Remove the arg+env limit of MAX_ARG_PAGES by copying the strings directly from
the old mm into the new mm.
We create the new mm before the binfmt code runs, and place the new stack at
the very top of the address space. Once the binfmt code runs and figures out
where the stack should be, we move it downwards.
It is a bit peculiar in that we have one task with two mm's, one of which is
inactive.
[a.p.zijlstra@chello.nl: limit stack size]
Signed-off-by: Ollie Wild <aaw@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: <linux-arch@vger.kernel.org>
Cc: Hugh Dickins <hugh@veritas.com>
[bunk@stusta.de: unexport bprm_mm_init]
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently most of the per cpu data, which is accessed by different cpus,
has a ____cacheline_aligned_in_smp attribute. Move all this data to the
new per cpu shared data section: .data.percpu.shared_aligned.
This will seperate the percpu data which is referenced frequently by other
cpus from the local only percpu data.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: "Luck, Tony" <tony.luck@intel.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>
per cpu data section contains two types of data. One set which is
exclusively accessed by the local cpu and the other set which is per cpu,
but also shared by remote cpus. In the current kernel, these two sets are
not clearely separated out. This can potentially cause the same data
cacheline shared between the two sets of data, which will result in
unnecessary bouncing of the cacheline between cpus.
One way to fix the problem is to cacheline align the remotely accessed per
cpu data, both at the beginning and at the end. Because of the padding at
both ends, this will likely cause some memory wastage and also the
interface to achieve this is not clean.
This patch:
Moves the remotely accessed per cpu data (which is currently marked
as ____cacheline_aligned_in_smp) into a different section, where all the data
elements are cacheline aligned. And as such, this differentiates the local
only data and remotely accessed data cleanly.
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Acked-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Christoph Lameter <clameter@sgi.com>
Cc: <linux-arch@vger.kernel.org>
Cc: "Luck, Tony" <tony.luck@intel.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>
I realise jprobes are a razor-blades-included type of interface, but that
doesn't mean we can't try and make them safer to use. This guy I know once
wrote code like this:
struct jprobe jp = { .kp.symbol_name = "foo", .entry = "jprobe_foo" };
And then his kernel exploded. Oops.
This patch adds an arch hook, arch_deref_entry_point() (I don't like it
either) which takes the void * in a struct jprobe, and gives back the text
address that it represents.
We can then use that in register_jprobe() to check that the entry point we're
passed is actually in the kernel text, rather than just some random value.
Signed-off-by: Michael Ellerman <michael@ellerman.id.au>
Cc: Prasanna S Panchamukhi <prasanna@in.ibm.com>
Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@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>
unregister_chrdev() always returns 0. There is no need to check the return
value.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Move "debug during resume from s2ram" into the variable we already use
for real-mode flags to simplify code. It also closes nasty trap for
the user in acpi_sleep_setup; order of parameters actually mattered there,
acpi_sleep=s3_bios,s3_mode doing something different from
acpi_sleep=s3_mode,s3_bios.
Signed-off-by: Pavel Machek <pavel@suse.cz>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add a feature allowing the user to make the system beep during a resume from
suspend to RAM, on x86_64 and i386.
This is useful for the users with broken resume from RAM, so that they can
verify if the control reaches the kernel after a wake-up event.
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This patch completes Linus's wish that the fault return codes be made into
bit flags, which I agree makes everything nicer. This requires requires
all handle_mm_fault callers to be modified (possibly the modifications
should go further and do things like fault accounting in handle_mm_fault --
however that would be for another patch).
[akpm@linux-foundation.org: fix alpha build]
[akpm@linux-foundation.org: fix s390 build]
[akpm@linux-foundation.org: fix sparc build]
[akpm@linux-foundation.org: fix sparc64 build]
[akpm@linux-foundation.org: fix ia64 build]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ian Molton <spyro@f2s.com>
Cc: Bryan Wu <bryan.wu@analog.com>
Cc: Mikael Starvik <starvik@axis.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Greg Ungerer <gerg@uclinux.org>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Kazumoto Kojima <kkojima@rr.iij4u.or.jp>
Cc: Richard Curnow <rc@rc0.org.uk>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Miles Bader <uclinux-v850@lsi.nec.co.jp>
Cc: Chris Zankel <chris@zankel.net>
Acked-by: Kyle McMartin <kyle@mcmartin.ca>
Acked-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Still apparently needs some ARM and PPC loving - Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The TSEC/eTSEC can detect the interface to the PHY automatically,
but it isn't able to detect whether the RGMII connection needs internal
delay. So we need to detect that change in the device tree, propagate
it to the platform data, and then check it if we're in RGMII. This fixes
a bug on the 8641D HPCN board where the Vitesse PHY doesn't use the delay
for RGMII.
Signed-off-by: Andy Fleming <afleming@freescale.com>
The TSEC/eTSEC automatically detect their PHY interface type, unless
the type is RGMII-ID (RGMII with internal delay). In that situation,
it just detects RGMII. In order to fix this, we need to pass in rgmii-id
if that is the connection type.
