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Need to provide {claim,release}_dma_lock() for this guy too.
Signed-off-by: David S. Miller <davem@davemloft.net>
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IA64 and ARM-OABI are currently using their own version of epoll compat_
code.
An architecture needs epoll_event translation if alignof(u64) in 32 bit
mode is different from alignof(u64) in 64 bit mode. If an architecture
needs epoll_event translation, it must define struct compat_epoll_event in
asm/compat.h and set CONFIG_HAVE_COMPAT_EPOLL_EVENT and use
compat_sys_epoll_ctl and compat_sys_epoll_wait.
All 64 bit architecture should use compat_sys_epoll_pwait.
[sfr: restructure and move to fs/compat.c, remove MIPS version
of compat_sys_epoll_pwait, use __put_user_unaligned]
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[BRIDGE]: adding new device to bridge should enable if up
[IPV6]: Do not set IF_READY if device is down
[IPSEC]: xfrm audit hook misplaced in pfkey_delete and xfrm_del_sa
[IPSEC]: Add xfrm policy change auditing to pfkey_spdget
[IPSEC]: xfrm_policy delete security check misplaced
[CONNECTOR]: Bugfix for cn_call_callback()
[DCCP]: Revert patch which disables bidirectional mode
[IPV6]: Handle np->opt being NULL in ipv6_getsockopt_sticky().
[UDP]: Reread uh pointer after pskb_trim
[NETFILTER]: nfnetlink_log: fix crash on bridged packet
[NETFILTER]: nfnetlink_log: zero-terminate prefix
[NETFILTER]: nf_conntrack_ipv6: fix incorrect classification of IPv6 fragments as ESTABLISHED
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Lost CONFIG_ prefix discovered by Robert P. J. Day <rpjday@mindspring.com>.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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The security hooks to check permissions to remove an xfrm_policy were
actually done after the policy was removed. Since the unlinking and
deletion are done in xfrm_policy_by* functions this moves the hooks
inside those 2 functions. There we have all the information needed to
do the security check and it can be done before the deletion. Since
auditing requires the result of that security check err has to be passed
back and forth from the xfrm_policy_by* functions.
This patch also fixes a bug where a deletion that failed the security
check could cause improper accounting on the xfrm_policy
(xfrm_get_policy didn't have a put on the exit path for the hold taken
by xfrm_policy_by*)
It also fixes the return code when no policy is found in
xfrm_add_pol_expire. In old code (at least back in the 2.6.18 days) err
wasn't used before the return when no policy is found and so the
initialization would cause err to be ENOENT. But since err has since
been used above when we don't get a policy back from the xfrm_policy_by*
function we would always return 0 instead of the intended ENOENT. Also
fixed some white space damage in the same area.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Venkat Yekkirala <vyekkirala@trustedcs.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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* 'for-linus' of git://www.atmel.no/~hskinnemoen/linux/kernel/avr32:
avr32: dma-mapping.h
[AVR32] Don't use kmap() in flush_icache_page()
[AVR32] Fix bogus ti->flags manipulation in debug handler
[AVR32] Fix typo in include/asm-avr32/Kbuild
[AVR32] show_trace: Only walk valid stack addresses
[AVR32] at32_spi_setup_slaves should be __init
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* master.kernel.org:/pub/scm/linux/kernel/git/lethal/sh-2.6:
sh: Kill off I/O cruft for R7780RP.
sh: Revert lazy dcache writeback changes.
sh: Enable SM501 support for RTS7751R2D.
sh: Use L1_CACHE_BYTES for .data.cacheline_aligned.
sysctl: Support vdso_enabled sysctl on SH.
sh: Fix kernel thread stack corruption with preempt.
doc: Add SH to vdso and earlyprintk in kernel-parameters.txt
sh: Fix sigmask trampling in signal delivery.
sh: Clear UBC when not in use.
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Added dma_sync_single_range_for_cpu/device to dma-mapping.h in asm-avr32 to
call dma_sync_single_for_cpu/device. This patch enables b44 to compile on
systems with these cpus. This patch was created with the assumption that
another method of dma_sync_single_range_for_cpu/device does not exist on these
architectures.
