: Michal Marek <mmarek@suse.cz> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Michal Marek <mmarek@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The r8169 driver currently limits the DMA burst for TX to 1024 bytes. I have
a box where this prevents the interface from using the gigabit line to its full
potential. This patch solves the problem by setting TX_DMA_BURST to unlimited.
The box has an ASRock B75M motherboard with on-board RTL8168evl/8111evl
(XID 0c900880). TSO is enabled.
I used netperf (TCP_STREAM test) to measure the dependency of TX throughput
on MTU. I did it for three different values of TX_DMA_BURST ('5'=512, '6'=1024,
'7'=unlimited). This chart shows the results:
http://michich.fedorapeople.org/r8169/r8169-effects-of-TX_DMA_BURST.png
Interesting points:
- With the current DMA burst limit (1024):
- at the default MTU=1500 I get only 842 Mbit/s.
- when going from small MTU, the performance rises monotonically with
increasing MTU only up to a peak at MTU=1076 (908 MBit/s). Then there's
a sudden drop to 762 MBit/s from which the throughput rises monotonically
again with further MTU increases.
- With a smaller DMA burst limit (512):
- there's a similar peak at MTU=1076 and another one at MTU=564.
- With unlimited DMA burst:
- at the default MTU=1500 I get nice 940 Mbit/s.
- the throughput rises monotonically with increasing MTU with no strange
peaks.
Notice that the peaks occur at MTU sizes that are multiples of the DMA burst
limit plus 52. Why 52? Because:
20 (IP header) + 20 (TCP header) + 12 (TCP options) = 52
The Realtek-provided r8168 driver (v8.032.00) uses unlimited TX DMA burst too,
except for CFG_METHOD_1 where the TX DMA burst is set to 512 bytes.
CFG_METHOD_1 appears to be the oldest MAC version of "RTL8168B/8111B",
i.e. RTL_GIGA_MAC_VER_11 in r8169. Not sure if this MAC version really needs
the smaller burst limit, or if any other versions have similar requirements.
Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Acked-by: Francois Romieu <romieu@fr.zoreil.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In commit c445477d74ab3779 which adds aRFS to the kernel, the CPU
selected for RFS is not set correctly when CPU is changing.
This is causing OOO packets and probably other issues.
Signed-off-by: Tom Herbert <therbert@google.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Ben Hutchings <bhutchings@solarflare.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Check (ha->addr == dev->dev_addr) is always true because dev_addr_init()
sets this. Correct the check to behave properly on addr removal.
Signed-off-by: Jiri Pirko <jiri@resnulli.us> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
(1<<optname) is undefined behavior in C with a negative optname or
optname larger than 31. In those cases the result of the shift is
not necessarily zero (e.g., on x86).
This patch simplifies the code with a switch statement on optname.
It also allows the compiler to generate better code (e.g., using a
64-bit mask).
Signed-off-by: Xi Wang <xi.wang@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The sigaddset/sigdelset/sigismember functions that are implemented with
bitfield insn cannot allow the sigset argument to be placed in a data
register since the sigset is wider than 32 bits. Remove the "d"
constraint from the asm statements.
The effect of the bug is that sending RT signals does not work, the signal
number is truncated modulo 32.
When in world roaming mode, allow 40 MHz to be used
on channels 12 and 13 so that an AP that is, e.g.,
using HT40+ on channel 9 (in the UK) can be used.
Reported-by: Eddie Chapman <eddie@ehuk.net> Tested-by: Eddie Chapman <eddie@ehuk.net> Acked-by: Luis R. Rodriguez <mcgrof@qca.qualcomm.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When walking page tables we need to make sure that everything
is within bounds of the ASCE limit of the task's address space.
Otherwise we might calculate e.g. a pud pointer which is not
within a pud and dereference it.
So check against TASK_SIZE (which is the ASCE limit) before
walking page tables.