Signed-off-by: Andy Fleming <afleming@freescale.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6:
[AVR32] Initialize phy_mask for both macb devices
[AVR32] Fix atomic_add_unless() and atomic_sub_unless()
[AVR32] Correct misspelled CONFIG_BLK_DEV_INITRD variable.
[AVR32] Fix build error in parse_tag_rdimg()
[AVR32] Don't wire up macb0 unless SW6 is in default position
[AVR32] Wire up SSC platform device 0 as TX on ATSTK1000 board
[AVR32] Add Atmel SSC driver platform device to AT32AP architecture
[AVR32] Remove optimization of unaligned word loads
[AVR32] Make STK1000 mux settings configurable
[AVR32] CPU frequency scaling for AT32AP
[AVR32] Split SM device into PM, RTC, WDT and EIC
[AVR32] faster avr32 unaligned access
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/hpa/linux-2.6-x86setup:
[PATCH] x86: do not recompile boot for each build
[x86 setup] Save/restore DS around invocations of INT 10h
[x86 setup] VGA: Clear the Protect bit before setting the vertical height
[x86 setup] Fix assembly constraints
[x86 setup] build/tools.c: fix comment
[x86 setup] MAINTAINERS: document x86 setup code git tree
The TRACE_IRQS_ON function in iret_exc: calls a C function without
ensuring that the segments are set properly. Move the trace function and
the enabling of interrupt into the C stub.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The code for LDT segment selectors was not robust in the face of a bogus
selector set in %cs via ptrace before the single-step was done.
Signed-off-by: Roland McGrath <roland@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The STK1000 uses pullups on the MDIO lines to the PHY, but they are
too weak. This causes the PHY layer to detect PHYs on all possible MII
addresses. Mask out all but the correct address to prevent this from
happening.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This code is inside an #ifdef with a misspelled config symbol, so it
hasn't been used for a long time. Fix it before fixing the config
symbol to keep bisection working.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This patch adds register definitions, clocks and IRQs to the platform devices.
Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This adds some STK1002-specific config options covering the jumper settings,
so the kernel can automatically be configured to include the relevant devices.
One of them replaces the previous internal SW2_DEFAULT setting; SPI config
is affected by two of the jumpers; and a fourth one switches between LCD and
the second Ethernet connector. (There's more that to be done.)
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
This patch enables CPU frequency scaling for AT32AP devices. This will
enable the CPU to scale between the speed of the high speed bus and
the master clock and thus save some power.
The patch also adds a parent to cpu_clk and a cpu_clk_set_rate to
enable changing the CPU clock divider in a sane way.
The driver does not check if the given rate is 0, thus resulting in a
div by 0. I think this check should be go into the clk_set_rate
framework, and not here.
Tested on AT32AP7000/ATSTK1000.
Hardware documentation can be found in the AT32AP7000 datasheet.
Signed-off-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Split the SM platform device into separate platform devices for PM,
RTC, WDT and EIC. This is more correct according to the documentation
and allows us to simplify the code a little.
Also turn the EIC driver into a real platform driver.
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Acked-by: Hans-Christian Egtvedt <hcegtvedt@atmel.com>
Keep the arch/i386/boot directory from being rebuilt every time.
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
There exists at least one card, Trident TVGA8900CL (BIOS dated 1992/9/8)
which clobbers DS when "scrolling in an SVGA text mode of more than
800x600 pixels." Although we are extremely unlikely to run into that
situation, it is cheap insurance to save and restore DS, and it only adds
a grand total of 50 bytes to the total output.
Pointed out by Etienne Lorrain.
Cc: Etienne Lorrain <etienne_lorrain@yahoo.fr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
If the user has asked for the vertical height registers to be recomputed
by setting bit 15 in the video mode number, we do so without clearing the
Protect bit in the Vertical Retrace Register before setting the Overflow
register. As a result, if the VGA BIOS had set the Protect bit, the
write to the Overflow register will be dropped, and bits [9:8] of the
vertical height will be left unchanged.
This is a bug imported from the assembly version of this code. It was
pointed out by Etienne Lorrain.
Cc: Etienne Lorrain <etienne_lorrain@yahoo.fr>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Fix incorrect assembly constraints. In particular, fix memory
constraints used inside push..pop, which can cause invalid operation
since gcc may generate %esp-relative references.
Additionally:
outl() should have "dN" not "dn".
query_mca() shouldn't listen 16/32-bit registers in an 8-bit only
context.
has_eflag(): the "mask" is only used well after both the stack pointer
and the output registers have been touched; this requires the output
registers to be earlyclobbers (=&) and the input to exclude memory (so
"ri", not "g").
Thanks to Etienne Lorrain and Chuck Ebbert for prompting this review.
Cc: Etienne Lorrain <etienne_lorrain@yahoo.fr>
Cc: Chuck Ebbert <cebbert@redhat.com>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Correct a comment in arch/i386/boot/build/tools.c; we now build the
kernel from only two components instead of three, since the boot
sector has been integrated in the setup code.
