While running 20 parallel instances of dd as follows:
#!/bin/bash
for i in `seq 1 20`; do
dd if=/dev/zero of=/export/hda3/dd_$i bs=1073741824 count=1 &
done
wait
on a 16G machine, we noticed that rather than just killing the processes,
the entire kernel went down. Stracing dd reveals that it first does an
mmap2, which makes 1GB worth of zero page mappings. Then it performs a
read on those pages from /dev/zero, and finally it performs a write.
The machine died during the reads. Looking at the code, it was noticed
that /dev/zero's read operation had been changed by
557ed1fa26 ("remove ZERO_PAGE") from giving
zero page mappings to actually zeroing the page.
The zeroing of the pages causes physical pages to be allocated to the
process. But, when the process exhausts all the memory that it can, the
kernel cannot kill it, as it is still in the kernel mode allocating more
memory. Consequently, the kernel eventually crashes.
To fix this, I propose that when a fatal signal is pending during
/dev/zero read operation, we simply return and let the user process die.
Signed-off-by: Salman Qazi <sqazi@google.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Modified error return and comment trivially. - Linus]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixed oops when calling device_unregister followed by device_register
(changing __init to __devinit) and removed request_mem_region() as
platform_device_register already does this which can result in EBUSY
Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix Kconfig to build via-rng.ko on X86_64 builds, as the VIA Nano
CPU supports x86_64, too.
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The VIA Nano CPU supports the same XSTORE instruction based RNG,
but it lacks the MSR present in earlier CPUs.
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This is a cosmetic change, fixing the MODULE_DESCRIPTION() of via-rng.c
Signed-off-by: Harald Welte <HaraldWelte@viatech.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
A pointer to omap_rng_probe is passed to the core via
platform_driver_register and so the function must not disappear when the
.init sections are discarded. Otherwise (if also having HOTPLUG=y)
unbinding and binding a device to the driver via sysfs will result in an
oops as does a device being registered late.
An alternative to this patch is using platform_driver_probe instead of
platform_driver_register plus removing the pointer to the probe function
from the struct platform_driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Cc: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: David Brownell <dbrownell@users.sourceforge.net>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jan Engelhardt <jengelh@gmx.de>
Cc: Michael Buesch <mb@bu3sch.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Do not go beyond ARRAY_SIZE of tape_device and viotape_unitinfo
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Conflicts:
arch/mips/sibyte/bcm1480/irq.c
arch/mips/sibyte/sb1250/irq.c
Merge reason: we gathered a few conflicts plus update to latest upstream fixes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Merge reason: merge almost-rc8 into perfcounters/core, which was -rc6
based - to pick up the latest upstream fixes.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Until now we have had a 1:1 mapping between storage device physical
block size and the logical block sized used when addressing the device.
With SATA 4KB drives coming out that will no longer be the case. The
sector size will be 4KB but the logical block size will remain
512-bytes. Hence we need to distinguish between the physical block size
and the logical ditto.
This patch renames hardsect_size to logical_block_size.
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
Instead of queuing IPMB messages before channel initialization, just
throw them away. Nobody will be listening for them at this point,
anyway, and they will clog up the queue and nothing will be delivered
if we queue them.
Also set the current channel to the number of channels, as this value
is used to tell if the channel information has been initialized.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Ferenc Wagner <wferi@niif.hu>
Cc: Dan Frazier <dannf@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
get_event_name uses sprintf to fill a buffer declared on the stack. It fills
the buffer 2 bytes at a time. What the code doesn't take into account is that
sprintf(buf, "%02x", data) actually writes 3 bytes. 2 bytes for the data and
then it nul terminates the string. Since we declare buf to be 40 characters
long and then we write 40 bytes of data into buf sprintf is going to write 41
characters. The fix is to leave room in buf for the nul terminator.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
Martin Knoblauch reports that trying to build 2.6.30-rc6-git3 with
RHEL4.3 userspace (gcc (GCC) 3.4.5 20051201 (Red Hat 3.4.5-2)) causes an
internal compiler error (ICE):
drivers/char/random.c: In function `get_random_int':
drivers/char/random.c:1672: error: unrecognizable insn:
(insn 202 148 150 0 /scratch/build/linux-2.6.30-rc6-git3/arch/x86/include/asm/tsc.h:23 (set (reg:SI 0 ax [91])
(subreg:SI (plus:DI (plus:DI (reg:DI 0 ax [88])
(subreg:DI (reg:SI 6 bp) 0))
(const_int -4 [0xfffffffffffffffc])) 0)) -1 (nil)
(nil))
drivers/char/random.c:1672: internal compiler error: in extract_insn, at recog.c:2083
and after some debugging it turns out that it's due to the code trying
to figure out the rough value of the current stack pointer by taking an
address of an uninitialized variable and casting that to an integer.
