Thomas Gleixner [Mon, 23 Jun 2008 09:21:58 +0000 (11:21 +0200)]
futexes: fix fault handling in futex_lock_pi
This patch addresses a very sporadic pi-futex related failure in
highly threaded java apps on large SMP systems.
David Holmes reported that the pi_state consistency check in
lookup_pi_state triggered with his test application. This means that
the kernel internal pi_state and the user space futex variable are out
of sync. First we assumed that this is a user space data corruption,
but deeper investigation revieled that the problem happend because the
pi-futex code is not handling a fault in the futex_lock_pi path when
the user space variable needs to be fixed up.
The fault happens when a fork mapped the anon memory which contains
the futex readonly for COW or the page got swapped out exactly between
the unlock of the futex and the return of either the new futex owner
or the task which was the expected owner but failed to acquire the
kernel internal rtmutex. The current futex_lock_pi() code drops out
with an inconsistent in case it faults and returns -EFAULT to user
space. User space has no way to fixup that state.
When we wrote this code we thought that we could not drop the hash
bucket lock at this point to handle the fault.
After analysing the code again it turned out to be wrong because there
are only two tasks involved which might modify the pi_state and the
user space variable:
- the task which acquired the rtmutex
- the pending owner of the pi_state which did not get the rtmutex
Both tasks drop into the fixup_pi_state() function before returning to
user space. The first task which acquired the hash bucket lock faults
in the fixup of the user space variable, drops the spinlock and calls
futex_handle_fault() to fault in the page. Now the second task could
acquire the hash bucket lock and tries to fixup the user space
variable as well. It either faults as well or it succeeds because the
first task already faulted the page in.
One caveat is to avoid a double fixup. After returning from the fault
handling we reacquire the hash bucket lock and check whether the
pi_state owner has been modified already.
Reported-by: David Holmes <david.holmes@sun.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: David Holmes <david.holmes@sun.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
kernel/futex.c | 93 ++++++++++++++++++++++++++++++++++++++++++++-------------
1 file changed, 73 insertions(+), 20 deletions(-)
The zonelist patches caused the loop that checks for available
objects in permitted zones to not terminate immediately. One object
per zone per allocation may be allocated and then abandoned.
Break the loop when we have successfully allocated one object.
Signed-off-by: Christoph Lameter <clameter@sgi.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
netns: Don't receive new packets in a dead network namespace.
sctp: Make sure N * sizeof(union sctp_addr) does not overflow.
pppoe: warning fix
ipv6: Drop packets for loopback address from outside of the box.
ipv6: Remove options header when setsockopt's optlen is 0
mac80211: detect driver tx bugs
Receiving packets while we are cleaning up a network namespace is a
racy proposition. It is possible when the packet arrives that we have
removed some but not all of the state we need to fully process it. We
have the choice of either playing wack-a-mole with the cleanup routines
or simply dropping packets when we don't have a network namespace to
handle them.
Since the check looks inexpensive in netif_receive_skb let's just
drop the incoming packets.
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Fix warning:
drivers/net/pppoe.c: In function 'pppoe_recvmsg':
drivers/net/pppoe.c:945: warning: comparison of distinct pointer types lacks a cast
because skb->len is unsigned int and total_len is size_t
Signed-off-by: Stephen Hemminger <shemminger@vyatta.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Ivan Kokshaysky [Fri, 20 Jun 2008 23:28:54 +0000 (03:28 +0400)]
alpha: resurrect Cypress IDE quirk
Which was removed in the hope that generic legacy IDE quirk in
drivers/pci/probe.c is sufficient for Cypress IDE.
It isn't, as this controller has non-standard BAR layout:
secondary channel registers are in the BAR0-1 of the second
PCI function - not in the BAR2-3 of the same function, as the
generic quirk routine assumes.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ivan Kokshaysky [Fri, 20 Jun 2008 23:28:31 +0000 (03:28 +0400)]
alpha: fix compile failures with gcc-4.3 (bug #10438)
Vast majority of these build failures are gcc-4.3 warnings
about static functions and objects being referenced from
non-static (read: "extern inline") functions, in conjunction
with our -Werror.