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: extent macros cleanup
Fix compilation with EXT_DEBUG, also fix leXX_to_cpu conversions.
ext4: remove extra IS_RDONLY() check
ext4: Use is_power_of_2()
Use zero_user_page() in ext4 where possible
ext4: Remove 65000 subdirectory limit
ext4: Expand extra_inodes space per the s_{want,min}_extra_isize fields
ext4: Add nanosecond timestamps
jbd2: Move jbd2-debug file to debugfs
jbd2: Fix CONFIG_JBD_DEBUG ifdef to be CONFIG_JBD2_DEBUG
ext4: Set the journal JBD2_FEATURE_INCOMPAT_64BIT on large devices
ext4: Make extents code sanely handle on-disk corruption
ext4: copy i_flags to inode flags on write
ext4: Enable extents by default
Change on-disk format to support 2^15 uninitialized extents
write support for preallocated blocks
fallocate support in ext4
sys_fallocate() implementation on i386, x86_64 and powerpc
* 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/sparc-2.6:
[SPARC64]: Set vio->desc_buf to NULL after freeing.
[SPARC]: Mark sparc and sparc64 as not having virt_to_bus
[SPARC64]: Fix reset handling in VNET driver.
[SPARC64]: Handle reset events in vio_link_state_change().
[SPARC64]: Handle LDC resets properly in domain-services driver.
[SPARC64]: Massively simplify VIO device layer and support hot add/remove.
[SPARC64]: Simplify VNET probing.
[SPARC64]: Simplify VDC device probing.
[SPARC64]: Add basic infrastructure for MD add/remove notification.
* 'xen-upstream' of ssh://master.kernel.org/pub/scm/linux/kernel/git/jeremy/xen: (44 commits)
xen: disable all non-virtual drivers
xen: use iret directly when possible
xen: suppress abs symbol warnings for unused reloc pointers
xen: Attempt to patch inline versions of common operations
xen: Place vcpu_info structure into per-cpu memory
xen: handle external requests for shutdown, reboot and sysrq
xen: machine operations
xen: add virtual network device driver
xen: add virtual block device driver.
xen: add the Xenbus sysfs and virtual device hotplug driver
xen: Add grant table support
xen: use the hvc console infrastructure for Xen console
xen: hack to prevent bad segment register reload
xen: lazy-mmu operations
xen: Add support for preemption
xen: SMP guest support
xen: Implement sched_clock
xen: Account for stolen time
xen: ignore RW mapping of RO pages in pagetable_init
xen: Complete pagetable pinning
...
This reverts commit 5a26f6bbb7.
The original patch causes boot failures when built with ppc64_defconfig. The
quickest fix is to revert it while alterates are investigated.
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This fixes the fallout from the recent powerpc merge (commit
489de30259):
CC arch/powerpc/kernel/pci-common.o
arch/powerpc/kernel/pci-common.c:160: error: conflicting types for 'pcibios_add_platform_entries'
include/linux/pci.h:889: error: previous declaration of 'pcibios_add_platform_entries' was here
Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Tested-by: Bret Towe <magnade@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A domU Xen environment has no non-virtual drivers, so make sure
they're all disabled at once.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Most of the time we can simply use the iret instruction to exit the
kernel, rather than having to use the iret hypercall - the only
exception is if we're returning into vm86 mode, or from delivering an
NMI (which we don't support yet).
When running native, iret has the behaviour of testing for a pending
interrupt atomically with re-enabling interrupts. Unfortunately
there's no way to do this with Xen, so there's a window in which we
could get a recursive exception after enabling events but before
actually returning to userspace.
This causes a problem: if the nested interrupt causes one of the
task's TIF_WORK_MASK flags to be set, they will not be checked again
before returning to userspace. This means that pending work may be
left pending indefinitely, until the process enters and leaves the
kernel again. The net effect is that a pending signal or reschedule
event could be delayed for an unbounded amount of time.
To deal with this, the xen event upcall handler checks to see if the
EIP is within the critical section of the iret code, after events
are (potentially) enabled up to the iret itself. If its within this
range, it calls the iret critical section fixup, which adjusts the
stack to deal with any unrestored registers, and then shifts the
stack frame up to replace the previous invocation.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
arch/i386/xen/xen-asm.S defines some small pieces of code which are
used to implement a few paravirt_ops. They're designed so they can be
used either in-place, or be inline patched into their callsites if
there's enough space.
Some of those operations need to make calls out (specifically, if you
re-enable events [interrupts], and there's a pending event at that
time). These calls need the call instruction to be relocated if the
code is patched inline. In this case xen_foo_reloc is a
section-relative symbol which points to xen_foo's required relocation.
Other operations have no need of a relocation, and so their
corresponding xen_bar_reloc is absolute 0. These are the cases which
are triggering the warning.
