2.6.36 introduces an API for drivers to switch the IO scheduler
instead of manually calling the elevator exit and init functions.
This API was added since q->elevator must be cleared in between
those two calls. And since we already have this functionality
directly from use by the sysfs interface to switch schedulers
online, it was prudent to reuse it internally too.
But this API needs the queue to be in a fully initialized state
before it is called, or it will attempt to unregister elevator
kobjects before they have been added. This results in an oops
like this:
BUG: unable to handle kernel NULL pointer dereference at 0000000000000051
IP: [<ffffffff8116f15e>] sysfs_create_dir+0x2e/0xc0
PGD 47ddfc067 PUD 47c6a1067 PMD 0
Oops: 0000 [#1] PREEMPT SMP
last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/0000:04:00.1/irq
CPU 2
Modules linked in: t(+) loop hid_apple usbhid ahci ehci_hcd uhci_hcd libahci usbcore nls_base igb
Pid: 7319, comm: modprobe Not tainted 2.6.36-rc6+ #132 QSSC-S4R/QSSC-S4R
RIP: 0010:[<ffffffff8116f15e>] [<ffffffff8116f15e>] sysfs_create_dir+0x2e/0xc0
RSP: 0018:ffff88027da25d08 EFLAGS: 00010246
RAX: ffff88047c68c528 RBX: 00000000fffffffe RCX: 0000000000000000
RDX: 000000000000002f RSI: 000000000000002f RDI: ffff88047e196c88
RBP: ffff88027da25d38 R08: 0000000000000000 R09: d84156c5635688c0
R10: d84156c5635688c0 R11: 0000000000000000 R12: ffff88047e196c88
R13: 0000000000000000 R14: 0000000000000000 R15: ffff88047c68c528
FS: 00007fcb0b26f6e0(0000) GS:ffff880287400000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
CR2: 0000000000000051 CR3: 000000047e76e000 CR4: 00000000000006e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process modprobe (pid: 7319, threadinfo ffff88027da24000, task ffff88027d377090)
Stack:
ffff88027da25d58 ffff88047c68c528 00000000fffffffe ffff88047e196c88
<0> ffff88047c68c528 ffff88047e05bd90 ffff88027da25d78 ffffffff8123fb77
<0> ffff88047e05bd90 0000000000000000 ffff88047e196c88 ffff88047c68c528
Call Trace:
[<ffffffff8123fb77>] kobject_add_internal+0xe7/0x1f0
[<ffffffff8123fd98>] kobject_add_varg+0x38/0x60
[<ffffffff8123feb9>] kobject_add+0x69/0x90
[<ffffffff8116efe0>] ? sysfs_remove_dir+0x20/0xa0
[<ffffffff8103d48d>] ? sub_preempt_count+0x9d/0xe0
[<ffffffff8143de20>] ? _raw_spin_unlock+0x30/0x50
[<ffffffff8116efe0>] ? sysfs_remove_dir+0x20/0xa0
[<ffffffff8116eff4>] ? sysfs_remove_dir+0x34/0xa0
[<ffffffff81224204>] elv_register_queue+0x34/0xa0
[<ffffffff81224aad>] elevator_change+0xfd/0x250
[<ffffffffa007e000>] ? t_init+0x0/0x361 [t]
[<ffffffffa007e000>] ? t_init+0x0/0x361 [t]
[<ffffffffa007e0a8>] t_init+0xa8/0x361 [t]
[<ffffffff810001de>] do_one_initcall+0x3e/0x170
[<ffffffff8108c3fd>] sys_init_module+0xbd/0x220
[<ffffffff81002f2b>] system_call_fastpath+0x16/0x1b
Code: e5 41 56 41 55 41 54 49 89 fc 53 48 83 ec 10 48 85 ff 74 52 48 8b 47 18 49 c7 c5 00 46 61 81 48 85 c0 74 04 4c 8b 68 30 45 31 f6 <41> 80 7d 51 00 74 0e 49 8b 44 24 28 4c 89 e7 ff 50 20 49 89 c6
RIP [<ffffffff8116f15e>] sysfs_create_dir+0x2e/0xc0
RSP <ffff88027da25d08>
CR2: 0000000000000051
---[ end trace a6541d3bf07945df ]---
Fix this by adding a registered bit to the elevator queue, which is
set when the sysfs kobjects have been registered.