We cannot just convert "extern inline" to "static inline",
as people keep suggesting all the time, because "extern inline"
logic is crucial for generic kernel build.
So
- just make sure that all callees of critical "extern inline"
functions are also "extern inline";
- use "static inline", wherever it's possible.
traps.c: work around gcc-4.3 being too smart about array
bounds-checking.
TODO: add "gnu_inline" attribute to all our "extern inline"
functions to ensure desired behaviour with future compilers.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ivan Kokshaysky [Fri, 20 Jun 2008 23:26:21 +0000 (03:26 +0400)]
alpha: link failure fix
With built-in scsi disk driver, the final link fails with a following
error:
`.exit.text' referenced in section `.rodata' of drivers/built-in.o:
defined in discarded section `.exit.text' of drivers/built-in.o
This happens with -Os (CONFIG_CC_OPTIMIZE_FOR_SIZE=y) with all gcc-4
versions, and also with -O2 and gcc-4.3.
The problem is in sd.c:sd_major() being inlined into __exit function
exit_sd(), and the compiler generating a jump table in .rodata section
for the 'switch' statement in sd_major(). So we have references to
discarded section.
Fixed with a big hammer in the form of -fno-jump-tables.
Note that jump tables vs. discarded sections is a generic problem,
other architectures are just lucky not to suffer from it. But with
a slightly more complex switch/case statement it can be reproduced
on x86 as well. So maybe at some point we should consider
-fno-jump-tables as a generic compile option...
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Ivan Kokshaysky [Fri, 20 Jun 2008 23:25:39 +0000 (03:25 +0400)]
alpha: fix module load failures on smp (bug #10926)
To calculate addresses of locally defined variables, GCC uses 32-bit
displacement from the GP. Which doesn't work for per cpu variables in
modules, as an offset to the kernel per cpu area is way above 4G.
The workaround is to force allocation of a GOT entry for per cpu variable
using ldq instruction with a 'literal' relocation.
I had to use custom asm/percpu.h, as a required argument magic doesn't
work with asm-generic/percpu.h macros.
Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/bart/ide-2.6:
BAST: Remove old IDE driver
pcmcia ide kingston compactflash's have a new manufacturer id
pcmcia: add another pata/ide ID
pcmcia: add an pata/ide ID
ide: increase timeout in wait_drive_not_busy()
palm_bk3710: fix resource management
Linus Torvalds [Fri, 20 Jun 2008 19:41:10 +0000 (12:41 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6:
ieee1394: Kconfig menu touch-up
firewire: Kconfig menu touch-up
firewire: deadline for PHY config transmission
firewire: fw-ohci: unify printk prefixes
firewire: fill_bus_reset_event needs lock protection
firewire: fw-ohci: write selfIDBufferPtr before LinkControl.rcvSelfID
firewire: fw-ohci: disable PHY packet reception into AR context
firewire: fw-ohci: use of uninitialized data in AR handler
firewire: don't panic on invalid AR request buffer
Linus Torvalds [Fri, 20 Jun 2008 19:39:12 +0000 (12:39 -0700)]
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux-acpi-2.6:
ACPI: no AC status notification
ACPI Exception (video-1721): UNKNOWN_STATUS_CODE, Cant attach device
Linus Torvalds [Fri, 20 Jun 2008 19:38:18 +0000 (12:38 -0700)]
Merge branch 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6
* 'drm-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6: (21 commits)
drm: only trust core drm ioctls - driver ioctls are a mess.
drm/i915: add support for Intel series 4 chipsets.
drm/radeon: add hier-z registers for r300 and r500 chipsets
drm/radeon: use DSTCACHE_CTLSTAT rather than RB2D_DSTCACHE_CTLSTAT
drm/radeon: switch IGP gart to use radeon_write_agp_base()
drm/radeon: Restore sw interrupt on resume
drm/r500: add support for AGP based cards.
drm/radeon: fix texture uploads with large 3d textures (bug 13980)
drm/radeon: add initial r500 support.
drm/radeon: init pipe setup in kernel code.
drm/radeon: fixup radeon_do_engine_reset
drm/radeon: fix pixcache and purge/cache flushing registers
drm/radeon: write AGP_BASE_2 on chips that support it.
drm/radeon: merge IGP chip setup and fixup RS400 vs RS480 support
drm/radeon: IGP clean up register and magic numbers.
drm/rs690: set base 2 to 0.
drm/rs690: set all of gart base address.
radeon: add production microcode from AMD
drm: pcigart use proper pci map interfaces.
drm: the sg alloc ioctl should write back the handle to userspace
...