This is a bugfix for a problem with the following symptoms:
1. A power cut happens
2. After reboot, we try to mount UBIFS
3. Mount fails with "No space left on device" error message
UBIFS complains like this:
UBIFS error (pid 28225): grab_empty_leb: could not find an empty LEB
The root cause of this problem is that when we mount, not all LEBs are
categorized. Only those which were read are. However, the
'ubifs_find_free_leb_for_idx()' function assumes that all LEBs were
categorized and 'c->freeable_cnt' is valid, which is a false assumption.
This patch fixes the problem by teaching 'ubifs_find_free_leb_for_idx()'
to always fall back to LPT scanning if no freeable LEBs were found.
This problem was reported by few people in the past, but Brent Taylor
was able to reproduce it and send me a flash image which cannot be mounted,
which made it easy to hunt the bug. Kudos to Brent.
DAPM shutdown incorrectly uses "list" field of codec struct while
iterating over probed components (codec_dev_list). "list" field
refers to codecs registered in the system, "card_list" field is
used for probed components.
Signed-off-by: Misael Lopez Cruz <misael.lopez@ti.com> Signed-off-by: Liam Girdwood <lrg@ti.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When MCLK is supplied externally and BCLK and LRC are configured as outputs
(codec is master), the PLL values are only calculated correctly on the first
transmission. On subsequent transmissions, at differenct sample rates, the
wrong PLL values are used. Test for f_opclk instead of f_pllout to determine
if the PLL values are needed.
Signed-off-by: Eric Millbrandt <emillbrandt@dekaresearch.com> Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Several bug reports suggest that the forcibly resetting IEC958 status
bits is required for AD codecs to get the SPDIF output working
properly after changing streams.
cryptd_queue_worker attempts to prevent simultaneous accesses to crypto
workqueue by cryptd_enqueue_request using preempt_disable/preempt_enable.
However cryptd_enqueue_request might be called from softirq context,
so add local_bh_disable/local_bh_enable to prevent data corruption and
panics.
Bug report at http://marc.info/?l=linux-crypto-vger&m=134858649616319&w=2
v2:
- Disable software interrupts instead of hardware interrupts
Reported-by: Gurucharan Shetty <gurucharan.shetty@gmail.com> Signed-off-by: Jussi Kivilinna <jussi.kivilinna@mbnet.fi> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
but never applied it. Repeated attempts over time to actually get him
to apply it have never had a reply from anyone who has raised it
So apply it anyway
Signed-off-by: Alan Cox <alan@linux.intel.com> Reported-by: Anders Blomdell <anders.blomdell@control.lth.se> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In kswapd(), set current->reclaim_state to NULL before returning, as
current->reclaim_state holds reference to variable on kswapd()'s stack.
In rare cases, while returning from kswapd() during memory offlining,
__free_slab() and freepages() can access the dangling pointer of
current->reclaim_state.
The recent change for USB-audio disconnection race fixes introduced a
mutex deadlock again. There is a circular dependency between
chip->shutdown_rwsem and pcm->open_mutex, depicted like below, when a
device is opened during the disconnection operation:
B. snd_pcm_open() ->
pcm->open_mutex ->
snd_usb_pcm_open() ->
chip->shutdown_rwsem (read)
Since the chip->shutdown_rwsem protection in the case A is required
only for turning on the chip->shutdown flag and it doesn't have to be
taken for the whole operation, we can reduce its window in
snd_usb_audio_disconnect().
There are uncovered cases whether the card refcount introduced by the
commit a0830dbd isn't properly increased or decreased:
- OSS PCM and mixer success paths
- When lookup function gets NULL
When unbinding a device so that I could pass it through to a KVM VM, I
got the lockdep report below. It looks like a legitimate lock
ordering problem:
- domain_context_mapping_one() takes iommu->lock and calls
iommu_support_dev_iotlb(), which takes device_domain_lock (inside
iommu->lock).
- domain_remove_one_dev_info() starts by taking device_domain_lock
then takes iommu->lock inside it (near the end of the function).
So this is the classic AB-BA deadlock. It looks like a safe fix is to
simply release device_domain_lock a bit earlier, since as far as I can
tell, it doesn't protect any of the stuff accessed at the end of
domain_remove_one_dev_info() anyway.