This is clearly a compiler bug, but it's not worth fighting - while the
current stack kernel pointer might be somewhat hard to predict in user
space, it's also not generally going to change for a lot of the call
chains for a particular process.
So just drop it, and mumble some incoherent curses at the compiler.
Tested-by: Martin Knoblauch <spamtrap@knobisoft.de>
Cc: Matt Mackall <mpm@selenic.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Commit 79e539453b introduced a
regression where you cannot use sysrq 'g' to enter kgdb. The solution
is to move the intel fb sysrq over to V for video instead of G for
graphics. The SMP VOYAGER code to register for the sysrq-v is not
anywhere to be found in the mainline kernel, so the comments in the
code were cleaned up as well.
This patch also cleans up the sysrq definitions for kgdb to make it
generic for the kernel debugger, such that the sysrq 'g' can be used
in the future to enter a gdbstub or another kernel debugger.
Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Merge reason: both topics modify the APIC code but were able to do it in
parallel so far. An upcoming patch generates a conflict so
merge them to avoid the conflict.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
It's a really simple patch that basically just open-codes the current
"secure_ip_id()" call, but when open-coding it we now use a _static_
hashing area, so that it gets updated every time.
And to make sure somebody can't just start from the same original seed of
all-zeroes, and then do the "half_md4_transform()" over and over until
they get the same sequence as the kernel has, each iteration also mixes in
the same old "current->pid + jiffies" we used - so we should now have a
regular strong pseudo-number generator, but we also have one that doesn't
have a single seed.
Note: the "pid + jiffies" is just meant to be a tiny tiny bit of noise. It
has no real meaning. It could be anything. I just picked the previous
seed, it's just that now we keep the state in between calls and that will
feed into the next result, and that should make all the difference.
I made that hash be a per-cpu data just to avoid cache-line ping-pong:
having multiple CPU's write to the same data would be fine for randomness,
and add yet another layer of chaos to it, but since get_random_int() is
supposed to be a fast interface I did it that way instead. I considered
using "__raw_get_cpu_var()" to avoid any preemption overhead while still
getting the hash be _mostly_ ping-pong free, but in the end good taste won
out.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This hw-random driver add support to RNGA hardware found
on some i.MX processors.
Signed-off-by: Alan Carvalho de Assis <acassis@gmail.com>
Acked-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
This is one area where we can't just magic away the bizarre use of
CLOCK_TICK_RATE as it leaks to user space APIs. It also means the visible
CLOCK_TICK_RATE is frozen for architectures which is horrible.
We need to fix this somehow
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We want to use dev_to_node() later on, to be aware of the 'home node'
of the GSI in question.
[ Impact: cleanup, prepare the IRQ code to be more NUMA aware ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Len Brown <lenb@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Len Brown <lenb@kernel.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-acpi@vger.kernel.org
Cc: linux-ia64@vger.kernel.org
LKML-Reference: <49F65560.20904@kernel.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
The virtio-rng drivers checks for spurious callbacks. Since
callbacks can be implemented via shared interrupts (e.g. PCI) this
could lead to guest kernel oopses with lots of virtio devices.
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Enable userspace to receive messages that a BMC transmits using an OEM
medium. This is used by the HP iLO2.
Based on code originally written by Patrick Schoeller.
Signed-off-by: dann frazier <dannf@hp.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Bela Lubkin noticed that the statistics for send IPMB and LAN commands
in the IPMI driver could be incremented even if an error occurred. Move
the increments to the proper place to avoid this.
Also add some statistics for retransmissions that failed, and some little
helper functions to neaten up the code a little.
Signed-off-by: Corey Minyard <cminyard@mvista.com>
Cc: Bela Lubkin <blubkin@vmware.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The IPMI driver would attempt to use the event buffer even if that
didn't exist on the BMC. This patch modified the IPMI driver to check
for the event buffer's existence before trying to use it.
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The wrong return value is being tested when allocating a platform device
in the IPMI SI code. Check the right value.
Signed-off-by: Corey Minyard <minyard@acm.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pass clocksource pointer to the read() callback for clocksources. This
allows us to share the callback between multiple instances.
[hugh@veritas.com: fix powerpc build of clocksource pass clocksource mods]
[akpm@linux-foundation.org: cleanup]
Signed-off-by: Magnus Damm <damm@igel.co.jp>
Acked-by: John Stultz <johnstul@us.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This warning made sense when legacy keyboard driver was preferred
driver in X, but now that evdev driver is the default we can remove
the warning.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
* 'drm-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/airlied/drm-2.6:
agp: zero pages before sending to userspace
drm: check for minor master before allowing drop master.
drm: set/clear is_master when master changed
drm: clean dirty memory after device release
drm: count reaches -1
AGP pages might be mapped into userspace finally, so the pages should be
set to zero before userspace can use it. Otherwise there is potential
information leakage.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
This reverts commit 1c55f18717.