This patch adds those symbols to the list of safe abs symbols.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Adrian Bunk <bunk@stusta.de>
This patchs adds the mechanism to allow us to patch inline versions of
common operations.
The implementations of the direct-access versions save_fl, restore_fl,
irq_enable and irq_disable are now in assembler, and the same code is
used for both out of line and inline uses.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Keir Fraser <keir@xensource.com>
An experimental patch for Xen allows guests to place their vcpu_info
structs anywhere. We try to use this to place the vcpu_info into the
PDA, which allows direct access.
If this works, then switch to using direct access operations for
irq_enable, disable, save_fl and restore_fl.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: Keir Fraser <keir@xensource.com>
The guest domain can be asked to shutdown or reboot itself, or have a
sysrq key injected, via xenbus. This patch adds a watcher for those
events, and does the appropriate action.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Make the appropriate hypercalls to halt and reboot the virtual machine.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Implement a Xen back-end for hvc console.
* * *
Add early printk support via hvc console, enable using
"earlyprintk=xen" on the kernel command line.
From: Gerd Hoffmann <kraxel@suse.de>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Olof Johansson <olof@lixom.net>
The hypervisor saves and restores the segment registers as part of the
state is saves while context switching. If, during a context switch,
the next process doesn't use the TLS segments, it invalidates the GDT
entry, causing the segment register reload to fault. This fault
effectively doubles the cost of a context switch.
This patch is a band-aid workaround which clears the usermode %gs
after it has been saved for the previous process, but before it gets
reloaded for the next, and it avoids having the hypervisor attempt to
erroneously reload it.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
This patch uses the lazy-mmu hooks to batch mmu operations where
possible. This is primarily useful for batching operations applied to
active pagetables, which happens during mprotect, munmap, mremap and
the like (mmap does not do bulk pagetable operations, so it isn't
helped).
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Add Xen support for preemption. This is mostly a cleanup of existing
preempt_enable/disable calls, or just comments to explain the current
usage.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
This is a fairly straightforward Xen implementation of smp_ops.
Xen has its own IPI mechanisms, and has no dependency on any
APIC-based IPI. The smp_ops hooks and the flush_tlb_others pv_op
allow a Xen guest to avoid all APIC code in arch/i386 (the only apic
operation is a single apic_read for the apic version number).
One subtle point which needs to be addressed is unpinning pagetables
when another cpu may have a lazy tlb reference to the pagetable. Xen
will not allow an in-use pagetable to be unpinned, so we must find any
other cpus with a reference to the pagetable and get them to shoot
down their references.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Andi Kleen <ak@suse.de>
Implement xen_sched_clock, which returns the number of ns the current
vcpu has been actually in an unstolen state (ie, running or blocked,
vs runnable-but-not-running, or offline) since boot.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: john stultz <johnstul@us.ibm.com>
This patch accounts for the time stolen from our VCPUs. Stolen time is
time where a vcpu is runnable and could be running, but all available
physical CPUs are being used for something else.
This accounting gets run on each timer interrupt, just as a way to get
it run relatively often, and when interesting things are going on.
Stolen time is not really used by much in the kernel; it is reported
in /proc/stats, and that's about it.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Rik van Riel <riel@redhat.com>
When setting up the initial pagetable, which includes mappings of all
low physical memory, ignore a mapping which tries to set the RW bit on
an RO pte. An RO pte indicates a page which is part of the current
pagetable, and so it cannot be allowed to become RW.
Once xen_pagetable_setup_done is called, set_pte reverts to its normal
behaviour.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Cc: ebiederm@xmission.com (Eric W. Biederman)
Xen requires all active pagetables to be marked read-only. When the
base of the pagetable is loaded into %cr3, the hypervisor validates
the entire pagetable and only allows the load to proceed if it all
checks out.
This is pretty slow, so to mitigate this cost Xen has a notion of
pinned pagetables. Pinned pagetables are pagetables which are
considered to be active even if no processor's cr3 is pointing to is.
This means that it must remain read-only and all updates are validated
by the hypervisor. This makes context switches much cheaper, because
the hypervisor doesn't need to revalidate the pagetable each time.
This also adds a new paravirt hook which is called during setup once
the zones and memory allocator have been initialized. When the
init_mm pagetable is first built, the struct page array does not yet
exist, and so there's nowhere to put he init_mm pagetable's PG_pinned
flags. Once the zones are initialized and the struct page array
exists, we can set the PG_pinned flags for those pages.
This patch also adds the Xen support for pte pages allocated out of
highmem (highpte) by implementing xen_kmap_atomic_pte.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Zach Amsden <zach@vmware.com>
Put config options for Xen after the core pieces are in place.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Xen maintains a base clock which measures nanoseconds since system
boot. This is provided to guests via a shared page which contains a
base time in ns, a tsc timestamp at that point and tsc frequency
parameters. Guests can compute the current time by reading the tsc
and using it to extrapolate the current time from the basetime. The
hypervisor makes sure that the frequency parameters are updated
regularly, paricularly if the tsc changes rate or stops.
