Support for uevent_helper, aka hotplug, is not required on many systems
these days but it can still be enabled via sysfs or sysctl.
Reported-by: Darren Shepherd <darren.s.shepherd@gmail.com>
Signed-off-by: Michael Marineau <mike@marineau.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To increase compiler portability there is <linux/compiler.h> which
provides convenience macros for various gcc constructs. Eg: __weak for
__attribute__((weak)). I've replaced all instances of gcc attributes
with the right macro in the kernel subsystem.
Signed-off-by: Gideon Israel Dsouza <gidisrael@gmail.com>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit fixes the follwoing warning:
kernel/ksysfs.c:143:5: warning: symbol 'rcu_expedited' was not declared. Should it be static?
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
[ paulmck: Moved the declaration to include/linux/rcupdate.h to avoid
including the RCU-internal rcu.h file outside of RCU. ]
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Right now we seem to be exporting the max data size contained inside
vmcoreinfo note. But this does not include the size of meta data around
vmcore info data. Like name of the note and starting and ending elf_note.
I think user space expects total size and that size is put in PT_NOTE elf
header. Things seem to be fine so far because we are not using vmcoreinfo
note to the maximum capacity. But as it starts filling up, to capacity,
at some point of time, problem will be visible.
I don't think user space will be broken with this change. So there is no
need to introduce vmcoreinfo2. This change is safe and backward
compatible. More explanation on why this change is safe is below.
vmcoreinfo contains information about kernel which user space needs to
know to do things like filtering. For example, various kernel config
options or information about size or offset of some data structures etc.
All this information is commmunicated to user space with an ELF note
present in ELF /proc/vmcore file.
Currently vmcoreinfo data size is 4096. With some elf note meta data
around it, actual size is 4132 bytes. But we are using barely 25% of that
size. Rest is empty. So even if we tell user space that size of ELf note
is 4096 and not 4132, nothing will be broken becase after around 1000
bytes, everything is zero anyway.
But once we start filling up the note to the capacity, and not report the
full size of note, bad things will start happening. Either some data will
be lost or tools will be confused that they did not fine the zero note at
the end.
So I think this change is safe and should not break existing tools.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Cc: Ken'ichi Ohmichi <oomichi@mxs.nes.nec.co.jp>
Cc: Dan Aloni <da-x@monatomic.org>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull RCU update from Ingo Molnar:
"The major features of this tree are:
1. A first version of no-callbacks CPUs. This version prohibits
offlining CPU 0, but only when enabled via CONFIG_RCU_NOCB_CPU=y.
Relaxing this constraint is in progress, but not yet ready
for prime time. These commits were posted to LKML at
https://lkml.org/lkml/2012/10/30/724.
2. Changes to SRCU that allows statically initialized srcu_struct
structures. These commits were posted to LKML at
https://lkml.org/lkml/2012/10/30/296.
3. Restructuring of RCU's debugfs output. These commits were posted
to LKML at https://lkml.org/lkml/2012/10/30/341.
4. Additional CPU-hotplug/RCU improvements, posted to LKML at
https://lkml.org/lkml/2012/10/30/327.
Note that the commit eliminating __stop_machine() was judged to
be too-high of risk, so is deferred to 3.9.
5. Changes to RCU's idle interface, most notably a new module
parameter that redirects normal grace-period operations to
their expedited equivalents. These were posted to LKML at
https://lkml.org/lkml/2012/10/30/739.
6. Additional diagnostics for RCU's CPU stall warning facility,
posted to LKML at https://lkml.org/lkml/2012/10/30/315.
The most notable change reduces the
default RCU CPU stall-warning time from 60 seconds to 21 seconds,
so that it once again happens sooner than the softlockup timeout.
7. Documentation updates, which were posted to LKML at
https://lkml.org/lkml/2012/10/30/280.
A couple of late-breaking changes were posted at
https://lkml.org/lkml/2012/11/16/634 and
https://lkml.org/lkml/2012/11/16/547.
8. Miscellaneous fixes, which were posted to LKML at
https://lkml.org/lkml/2012/10/30/309.
9. Finally, a fix for an lockdep-RCU splat was posted to LKML
at https://lkml.org/lkml/2012/11/7/486."
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (49 commits)
context_tracking: New context tracking susbsystem
sched: Mark RCU reader in sched_show_task()
rcu: Separate accounting of callbacks from callback-free CPUs
rcu: Add callback-free CPUs
rcu: Add documentation for the new rcuexp debugfs trace file
rcu: Update documentation for TREE_RCU debugfs tracing
rcu: Reduce default RCU CPU stall warning timeout
rcu: Fix TINY_RCU rcu_is_cpu_rrupt_from_idle check
rcu: Clarify memory-ordering properties of grace-period primitives
rcu: Add new rcutorture module parameters to start/end test messages
rcu: Remove list_for_each_continue_rcu()
rcu: Fix batch-limit size problem
rcu: Add tracing for synchronize_sched_expedited()
rcu: Remove old debugfs interfaces and also RCU flavor name
rcu: split 'rcuhier' to each flavor
rcu: split 'rcugp' to each flavor
rcu: split 'rcuboost' to each flavor
rcu: split 'rcubarrier' to each flavor
rcu: Fix tracing formatting
rcu: Remove the interface "rcudata.csv"
...