Ingo Brueckl was assuming that reverting to 1:1 mapping for chars >= 128
was not useful, but it happens to be: due to the limitations of the
Linux console, when a blind user wants to read BIG5 on it, he has no
other way than loading a font without SFM and let the 1:1 mapping permit
the screen reader to get the BIG5 encoding.
Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
x86: fix microcode driver newly spewing warnings
x86, PAT: Remove page granularity tracking for vm_insert_pfn maps
x86: disable X86_PTRACE_BTS for now
x86, documentation: kernel-parameters replace X86-32,X86-64 with X86
x86: pci-swiotlb.c swiotlb_dma_ops should be static
x86, PAT: Remove duplicate memtype reserve in devmem mmap
x86, PAT: Consolidate code in pat_x_mtrr_type() and reserve_memtype()
x86, PAT: Changing memtype to WC ensuring no WB alias
x86, PAT: Handle faults cleanly in set_memory_ APIs
x86, PAT: Change order of cpa and free in set_memory_wb
x86, CPA: Change idmap attribute before ioremap attribute setup
Support the Intel 854 Chipset in fbdev.
We test and use the patch on a Thomson IP1101 IPTV-Box. On the VGA-Port
we get a normal signal.
Here is the link to the Mambux-Project: http://www.mambux.de
Cc: Keith Packard <keithp@keithp.com>
Cc: Dave Airlie <airlied@linux.ie>
Cc: Krzysztof Helt <krzysztof.h1@poczta.fm>
Signed-off-by: Stefan Husemann <shusemann@googlemail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
/dev/mem mmap code was doing memtype reserve/free for a while now.
Recently we added memtype tracking in remap_pfn_range, and /dev/mem mmap
uses it indirectly. So, we don't need seperate tracking in /dev/mem code
any more. That means another ~100 lines of code removed :-).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
LKML-Reference: <20090409212709.085210000@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Conflicts:
arch/powerpc/include/asm/systbl.h
arch/powerpc/include/asm/unistd.h
include/linux/init_task.h
Merge reason: the conflicts are non-trivial: PowerPC placement
of sys_perf_counter_open has to be mixed with the
new preadv/pwrite syscalls.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Not critical.
WARNING: drivers/char/esp.o(.text+0x278): Section mismatch in reference from the function show_serial_version() to the variable .init.data:serial_version
The function show_serial_version() references
the variable __initdata serial_version.
This is often because show_serial_version lacks a __initdata
annotation or the annotation of serial_version is wrong.
WARNING: drivers/char/esp.o(.text+0x27d): Section mismatch in reference from the function show_serial_version() to the variable .init.data:serial_name
The function show_serial_version() references
the variable __initdata serial_name.
This is often because show_serial_version lacks a __initdata
annotation or the annotation of serial_name is wrong.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Andrew J. Robinson <arobinso@nyx.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mxser_check_modem_status is called with tty parameter, so the
reference should be increased by callers already -- for ioctl
syscall it is held whole time gap since open to close, for
interrupt, the reference count is increased in the irq handler.
There is no tty_kref_put in that function, so this also fixes
a refcounting bug.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is missing tty_kref_put on some paths in moxa_poll_port,
although the reference is always taken. Fix it.
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Reported-by: Jan 'Yenya' Kasprzak <kas@fi.muni.cz>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The isicom driver leaks a kref on the shutdown path. Drop the additional
kref we took
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The riscom8 module is missing the char-major-48-* alias that would cause
it to be auto-loaded when a device of that type is opened. This patch
adds the alias.
Signed-off-by: Scott James Remnant <scott@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The specialix module is missing the char-major-75-* alias that would
cause it to be auto-loaded when a device of that type is opened. This
patch adds the alias.
Signed-off-by: Scott James Remnant <scott@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The cyclades module is missing the char-major-19-* alias that would
cause it to be auto-loaded when a device of that type is opened. This
patch adds the alias.
Signed-off-by: Scott James Remnant <scott@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The applicom module is missing the char-major-10-157 alias that would
cause it to be auto-loaded when a device of that type is opened. This
patch adds the alias.