BTW, the use of device_domain_lock looks a bit unsafe to me... it's
at least not obvious to me why we aren't vulnerable to the race below:
Commit 4439647 ("xfs: reset buffer pointers before freeing them") in
3.0-rc1 introduced a regression when recovering log buffers that
wrapped around the end of log. The second part of the log buffer at
the start of the physical log was being read into the header buffer
rather than the data buffer, and hence recovery was seeing garbage
in the data buffer when it got to the region of the log buffer that
was incorrectly read.
Reported-by: Torsten Kaiser <just.for.lkml@googlemail.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drm/i915: make sure we write all the DIP data bytes
we need to clear the entire sdvo buffer to avoid upsetting the
display.
Since infoframe buffer writing is now a bit more elaborate, extract it
into it's own function. This will be useful if we ever get around to
properly update the ELD for sdvo. Also #define proper names for the
two buffer indexes with fixed usage.
v2: Cite the right commit above, spotted by Paulo Zanoni.
v3: I'm too stupid to paste the right commit.
v4: Ben Hutchings noticed that I've failed to handle an underflow in
my loop logic, breaking it for i >= length + 8. Since I've just lost C
programmer license, use his solution. Also, make the frustrated 0-base
buffer size a notch more clear.
Reported-and-tested-by: Jürg Billeter <j@bitron.ch>
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=25732 Cc: Paulo Zanoni <przanoni@gmail.com> Cc: Ben Hutchings <ben@decadent.org.uk> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At least the worst offenders:
- SDVO specifies that the encoder should compute the ecc. Testing also
shows that we must not send the ecc field, so copy the dip_infoframe
struct to a temporay place and avoid the ecc field. This way the avi
infoframe is exactly 17 bytes long, which agrees with what the spec
mandates as a minimal storage capacity (with the ecc field it would
be 18 bytes).
- Only 17 when sending the avi infoframe. The SDVO spec explicitly
says that sending more data than what the device announces results
in undefined behaviour.
- Add __attribute__((packed)) to the avi and spd infoframes, for
otherwise they're wrongly aligned. Noticed because the avi infoframe
ended up being 18 bytes large instead of 17. We haven't noticed this
yet because we don't use the uint16_t fields yet (which are the only
ones that would be wrongly aligned).
Siddhesh analyzed a failure in the take over of pi futexes in case the
owner died and provided a workaround.
See: http://sourceware.org/bugzilla/show_bug.cgi?id=14076
The detailed problem analysis shows:
Futex F is initialized with PTHREAD_PRIO_INHERIT and
PTHREAD_MUTEX_ROBUST_NP attributes.
T1 lock_futex_pi(F);
T2 lock_futex_pi(F);
--> T2 blocks on the futex and creates pi_state which is associated
to T1.
T1 exits
--> exit_robust_list() runs
--> Futex F userspace value TID field is set to 0 and
FUTEX_OWNER_DIED bit is set.
T3 lock_futex_pi(F);
--> Succeeds due to the check for F's userspace TID field == 0
--> Claims ownership of the futex and sets its own TID into the
userspace TID field of futex F
--> returns to user space
T1 --> exit_pi_state_list()
--> Transfers pi_state to waiter T2 and wakes T2 via
rt_mutex_unlock(&pi_state->mutex)
T2 --> acquires pi_state->mutex and gains real ownership of the
pi_state
--> Claims ownership of the futex and sets its own TID into the
userspace TID field of futex F
--> returns to user space
T3 --> observes inconsistent state
This problem is independent of UP/SMP, preemptible/non preemptible
kernels, or process shared vs. private. The only difference is that
certain configurations are more likely to expose it.
So as Siddhesh correctly analyzed the following check in
futex_lock_pi_atomic() is the culprit:
if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
We check the userspace value for a TID value of 0 and take over the
futex unconditionally if that's true.
AFAICT this check is there as it is correct for a different corner
case of futexes: the WAITERS bit became stale.