This is implemented as a clocksource, so the interface to the rest of
the kernel is a simple clocksource which simply returns the current
time directly in nanoseconds.
Xen also provides a simple timer mechanism, which allows a timeout to
be set in the future. When that time arrives, a timer event is sent
to the guest. There are two timer interfaces:
- An old one which also delivers a stream of (unused) ticks at 100Hz,
and on the same event, the actual timer events. The 100Hz ticks
cause a lot of spurious wakeups, but are basically harmless.
- The new timer interface doesn't have the 100Hz ticks, and can also
fail if the specified time is in the past.
This code presents the Xen timer as a clockevent driver, and uses the
new interface by preference.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Xen implements interrupts in terms of event channels. Each guest
domain gets 1024 event channels which can be used for a variety of
purposes, such as Xen timer events, inter-domain events,
inter-processor events (IPI) or for real hardware IRQs.
Within the kernel, we map the event channels to IRQs, and implement
the whole interrupt handling using a Xen irq_chip.
Rather than setting NR_IRQ to 1024 under PARAVIRT in order to
accomodate Xen, we create a dynamic mapping between event channels and
IRQs. Ideally, Linux will eventually move towards dynamically
allocating per-irq structures, and we can use a 1:1 mapping between
event channels and irqs.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Xen pagetable handling, including the machinery to implement direct
pagetables.
Xen presents the real CPU's pagetables directly to guests, with no
added shadowing or other layer of abstraction. Naturally this means
the hypervisor must maintain close control over what the guest can put
into the pagetable.
When the guest modifies the pte/pmd/pgd, it must convert its
domain-specific notion of a "physical" pfn into a global machine frame
number (mfn) before inserting the entry into the pagetable. Xen will
check to make sure the domain is allowed to create a mapping of the
given mfn.
Xen also requires that all mappings the guest has of its own active
pagetable are read-only. This is relatively easy to implement in
Linux because all pagetables share the same pte pages for kernel
mappings, so updating the pte in one pagetable will implicitly update
the mapping in all pagetables.
Normally a pagetable becomes active when you point to it with cr3 (or
the Xen equivalent), but when you do so, Xen must check the whole
pagetable for correctness, which is clearly a performance problem.
Xen solves this with pinning which keeps a pagetable effectively
active even if its currently unused, which means that all the normal
update rules are enforced. This means that it need not revalidate the
pagetable when loading cr3.
This patch has a first-cut implementation of pinning, but it is more
fully implemented in a later patch.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
This patch is a rollup of all the core pieces of the Xen
implementation, including:
- booting and setup
- pagetable setup
- privileged instructions
- segmentation
- interrupt flags
- upcalls
- multicall batching
BOOTING AND SETUP
The vmlinux image is decorated with ELF notes which tell the Xen
domain builder what the kernel's requirements are; the domain builder
then constructs the address space accordingly and starts the kernel.
Xen has its own entrypoint for the kernel (contained in an ELF note).
The ELF notes are set up by xen-head.S, which is included into head.S.
In principle it could be linked separately, but it seems to provoke
lots of binutils bugs.
Because the domain builder starts the kernel in a fairly sane state
(32-bit protected mode, paging enabled, flat segments set up), there's
not a lot of setup needed before starting the kernel proper. The main
steps are:
1. Install the Xen paravirt_ops, which is simply a matter of a
structure assignment.
2. Set init_mm to use the Xen-supplied pagetables (analogous to the
head.S generated pagetables in a native boot).
3. Reserve address space for Xen, since it takes a chunk at the top
of the address space for its own use.
4. Call start_kernel()
PAGETABLE SETUP
Once we hit the main kernel boot sequence, it will end up calling back
via paravirt_ops to set up various pieces of Xen specific state. One
of the critical things which requires a bit of extra care is the
construction of the initial init_mm pagetable. Because Xen places
tight constraints on pagetables (an active pagetable must always be
valid, and must always be mapped read-only to the guest domain), we
need to be careful when constructing the new pagetable to keep these
constraints in mind. It turns out that the easiest way to do this is
use the initial Xen-provided pagetable as a template, and then just
insert new mappings for memory where a mapping doesn't already exist.
This means that during pagetable setup, it uses a special version of
xen_set_pte which ignores any attempt to remap a read-only page as
read-write (since Xen will map its own initial pagetable as RO), but
lets other changes to the ptes happen, so that things like NX are set
properly.
PRIVILEGED INSTRUCTIONS AND SEGMENTATION
When the kernel runs under Xen, it runs in ring 1 rather than ring 0.
This means that it is more privileged than user-mode in ring 3, but it
still can't run privileged instructions directly. Non-performance
critical instructions are dealt with by taking a privilege exception
and trapping into the hypervisor and emulating the instruction, but
more performance-critical instructions have their own specific
paravirt_ops. In many cases we can avoid having to do any hypercalls
for these instructions, or the Xen implementation is quite different
from the normal native version.