Signed-off-by: Scott James Remnant <scott@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Merge reason: we have gathered quite a few conflicts, need to merge upstream
Conflicts:
arch/powerpc/kernel/Makefile
arch/x86/ia32/ia32entry.S
arch/x86/include/asm/hardirq.h
arch/x86/include/asm/unistd_32.h
arch/x86/include/asm/unistd_64.h
arch/x86/kernel/cpu/common.c
arch/x86/kernel/irq.c
arch/x86/kernel/syscall_table_32.S
arch/x86/mm/iomap_32.c
include/linux/sched.h
kernel/Makefile
Signed-off-by: Ingo Molnar <mingo@elte.hu>
* 'tracing-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (413 commits)
tracing, net: fix net tree and tracing tree merge interaction
tracing, powerpc: fix powerpc tree and tracing tree interaction
ring-buffer: do not remove reader page from list on ring buffer free
function-graph: allow unregistering twice
trace: make argument 'mem' of trace_seq_putmem() const
tracing: add missing 'extern' keywords to trace_output.h
tracing: provide trace_seq_reserve()
blktrace: print out BLK_TN_MESSAGE properly
blktrace: extract duplidate code
blktrace: fix memory leak when freeing struct blk_io_trace
blktrace: fix blk_probes_ref chaos
blktrace: make classic output more classic
blktrace: fix off-by-one bug
blktrace: fix the original blktrace
blktrace: fix a race when creating blk_tree_root in debugfs
blktrace: fix timestamp in binary output
tracing, Text Edit Lock: cleanup
tracing: filter fix for TRACE_EVENT_FORMAT events
ftrace: Using FTRACE_WARN_ON() to check "freed record" in ftrace_release()
x86: kretprobe-booster interrupt emulation code fix
...
Fix up trivial conflicts in
arch/parisc/include/asm/ftrace.h
include/linux/memory.h
kernel/extable.c
kernel/module.c
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (28 commits)
trivial: Update my email address
trivial: NULL noise: drivers/mtd/tests/mtd_*test.c
trivial: NULL noise: drivers/media/dvb/frontends/drx397xD_fw.h
trivial: Fix misspelling of "Celsius".
trivial: remove unused variable 'path' in alloc_file()
trivial: fix a pdlfush -> pdflush typo in comment
trivial: jbd header comment typo fix for JBD_PARANOID_IOFAIL
trivial: wusb: Storage class should be before const qualifier
trivial: drivers/char/bsr.c: Storage class should be before const qualifier
trivial: h8300: Storage class should be before const qualifier
trivial: fix where cgroup documentation is not correctly referred to
trivial: Give the right path in Documentation example
trivial: MTD: remove EOL from MODULE_DESCRIPTION
trivial: Fix typo in bio_split()'s documentation
trivial: PWM: fix of #endif comment
trivial: fix typos/grammar errors in Kconfig texts
trivial: Fix misspelling of firmware
trivial: cgroups: documentation typo and spelling corrections
trivial: Update contact info for Jochen Hein
trivial: fix typo "resgister" -> "register"
...
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: ixp4xx - Fix handling of chained sg buffers
crypto: shash - Fix unaligned calculation with short length
hwrng: timeriomem - Use phys address rather than virt
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
Remove two unneeded exports and make two symbols static in fs/mpage.c
Cleanup after commit 585d3bc06f
Trim includes of fdtable.h
Don't crap into descriptor table in binfmt_som
Trim includes in binfmt_elf
Don't mess with descriptor table in load_elf_binary()
Get rid of indirect include of fs_struct.h
New helper - current_umask()
check_unsafe_exec() doesn't care about signal handlers sharing
New locking/refcounting for fs_struct
Take fs_struct handling to new file (fs/fs_struct.c)
Get rid of bumping fs_struct refcount in pivot_root(2)
Kill unsharing fs_struct in __set_personality()
We are wasting 2 words in signal_struct without any reason to implement
task_pgrp_nr() and task_session_nr().
task_session_nr() has no callers since
2e2ba22ea4, we can remove it.
task_pgrp_nr() is still (I believe wrongly) used in fs/autofsX and
fs/coda.
This patch reimplements task_pgrp_nr() via task_pgrp_nr_ns(), and kills
__pgrp/__session and the related helpers.
The change in drivers/char/tty_io.c is cosmetic, but hopefully makes sense
anyway.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Alan Cox <number6@the-village.bc.nu> [tty parts]
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Dave Hansen <haveblue@us.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
hpet_calibrate() has a possibility of miss-calibration due to SMI. If SMI
interrupts in the while loop of calibration, then return value will be
big. This change calibrates until stabilizing by the return value with a
small value.
[akpm@linux-foundation.org: trivial style tweaks]
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Acked-by: Clemens Ladisch <clemens@ladisch.de>
Acked-by: Vojtech Pavlik <vojtech@suse.cz>
Cc: Robert Picco <Robert.Picco@hp.com>
Cc: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Acked-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add support for x8 asynchronous sample rate and ability to specify base
clock frequency.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Align rekey_work. Even though it's infrequent, we may as well line it up.
Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Matt Mackall <mpm@selenic.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
filp->f_flags is unsigned, so use that type for the local copy.
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6:
[S390] cio: online_store - trigger recognition for boxed devices
[S390] cio: disallow online setting of device in transient state
[S390] cio: introduce notifier for boxed state
[S390] cio: introduce ccw_device_schedule_sch_unregister
[S390] cio: wake up on failed recognition
[S390] fix hypfs build failure
[PATCH] sysrq: include interrupt.h instead of irq.h
Introduce keyed event wakeups inside the TTY code.