Linus Torvalds [Fri, 20 Jun 2008 19:37:55 +0000 (12:37 -0700)]
Merge branch 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6
* 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
[agp]: fixup chipset flush for new Intel G4x.
agp: brown paper bag patch - put back the two lines it took out.
Linus Torvalds [Fri, 20 Jun 2008 19:37:13 +0000 (12:37 -0700)]
Merge branch 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
softlockup: fix NMI hangs due to lock race - 2.6.26-rc regression
rcupreempt: remove export of rcu_batches_completed_bh
cpuset: limit the input of cpuset.sched_relax_domain_level
Linus Torvalds [Fri, 20 Jun 2008 19:36:55 +0000 (12:36 -0700)]
Merge branch 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue
sched: CPU hotplug events must not destroy scheduler domains created by the cpusets
sched: rt-group: fix RR buglet
sched: rt-group: heirarchy aware throttle
sched: rt-group: fix hierarchy
sched: NULL pointer dereference while setting sched_rt_period_us
sched: fix defined-but-unused warning
Linus Torvalds [Fri, 20 Jun 2008 19:36:38 +0000 (12:36 -0700)]
Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86, geode: add a VSA2 ID for General Software
x86: use BOOTMEM_EXCLUSIVE on 32-bit
x86, 32-bit: fix boot failure on TSC-less processors
x86: fix NULL pointer deref in __switch_to
x86: set PAE PHYSICAL_MASK_SHIFT to 44 bits.
Linus Torvalds [Fri, 20 Jun 2008 19:34:43 +0000 (12:34 -0700)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/cooloney/blackfin-2.6:
Blackfin Serial Driver: Use timer to poll CTS PIN instead of workqueue.
Blackfin arch: fix typo error in bf548 serial header file
Linus Torvalds [Fri, 20 Jun 2008 19:31:03 +0000 (12:31 -0700)]
Merge branch 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jgarzik/libata-dev:
ahci: sis can't do PMP
ata_piix: add TECRA M4 to broken suspend list
LIBATA: Add HAVE_PATA_PLATFORM to select PATA_PLATFORM driver
sata_mv: warn on PIO with multiple DRQs
sata_mv: enable async_notify for 60x1 Rev.C0 and higher
libata: don't check whether to use DMA or not for no data commands
ahci: jmb361 has only one port
Linus Torvalds [Fri, 20 Jun 2008 19:19:28 +0000 (12:19 -0700)]
[watchdog] hpwdt: fix use of inline assembly
The inline assembly in drivers/watchdog/hpwdt.c was incredibly broken,
and included all the function prologue and epilogue stuff, even though
it was itself then inside a C function where the compiler would add its
own prologue and epilogue on top of it all.
This then just _happened_ to work if you had exactly the right compiler
version and exactly the right compiler flags, so that gcc just happened
to not create any prologue at all (the gcc-generated epilogue wouldn't
matter, since it would never be reached).
But the more proper way to fix it is to simply not do this. Move the
inline asm to the top level, with no surrounding function at all (the
better alternative would be to remove the prologue and make it actually
use proper description of the arguments to the inline asm, but that's a
bigger change than the one I'm willing to make right now).
pcmcia ide kingston compactflash's have a new manufacturer id
Up to now, Kingston compactflash cards (ab)used the Toshiba Manufacturer's ID,
In their new CF cards, they use a new one. Let's the ide subsystem
recognize CF cards with the new id.