Now the proposed change
- if (unlikely(ownerdied || !(curval & FUTEX_TID_MASK))) {
+ if (unlikely(ownerdied ||
+ !(curval & (FUTEX_TID_MASK | FUTEX_WAITERS)))) {
solves the problem, but it's not obvious why and it wreckages the
"stale WAITERS bit" case.
What happens is, that due to the WAITERS bit being set (T2 is blocked
on that futex) it enforces T3 to go through lookup_pi_state(), which
in the above case returns an existing pi_state and therefor forces T3
to legitimately fight with T2 over the ownership of the pi_state (via
pi_state->mutex). Probelm solved!
Though that does not work for the "WAITERS bit is stale" problem
because if lookup_pi_state() does not find existing pi_state it
returns -ERSCH (due to TID == 0) which causes futex_lock_pi() to
return -ESRCH to user space because the OWNER_DIED bit is not set.
Now there is a different solution to that problem. Do not look at the
user space value at all and enforce a lookup of possibly available
pi_state. If pi_state can be found, then the new incoming locker T3
blocks on that pi_state and legitimately races with T2 to acquire the
rt_mutex and the pi_state and therefor the proper ownership of the
user space futex.
lookup_pi_state() has the correct order of checks. It first tries to
find a pi_state associated with the user space futex and only if that
fails it checks for futex TID value = 0. If no pi_state is available
nothing can create new state at that point because this happens with
the hash bucket lock held.
So the above scenario changes to:
T1 lock_futex_pi(F);
T2 lock_futex_pi(F);
--> T2 blocks on the futex and creates pi_state which is associated
to T1.
T1 exits
--> exit_robust_list() runs
--> Futex F userspace value TID field is set to 0 and
FUTEX_OWNER_DIED bit is set.
T3 lock_futex_pi(F);
--> Finds pi_state and blocks on pi_state->rt_mutex
T1 --> exit_pi_state_list()
--> Transfers pi_state to waiter T2 and wakes it via
rt_mutex_unlock(&pi_state->mutex)
T2 --> acquires pi_state->mutex and gains ownership of the pi_state
--> Claims ownership of the futex and sets its own TID into the
userspace TID field of futex F
--> returns to user space
This covers all gazillion points on which T3 might come in between
T1's exit_robust_list() clearing the TID field and T2 fixing it up. It
also solves the "WAITERS bit stale" problem by forcing the take over.
Another benefit of changing the code this way is that it makes it less
dependent on untrusted user space values and therefor minimizes the
possible wreckage which might be inflicted.
As usual after staring for too long at the futex code my brain hurts
so much that I really want to ditch that whole optimization of
avoiding the syscall for the non contended case for PI futexes and rip
out the maze of corner case handling code. Unfortunately we can't as
user space relies on that existing behaviour, but at least thinking
about it helps me to preserve my mental sanity. Maybe we should
nevertheless :)
Reported-and-tested-by: Siddhesh Poyarekar <siddhesh.poyarekar@gmail.com> Link: http://lkml.kernel.org/r/alpine.LFD.2.02.1210232138540.2756@ionos Acked-by: Darren Hart <dvhart@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
As documented in RFC4861 (Neighbor Discovery for IP version 6) 7.2.6.,
unsolicited neighbour advertisements should be sent to the all-nodes
multicast address.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When creating an L2TPv3 Ethernet session, if register_netdev() should fail for
any reason (for example, automatic naming for "l2tpeth%d" interfaces hits the
32k-interface limit), the netdev is freed in the error path. However, the
l2tp_eth_sess structure's dev pointer is left uncleared, and this results in
l2tp_eth_delete() then attempting to unregister the same netdev later in the
session teardown. This results in an oops.
To avoid this, clear the session dev pointer in the error path.
Signed-off-by: Tom Parkin <tparkin@katalix.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reading TCP stats when using TCP Illinois congestion control algorithm
can cause a divide by zero kernel oops.