Signed-off-by: Davide Libenzi <davidel@xmailserver.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: David Miller <davem@davemloft.net>
Cc: William Lee Irwin III <wli@movementarian.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Now that the filesystem freeze operation has been elevated to the VFS, and
is just an ioctl away, some sort of safety net for unintentionally frozen
root filesystems may be in order.
The timeout thaw originally proposed did not get merged, but perhaps
something like this would be useful in emergencies.
For example, freeze /path/to/mountpoint may freeze your root filesystem if
you forgot that you had that unmounted.
I chose 'j' as the last remaining character other than 'h' which is sort
of reserved for help (because help is generated on any unknown character).
I've tested this on a non-root fs with multiple (nested) freezers, as well
as on a system rendered unresponsive due to a frozen root fs.
[randy.dunlap@oracle.com: emergency thaw only if CONFIG_BLOCK enabled]
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Cc: Takashi Sato <t-sato@yk.jp.nec.com>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With "cpumask: update irq_desc to use cpumask_var_t"
we get this build failure on s390:
CC drivers/char/sysrq.o
In file included from drivers/char/sysrq.c:38:
include/linux/irq.h: In function 'init_alloc_desc_masks':
include/linux/irq.h:442: error: dereferencing pointer to incomplete type
drivers/char/sysrq.c should include interrupt.h instead of irq.h.
Cc: Mike Travis <travis@sgi.com>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.
We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.
But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.
->read_proc/->write_proc were just fixed to not require ->owner for
protection.
rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.
Removing ->owner will also make PDE smaller.
So, let's nuke it.
Kudos to Jeff Layton for reminding about this, let's say, oversight.
http://bugzilla.kernel.org/show_bug.cgi?id=12454
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
The C99 specification states in section 6.11.5:
The placement of a storage-class specifier other than at the
beginning of the declaration specifiers in a declaration is an
obsolescent feature.
Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
There is no ioremap'ing or anything in timeriomem-rng.c as I foolishly
used already remapped virtual addresses instead of passing the physical
address to be polled.
This patch fixes this flaw and lets developers do the Right Thing(tm).
Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
* 'bkl-removal' of git://git.lwn.net/linux-2.6:
Rationalize fasync return values
Move FASYNC bit handling to f_op->fasync()
Use f_lock to protect f_flags
Rename struct file->f_ep_lock
* 'irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (32 commits)
x86: disable __do_IRQ support
sparseirq, powerpc/cell: fix unused variable warning in interrupt.c
genirq: deprecate obsolete typedefs and defines
genirq: deprecate __do_IRQ
genirq: add doc to struct irqaction
genirq: use kzalloc instead of explicit zero initialization
genirq: make irqreturn_t an enum
genirq: remove redundant if condition
genirq: remove unused hw_irq_controller typedef
irq: export remove_irq() and setup_irq() symbols
irq: match remove_irq() args with setup_irq()
irq: add remove_irq() for freeing of setup_irq() irqs
genirq: assert that irq handlers are indeed running in hardirq context
irq: name 'p' variables a bit better
irq: further clean up the free_irq() code flow
irq: refactor and clean up the free_irq() code flow
irq: clean up manage.c
irq: use GFP_KERNEL for action allocation in request_irq()
kernel/irq: fix sparse warning: make symbol static
irq: optimize init_kstat_irqs/init_copy_kstat_irqs
...
* 'for-linus' of git://git390.marist.edu/pub/scm/linux-2.6: (81 commits)
[S390] remove duplicated #includes
[S390] cpumask: use mm_cpumask() wrapper
[S390] cpumask: Use accessors code.
[S390] cpumask: prepare for iterators to only go to nr_cpu_ids/nr_cpumask_bits.
[S390] cpumask: remove cpu_coregroup_map
[S390] fix clock comparator save area usage
[S390] Add hwcap flag for the etf3 enhancement facility
[S390] Ensure that ipl panic notifier is called late.
[S390] fix dfp elf hwcap/facility bit detection
[S390] smp: perform initial cpu reset before starting a cpu
[S390] smp: fix memory leak on __cpu_up
[S390] ipl: Improve checking logic and remove switch defaults.
[S390] s390dbf: Remove needless check for NULL pointer.
[S390] s390dbf: Remove redundant initilizations.
[S390] use kzfree()
[S390] BUG to BUG_ON changes
[S390] zfcpdump: Prevent zcore from beeing built as a kernel module.
[S390] Use csum_partial in checksum.h
[S390] cleanup lowcore.h
[S390] eliminate ipl_device from lowcore
...