Signed-off-by: Christophe Niclaes <cniclaes@develtech.com> Acked-by: Philippe De Muyter <phdm@macqel.be> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Some ATAPI devices take longer than the current max timeout value to
become ready (i.e. TEAC DV-W28ECW takes 6 ms) so increase the timeout
value to 10 ms.
This fixes kernel.org bugzilla bug #10887:
http://bugzilla.kernel.org/show_bug.cgi?id=10887
Sergei Shtylyov [Fri, 20 Jun 2008 18:53:32 +0000 (20:53 +0200)]
palm_bk3710: fix resource management
The driver expected a *virtual* address in the IDE platform device's memory
resource and didn't request the memory region for the register block. Fix this
taking into account the fact that DaVinci SoC devices are fixed-mapped to the
virtual memory early and we can get their virtual addresses using IO_ADDRESS()
macro, not having to call ioremap()...
While at it, also do some cosmetic changes...
Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Linus Torvalds [Fri, 20 Jun 2008 18:18:25 +0000 (11:18 -0700)]
Reinstate ZERO_PAGE optimization in 'get_user_pages()' and fix XIP
KAMEZAWA Hiroyuki and Oleg Nesterov point out that since the commit 557ed1fa2620dc119adb86b34c614e152a629a80 ("remove ZERO_PAGE") removed
the ZERO_PAGE from the VM mappings, any users of get_user_pages() will
generally now populate the VM with real empty pages needlessly.
We used to get the ZERO_PAGE when we did the "handle_mm_fault()", but
since fault handling no longer uses ZERO_PAGE for new anonymous pages,
we now need to handle that special case in follow_page() instead.
In particular, the removal of ZERO_PAGE effectively removed the core
file writing optimization where we would skip writing pages that had not
been populated at all, and increased memory pressure a lot by allocating
all those useless newly zeroed pages.
This reinstates the optimization by making the unmapped PTE case the
same as for a non-existent page table, which already did this correctly.
While at it, this also fixes the XIP case for follow_page(), where the
caller could not differentiate between the case of a page that simply
could not be used (because it had no "struct page" associated with it)
and a page that just wasn't mapped.
We do that by simply returning an error pointer for pages that could not
be turned into a "struct page *". The error is arbitrarily picked to be
EFAULT, since that was what get_user_pages() already used for the
equivalent IO-mapped page case.
[ Also removed an impossible test for pte_offset_map_lock() failing:
that's not how that function works ]
Frederic Bohe [Fri, 20 Jun 2008 15:48:48 +0000 (11:48 -0400)]
Ext4: Fix online resize block group descriptor corruption
This is the patch for the group descriptor table corruption during
online resize pointed out by Theodore Tso. The problem was caused by
the fact that the ext4 group descriptor can be either 32 or 64 bytes
long. Only the 64 bytes structure was taken into account.
ipv6: Drop packets for loopback address from outside of the box.
[ Based upon original report and patch by Karsten Keil. Karsten
has verified that this fixes the TAHI test case "ICMPv6 test
v6LC.5.1.2 Part F". -DaveM ]
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Shan Wei [Thu, 19 Jun 2008 23:29:39 +0000 (16:29 -0700)]
ipv6: Remove options header when setsockopt's optlen is 0
Remove the sticky Hop-by-Hop options header by calling setsockopt()
for IPV6_HOPOPTS with a zero option length, per RFC3542.
Routing header and Destination options header does the same as
Hop-by-Hop options header.
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Acked-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Jordan Crouse [Wed, 18 Jun 2008 17:34:38 +0000 (11:34 -0600)]
x86, geode: add a VSA2 ID for General Software
General Software writes their own VSA2 module for their version
of the Geode BIOS, which returns a different ID then the standard
VSA2. This was causing the framebuffer driver to break for most
GSW boards.