The division by zero occur in tcp_illinois_info() at:
do_div(t, ca->cnt_rtt);
where ca->cnt_rtt can become zero (when rtt_reset is called)
Steps to Reproduce:
1. Register tcp_illinois:
# sysctl -w net.ipv4.tcp_congestion_control=illinois
2. Monitor internal TCP information via command "ss -i"
# watch -d ss -i
3. Establish new TCP conn to machine
Either it fails at the initial conn, or else it needs to wait
for a loss or a reset.
This is only related to reading stats. The function avg_delay() also
performs the same divide, but is guarded with a (ca->cnt_rtt > 0) at its
calling point in update_params(). Thus, simply fix tcp_illinois_info().
Function tcp_illinois_info() / get_info() is called without
socket lock. Thus, eliminate any race condition on ca->cnt_rtt
by using a local stack variable. Simply reuse info.tcpv_rttcnt,
as its already set to ca->cnt_rtt.
Function avg_delay() is not affected by this race condition, as
its called with the socket lock.
Cc: Petr Matousek <pmatouse@redhat.com> Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Eric Dumazet <edumazet@google.com> Acked-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Driver anchors the tx urbs and defers the urb submission if
a transmit request comes when the interface is suspended.
Anchoring urb increments the urb reference count. These
deferred urbs are later accessed by calling usb_get_from_anchor()
for submission during interface resume. usb_get_from_anchor()
unanchors the urb but urb reference count remains same.
This causes the urb reference count to remain non-zero
after usb_free_urb() gets called and urb never gets freed.
Hence call usb_put_urb() after anchoring the urb to properly
balance the reference count for these deferred urbs. Also,
unanchor these deferred urbs during disconnect, to free them
up.
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Commit a02e4b7dae4551(Demark default hoplimit as zero) only changes the
hoplimit checking condition and default value in ip6_dst_hoplimit, not
zeros all hoplimit default value.
Keep the zeroing ip6_template_metrics[RTAX_HOPLIMIT - 1] to force it as
const, cause as a37e6e344910(net: force dst_default_metrics to const
section)
Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tcp_ioctl() tries to take into account if tcp socket received a FIN
to report correct number bytes in receive queue.
But its flaky because if the application ate the last skb,
we return 1 instead of 0.
Correct way to detect that FIN was received is to test SOCK_DONE.
Reported-by: Elliot Hughes <enh@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Neal Cardwell <ncardwell@google.com> Cc: Tom Herbert <therbert@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On some suspend/resume operations involving wimax device, we have
noticed some intermittent memory corruptions in netlink code.
Stéphane Marchesin tracked this corruption in netlink_update_listeners()
and suggested a patch.
It appears netlink_release() should use kfree_rcu() instead of kfree()
for the listeners structure as it may be used by other cpus using RCU
protection.
netlink_release() must set to NULL the listeners pointer when
it is about to be freed.
Also have to protect netlink_update_listeners() and
netlink_has_listeners() if listeners is NULL.
Add a nl_deref_protected() lockdep helper to properly document which
locks protects us.
Reported-by: Jonathan Kliegman <kliegs@google.com> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Stéphane Marchesin <marcheu@google.com> Cc: Sam Leffler <sleffler@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Zijie Pan <zijie.pan@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Acked-by: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When disconnect callback is called, each component should wake up
sleepers and check card->shutdown flag for avoiding the endless sleep
blocking the proper resource release.
For more strict protection for wild disconnections, a refcount is
introduced to the card instance, and let it up/down when an object is
referred via snd_lookup_*() in the open ops.
The free-after-last-close check is also changed to check this refcount
instead of the empty list, too.
Close some races at disconnection of a USB audio device by adding the
chip->shutdown_mutex and chip->shutdown check at appropriate places.
The spots to put bandaids are:
- PCM prepare, hw_params and hw_free
- where the usb device is accessed for communication or get speed, in
mixer.c and others; the device speed is now cached in subs->speed
instead of accessing to chip->dev
The accesses in PCM open and close don't need the mutex protection
because these are already handled in the core PCM disconnection code.