* git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6: (29 commits)
crypto: sha512-s390 - Add missing block size
hwrng: timeriomem - Breaks an allyesconfig build on s390:
nlattr: Fix build error with NET off
crypto: testmgr - add zlib test
crypto: zlib - New zlib crypto module, using pcomp
crypto: testmgr - Add support for the pcomp interface
crypto: compress - Add pcomp interface
netlink: Move netlink attribute parsing support to lib
crypto: Fix dead links
hwrng: timeriomem - New driver
crypto: chainiv - Use kcrypto_wq instead of keventd_wq
crypto: cryptd - Per-CPU thread implementation based on kcrypto_wq
crypto: api - Use dedicated workqueue for crypto subsystem
crypto: testmgr - Test skciphers with no IVs
crypto: aead - Avoid infinite loop when nivaead fails selftest
crypto: skcipher - Avoid infinite loop when cipher fails selftest
crypto: api - Fix crypto_alloc_tfm/create_create_tfm return convention
crypto: api - crypto_alg_mod_lookup either tested or untested
crypto: amcc - Add crypt4xx driver
crypto: ansi_cprng - Add maintainer
...
This patch introduces the kernel parameter hvc_iucv_allow= that specifies
a comma-separated list of z/VM user IDs.
If specified, the z/VM IUCV hypervisor console device driver accepts IUCV
connections from listed z/VM user IDs only.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
If the hvc_iucv= kernel parameter specifies a value that is not
valid, display an error message.
Minor changes to existing kernel messages.
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
During bootup performance tracing I noticed many occurrences of
vca* device creation and removal, leading to the usual userspace
uevent processing, which are, in this case, rather pointless.
A simple test showing the kernel timing (not including all the
work userspace has to do), gives us these numbers:
$ time for i in `seq 1000`; do echo a > /dev/tty2; done
real 0m1.142s
user 0m0.015s
sys 0m0.540s
If we move the hook for the vcs* driver core devices from the
tty "binding" to the vc allocation/deallocation, which is what
the vcs* devices represent, we get the following numbers:
$ time for i in `seq 1000`; do echo a > /dev/tty2; done
real 0m0.152s
user 0m0.030s
sys 0m0.072s
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This patch fixes the bug reported in
http://bugzilla.kernel.org/show_bug.cgi?id=11681.
"Lots of device drivers register a 'struct device_driver' with
the '.bus' member set to '&platform_bus_type'. This is wrong,
since the platform_bus functions expect the 'struct device_driver'
to be wrapped up in a 'struct platform_driver' which provides
some additional callbacks (like suspend_late, resume_early).
The effect may be that platform_suspend_late() uses bogus data
outside the device_driver struct as a pointer pointer to the
device driver's suspend_late() function or other hard to
reproduce failures."(Lothar Wassmann)
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Acked-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
CC drivers/char/hw_random/timeriomem-rng.o
drivers/char/hw_random/timeriomem-rng.c: In function 'timeriomem_rng_data_read':
drivers/char/hw_random/timeriomem-rng.c:60: error: implicit declaration of function 'readl'
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Most fasync implementations do something like:
return fasync_helper(...);
But fasync_helper() will return a positive value at times - a feature used
in at least one place. Thus, a number of other drivers do:
err = fasync_helper(...);
if (err < 0)
return err;
return 0;
In the interests of consistency and more concise code, it makes sense to
map positive return values onto zero where ->fasync() is called.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Traditionally, changes to struct file->f_flags have been done under BKL
protection, or with no protection at all. This patch causes all f_flags
changes after file open/creation time to be done under protection of
f_lock. This allows the removal of some BKL usage and fixes a number of
longstanding (if microscopic) races.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
commit 11c3b5c3e0
Author: Greg Kroah-Hartman <gregkh@suse.de>
Date: Tue Dec 16 12:24:56 2008 -0800
driver core: move klist_children into private structure
Broke our parisc build pretty badly because we touch the klists directly
in three cases (AGP, SBA and GSC). Although GregKH will revert this
patch, there's no reason we should be using the iterators directly, we
can just move to the standard device_for_each_child() API.
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
Tested-by: Helge Deller <deller@gmx.de>
Tested-by: Kyle McMartin <kyle@mcmartin.ca>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
* 'merge' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc:
radeonfb/aty128fb: Disable broken early resume hook for PowerBooks
hvc_console: Remove tty->low_latency on pseries backends
powerpc: fix linkstation and storcenter compilation breakage
powerpc/4xx: Enable SERIAL_OF support by default for Virtex platforms
The hvcs and hvsi backends both set tty->low_latency to one, along
with more or less scary comments regarding bugs or races that would
happen if not doing so.
However, they also both call tty_flip_buffer_push() in conexts where
it's illegal to do so since some recent tty changes (or at least it
may have been illegal always but it nows blows) when low_latency is
set (ie, hard interrupt or with spinlock held and irqs disabled).