Bharath Ravi [Mon, 16 Jun 2008 09:41:01 +0000 (15:11 +0530)]
sched, delay accounting: fix incorrect delay time when constantly waiting on runqueue
This patch corrects the incorrect value of per process run-queue wait
time reported by delay statistics. The anomaly was due to the following
reason. When a process leaves the CPU and immediately starts waiting for
CPU on the runqueue (which means it remains in the TASK_RUNNABLE state),
the time of re-entry into the run-queue is never recorded. Due to this,
the waiting time on the runqueue from this point of re-entry upto the
next time it hits the CPU is not accounted for. This is solved by
recording the time of re-entry of a process leaving the CPU in the
sched_info_depart() function IF the process will go back to waiting on
the run-queue. This IF condition is verified by checking whether the
process is still in the TASK_RUNNABLE state.
The patch was tested on 2.6.26-rc6 using two simple CPU hog programs.
The values noted prior to the fix did not account for the time spent on
the runqueue waiting. After the fix, the correct values were reported
back to user space.
Signed-off-by: Bharath Ravi <bharathravi1@gmail.com> Signed-off-by: Madhava K R <madhavakr@gmail.com> Cc: dhaval@linux.vnet.ibm.com Cc: vatsa@in.ibm.com Cc: balbir@in.ibm.com Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
David Brownell [Sun, 4 May 2008 02:19:16 +0000 (19:19 -0700)]
hwmon: (lm75) sensor reading bugfix
LM75 sensor reading bugfix: never save error status as valid
sensor output. This could be improved, but at least this
prevents certain rude failure modes.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Hans de Goede [Fri, 23 May 2008 14:10:41 +0000 (16:10 +0200)]
hwmon: (abituguru3) update driver detection
It has been reported that the abituguru3 driver fails to load after a BIOS
update. This patch fixes this by loosening the detection routine so that it
will work after the BIOS update too. To compensate for the now very loose
detection an additional check is added on the DMI Base Board vendor string to
make sure we only load on Abit motherboards, this is the same as the check in
the abituguru (1 / 2) driver.
Signed-of-by: Hans de Goede <j.w.r.degoede@hhs.nl> Signed-off-by: Alistair John Strachan <alistair@devzero.co.uk> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Hans de Goede [Tue, 26 Feb 2008 18:34:48 +0000 (19:34 +0100)]
hwmon: (abituguru3) Identify Abit AW8D board as such
This patch identifies the Abit AW8D board as such, and adds support for its
aux5 fan connector
Signed-off-by: Hans de Goede <j.w.r.degoede@hhs.nl> Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Jean Delvare [Sat, 23 Feb 2008 09:57:53 +0000 (10:57 +0100)]
hwmon: Update the sysfs interface documentation
* Document the characteristics of libsensors 3.0.0 and 3.0.1.
* The sysfs interface is no longer subject to changes.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Juerg Haefliger <juergh at gmail.com> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Jean Delvare [Sat, 26 Apr 2008 14:34:26 +0000 (16:34 +0200)]
hwmon: (adt7473) Initialize max_duty_at_overheat before use
data->max_duty_at_overheat is not updated in adt7473_update_device,
so it might be used before it is initialized (if the user reads from
sysfs file max_duty_at_crit before writing to it.)
Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Darrick J. Wong <djwong@us.ibm.com> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
Jean Delvare [Thu, 3 Apr 2008 08:40:39 +0000 (10:40 +0200)]
hwmon: (lm85) Fix function RANGE_TO_REG()
Function RANGE_TO_REG() is broken. For a requested range of 2000 (2
degrees C), it will return an index value of 15, i.e. 80.0 degrees C,
instead of the expected index value of 0. All other values are handled
properly, just 2000 isn't.
The bug was introduced back in November 2004 by this patch:
http://git.kernel.org/?p=linux/kernel/git/tglx/history.git;a=commit;h=1c28d80f1992240373099d863e4996cdd5d646d0
While this can be fixed easily with the current code, I'd rather
rewrite the whole function in a way which is more obviously correct.
Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Justin Thiessen <jthiessen@penguincomputing.com> Signed-off-by: Mark M. Hoffman <mhoffman@lightlink.com>
x86, 32-bit: fix boot failure on TSC-less processors
Booting 2.6.26-rc6 on my 486 DX/4 fails with a "BUG: Int 6"
(invalid opcode) and a kernel halt immediately after the
kernel has been uncompressed. The BUG shows EIP pointing
to an rdtsc instruction in native_read_tsc(), invoked from
native_sched_clock().