The autosuspend/autoresume codes are still uncovered by this patch
because of possible mutex deadlocks. They'll be covered by the
upcoming change to rwsem.
Also the mixer codes are untouched, too. These will be fixed in
another patch, too.
Fix races at PCM disconnection:
- while a PCM device is being opened or closed
- while the PCM state is being changed without lock in prepare,
hw_params, hw_free ops
Don't assume bank 0 is selected at device probe time. This may not be
the case. Force bank selection at first register access to guarantee
that we read the right registers upon driver loading.
This Oops affects 3.5 kernels and older, and is due to lookup_one_len()
calling down to the dentry revalidation code with a NULL pointer
to struct nameidata.
It is fixed upstream by commit 0b728e1911c (stop passing nameidata *
to ->d_revalidate())
The DNS resolver's use of the sunrpc cache involves a 'ttl' number
(relative) rather that a timeout (absolute). This confused me when
I wrote
commit c5b29f885afe890f953f7f23424045cdad31d3e4
"sunrpc: use seconds since boot in expiry cache"
and I managed to break it. The effect is that any TTL is interpreted
as 0, and nothing useful gets into the cache.
This patch removes the use of get_expiry() - which really expects an
expiry time - and uses get_uint() instead, treating the int correctly
as a ttl.
This fixes a regression that has been present since 2.6.37, causing
certain NFS accesses in certain environments to incorrectly fail.
Reported-by: Chuck Lever <chuck.lever@oracle.com> Tested-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since commit c7f404b ('vfs: new superblock methods to override
/proc/*/mount{s,info}'), nfs_path() is used to generate the mounted
device name reported back to userland.
nfs_path() always generates a trailing slash when the given dentry is
the root of an NFS mount, but userland may expect the original device
name to be returned verbatim (as it used to be). Make this
canonicalisation optional and change the callers accordingly.
[jrnieder@gmail.com: use flag instead of bool argument] Reported-and-tested-by: Chris Hiestand <chiestand@salk.edu>
Reference: http://bugs.debian.org/669314 Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Signed-off-by: Jonathan Nieder <jrnieder@gmail.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
In very busy v3 environment, rpc.mountd can respond to the NULL
procedure but not the MNT procedure in a timely manner causing
the MNT procedure to time out. The problem is the mount system
call returns EIO which causes the mount to fail, instead of
ETIMEDOUT, which would cause the mount to be retried.
This patch sets the RPC_TASK_SOFT|RPC_TASK_TIMEOUT flags to
the rpc_call_sync() call in nfs_mount() which causes
ETIMEDOUT to be returned on timed out connections.
Due to pskb_may_pull() checking the skb length, all
non-management frames are checked on input whether
their 802.11 header is fully present. Also add that
check for management frames and remove a check that
is now duplicate. This prevents accessing skb data
beyond the frame end.
Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Per IEEE Std. 802.11-2012, Sec 8.2.4.4.1, the sequence Control field is
not present in control frames. We noticed this problem when processing
Block Ack Requests.
Signed-off-by: Javier Cardona <javier@cozybit.com> Signed-off-by: Javier Lopez <jlopex@cozybit.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The mesh header can have address extension by a 4th
or a 5th and 6th address, but never both. Drop such
frames in 802.11 -> 802.3 conversion along with any
frames that have the wrong extension.
Reviewed-by: Javier Cardona <javier@cozybit.com> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
No driver initializes chan->max_antenna_gain to something sensible, and
the only place where it is being used right now is inside ath9k. This
leads to ath9k potentially using less tx power than it can use, which can
decrease performance/range in some rare cases.
Rather than going through every single driver, this patch initializes
chan->orig_mag in wiphy_register(), ignoring whatever value the driver
left in there. If a driver for some reason wishes to limit it independent
from regulatory rulesets, it can do so internally.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If the call to core_dev_release_virtual_lun0() fails, then nothing
sets ret to anything other than 0, so even though everything is
torn down and freed, target_core_init_configfs() will seem to succeed
and the module will be loaded. Fix this by passing the return value
on up the chain.