Signed-off by: Gary Zambrano <zambrano@broadcom.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
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It's header-y, not headers-y.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
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* master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SPARC64]: Fix floppy build failure.
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* master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6:
[DCCP]: Set RTO for newly created child socket
[DCCP]: Correctly split CCID half connections
[NET]: Fix compat_sock_common_getsockopt typo.
[NET]: Revert incorrect accept queue backlog changes.
[INET]: twcal_jiffie should be unsigned long, not int
[GIANFAR]: Fix compile error in latest git
[PPPOE]: Use ifindex instead of device pointer in key lookups.
[NETFILTER]: ip6_route_me_harder should take into account mark
[NETFILTER]: nfnetlink_log: fix reference counting
[NETFILTER]: nfnetlink_log: fix module reference counting
[NETFILTER]: nfnetlink_log: fix possible NULL pointer dereference
[NETFILTER]: nfnetlink_log: fix NULL pointer dereference
[NETFILTER]: nfnetlink_log: fix use after free
[NETFILTER]: nfnetlink_log: fix reference leak
[NETFILTER]: tcp conntrack: accept SYN|URG as valid
[NETFILTER]: nf_conntrack/nf_nat: fix incorrect config ifdefs
[NETFILTER]: conntrack: fix {nf,ip}_ct_iterate_cleanup endless loops
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* 'for-linus' of git://git390.osdl.marist.edu/pub/scm/linux-2.6:
[S390] cio: Call cancel_halt_clear even when actl == 0.
[S390] cio: Use path verification to check for path state.
[S390] cio: Fix locking when calling notify function.
[S390] Fixed handling of access register mode faults.
[S390] dasd: Use default recovery for SNSS requests
[S390] check_bugs() should be inline.
[S390] tape: Compression overwrites crypto setting
[S390] nss: disable kexec.
[S390] reipl: move dump_prefix_page out of text section.
[S390] smp: disable preemption in smp_call_function/smp_call_function_on
[S390] kprobes breaks BUG_ON
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on a constant"
This reverts commit 39d61db0edb34d60b83c5e0d62d0e906578cc707.
The commit was buggy in multiple ways:
- the conversion to ilog2() was incorrect to begin with
- it tested the wrong #defines, so on all architectures but FRV you'd
never see the bug except for constant arguments.
- the new "get_order()" macro used its arguments multiple times, and
didn't even parenthesize them properly
- despite the comments, it was not true that you could use it for
constant initializers, since not all architectures even use the
generic page.h header file.
All of the problems are individually fixable, but it all boils down to:
better just revert it, and re-do it from scratch.
Cc: David Howells <dhowells@redhat.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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For the Freescale M5282 ColdFire,
Port UA Pin Assignment Register should set to UART mode.
Patch submitted by David Wu <davidwu@arcturusnetworks.com>.
Signed-off-by: Greg Ungerer <gerg@uclinux.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] kexec: Use EFI_LOADER_DATA for ELF core header
[IA64] permon use-after-free fix
[IA64] sync compat getdents
[IA64] always build arch/ia64/lib/xor.o
[IA64] Remove stack hard limit on ia64
[IA64] point saved_max_pfn to the max_pfn of the entire system
Revert "[IA64] swiotlb abstraction (e.g. for Xen)"
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* 'upstream' of git://ftp.linux-mips.org/pub/scm/upstream-linus:
[MIPS] IP27: Build fix
[MIPS] Wire up ioprio_set and ioprio_get.
[MIPS] Fix __raw_read_trylock() to allow multiple readers
[MIPS] Export __copy_user_inatomic.
[MIPS] R2 bitops compile fix for gcc < 4.0.
[MIPS] TX39: Remove redundant tx39_blast_icache() calls
[MIPS] Cobalt: Fix early printk
[MIPS] SMTC: De-obscure Malta hooks.
[MIPS] SMTC: Add fordward declarations for mm_struct and task_struct.
[MIPS] SMTC: <asm/mips_mt.h> must include <linux/cpumask.h>
[MIPS] SMTC: <asm/smtc_ipi.h> must include <linux/spinlock.h>
[MIPS] Atlas, Malta: Fix build warning.