(This error occurs so early that not even the serial console
can capture it.)
>x86: distangle user disabled TSC from unstable
>
>tsc_enabled is set to 0 from the command line switch "notsc" and from
>the mark_tsc_unstable code. Seperate those functionalities and replace
>tsc_enable with tsc_disable. This makes also the native_sched_clock()
>decision when to use TSC understandable.
>
>Preparatory patch to solve the sched_clock() issue on 32 bit.
>
>Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
The core reason for this bug is that native_sched_clock() gets
called before tsc_init().
Before the commit above, tsc_32.c used a "tsc_enabled" variable
which defaulted to 0 == disabled, and which only got enabled late
in tsc_init(). Thus early calls to native_sched_clock() would skip
the TSC and use jiffies instead.
After the commit above, tsc_32.c uses a "tsc_disabled" variable
which defaults to 0, meaning that the TSC is Ok to use. Early calls
to native_sched_clock() now erroneously try to use the TSC on
!cpu_has_tsc processors, leading to invalid opcode exceptions.
My proposed fix is to initialise tsc_disabled to a "soft disabled"
state distinct from the hard disabled state set up by the "notsc"
kernel option. This fixes the native_sched_clock() problem. It also
allows tsc_init() to be simplified: instead of setting tsc_disabled = 1
on every error return, we just set tsc_disabled = 0 once when all
checks have succeeded.
I've verified that this lets my 486 boot again. I've also verified
that a Core2 machine still uses the TSC as clocksource after the patch.
Signed-off-by: Mikael Pettersson <mikpe@it.uu.se> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Suresh Siddha [Fri, 13 Jun 2008 22:47:12 +0000 (15:47 -0700)]
x86: fix NULL pointer deref in __switch_to
Patrick McHardy reported a crash:
> > I get this oops once a day, its apparently triggered by something
> > run by cron, but the process is a different one each time.
> >
> > Kernel is -git from yesterday shortly before the -rc6 release
> > (last commit is the usb-2.6 merge, the x86 patches are missing),
> > .config is attached.
> >
> > I'll retry with current -git, but the patches that have gone in
> > since I last updated don't look related.
> >
> > [62060.043009] BUG: unable to handle kernel NULL pointer dereference at
> > 000001ff
> > [62060.043009] IP: [<c0102a9b>] __switch_to+0x2f/0x118
> > [62060.043009] *pde = 00000000
> > [62060.043009] Oops: 0002 [#1] PREEMPT
Vegard Nossum analyzed it:
> This decodes to
>
> 0: 0f ae 00 fxsave (%eax)
>
> so it's related to the floating-point context. This is the exact
> location of the crash:
>
> $ addr2line -e arch/x86/kernel/process_32.o -i ab0
> include/asm/i387.h:232
> include/asm/i387.h:262
> arch/x86/kernel/process_32.c:595
>
> ...so it looks like prev_task->thread.xstate->fxsave has become NULL.
> Or maybe it never had any other value.
Somehow (as described below) TS_USEDFPU is set but the fpu is not
allocated or freed.
Another possible FPU pre-emption issue with the sleazy FPU optimization
which was benign before but not so anymore, with the dynamic FPU allocation
patch.
New task is getting exec'd and it is prempted at the below point.
Now when it context switches in again, as the used_math() is still set
and fpu_counter can be > 5, we will do a math_state_restore() which sets
the task's TS_USEDFPU. After it continues from the above preemption point
it does clear_used_math() and much later free_thread_xstate().
Now, at the next context switch, it is quite possible that xstate is
null, used_math() is not set and TS_USEDFPU is still set. This will
trigger unlazy_fpu() causing kernel oops.
Fix this by clearing tsk's fpu_counter before clearing task's fpu.
When a 64-bit x86 processor runs in 32-bit PAE mode, a pte can
potentially have the same number of physical address bits as the
64-bit host ("Enhanced Legacy PAE Paging"). This means, in theory,
we could have up to 52 bits of physical address in a pte.
