cftype->max_write_len is used to extend the maximum size of writes.
It's interpreted in such a way that the actual maximum size is one
less than the specified value. The default size is defined by
CGROUP_LOCAL_BUFFER_SIZE. Its interpretation is quite confusing - its
value is decremented by 1 and then compared for equality with max
size, which means that the actual default size is
CGROUP_LOCAL_BUFFER_SIZE - 2, which is 62 chars.
There's no point in having a limit that low. Update its definition so
that it means the actual string length sans termination and anything
below PAGE_SIZE-1 is treated as PAGE_SIZE-1.
.max_write_len for "release_agent" is updated to PATH_MAX-1 and
cgroup_release_agent_write() is updated so that the redundant strlen()
check is removed and it uses strlcpy() instead of strcpy().
.max_write_len initializations in blk-throttle.c and cfq-iosched.c are
no longer necessary and removed. The one in cpuset is kept unchanged
as it's an approximated value to begin with.
This will also make transition to kernfs smoother.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Currently, cgroup_subsys->base_cftypes registration is different from
dynamic cftypes registartion. Instead of going through
cgroup_add_cftypes(), cgroup_init_subsys() invokes
cgroup_init_cftsets() which makes use of cgroup_subsys->base_cftset
which doesn't involve dynamic allocation.
While avoiding dynamic allocation is somewhat nice, having two
separate paths for cftypes registration is nasty, especially as we're
planning to add more operations during cftypes registration.
This patch drops cgroup_init_cftsets() and cgroup_subsys->base_cftset
and registers base_cftypes using cgroup_add_cftypes(). This is done
as a separate step in cgroup_init() instead of a part of
cgroup_init_subsys(). This is because cgroup_init_subsys() can be
called very early during boot when kmalloc() isn't available yet.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Straightforward updates to cgroup name handling in preparation of
kernfs conversion.
* cgroup_alloc_name() is updated to take const char * isntead of
dentry * for name source.
* cgroup name formatting is separated out into cgroup_file_name().
While at it, buffer length protection is added.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Factor out new root initialization into cgroup_setup_root() from
cgroup_mount(). This makes it easier to follow and will ease kernfs
conversion.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
cgroup is scheduled to be converted to kernfs. After conversion,
cgroup_mount() won't use the sget() machinery for finding out existing
super_blocks but instead would do that directly. It'll search the
existing cgroupfs_roots for a matching one and create a new one iff a
match doesn't exist. To ease such conversion, this patch restructures
locking and error handling of the function.
cgroup_tree_mutex and cgroup_mutex are grabbed from the get-go and
held until return. For now, due to the way vfs locks nest outside
cgroup mutexes, the two cgroup mutexes are temporarily dropped across
sget() and inode mutex locking, which looks quite ridiculous; however,
these will be removed through kernfs conversion and structuring the
code this way makes the conversion less painful.
The error goto labels are consolidated to two. This looks unwieldy
now but the next patch will factor out creation of new root into a
separate function with accompanying error handling and it'll look a
lot better.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Now that cftypes and all tree modification operations are protected by
cgroup_tree_mutex, we can drop cgroup_mutex while deleting files and
directories. Drop cgroup_mutex over removals.
This doesn't make any noticeable difference now but is to help kernfs
conversion. In kernfs, removals are sync points which drain in-flight
operations as those operations would grab cgroup_mutex, trying to
delete under cgroup_mutex would deadlock. This can be resolved by
just holding the outer cgroup_tree_mutex which nests outside both
kernfs active reference and cgroup_mutex.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Currently cgroup uses combination of inode->i_mutex'es and
cgroup_mutex for synchronization. With the scheduled kernfs
conversion, i_mutex'es will be removed. Unfortunately, just using
cgroup_mutex isn't possible. All kernfs file and syscall operations,
most of which require grabbing cgroup_mutex, will be called with
kernfs active ref held and, if we try to perform kernfs removals under
cgroup_mutex, it can deadlock as kernfs_remove() tries to drain the
target node.
Let's introduce a new outer mutex, cgroup_tree_mutex, which protects
stuff used during hierarchy changing operations - cftypes and all the
operations which may affect the cgroupfs. It also covers css
association and iteration. This allows cgroup_css(), for_each_css()
and other css iterators to be called under cgroup_tree_mutex. The new
mutex will nest above both kernfs's active ref protection and
cgroup_mutex. By protecting tree modifications with a separate outer
mutex, we can get rid of the forementioned deadlock condition.