The privileged instructions fall into the broad classes of:
Segmentation: setting up the GDT and the GDT entries, LDT,
TLS and so on. Xen doesn't allow the GDT to be directly
modified; all GDT updates are done via hypercalls where the new
entries can be validated. This is important because Xen uses
segment limits to prevent the guest kernel from damaging the
hypervisor itself.
Traps and exceptions: Xen uses a special format for trap entrypoints,
so when the kernel wants to set an IDT entry, it needs to be
converted to the form Xen expects. Xen sets int 0x80 up specially
so that the trap goes straight from userspace into the guest kernel
without going via the hypervisor. sysenter isn't supported.
Kernel stack: The esp0 entry is extracted from the tss and provided to
Xen.
TLB operations: the various TLB calls are mapped into corresponding
Xen hypercalls.
Control registers: all the control registers are privileged. The most
important is cr3, which points to the base of the current pagetable,
and we handle it specially.
Another instruction we treat specially is CPUID, even though its not
privileged. We want to control what CPU features are visible to the
rest of the kernel, and so CPUID ends up going into a paravirt_op.
Xen implements this mainly to disable the ACPI and APIC subsystems.
INTERRUPT FLAGS
Xen maintains its own separate flag for masking events, which is
contained within the per-cpu vcpu_info structure. Because the guest
kernel runs in ring 1 and not 0, the IF flag in EFLAGS is completely
ignored (and must be, because even if a guest domain disables
interrupts for itself, it can't disable them overall).
(A note on terminology: "events" and interrupts are effectively
synonymous. However, rather than using an "enable flag", Xen uses a
"mask flag", which blocks event delivery when it is non-zero.)
There are paravirt_ops for each of cli/sti/save_fl/restore_fl, which
are implemented to manage the Xen event mask state. The only thing
worth noting is that when events are unmasked, we need to explicitly
see if there's a pending event and call into the hypervisor to make
sure it gets delivered.
UPCALLS
Xen needs a couple of upcall (or callback) functions to be implemented
by each guest. One is the event upcalls, which is how events
(interrupts, effectively) are delivered to the guests. The other is
the failsafe callback, which is used to report errors in either
reloading a segment register, or caused by iret. These are
implemented in i386/kernel/entry.S so they can jump into the normal
iret_exc path when necessary.
MULTICALL BATCHING
Xen provides a multicall mechanism, which allows multiple hypercalls
to be issued at once in order to mitigate the cost of trapping into
the hypervisor. This is particularly useful for context switches,
since the 4-5 hypercalls they would normally need (reload cr3, update
TLS, maybe update LDT) can be reduced to one. This patch implements a
generic batching mechanism for hypercalls, which gets used in many
places in the Xen code.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Ian Pratt <ian.pratt@xensource.com>
Cc: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Cc: Adrian Bunk <bunk@stusta.de>
Add the "nosegneg" fake capabilty to the vsyscall page notes. This is
used by the runtime linker to select a glibc version which then
disables negative-offset accesses to the thread-local segment via
%gs. These accesses require emulation in Xen (because segments are
truncated to protect the hypervisor address space) and avoiding them
provides a measurable performance boost.
Signed-off-by: Ian Pratt <ian.pratt@xensource.com>
Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Acked-by: Zachary Amsden <zach@vmware.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Ulrich Drepper <drepper@redhat.com>
The tsc-based get_scheduled_cycles interface is not a good match for
Xen's runstate accounting, which reports everything in nanoseconds.
This patch replaces this interface with a sched_clock interface, which
matches both Xen and VMI's requirements.
In order to do this, we:
1. replace get_scheduled_cycles with sched_clock
2. hoist cycles_2_ns into a common header
3. update vmi accordingly
One thing to note: because sched_clock is implemented as a weak
function in kernel/sched.c, we must define a real function in order to
override this weak binding. This means the usual paravirt_ops
technique of using an inline function won't work in this case.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Zachary Amsden <zach@vmware.com>
Cc: Dan Hecht <dhecht@vmware.com>
Cc: john stultz <johnstul@us.ibm.com>
In a virtual environment, device drivers such as legacy IDE will waste
quite a lot of time probing for their devices which will never appear.
This helper function allows a paravirt implementation to lay claim to
the whole iomem and ioport space, thereby disabling all device drivers
trying to claim IO resources.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
__supported_pte_mask is needed when constructing pte values. Xen
device drivers need to do this to make mappings of foreign pages (ie,
pages granted to us by other domains).
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Make globally leave_mm visible, specifically so that Xen can use it to
shoot-down lazy uses of cr3.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Add a hook so that the paravirt backend knows when the allocator is
ready. This is useful for the obvious reason that the allocator is
available, but the other side-effect of having the bootmem allocator
available is that each page now has an associated "struct page".