The 32-bit kernel uses a 32-bit unsigned long to represent a pfn.
This means that it can only represent physical addresses up to 32+12=44
bits wide. Rather than widening pfns everywhere, just set 2^44 as the
Linux x86_32-PAE architectural limit for physical address size.
This is a bugfix for two cases:
1. running a 32-bit PAE kernel on a machine with
more than 64GB RAM.
2. running a 32-bit PAE Xen guest on a host machine with
more than 64GB RAM
In both cases, a pte could need to have more than 36 bits of physical,
and masking it to 36-bits will cause fairly severe havoc.
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com> Cc: Jan Beulich <jbeulich@novell.com> Cc: <stable@kernel.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Jason Wessel [Tue, 27 May 2008 17:23:29 +0000 (12:23 -0500)]
softlockup: fix NMI hangs due to lock race - 2.6.26-rc regression
The touch_nmi_watchdog() routine on x86 ultimately calls
touch_softlockup_watchdog(). The problem is that to touch the
softlockup watchdog, the cpu_clock code has to be called which could
involve multiple cpu locks and can lead to a hard hang if one of the
locks is held by a processor that is not going to return anytime soon
(such as could be the case with kgdb or perhaps even with some other
kind of exception).
This patch causes the public version of the
touch_softlockup_watchdog() to defer the cpu clock access to a later
point.
The test case for this problem is to use the following kernel config
options:
It should be noted that kgdb test suite and these options were not
available until 2.6.26-rc2, so it was necessary to patch the kgdb
test suite during the bisection.
I would consider this patch a regression fix because the problem first
appeared in commit 27ec4407790d075c325e1f4da0a19c56953cce23 when some
logic was added to try to periodically sync the clocks. It was
possible to work around this particular problem by simply not
performing the sync anytime the system was in a critical context.
This was ok until commit 3e51f33fcc7f55e6df25d15b55ed10c8b4da84cd,
which added config option CONFIG_HAVE_UNSTABLE_SCHED_CLOCK and some
multi-cpu locks to sync the clocks. It became clear that accessing
this code from an nmi was the source of the lockups. Avoiding the
access to the low level clock code from an code inside the NMI
processing also fixed the problem with the 27ec44... commit.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Steven Rostedt [Thu, 22 May 2008 18:18:17 +0000 (14:18 -0400)]
rcupreempt: remove export of rcu_batches_completed_bh
In rcupreempt, rcu_batches_completed_bh is defined as a static inline in
the header file. This does not need to be exported, and not only that,
this breaks my PPC build.
Signed-off-by: Steven Rostedt <srostedt@redhat.com> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: paulus@samba.org Cc: linuxppc-dev@ozlabs.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Li Zefan [Tue, 13 May 2008 02:27:17 +0000 (10:27 +0800)]
cpuset: limit the input of cpuset.sched_relax_domain_level
We allow the inputs to be [-1 ... SD_LV_MAX), and return -EINVAL
for inputs outside this range.
Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Paul Menage <menage@google.com> Acked-by: Paul Jackson <pj@sgi.com> Acked-by: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Max Krasnyansky [Thu, 29 May 2008 18:17:01 +0000 (11:17 -0700)]
sched: CPU hotplug events must not destroy scheduler domains created by the cpusets
First issue is not related to the cpusets. We're simply leaking doms_cur.
It's allocated in arch_init_sched_domains() which is called for every
hotplug event. So we just keep reallocation doms_cur without freeing it.
I introduced free_sched_domains() function that cleans things up.
Second issue is that sched domains created by the cpusets are
completely destroyed by the CPU hotplug events. For all CPU hotplug
events scheduler attaches all CPUs to the NULL domain and then puts
them all into the single domain thereby destroying domains created
by the cpusets (partition_sched_domains).
The solution is simple, when cpusets are enabled scheduler should not
create default domain and instead let cpusets do that. Which is
exactly what the patch does.
