There are several functions that might seem appropriate for a timestamp:
get_cycles()
current_kernel_time()
do_gettimeofday()
<read jiffies/jiffies_64>
Each has problems with combinations of SMP-safety, low resolution, and
monotonicity. This patch adds a new function that returns a monotonic SMP-safe
timestamp with nanosecond resolution where available.
Changes:
Split timestamp into separate patch
Moved to kernel/time.c
Renamed to getnstimestamp
Fixed unintended-pointer-arithmetic bug
Signed-off-by: Matt Helsley <matthltc@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Commit f549d6c18c introduced a generic
fallback for security xattrs, but appears to include a subtle bug.
Gentoo users with kernels with selinux compiled in, and coreutils compiled
with acl support, noticed that they could not copy files on tmpfs using
'cp'.
cp (compiled with acl support) copies the file, lists the extended
attributes on the old file, copies them all to the new file, and then
exits. However the listxattr() calls were failing with this odd behaviour:
llistxattr("a.out", (nil), 0) = 17
llistxattr("a.out", 0x7fffff8c6cb0, 17) = -1 ERANGE (Numerical result out of
range)
I believe this is a simple problem in the logic used to check the buffer
sizes; if the user sends a buffer the exact size of the data, then its ok
:)
This change solves the problem.
More info can be found at http://bugs.gentoo.org/113138
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Accessing nohz_cpu_mask before incrementing rcp->cur is racy. It can cause
tickless idle CPUs to be included in rsp->cpumask, which will extend
graceperiods unnecessarily.
Fix this race. It has been tested using extensions to RCU torture module
that forces various CPUs to become idle.
Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
While doing some test of RCU torture module, I hit a OOPS in rcu_do_batch,
which was trying to processes callback of a module that was just removed.
This is because we weren't waiting long enough for all callbacks to fire.
Signed-off-by: Srivatsa Vaddagiri <vatsa@in.ibm.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Acked-by: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This introduces a new interface - rcu_barrier() which waits until all
the RCUs queued until this call have been completed.
Reiser4 needs this, because we do more than just freeing memory object
in our RCU callback: we also remove it from the list hanging off
super-block. This means, that before freeing reiser4-specific portion
of super-block (during umount) we have to wait until all pending RCU
callbacks are executed.
The only change of reiser4 made to the original patch, is exporting of
rcu_barrier().
Cc: Hans Reiser <reiser@namesys.com>
Cc: Vladimir V. Saveliev <vs@namesys.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Sam Ravnborg <sam@ravnborg.org> writes:
> Author: Uwe Zeisberger <zeisberg@informatik.uni-freiburg.de>
>
> [PATCH] kbuild: make kernelrelease in unconfigured kernel prints an error
>
> Do not include .config for target kernelrelease
This is wrong. KERNELRELEASE depends on CONFIG_LOCALVERSION, thus you
need .config.
Signed-off-by: Andreas Schwab <schwab@suse.de>
Cc: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With CPU hotplug enabled, NMI watchdog stoped working. It appears the
violation is the cpu_online check in nmi handler. local ACPI based NMI
watchdog is initialized before we set CPU online for APs. It's quite
possible a NMI is fired before we set CPU online, and that's what happens
here.
Signed-off-by: Shaohua Li <shaohua.li@intel.com>
Acked-by: Zwane Mwaikambo <zwane@arm.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When a Kprobes are inserted/removed on a modules, the modules must be ref
counted so as not to allow to unload while probes are registered on that
module.
Without this patch, the probed module is free to unload, and when the
probing module unregister the probe, the kpobes code while trying to
replace the original instruction might crash.
Signed-off-by: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Signed-off-by: Mao Bibo <bibo.mao@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SetPageDirty() and ClearPageDirty() are low-level thing which filesystems
shouldn't be using. They bypass dirty page accounting.
Cc: David Woodhouse <dwmw2@infradead.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The VM layer (for historical reasons) turns a read-only shared mmap into
a private-like mapping with the VM_MAYWRITE bit clear. Thus checking
just VM_SHARED isn't actually sufficient.
So use a trivial helper function for the cases where we wanted to inquire
if a mapping was COW-like or not.
Moo!