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
It's useful to know which mm is allocating a pagetable. Xen uses this
to determine whether the pagetable being added to is pinned or not.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Use existing elfnote.h to generate vsyscall notes, rather than doing
it locally. Changes elfnote.h a bit to suit, since this is the first
asm user, and it wasn't quite right.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Andrew Morton <akpm@linux-foundation.com>
Rather than using a tri-state integer for the wait flag in
call_usermodehelper_exec, define a proper enum, and use that. I've
preserved the integer values so that any callers I've missed should
still work OK.
Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Joel Becker <joel.becker@oracle.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: David Howells <dhowells@redhat.com>
early_serial_setup was removed from serial.h, but forgot to put in
serial_8250.h
Signed-off-by: Yinghai Lu <yinghai.lu@sun.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Reset the handshake and per-capability state so that when the
link comes back up we'll renegotiate the DS version and then
reregister all of the services.
Signed-off-by: David S. Miller <davem@davemloft.net>
Create and destroy VIO devices in response to MD update events. These
run synchronously inside of the MD update mutex so the VIO layer
doesn't need to do internal locking of any sort.
Signed-off-by: David S. Miller <davem@davemloft.net>
And add dummy handlers for the VIO device layer. These will be filled
in with real code after the vdc, vnet, and ds drivers are reworked to
have simpler dependencies on the VIO device tree.
Signed-off-by: David S. Miller <davem@davemloft.net>
fallocate() is a new system call being proposed here which will allow
applications to preallocate space to any file(s) in a file system.
Each file system implementation that wants to use this feature will need
to support an inode operation called ->fallocate().
Applications can use this feature to avoid fragmentation to certain
level and thus get faster access speed. With preallocation, applications
also get a guarantee of space for particular file(s) - even if later the
the system becomes full.
Currently, glibc provides an interface called posix_fallocate() which
can be used for similar cause. Though this has the advantage of working
on all file systems, but it is quite slow (since it writes zeroes to
each block that has to be preallocated). Without a doubt, file systems
can do this more efficiently within the kernel, by implementing
the proposed fallocate() system call. It is expected that
posix_fallocate() will be modified to call this new system call first
and incase the kernel/filesystem does not implement it, it should fall
back to the current implementation of writing zeroes to the new blocks.
ToDos:
1. Implementation on other architectures (other than i386, x86_64,
and ppc). Patches for s390(x) and ia64 are already available from
previous posts, but it was decided that they should be added later
once fallocate is in the mainline. Hence not including those patches
in this take.
2. Changes to glibc,
a) to support fallocate() system call
b) to make posix_fallocate() and posix_fallocate64() call fallocate()
Signed-off-by: Amit Arora <aarora@in.ibm.com>
Mark variables with uninitialized_var() if such a warning appears,
and analysis proves that the var is initialized properly on all paths
it is used.
Signed-off-by: Jeff Garzik <jeff@garzik.org>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/avi/kvm: (80 commits)
KVM: Use CPU_DYING for disabling virtualization
KVM: Tune hotplug/suspend IPIs
KVM: Keep track of which cpus have virtualization enabled
SMP: Allow smp_call_function_single() to current cpu
i386: Allow smp_call_function_single() to current cpu
x86_64: Allow smp_call_function_single() to current cpu
HOTPLUG: Adapt thermal throttle to CPU_DYING
HOTPLUG: Adapt cpuset hotplug callback to CPU_DYING
HOTPLUG: Add CPU_DYING notifier
KVM: Clean up #includes
KVM: Remove kvmfs in favor of the anonymous inodes source
KVM: SVM: Reliably detect if SVM was disabled by BIOS
KVM: VMX: Remove unnecessary code in vmx_tlb_flush()
KVM: MMU: Fix Wrong tlb flush order
KVM: VMX: Reinitialize the real-mode tss when entering real mode
KVM: Avoid useless memory write when possible
KVM: Fix x86 emulator writeback
KVM: Add support for in-kernel pio handlers
KVM: VMX: Fix interrupt checking on lightweight exit
KVM: Adds support for in-kernel mmio handlers
...
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6:
[IA64] Clean away some code inside some non-existent CONFIG ifdefs
[IA64] ar.itc access must really be after xtime_lock.sequence has been read
[IA64] correctly count CPU objects in the ia64/sn hwperf interface
[IA64] arbitary speed tty ioctl support
[IA64] use machvec=dig on hpzx1 platforms
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
__init and __initdata stuff used from __devinit one
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Let spu_management_ops.enumerate_spus() return the number of found SPEs
and use that information to draw some little helper penguin logos.
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Signed-off-by: Geoff Levand <geoffrey.levand@am.sony.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-By: James Simmons <jsimmons@infradead.org>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Allow fbcon to select the primary display adapter using the
fb_is_primary_device() arch-specific helper. If a a primary adapter is
detected, fbcon will unbind the old adapter from the VT layer, then rebind
using the new adapter. This requires that bind_/unbind_con_driver() be made
public.
Because this feature may produce unexpected behavior (from the user's POV),
this must be explicitly enabled in Kconfig.
[akpm@linux-foundation.org: export unbind_con_driver]
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add function helper, fb_is_primary_device(). Given struct fb_info, it will
return a nonzero value if the device is the primary display.