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
* 'upstream' of git://git.linux-mips.org/pub/scm/upstream-linus:
MIPS: Octeon: Place cnmips_cu2_setup in __init memory.
MIPS: Don't place cu2 notifiers in __cpuinitdata
MIPS: Calculate VMLINUZ_LOAD_ADDRESS based on the length of vmlinux.bin
MIPS: Alchemy: Resolve prom section mismatches
MIPS: Fix syscall 64 bit number comments.
MIPS: Hookup fanotify_init, fanotify_mark, and prlimit64 syscalls.
MIPS: TX49xx: Rename ARCH_KMALLOC_MINALIGN to ARCH_DMA_MINALIGN
MIPS: N32: Fix getdents64 syscall for n32
MIPS: Remove pr_<level> uses of KERN_<level>
MIPS: PNX8550: Sort out machine halt, restart and powerdown functions.
MIPS: GIC: Remove dependencies from Malta files.
MIPS: Kconfig: Fix and clarify kconfig help text for VSMP and SMTC.
MIPS: DMA: Fix computation of DMA flags from device's coherent_dma_mask.
MIPS: Audit: Fix hang in entry.S.
MIPS: Document why RELOC_HIDE is there.
MIPS: Octeon: Determine if helper needs to be built
MIPS: Use generic atomic64 for 32-bit kernels
MIPS: RM7000: Symbol should be static
MIPS: kspd: Adjust confusing if indentation
MIPS: Fix a typo.
* 'v2.6.36-rc6-urgent-fixes' of git://xenbits.xen.org/people/sstabellini/linux-pvhvm:
xen: do not initialize PV timers on HVM if !xen_have_vector_callback
xen: do not set xenstored_ready before xenbus_probe on hvm
Since powerpc uses -Werror on arch powerpc, the build was broken like
this:
cc1: warnings being treated as errors
arch/powerpc/kernel/module.c: In function 'module_finalize':
arch/powerpc/kernel/module.c:66: error: unused variable 'err'
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
perf trace scripting: Fix extern struct definitions
perf ui hist browser: Fix segfault on 'a' for annotate
perf tools: Fix build breakage
perf, x86: Handle in flight NMIs on P4 platform
oprofile, ARM: Release resources on failure
oprofile: Add Support for Intel CPU Family 6 / Model 29
The "flags" member of "struct wait_queue_t" is used in several places in
the kernel code without beeing initialized by init_wait(). "flags" is
used in bitwise operations.
If "flags" not initialized then unexpected behaviour may take place.
Incorrect flags might used later in code.
Added initialization of "wait_queue_t.flags" with zero value into
"init_wait".
Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
[ The bit we care about does end up being initialized by both
prepare_to_wait() and add_to_wait_queue(), so this doesn't seem to
cause actual bugs, but is definitely the right thing to do -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.
However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling. That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.
Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.
So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.
Future fixups:
- move the module list handling code into kernel/module.c where it
belongs.
- get rid of 'module_bug_list' and just use the regular list of modules
(called 'modules' - imagine that) that we already create and maintain
for other reasons.
Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
if !xen_have_vector_callback do not initialize PV timer unconditionally
because we still don't know how many cpus are available and if there is
more than one we won't be able to receive the timer interrupts on
cpu > 0.
This patch fixes an hang at boot when Xen does not support vector
callbacks and the guest has multiple vcpus.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
Register_xenstore_notifier should guarantee that the caller gets
notified even if xenstore is already up.
Therefore we revert "do not notify callers from
register_xenstore_notifier" and set xenstored_read at the right time for
PV on HVM guests too.
In fact in case of PV on HVM guests xenstored is ready only after the
platform pci driver has completed the initialization, so do not set
xenstored_ready before the call to xenbus_probe().