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* 'linus' of master.kernel.org:/pub/scm/linux/kernel/git/perex/alsa:
[ALSA] version 1.0.14rc3
[ALSA] cmipci - Allow to disable integrated FM port
[ALSA] hda-codec - Fix logic error in headphone mute for Conexant codecs
[ALSA] hda-codec - Add missing Mic Boost for AD1986A codec
[ALSA] ac97 - Add Thinkpad X31 and R40 to AD1981x blacklist
[ALSA] Add missing sysfs device assignment for ALSA PCI drivers
[ALSA] hda-codec - Define pin configs for MacBooks
[ALSA] hda-codec - Add missing Mic Boost controls for ALC262
[ALSA] soc - WM9712 PCM volume
[ALSA] soc - Fix WM9712 register cache entry
[ALSA] hda-codec - Add method for configuring Mac Pro without PCI SSID
[ALSA] hda-codec - Add LFE support on Dell M90
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git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/drzeus/mmc:
sdhci: release irq during suspend
sdhci: make isr tolerant of read errors
mmc: require explicit support for high-speed
ncpfs: make sure server connection survives a kill
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master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6
* 'upstream-linus' of master.kernel.org:/pub/scm/linux/kernel/git/jgarzik/netdev-2.6:
sis900 warning fixes
mv643xx_eth: Place explicit port number in mv643xx_eth_platform_data
pcnet32: Fix PCnet32 performance bug on non-coherent architecutres
__devinit & __devexit cleanups for de2104x driver
3c59x: Handle pci_enable_device() failure while resuming
dmfe: Fix link detection
dmfe: fix two bugs
dmfe: trivial/spelling fixes
revert "drivers/net/tulip/dmfe: support basic carrier detection"
ucc_geth: returns NETDEV_TX_BUSY when BD ring is full
ucc_geth: Fix BD processing
natsemi: netpoll fixes
bonding: Improve IGMP join processing
bonding: only receive ARPs for us
bonding: fix double dev_add_pack
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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A deadlock can occur for mixed irq and non-irq rwlock readers if a 2nd
reader attempts to take lock by looping around __raw_read_trylock().
Signed-off-by: Dave Johnson <djohnson+linux-mips@sw.starentnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
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The address where the ELF core header is stored is passed to the secondary
kernel as a kernel command line option. The memory area for this header is
also marked as a separate EFI memory descriptor on ia64.
The separate EFI memory descriptor is at the moment of the type
EFI_UNUSABLE_MEMORY. With such a type the secondary kernel skips over the
entire memory granule (config option, 16M or 64M) when detecting memory.
If we are lucky we will just lose some memory, but if we happen to have
data in the same granule (such as an initramfs image), then this data will
never get mapped and the kernel bombs out when trying to access it.
So this is an attempt to fix this by changing the EFI memory descriptor
type into EFI_LOADER_DATA. This type is the same type used for the kernel
data and for initramfs. In the secondary kernel we then handle the ELF
core header data the same way as we handle the initramfs image.
This patch contains the kernel changes to make this happen. Pretty
straightforward, we reserve the area in reserve_memory(). The address for
the area comes from the kernel command line and the size comes from the
specialized EFI parsing function vmcore_find_descriptor_size().
The kexec-tools-testing code for this can be found here:
http://lists.osdl.org/pipermail/fastboot/2007-February/005983.html
Signed-off-by: Magnus Damm <magnus@valinux.co.jp>
Cc: Simon Horman <horms@verge.net.au>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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Un-Breaks pthreads, since Oct 2003.
Signed-off-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
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This reverts commit 51099005ab8e09d68a13fea8d55bc739c1040ca6.
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This reverts two changes:
8488df894d05d6fa41c2bd298c335f944bb0e401
248f06726e866942b3d8ca8f411f9067713b7ff8
A backlog value of N really does mean allow "N + 1" connections
to queue to a listening socket. This allows one to specify
"0" as the backlog and still get 1 connection.
Noticed by Gerrit Renker and Rick Jones.
Signed-off-by: David S. Miller <davem@davemloft.net>
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server
When the last thread of nfsd exits, it shuts down all related sockets. It
currently uses svc_close_socket to do this, but that only is immediately
effective if the socket is not SK_BUSY.