This removes the setting for now to get them back to working condition,
we'll have to address the races described in the comments separately
if they are still an issue (some of this might have been fixed already).
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
When GTT size is equal to amount of video memory, the amount of GTT
entries is computed lower than zero, which is invalid and leads to
off-by-one error in intel_i915_configure()
Originally posted here:
http://bugzilla.kernel.org/show_bug.cgi?id=12539http://bugzilla.redhat.com/show_bug.cgi?id=445592
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Cc: Lubomir Rintel <lkundrak@v3.sk>
Cc: Dave Airlie <airlied@linux.ie>
Reviewed-by: Eric Anholt <eric@anholt.net>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Impact: fix bug to make agp work with dri
Jeffrey reported that dri does work with 64bit, but doesn't work with
32bit it turns out NB aperture is 32M, aperture on agp is 128M
64bit is using 64M for vaidation for 64 iommu/gart 32bit is only using
32M..., and will not update the nb aperture.
So try to compare nb apterture and agp apterture before leaving not
touch nb aperture.
Reported-by: Jeffrey Trull <jetrull@sbcglobal.net>
Tested-by: Jeffrey Trull <jetrull@sbcglobal.net>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Acked-by: Dave Airlie <airlied@linux.ie>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
http://kisskb.ellerman.id.au/kisskb/buildresult/72115/:
| net/mac80211/ieee80211_i.h:327: error: syntax error before 'volatile'
| net/mac80211/ieee80211_i.h:350: error: syntax error before '}' token
| net/mac80211/ieee80211_i.h:455: error: field 'sta' has incomplete type
| distcc[19430] ERROR: compile net/mac80211/main.c on sprygo/32 failed
This is caused by
| # define mfp ((*(volatile struct MFP*)MFP_BAS))
in arch/m68k/include/asm/atarihw.h, which conflicts with the new "mfp" enum in
net/mac80211/ieee80211_i.h.
Rename "mfp" to "st_mfp", as it's a way too generic name for a global #define.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Some hardware platforms, the TS-7800[1] is one for example, can
supply the kernel with an entropy source, albeit a slow one for
TS-7800 users, by just reading a particular IO address. This
source must not be read above a certain rate otherwise the quality
suffers.
The driver is then hooked into by calling
platform_device_(register|add|del) passing a structure similar to:
------
static struct timeriomem_rng_data ts78xx_ts_rng_data = {
.address = (u32 *__iomem) TS_RNG,
.period = 1000000, /* one second */
};
static struct platform_device ts78xx_ts_rng_device = {
.name = "timeriomem_rng",
.id = -1,
.dev = {
.platform_data = &ts78xx_ts_rng_data,
},
.num_resources = 0,
};
------
[1] http://www.embeddedarm.com/products/board-detail.php?product=TS-7800
Signed-off-by: Alexander Clouter <alex@digriz.org.uk>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The "break" would just result in reusing a free'd pointer. I don't have
the cards myself to test it though. :/
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Caused by 736d54533a (sx.c: fix missed unlock_kernel() on error path in
sx_fw_ioctl()). You guys keep breaking things this way in every single
kernel release in at least couple of places... :-(
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Acked-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix to function which is called by IMA, now tpm_chip_find_get() considers the case in which the machine doesn't have a TPM or, if it has, its TPM isn't enabled.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
If we return directly with -EPERM then lock_kernel() is still held.
This was found with a code checker (http://repo.or.cz/w/smatch.git/).
[akpm@linux-foundation.org: fix another such path - missed func_exit()]
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: <R.E.Wolff@BitWizard.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch adds internal kernel support for:
- reading/extending a pcr value
- looking up the tpm_chip for a given chip number
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
According to Dave Hansen's comments on the tpm_show_*, some of these functions
present a pattern when allocating data[] memory space and also when setting its
content. A new function was created so that this pattern could be consolidated.
Also, replaced the data[] command vectors and its indexes by meaningful structures
as pointed out by Matt Helsley too.
Signed-off-by: Rajiv Andrade <srajiv@linux.vnet.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
Fix an off-by-two memory error in console selection.
The loop below goes from sel_start to sel_end (inclusive), so it writes
one more character. This one more character was added to the allocated
size (+1), but it was not multiplied by an UTF-8 multiplier.
This patch fixes a memory corruption when UTF-8 console is used and the
user selects a few characters, all of them 3-byte in UTF-8 (for example
a frame line).
When memory redzones are enabled, a redzone corruption is reported.
When they are not enabled, trashing of random memory occurs.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/char/nvram.c uses rtc_lock, that (on ARM) is only defined if
RTC_DRV_CMOS is enabled.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
__tty_open could return (to userspace) holding the tty_mutex thanks to a
regression introduced by 4a2b5fddd5 ("Move
tty lookup/reopen to caller").