This patch fixes a shutdown_event watcher registration bug that causes
"xm shutdown" not to work properly.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Acked-by: Jeremy Fitzhardinge <jeremy@goop.org>
* 'fix/misc' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound-2.6:
ALSA: i2c/other/ak4xx-adda: Fix a compile warning with CONFIG_PROCFS=n
ALSA: prevent heap corruption in snd_ctl_new()
* 'merge-spi' of git://git.secretlab.ca/git/linux-2.6:
of/spi: Fix OF-style driver binding of spi devices
spi: spi-gpio.c tests SPI_MASTER_NO_RX bit twice, but not SPI_MASTER_NO_TX
spi/mpc8xxx: fix buffer overrun on large transfers
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
vlan: dont drop packets from unknown vlans in promiscuous mode
Phonet: Correct header retrieval after pskb_may_pull
um: Proper Fix for f25c80a4: remove duplicate structure field initialization
ip_gre: Fix dependencies wrt. ipv6.
net-2.6: SYN retransmits: Add new parameter to retransmits_timed_out()
iwl3945: queue the right work if the scan needs to be aborted
mac80211: fix use-after-free
* 'drm-intel-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/ickle/drm-intel:
drm/i915: Rephrase pwrite bounds checking to avoid any potential overflow
drm/i915: Sanity check pread/pwrite
drm/i915: Use pipe state to tell when pipe is off
drm/i915: vblank status not valid while training display port
drivers/gpu/drm/i915/i915_gem.c: Add missing error handling code
drm/i915: Fix refleak during eviction.
drm/i915: fix GMCH power reporting
Building under memory pressure, with KSM on 2.6.36-rc5, collapsed with
an internal compiler error: typically indicating an error in swapping.
Perhaps there's a timing issue which makes it now more likely, perhaps
it's just a long time since I tried for so long: this bug goes back to
KSM swapping in 2.6.33.
Notice how reuse_swap_page() allows an exclusive page to be reused, but
only does SetPageDirty if it can delete it from swap cache right then -
if it's currently under Writeback, it has to be left in cache and we
don't SetPageDirty, but the page can be reused. Fine, the dirty bit
will get set in the pte; but notice how zap_pte_range() does not bother
to transfer pte_dirty to page_dirty when unmapping a PageAnon.
If KSM chooses to share such a page, it will look like a clean copy of
swapcache, and not be written out to swap when its memory is needed;
then stale data read back from swap when it's needed again.
We could fix this in reuse_swap_page() (or even refuse to reuse a
page under writeback), but it's more honest to fix my oversight in
KSM's write_protect_page(). Several days of testing on three machines
confirms that this fixes the issue they showed.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2.6.36-rc1 commit 21d0d443cd "rmap:
resurrect page_address_in_vma anon_vma check" was right to resurrect
that check; but now that it's comparing anon_vma->roots instead of
just anon_vmas, there's a danger of oopsing on a NULL anon_vma.
In most cases no NULL anon_vma ever gets here; but it turns out that
occasionally KSM, when enabled on a forked or forking process, will
itself call page_address_in_vma() on a "half-KSM" page left over from
an earlier failed attempt to merge - whose page_anon_vma() is NULL.
It's my bug that those should be getting here at all: I thought they
were already dealt with, this oops proves me wrong, I'll fix it in
the next release - such pages are effectively pinned until their
process exits, since rmap cannot find their ptes (though swapoff can).
For now just work around it by making page_address_in_vma() safe (and
add a comment on why that check is wanted anyway). A similar check
in __page_check_anon_rmap() is safe because do_page_add_anon_rmap()
already excluded KSM pages.
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The notifiers may be called at any time, so the notifier_block cannot
be in init memory.
Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1592/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Fix VMLINUZ_LOAD_ADDRESS calculation to be based on the length of
vmlinux.bin, the actual uncompressed kernel binary.
Previously it was based on the length of KBUILD_IMAGE (the unstripped ELF
vmlinux), which is bigger than vmlinux.bin. As a result, vmlinuz was
loaded into a memory address higher then actually needed - a problem for
small memory platforms.
Signed-off-by: Shmulik Ladkani <shmulik.ladkani@gmail.com>
To: linux-mips@linux-mips.org
Cc: alex@digriz.org.uk
Cc: manuel.lauss@googlemail.com
Cc: sam@ravnborg.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1564/
Acked-by: Wu Zhangjin <wuzhangjin@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
The function prom_init_cmdline() references the variable __initdata
arcs_cmdline.
The function prom_get_ethernet_addr() references the variable __initdata
arcs_cmdline.
Annotate prom_init_cmdline() as __init, unexport and annotate
prom_get_ethernet_addr() since it's no longer called from within
driver code.
Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/1547/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
No rubbish printks - those belong to userspace. The halt function now
actually halts the system and the poweroff function was deleted because
it didn't actually power down the system.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This only matters for ISA devices with a 24-bit DMA limit or for devices
with a 32-bit DMA limit on systems with ZONE_DMA32 enabled. The latter
currently only affects 32-bit PCI cards on Sibyte-based systems with more
than 1GB RAM installed.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
_TIF_WORK_MASK false had _TIF_SYSCALL_AUDIT set. If a thread's
_TIF_SYSCALL_AUDIT is ever set this will lead to an endless loop on the
way out from a syscall.
Currently this is only a theoretic bug as init/Kconfig doesn't allow
AUDIT_SYSCALL to be enabled for MIPS.
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This patch adds an config switch to determine if we need to build some
workaround helper files.
The staging driver octeon-ethernet references some symbols which are only
built when PCI is enabled. The new config switch enables these symbols in
bothe cases.
Signed-off-by: Andreas Bießmann <biessmann@corscience.de>
To: linux-kernel@vger.kernel.org
Cc: Andreas Bießmann <biessmann@corscience.de>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1543/
Acked-by: David Daney <ddaney@caviumnetworks.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Indent the branch of an if.
The semantic match that finds this problem is as follows:
(http://coccinelle.lip6.fr/)
// <smpl>
@r disable braces4@
position p1,p2;
statement S1,S2;
@@
(
if (...) { ... }
|
if (...) S1@p1 S2@p2
)
@script:python@
p1 << r.p1;
p2 << r.p2;
@@
if (p1[0].column == p2[0].column):
cocci.print_main("branch",p1)
cocci.print_secs("after",p2)
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
To: linux-mips@linux-mips.org
To: linux-kernel@vger.kernel.org
To: kernel-janitors@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/1539/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Both python_scripting_ops and perl_scripting_ops have two global definitions.
One in trace-event-scripting.c and one in their respective scripting-engine
modules.
The issue is that depending on the linker order one definition or the other
is chosen. One is uninitialized (bss), while the other is initialized. If
the uninitialized version is chosen, then perf does not function properly.
This patch fixes this by adding the extern prefix to the definitions in
trace-event-scripting.c.
Cc: David S. Miller <davem@davemloft.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Robert Richter <robert.richter@amd.com>
LKML-Reference: <4c97e41a.078fd80a.7a8b.3cc9@mx.google.com>
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
There a typo in util/ui/browsers/hists.c that leads to a segfault when you
press the 'a' key on a non-resolved symbol (plain hex address).
LKML-Reference: <20100923201901.GE31726@gambetta>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@xprog.eu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
The patch ecafda6 introduced a problem where all object files would be
always rebuilt, fix it by using:
http://www.gnu.org/software/make/manual/html_node/Prerequisite-Types.html
Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Bernd Petrovitsch <bernd@sysprog.at>
Signed-off-by: Kusanagi Kouichi <slash@ac.auone-net.jp>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
We currently use struct backing_dev_info for various different purposes.
Originally it was introduced to describe a backing device which includes
an unplug and congestion function and various bits of readahead information
and VM-relevant flags. We're also using for tracking dirty inodes for
writeback.
To make writeback properly find all inodes we need to only access the
per-filesystem backing_device pointed to by the superblock in ->s_bdi
inside the writeback code, and not the instances pointeded to by
inode->i_mapping->backing_dev which can be overriden by special devices
or might not be set at all by some filesystems.
Long term we should split out the writeback-relevant bits of struct
backing_device_info (which includes more than the current bdi_writeback)
and only point to it from the superblock while leaving the traditional
backing device as a separate structure that can be overriden by devices.
The one exception for now is the block device filesystem which really
wants different writeback contexts for it's different (internal) inodes
to handle the writeout more efficiently. For now we do this with
a hack in fs-writeback.c because we're so late in the cycle, but in
the future I plan to replace this with a superblock method that allows
for multiple writeback contexts per filesystem.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
fs/fuse/dev.c:1357: warning: ‘total_len’ may be used uninitialized in this
function
Initialize total_len to zero, else its value will be undefined.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Move the access control up from the fast paths, which are no longer
universally taken first, up into the caller. This then duplicates some
sanity checking along the slow paths, but is much simpler.
Tracked as CVE-2010-2962.
Reported-by: Kees Cook <kees@ubuntu.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: stable@kernel.org