If the socket is busy - i.e. if a request has arrived that has not yet been
processes - svc_close_socket is not effective and the shutdown process spins.
So create a new svc_force_close_socket which removes the SK_BUSY flag is set
and then calls svc_close_socket.
Also change some open-codes loops in svc_destroy to use
list_for_each_entry_safe.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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They don't really save that much, and aren't worth the hassle.
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Include linux/types.h here because we need a definition of __u32. This file
appears not be exported verbatim by libc, so I think this doesn't have any
userspace consequences.
Signed-off-by: Jeff Dike <jdike@linux.intel.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The description for the hrtimer_clock_base struct describes "hrtimer_base".
That should be hrtimer_clock_base.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The description for HRTIMER_CB_IRQSAFE_NO_SOFTIRQ is backwards; "NO
SOFTIRQ" sounds a whole lot like it means it must not be run in a softirq.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Prior to commit 95492e4646e5de8b43d9a7908d6177fb737b61f0 ([PATCH] x86:
rewrite SMP TSC sync code), the headers in asm-i386 did not really require
anything in include/asm-x86_64. This means that distributions such as
fedora did not include asm-x86_64 in kernel-devel headers for i386. Ingo's
commit changed that, and broke things. This is easy enough to hack around
in package builds by just including asm-x86_64 on i386, but that's kind of
annoying. If anything, x86_64 should depend upon i386, not the other way
around.
This patch changes it so that asm-x86_64/tsc.h includes asm-i386/tsc.h,
rather than vice-versa.
Signed-off-by: Andres Salomon <dilinger@debian.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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arch/i386/kernel/vmi.c: In function 'vmi_safe_halt':
arch/i386/kernel/vmi.c:262: warning: implicit declaration of function 'vmi_stop_hz_timer'
arch/i386/kernel/vmi.c:266: warning: implicit declaration of function 'vmi_account_time_restart_hz_timer'
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Signed-off-by: Jaroslav Kysela <perex@suse.cz>
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The new high-speed timings are similar to each other and the old
system, but not identical. And although things "just work" most of
the time, sometimes it does not. So we need to start marking which
hosts are known to fully comply with the new timings.
Signed-off-by: Pierre Ossman <drzeus@drzeus.cx>
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Use internal buffers instead of the ones supplied by the caller
so that a caller can be interrupted without having to abort the
entire ncp connection.
Signed-off-by: Pierre Ossman <ossman@cendio.se>
Acked-by: Petr Vandrovec <petr@vandrovec.name>
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We were using the platform_device.id field to identify which ethernet
port is used for mv643xx_eth device. This is not generally correct.
It will be incorrect, for example, if a hardware platform uses a single
port but not the first port. Here, we add an explicit port_number field
to struct mv643xx_eth_platform_data.
This makes the mv643xx_eth_platform_data structure required, but that
isn't an issue since all users currently provide it already.
Signed-off-by: Dale Farnsworth <dale@farnsworth.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
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In active-backup mode, the current bonding code duplicates IGMP
traffic to all slaves, so that switches are up to date in case of a
failover from an active to a backup interface. If bonding then fails
back to the original active interface, it is likely that the "active
slave" switch's IGMP forwarding for the port will be out of date until
some event occurs to refresh the switch (e.g., a membership query).
This patch alters the behavior of bonding to no longer flood
IGMP to all ports, and to issue IGMP JOINs to the newly active port at
the time of a failover. This insures that switches are kept up to date
for all cases.
"GOELLESCH Niels" <niels.goellesch@eurocontrol.int> originally
reported this problem, and included a patch. His original patch was
modified by Jay Vosburgh to additionally remove the existing IGMP flood
behavior, use RCU, streamline code paths, fix trailing white space, and
adjust for style.
Signed-off-by: Jay Vosburgh <fubar@us.ibm.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>
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Don't have functions in header files unless they are inline.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Reipl doesn't work on older machines were s390_reset_machine() gets
called. The reason is that the text section is read-only but the
variable dump_prefix_page is there. Since s390_reset_machine() writes
to it we get a protection exception.