Remove conditional code based on CONFIG_HOTPLUG being false. It's
always on now in preparation of it going away as an option.
Signed-off-by: Bill Pemberton <wfp5p@virginia.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
There have been some embedded applications that would benefit from
use of expedited grace-period primitives. In some ways, this is
similar to synchronize_net() doing either a normal or an expedited
grace period depending on lock state, but with control outside of
the kernel.
This commit therefore adds rcu_expedited boot and sysfs parameters
that cause the kernel to substitute expedited primitives for the
normal grace-period primitives.
[ paulmck: Add trace/event/rcu.h to kernel/srcu.c to avoid build error.
Get rid of infinite loop through contention path.]
Signed-off-by: Antti P Miettinen <amiettinen@nvidia.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
With the module.h usage cleanup, we'll get this:
kernel/ksysfs.c:161: error: ‘S_IRUGO’ undeclared here (not in a function)
make[2]: *** [kernel/ksysfs.o] Error 1
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
The changed files were only including linux/module.h for the
EXPORT_SYMBOL infrastructure, and nothing else. Revector them
onto the isolated export header for faster compile times.
Nothing to see here but a whole lot of instances of:
-#include <linux/module.h>
+#include <linux/export.h>
This commit is only changing the kernel dir; next targets
will probably be mm, fs, the arch dirs, etc.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
A kernel booted with no_file_caps allows to install fscaps on a binary
but doesn't actually honor the fscaps when running the binary. Userspace
currently has no sane way to determine whether installing fscaps
actually has any effect. Since parsing /proc/cmdline is fragile this
patch exposes the current setting (1 or 0) via /sys/kernel/fscaps
Signed-off-by: Ludwig Nussel <ludwig.nussel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This allows bin_attr->read,write,mmap callbacks to check file specific data
(such as inode owner) as part of any privilege validation.
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Implement shrinking the reserved memory for crash kernel, if it is more
than enough.
For example, if you have already reserved 128M, now you just want 100M,
you can do:
# echo $((100*1024*1024)) > /sys/kernel/kexec_crash_size
Note, you can only do this before loading the crash kernel.
Signed-off-by: WANG Cong <amwang@redhat.com>
Cc: Neil Horman <nhorman@redhat.com>
Acked-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Access to uevent_seqnum and uevent_helper does not need to
depend on CONFIG_NET, so remove it.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Way too often, I have a machine that exhibits some kind of crappy
behavior. The CPU looks wedged in the kernel or it is spending way too
much system time and I wonder what is responsible.
I try to run readprofile. But, of course, Ubuntu doesn't enable it by
default. Dang!
The reason we boot-time enable it is that it takes a big bufffer that we
generally can only bootmem alloc. But, does it hurt to at least try and
runtime-alloc it?
To use:
echo 2 > /sys/kernel/profile
Then run readprofile like normal.
This should fix the compile issue with allmodconfig. I've compile-tested
on a bunch more configs now including a few more architectures.
Signed-off-by: Dave Hansen <dave@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is no need for kobject_unregister() anymore, thanks to Kay's
kobject cleanup changes, so replace all instances of it with
kobject_put().
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
kernel_kset does not need to be a kset, but a much simpler kobject now
that we have kobj_attributes.
We also rename kernel_kset to kernel_kobj to catch all users of this
symbol with a build error instead of an easy-to-ignore build warning.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Clean up the use of ksets and kobjects. Kobjects are instances of
objects (like struct user_info), ksets are collections of objects of a
similar type (like the uids directory containing the user_info directories).
So, use kobjects for the user_info directories, and a kset for the "uids"
directory.
On object cleanup, the final kobject_put() was missing.
Cc: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Cc: Srivatsa Vaddagiri <vatsa@linux.vnet.ibm.com>
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Switch all dynamically created ksets, that export simple attributes,
to kobj_attribute from subsys_attribute. Struct subsys_attribute will
be removed.
Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Cc: Mike Halcrow <mhalcrow@us.ibm.com>
Cc: Phillip Hellewell <phillip@hellewell.homeip.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Dynamically create the kset instead of declaring it statically. We also
rename kernel_subsys to kernel_kset to catch all users of this symbol
with a build error instead of an easy-to-ignore build warning.
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
We don't need a "default" ktype for a kset. We should set this
explicitly every time for each kset. This change is needed so that we
can make ksets dynamic, and cleans up one of the odd, undocumented
assumption that the kset/kobject/ktype model has.
This patch is based on a lot of help from Kay Sievers.
Nasty bug in the block code was found by Dave Young
<hidave.darkstar@gmail.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Cc: Dave Young <hidave.darkstar@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