Currently, only the i386 is supported where the function checks for the
IORESOURCE_ROM_SHADOW flag.
Signed-off-by: Antonino Daplas <adaplas@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Update csb337 board specific init to support "new style" rtc-ds1307 code.
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: Andrew Victor <andrew@sanpeople.com>
Cc: Bill Gatliff <bgat@billgatliff.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Russell King <rmk@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the new i2c framework to load rtc-rs5c372 for the Thecus N2100.
Signed-off-by: Martin Michlmayr <tbm@cyrius.com>
Tested-by: Voipio Riku <Riku.Voipio@movial.fi>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Lennert Buytenhek <buytenh@wantstofly.org>
Cc: Jean Delvare <khali@linux-fr.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Simple SPI master driver for Xilinx SPI controller.
No support for multiple masters.
Not using level 1 drivers from EDK.
[akpm@linux-foundation.org: uninlining]
Signed-off-by: Yuri Frolov <yfrolov@ru.mvista.com>
Signed-off-by: Andrei Konovalov <akonovalov@ru.mvista.com>
Cc: Kumar Gala <galak@gate.crashing.org>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid dirtying remote cpu's memory if it already has the correct value.
Cc: Andi Kleen <ak@suse.de>
Cc: Konrad Rzeszutek <konrad@darnok.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Avoid dirtying remote cpu's memory if it already has the correct value.
Cc: Andi Kleen <ak@suse.de>
Cc: Konrad Rzeszutek <konrad@darnok.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
On large memory configuration with not so fast CPUs the NMI watchdog is
triggered when memory addresses are being gathered and printed. The code
paths for Alt-SysRq-t are sprinkled with touch_nmi_watchdog in various
places but not in this routine (or in the loop that utilizes this
function). The patch has been tested for regression on large CPU+memory
configuration (128 logical CPUs + 224 GB) and 1,2,4,16-CPU sockets with
various memory sizes (1,2,4,6,20).
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Based on usage and testing over the past couple of years, kprobes on
i386, ia64, powerpc and x86_64 is no longer EXPERIMENTAL.
This is a follow-up to Robert P.J. Day's patch making "Instrumentation
support" non-EXPERIMENTAL:
http://marc.info/?l=linux-kernel&m=118396955423812&w=2
Arch maintainers for sparc64, avr32 and s390 need to take a similar call.
Signed-off-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com>
Cc: Andi Kleen <ak@suse.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
KSYM_NAME_LEN is peculiar in that it does not include the space for the
trailing '\0', forcing all users to use KSYM_NAME_LEN + 1 when allocating
buffer. This is nonsense and error-prone. Moreover, when the caller
forgets that it's very likely to subtly bite back by corrupting the stack
because the last position of the buffer is always cleared to zero.
This patch increments KSYM_NAME_LEN by one and updates code accordingly.
* off-by-one bug in asm-powerpc/kprobes.h::kprobe_lookup_name() macro
is fixed.
* Where MODULE_NAME_LEN and KSYM_NAME_LEN were used together,
MODULE_NAME_LEN was treated as if it didn't include space for the
trailing '\0'. Fix it.
Signed-off-by: Tejun Heo <htejun@gmail.com>
Acked-by: Paulo Marques <pmarques@grupopie.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a driver for the SB1250 DUART, a dual serial port implementation
included in the Broadcom family of SOCs descending from the SiByte SB1250
MIPS64 chip multiprocessor. It is a new implementation replacing the
old-fashioned driver currently present in the linux-mips.org tree. It
supports all the usual features one would expect from a(n asynchronous)
serial driver, including modem line control (as far as hardware supports it
-- there is edge detection logic missing from the DCD and RI lines and the
driver does not implement polling of these lines at the moment), the serial
console, BREAK transmission and reception, including the magic SysRq. The
receive FIFO threshold is not maintained though.
The driver was tested with a SWARM board which uses a BCM1250 SOC (which is
dual MIPS64 CMP) and has both ports of the single DUART implemented wired
externally. Both were tested. Testing included using the ports as
terminal lines at 1200bps (which is the ports minimum), 115200bps and a
couple of random speeds inbetween. The modem lines were verified to
operate correctly. No testing was performed with a use as a network
interface, like with SLIP or PPP.
Signed-off-by: Maciej W. Rozycki <macro@linux-mips.org>
Acked-by: Ralf Baechle <ralf@linux-mips.org>
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>
Identical implementations of PTRACE_POKEDATA go into generic_ptrace_pokedata()
function.
AFAICS, fix bug on xtensa where successful PTRACE_POKEDATA will nevertheless
return EPERM.
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the kernel OOPSed or BUGed then it probably should be considered as
tainted. Thus, all subsequent OOPSes and SysRq dumps will report the
tainted kernel. This saves a lot of time explaining oddities in the
calltraces.
Signed-off-by: Pavel Emelianov <xemul@openvz.org>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[ Added parisc patch from Matthew Wilson -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