Therefore move dump_prefix_page to the bss section.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
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Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Otherwise we can potentially try to dereference a NULL device
pointer in some cases.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fix {nf,ip}_ct_iterate_cleanup unconfirmed list handling:
- unconfirmed entries can not be killed manually, they are removed on
confirmation or final destruction of the conntrack entry, which means
we might iterate forever without making forward progress.
This can happen in combination with the conntrack event cache, which
holds a reference to the conntrack entry, which is only released when
the packet makes it all the way through the stack or a different
packet is handled.
- taking references to an unconfirmed entry and using it outside the
locked section doesn't work, the list entries are not refcounted and
another CPU might already be waiting to destroy the entry
What the code really wants to do is make sure the references of the hash
table to the selected conntrack entries are released, so they will be
destroyed once all references from skbs and the event cache are dropped.
Since unconfirmed entries haven't even entered the hash yet, simply mark
them as dying and skip confirmation based on that.
Reported and tested by Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Just define a local {claim,release}_dma_lock() implementation
for the floppy driver to use so we don't need to define and
export to modules the silly dma_spin_lock.
Signed-off-by: David S. Miller <davem@davemloft.net>
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there's a new NMI watchdog related problem: KVM crashes on certain
bzImages because ... we enable the NMI watchdog by default (even if the
user does not ask for it) , and no other OS on this planet does that so
KVM doesnt have emulation for that yet. So KVM injects a #GP, which
crashes the Linux guest:
general protection fault: 0000 [#1]
PREEMPT SMP
Modules linked in:
CPU: 0
EIP: 0060:[<c011a8ae>] Not tainted VLI
EFLAGS: 00000246 (2.6.20-rc5-rt0 #3)
EIP is at setup_apic_nmi_watchdog+0x26d/0x3d3
and no, i did /not/ request an nmi_watchdog on the boot command line!
Solution: turn off that darn thing! It's a debug tool, not a 'make life
harder' tool!!
with this patch the KVM guest boots up just fine.
And with this my laptop (Lenovo T60) also stopped its sporadic hard
hanging (sometimes in acpi_init(), sometimes later during bootup,
sometimes much later during actual use) as well. It hung with both
nmi_watchdog=1 and nmi_watchdog=2, so it's generally the fact of NMI
injection that is causing problems, not the NMI watchdog variant, nor
any particular bootup code.
[ NMI breaks on some systems, esp in combination with SMM -Arjan ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Doing something like this on a two cpu system
# echo 0 > /sys/devices/system/cpu/cpu0/online
# echo 1 > /sys/devices/system/cpu/cpu0/online
# echo 0 > /sys/devices/system/cpu/cpu1/online
will give me this:
=======================================================
[ INFO: possible circular locking dependency detected ]
2.6.21-rc2-g562aa1d4-dirty #7
-------------------------------------------------------
bash/1282 is trying to acquire lock:
(&cpu_base->lock_key){.+..}, at: [<000000000005f17e>] hrtimer_cpu_notify+0xc6/0x240
but task is already holding lock:
(&cpu_base->lock_key#2){.+..}, at: [<000000000005f174>] hrtimer_cpu_notify+0xbc/0x240
which lock already depends on the new lock.
This happens because we have the following code in kernel/hrtimer.c:
migrate_hrtimers(int cpu)
[...]
old_base = &per_cpu(hrtimer_bases, cpu);
new_base = &get_cpu_var(hrtimer_bases);
[...]
spin_lock(&new_base->lock);
spin_lock(&old_base->lock);
Which means the spinlocks are taken in an order which depends on which cpu
gets shut down from which other cpu. Therefore lockdep complains that there
might be an ABBA deadlock. Since migrate_hrtimers() gets only called on
cpu hotplug it's safe to assume that it isn't executed concurrently on a
The same problem exists in kernel/timer.c: migrate_timers().
As pointed out by Christian Borntraeger one possible solution to avoid
the locking order complaints would be to make sure that the locks are
always taken in the same order. E.g. by taking the lock of the cpu with
the lower number first.
To achieve this we introduce two new spinlock functions double_spin_lock
and double_spin_unlock which lock or unlock two locks in a given order.
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: John Stultz <johnstul@us.ibm.com>
Cc: Christian Borntraeger <cborntra@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: 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>
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