Actual file additions and removals now require cgroup_tree_mutex
instead of cgroup_mutex. Currently, cgroup_tree_mutex is never used
without cgroup_mutex; however, we'll soon add hierarchy modification
sections which are only protected by cgroup_tree_mutex. In the
future, we might want to make the locking more granular by better
splitting the coverages of the two mutexes. For now, this should do.
v2: Rebased on top of 0ab02ca8f8 ("cgroup: protect modifications to
cgroup_idr with cgroup_mutex").
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
css_from_dir() returns the matching css (cgroup_subsys_state) given a
dentry and subsystem. The function doesn't pin the css before
returning and requires the caller to be holding RCU read lock or
cgroup_mutex and handling pinning on the caller side.
Given that users of the function are likely to want to pin the
returned css (both existing users do) and that getting and putting
css's are very cheap, there's no reason for the interface to be tricky
like this.
Rename css_from_dir() to css_tryget_from_dir() and make it try to pin
the found css and return it only if pinning succeeded. The callers
are updated so that they no longer do RCU locking and pinning around
the function and just use the returned css.
This will also ease converting cgroup to kernfs.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Pull for-3.14-fixes to receive 0ab02ca8f8 ("cgroup: protect
modifications to cgroup_idr with cgroup_mutex") prior to kernfs
conversion series to avoid non-trivial conflicts.
Signed-off-by: Tejun Heo <tj@kernel.org>
Setup cgroupfs like this:
# mount -t cgroup -o cpuacct xxx /cgroup
# mkdir /cgroup/sub1
# mkdir /cgroup/sub2
Then run these two commands:
# for ((; ;)) { mkdir /cgroup/sub1/tmp && rmdir /mnt/sub1/tmp; } &
# for ((; ;)) { mkdir /cgroup/sub2/tmp && rmdir /mnt/sub2/tmp; } &
After seconds you may see this warning:
------------[ cut here ]------------
WARNING: CPU: 1 PID: 25243 at lib/idr.c:527 sub_remove+0x87/0x1b0()
idr_remove called for id=6 which is not allocated.
...
Call Trace:
[<ffffffff8156063c>] dump_stack+0x7a/0x96
[<ffffffff810591ac>] warn_slowpath_common+0x8c/0xc0
[<ffffffff81059296>] warn_slowpath_fmt+0x46/0x50
[<ffffffff81300aa7>] sub_remove+0x87/0x1b0
[<ffffffff810f3f02>] ? css_killed_work_fn+0x32/0x1b0
[<ffffffff81300bf5>] idr_remove+0x25/0xd0
[<ffffffff810f2bab>] cgroup_destroy_css_killed+0x5b/0xc0
[<ffffffff810f4000>] css_killed_work_fn+0x130/0x1b0
[<ffffffff8107cdbc>] process_one_work+0x26c/0x550
[<ffffffff8107eefe>] worker_thread+0x12e/0x3b0
[<ffffffff81085f96>] kthread+0xe6/0xf0
[<ffffffff81570bac>] ret_from_fork+0x7c/0xb0
---[ end trace 2d1577ec10cf80d0 ]---
It's because allocating/removing cgroup ID is not properly synchronized.
The bug was introduced when we converted cgroup_ida to cgroup_idr.
While synchronization is already done inside ida_simple_{get,remove}(),
users are responsible for concurrent calls to idr_{alloc,remove}().
tj: Refreshed on top of b58c89986a ("cgroup: fix error return from
cgroup_create()").
Fixes: 4e96ee8e98 ("cgroup: convert cgroup_ida to cgroup_idr")
Cc: <stable@vger.kernel.org> #3.12+
Reported-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
cgroup_root_mutex was added to avoid deadlock involving namespace_sem
via cgroup_show_options(). It added a lot of overhead for the small
purpose of it and, because it's nested under cgroup_mutex, it has very
limited usefulness. The previous patch made cgroup_show_options() not
use cgroup_root_mutex, so nobody needs it anymore. Remove it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
cgroup_show_options() grabs cgroup_root_mutex to protect the options
changing while printing; however, holding root_mutex or not doesn't
really make much difference for the function. subsys_mask can be
atomically tested and most of the options aren't allowed to change
anyway once mounted.
The only field which needs synchronization is ->release_agent_path.
This patch introduces a dedicated spinlock to synchronize accesses to
the field and drops cgroup_root_mutex locking from
cgroup_show_options(). The next patch will remove cgroup_root_mutex.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
It's no longer referenced outside cgroup core, so renaming is easy.
Let's rename it for consistency & brevity.
This patch is pure rename.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
cgroup_subsys is a bit messier than it needs to be.
* The name of a subsys can be different from its internal identifier
defined in cgroup_subsys.h. Most subsystems use the matching name
but three - cpu, memory and perf_event - use different ones.