Signed-off-by: Roland Dreier <roland@purestorage.com> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Some hardware has correct (!= 0xff) value of tssi_bounds[4] in the
EEPROM, but step is equal to 0xff. This results on ridiculous delta
calculations and completely broke TX power settings.
Reported-and-tested-by: Pavel Lucik <pavel.lucik@gmail.com> Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Ivo van Doorn <IvDoorn@gmail.com> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
bf->bf_next is only while buffers are chained as part of an A-MPDU
in the tx queue. When a tid queue is flushed (e.g. on tearing down
an aggregation session), frames can be enqueued again as normal
transmission, without bf_next being cleared. This can lead to the
old pointer being dereferenced again later.
This patch might fix crashes and "Failed to stop TX DMA!" messages.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
On s390 any write to a page (even from kernel itself) sets architecture
specific page dirty bit. Thus when a page is written to via buffered
write, HW dirty bit gets set and when we later map and unmap the page,
page_remove_rmap() finds the dirty bit and calls set_page_dirty().
Dirtying of a page which shouldn't be dirty can cause all sorts of
problems to filesystems. The bug we observed in practice is that
buffers from the page get freed, so when the page gets later marked as
dirty and writeback writes it, XFS crashes due to an assertion
BUG_ON(!PagePrivate(page)) in page_buffers() called from
xfs_count_page_state().
Similar problem can also happen when zero_user_segment() call from
xfs_vm_writepage() (or block_write_full_page() for that matter) set the
hardware dirty bit during writeback, later buffers get freed, and then
page unmapped.
Fix the issue by ignoring s390 HW dirty bit for page cache pages of
mappings with mapping_cap_account_dirty(). This is safe because for
such mappings when a page gets marked as writeable in PTE it is also
marked dirty in do_wp_page() or do_page_fault(). When the dirty bit is
cleared by clear_page_dirty_for_io(), the page gets writeprotected in
page_mkclean(). So pagecache page is writeable if and only if it is
dirty.
Thanks to Hugh Dickins for pointing out mapping has to have
mapping_cap_account_dirty() for things to work and proposing a cleaned
up variant of the patch.
The patch has survived about two hours of running fsx-linux on tmpfs
while heavily swapping and several days of running on out build machines
where the original problem was triggered.
Signed-off-by: Jan Kara <jack@suse.cz> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Hugh Dickins <hughd@google.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The X86_32-only disable_hlt/enable_hlt mechanism was used by the
32-bit floppy driver. Its effect was to replace the use of the
HLT instruction inside default_idle() with cpu_relax() - essentially
it turned off the use of HLT.
This workaround was commented in the code as:
"disable hlt during certain critical i/o operations"
"This halt magic was a workaround for ancient floppy DMA
wreckage. It should be safe to remove."
H. Peter Anvin additionally adds:
"To the best of my knowledge, no-hlt only existed because of
flaky power distributions on 386/486 systems which were sold to
run DOS. Since DOS did no power management of any kind,
including HLT, the power draw was fairly uniform; when exposed
to the much hhigher noise levels you got when Linux used HLT
caused some of these systems to fail.
They were by far in the minority even back then."
Alan Cox further says:
"Also for the Cyrix 5510 which tended to go castors up if a HLT
occurred during a DMA cycle and on a few other boxes HLT during
DMA tended to go astray.
Do we care ? I doubt it. The 5510 was pretty obscure, the 5520
fixed it, the 5530 is probably the oldest still in any kind of
use."
So, let's finally drop this.
Signed-off-by: Len Brown <len.brown@intel.com> Signed-off-by: Josh Boyer <jwboyer@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: "H. Peter Anvin" <hpa@zytor.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Stephen Hemminger <shemminger@vyatta.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/n/tip-3rhk9bzf0x9rljkv488tloib@git.kernel.org
[ If anyone cares then alternative instruction patching could be
used to replace HLT with a one-byte NOP instruction. Much simpler. ] Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
projects / karo-tx-linux.git / log