Signed-off-by: Max Krasnyansky <maxk@qualcomm.com> Cc: pj@sgi.com Cc: menage@google.com Cc: rostedt@goodmis.org Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Peter Zijlstra [Thu, 19 Jun 2008 07:06:59 +0000 (09:06 +0200)]
sched: rt-group: fix RR buglet
In tick_task_rt() we first call update_curr_rt() which can dequeue a runqueue
due to it running out of runtime, and then we try to requeue it, of it also
having exhausted its RR quota. Obviously requeueing something that is no longer
on the runqueue will not have the expected result.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Daniel K. <dk@uw.no> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Peter Zijlstra [Thu, 19 Jun 2008 07:06:57 +0000 (09:06 +0200)]
sched: rt-group: heirarchy aware throttle
The bandwidth throttle code dequeues a group when it runs out of quota, and
re-queues it once the period rolls over and the quota gets refreshed.
Sadly it failed to take the hierarchy into consideration. Share more of the
enqueue/dequeue code with regular task opterations.
Also, some operations like sched_setscheduler() can dequeue/enqueue tasks that
are in throttled runqueues, we should not inadvertly re-enqueue empty runqueues
so check for that.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Tested-by: Daniel K. <dk@uw.no> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Linus Torvalds [Thu, 19 Jun 2008 04:52:35 +0000 (21:52 -0700)]
Merge branch 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6
* 'agp-patches' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/agp-2.6:
agp/intel: cleanup some serious whitespace badness
[AGP] intel_agp: Add support for Intel 4 series chipsets
[AGP] intel_agp: extra stolen mem size available for IGD_GM chipset
agp: more boolean conversions.
drivers/char/agp - use bool
agp: two-stage page destruction issue
agp/via: fixup pci ids
drm/radeon: fix texture uploads with large 3d textures (bug 13980)
Texture uploads could hit the blitter coordinate limit, adjust the texture
offset when uploading the pieces. Make sure to check the end address of the
upload too.
Ben Dooks [Mon, 16 Jun 2008 11:16:26 +0000 (12:16 +0100)]
LIBATA: Add HAVE_PATA_PLATFORM to select PATA_PLATFORM driver
Add HAVE_PATA_PLATFORM to select the pata platform driver
to ensure that we do not end up with a long 'depends on' list
when other users of this driver turn up.
Signed-off-by: Ben Dooks <ben-linux@fluff.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Mark Lord [Wed, 18 Jun 2008 16:13:02 +0000 (12:13 -0400)]
sata_mv: warn on PIO with multiple DRQs
Chip errata sometimes prevents reliable use of PIO commands which involve
more than a single DRQ (data request). In normal operation, libata should
not generate such PIO commands (uses DMA instead), but they could be sent
in via SG_IO from userspace.
A full workaround might be to break up such commands into sequences
of single DRQ ones, but that's just way too complex for something
that doesn't normally happen in real life.
So, allow the attempt (it often works, despite the errata),
but log the event for reference when somebody screams.
Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Tejun Heo [Tue, 17 Jun 2008 03:36:26 +0000 (12:36 +0900)]
libata: don't check whether to use DMA or not for no data commands
There's no reason to check whether to use DMA or not for no data
commands. Don't do it. While at it, make local variable using_pio in
atapi_xlat() set iff ATAPI_PROT_PIO is going to be used and rename
ata_check_atapi_dma() to atapi_check_dma() for consistency.
Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
Jan Beulich [Wed, 18 Jun 2008 08:28:00 +0000 (09:28 +0100)]
agp: two-stage page destruction issue
besides it apparently being useful only in 2.6.24 (the changes in 2.6.25
really mean that it could be converted back to a single-stage mechanism),
I'm seeing an issue in Xen Dom0 kernels, which is caused by the calling
of gart_to_virt() in the second stage invocations of the destroy function.
I think that besides this being a real issue with Xen (where
unmap_page_from_agp() is not just a page table attribute change), this
also is invalid from a theoretical perspective: One should not assume that
gart_to_virt() is still valid after unmapping a page. So minimally (keeping
the 2-stage mechanism) a patch like the one below would be needed.
projects / linux-2.6 / log