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
With the previous commit, we can handle arbitrary shared re-mappings
even without this complexity, and since the only known private mappings
are for strange users of /dev/mem (which never create an incomplete one),
there seems to be no reason to support it.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
A shared mapping doesn't cause COW-pages, so we don't need to worry
about the whole vm_pgoff logic to decide if a PFN-remapped page has
gone through COW or not.
This makes it possible to entirely avoid the special "partial remapping"
logic for the common case.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
ppc32 kernel, when built with CONFIG_SMP and booted on a single CPU
machine, will not properly set smp_tb_synchronized, thus causing
gettimeofday() to not use the HW timebase and to be limited to jiffy
resolution. This, among others, causes unacceptable pauses when launching
X.org.
Signed-Off-By: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The code that sets the clock spreading feature of the Intrepid ASIC
must not be run on some machine models or those won't boot. This
fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
It is a simple bug which uses the wrong member.
This bug does not seriously affect ordinary use of IPsec.
But it is important to pass IPv6 ready logo phase-2
conformance test of IPsec SGW.
Signed-off-by: Kazunori MIYAZAWA <miyazawa@linux-ipv6.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
On ppc64, when opening a new hugepage region, we need to make sure any
old normal-page SLBs for the area are flushed on all CPUs. There was
a bug in this logic - after putting the new hugepage area masks into
the thread structure, we copied it into the paca (read by the SLB miss
handler) only on one CPU, not on all. This could cause incorrect SLB
entries to be loaded when a multithreaded program was running
simultaneously on several CPUs. This patch corrects the error,
copying the context information into the PACA on all CPUs using the mm
in question before flushing any existing SLB entries.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
On most powerpc CPUs, the dcache and icache are not coherent so
between writing and executing a page, the caches must be flushed.
Userspace programs assume pages given to them by the kernel are icache
clean, so we must do this flush between the kernel clearing a page and
it being mapped into userspace for execute. We were not doing this
for hugepages, this patch corrects the situation.
We use the same lazy mechanism as we use for normal pages, delaying
the flush until userspace actually attempts to execute from the page
in question.
Tested on G5.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Cache info is setup by walking the device tree in initialize_cache_info().
However, icache_flush_range might be called before that, in
slb_initialize()->patch_slb_encoding, which modifies the load immediate
instructions used with SLB fault code.
Not only that, but depending on memory layout, we might take SLB faults
during unflatten_device_tree. So that fault will load an SLB entry that
might not contain the right LLP flags for the segment.
Either we can walk the flattened device tree to setup cache info, or
we can pick the known defaults that are known to work. Doing it in the
flattened device tree is hairier since we need to know the machine type
to know what property to look for, etc, etc.
For now, it's just easier to go with the defaults. Worst thing that
happens from it is that we might waste a few cycles doing too small
dcbst/icbi increments.
Signed-off-by: Olof Johansson <olof@lixom.net>
Signed-off-by: Paul Mackerras <paulus@samba.org>
model_id fields of wf_smu_sys_all_params should match the model ID
they are supposed to represent (as commented). Fixes windfarm on some
iMac 8,1 models.
Signed-off-by: Michal Ostrowski <mostrows at watson ibm com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The problem I was seeing turned out to be that skb->dev is NULL when
the checksum is being completed in user context. This happens because
the reference to the device is dropped (to allow it to be released
when packets are in the queue).
Because skb->dev was NULL, the netdev_rx_csum_fault was panicing on
deref of dev->name. How about this?
Signed-off-by: Stephen Hemminger <shemminger@osdl.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Some debug code wasn't properly removed from the initial 64k pages
patch, and while it's harmless, it's also slowing down significantly a
very hot code path, thus it should really be removed.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
The 64k pages patch changed the meaning of one argument passed to the
low level hash functions (from "large" it became "psize" or page size
index), but one of the call sites wasn't properly updated, causing
potential random weird problems with huge pages. This fixes it.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Matt Helsley
Daniel Drake
Srivatsa Vaddagiri
Dipankar Sarma
Andreas Gruenbacher
Andreas Schwab
Shaohua Li
Mao, Bibo
Andrew Morton
Linus Torvalds
Johannes Berg
Benjamin Herrenschmidt
Kazunori MIYAZAWA
David Gibson
Olof Johansson
Michal Ostrowski
Stephen Hemminger