This was found by bisecting an fsfuzzer problem. Admittedly I have no
idea how it managed to tickle this 100% reliably, but it is clearly a
regression and when hit leaves the box in a completely unusable state.
This patch lets the fsfuzzer test complete every time.
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Also remove unneeded last_rx update from Synclink drivers.
Synclink part mostly by Stephen Hemminger.
Signed-off-by: Krzysztof Hałasa <khc@pm.waw.pl>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
arch/x86/include/asm/pda.h
We merge tip/core/percpu into tip/perfcounters/core because of a
semantic and contextual conflict: the former eliminates the PDA,
while the latter extends it with apic_perf_irqs field.
Resolve the conflict by moving the new field to the irq_cpustat
structure on 64-bit too.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This patch removes the tty->low_latency setting.
For irq based hvc_console backends the tty->low_latency must be set to 0,
because the tty_flip_buffer_push() function must not be called from IRQ context
(see drivers/char/tty_buffer.c).
For polled backends, the low_latency setting causes the bug trace below, because
tty_flip_buffer_push() is called within an atomic context and subsequent calls
might sleep due to mutex_lock.
BUG: sleeping function called from invalid context at /root/cvs/linux-2.6.git/kernel/mutex.c:207
in_atomic(): 1, irqs_disabled(): 0, pid: 748, name: khvcd
1 lock held by khvcd/748:
#0: (hvc_structs_lock){--..}, at: [<00000000002ceb50>] khvcd+0x58/0x12c
CPU: 0 Not tainted 2.6.29-rc1git #29
Process khvcd (pid: 748, task: 000000002fb9a480, ksp: 000000002f66bd78)
070000000000000a 000000002f66ba00 0000000000000002 (null)
000000002f66baa0 000000002f66ba18 000000002f66ba18 0000000000104f08
ffffffffffffc000 000000002f66bd78 (null) (null)
000000002f66ba00 000000000000000c 000000002f66ba00 000000002f66ba70
0000000000466af8 0000000000104f08 000000002f66ba00 000000002f66ba50
Call Trace:
([<0000000000104e7c>] show_trace+0x138/0x158)
[<0000000000104f62>] show_stack+0xc6/0xf8
[<0000000000105740>] dump_stack+0xb0/0xc0
[<000000000013144a>] __might_sleep+0x14e/0x17c
[<000000000045e226>] mutex_lock_nested+0x42/0x3b4
[<00000000002c443e>] echo_char_raw+0x3a/0x9c
[<00000000002c688c>] n_tty_receive_buf+0x1154/0x1208
[<00000000002ca0a2>] flush_to_ldisc+0x152/0x220
[<00000000002ca1da>] tty_flip_buffer_push+0x6a/0x90
[<00000000002cea74>] hvc_poll+0x244/0x2c8
[<00000000002ceb68>] khvcd+0x70/0x12c
[<000000000015bbd0>] kthread+0x68/0xa0
[<0000000000109d5a>] kernel_thread_starter+0x6/0xc
[<0000000000109d54>] kernel_thread_starter+0x0/0xc
1 lock held by khvcd/748:
#0: (hvc_structs_lock){--..}, at: [<00000000002ceb50>] khvcd+0x58/0x12c
Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Also a couple of min -> min_t changes.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
- Enable ring indicator interrupt.
- Remove vendor specific CVS version tags.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add an explanitory comment as to why we modify the kernel console loglevel
rather than simply moving sysrq messages to KERN_EMERG level.
Signed-off-by: Andy Whitcroft <apw@canonical.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If you issue an ioctl to flush a tty as the line discipline is changing or
otherwise unplugged you can get a crash. The bug is very old but the rest
of the BKL lock dropping and some very "good" luck on Ingo's part caught
an example.
Use the correct ldisc_ref form so that we wait for the ldisc change to
complete and then flush
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Replace kmalloc() + memset() with kzalloc().
Signed-off-by: Milton Miller <miltonm@bga.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
hvc_console is setting low_latency unconditionally, but some clients are
interrupt driven and will call hvc_poll from irq context. This will cause
tty_flip_buffer_push to be called from irq context, and it very clearly
states it must not be called from IRQ when low_latency is specified.
Looking back through history:
v2.6.16-rc1 via 33f0f88f1c
[PATCH] TTY layer buffering revamp
added this new api.
v2.6.16-rc3 via 8977d929e4
[PATCH] tty buffering stall fix
claims to fix a stall discovered with hvc_console
v2.6.16-rc5 via fb5c594c2a
[PATCH] Fix race condition in hvc console.
said set this flag to avoid a stall problem, and was merged through
the powerpc arch tree.
Without searching for email discussions, it would appear to be an
overlapping "fix", but one that did not consider all users.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Ingo Molnar