* cgroup_subsys_id enums are postfixed with _subsys_id and each
cgroup_subsys is postfixed with _subsys. cgroup.h is widely
included throughout various subsystems, it doesn't and shouldn't
have claim on such generic names which don't have any qualifier
indicating that they belong to cgroup.
* cgroup_subsys->subsys_id should always equal the matching
cgroup_subsys_id enum; however, we require each controller to
initialize it and then BUG if they don't match, which is a bit
silly.
This patch cleans up cgroup_subsys names and initialization by doing
the followings.
* cgroup_subsys_id enums are now postfixed with _cgrp_id, and each
cgroup_subsys with _cgrp_subsys.
* With the above, renaming subsys identifiers to match the userland
visible names doesn't cause any naming conflicts. All non-matching
identifiers are renamed to match the official names.
cpu_cgroup -> cpu
mem_cgroup -> memory
perf -> perf_event
* controllers no longer need to initialize ->subsys_id and ->name.
They're generated in cgroup core and set automatically during boot.
* Redundant cgroup_subsys declarations removed.
* While updating BUG_ON()s in cgroup_init_early(), convert them to
WARN()s. BUGging that early during boot is stupid - the kernel
can't print anything, even through serial console and the trap
handler doesn't even link stack frame properly for back-tracing.
This patch doesn't introduce any behavior changes.
v2: Rebased on top of fe1217c4f3 ("net: net_cls: move cgroupfs
classid handling into core").
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Acked-by: "David S. Miller" <davem@davemloft.net>
Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Acked-by: Michal Hocko <mhocko@suse.cz>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Aristeu Rozanski <aris@redhat.com>
Acked-by: Ingo Molnar <mingo@redhat.com>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Serge E. Hallyn <serue@us.ibm.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Thomas Graf <tgraf@suug.ch>
With module supported dropped from net_prio, no controller is using
cgroup module support. None of actual resource controllers can be
built as a module and we aren't gonna add new controllers which don't
control resources. This patch drops module support from cgroup.
* cgroup_[un]load_subsys() and cgroup_subsys->module removed.
* As there's no point in distinguishing IS_BUILTIN() and IS_MODULE(),
cgroup_subsys.h now uses IS_ENABLED() directly.
* enum cgroup_subsys_id now exactly matches the list of enabled
controllers as ordered in cgroup_subsys.h.
* cgroup_subsys[] is now a contiguously occupied array. Size
specification is no longer necessary and dropped.
* for_each_builtin_subsys() is removed and for_each_subsys() is
updated to not require any locking.
* module ref handling is removed from rebind_subsystems().
* Module related comments dropped.
v2: Rebased on top of fe1217c4f3 ("net: net_cls: move cgroupfs
classid handling into core").
v3: Added {} around the if (need_forkexit_callback) block in
cgroup_post_fork() for readability as suggested by Li.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
cgroup_cfts_commit() walks the cgroup hierarchy that the target
subsystem is attached to and tries to apply the file changes. Due to
the convolution with inode locking, it can't keep cgroup_mutex locked
while iterating. It currently holds only RCU read lock around the
actual iteration and then pins the found cgroup using dget().
Unfortunately, this is incorrect. Although the iteration does check
cgroup_is_dead() before invoking dget(), there's nothing which
prevents the dentry from going away inbetween. Note that this is
different from the usual css iterations where css_tryget() is used to
pin the css - css_tryget() tests whether the css can be pinned and
fails if not.
The problem can be solved by simply holding cgroup_mutex instead of
RCU read lock around the iteration, which actually reduces LOC.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
cgroup_create() was returning 0 after allocation failures. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
When cgroup_mount() fails to allocate an id for the root, it didn't
set ret before jumping to unlock_drop ending up returning 0 after a
failure. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Li Zefan <lizefan@huawei.com>
Cc: stable@vger.kernel.org
Sometimes the cleanup after memcg hierarchy testing gets stuck in
mem_cgroup_reparent_charges(), unable to bring non-kmem usage down to 0.
There may turn out to be several causes, but a major cause is this: the
workitem to offline parent can get run before workitem to offline child;
parent's mem_cgroup_reparent_charges() circles around waiting for the
child's pages to be reparented to its lrus, but it's holding cgroup_mutex
which prevents the child from reaching its mem_cgroup_reparent_charges().
Just use an ordered workqueue for cgroup_destroy_wq.
tj: Committing as the temporary fix until the reverse dependency can
be removed from memcg. Comment updated accordingly.
Fixes: e5fca243ab ("cgroup: use a dedicated workqueue for cgroup destruction")
Suggested-by: Filipe Brandenburger <filbranden@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Cc: stable@vger.kernel.org # 3.10+
Signed-off-by: Tejun Heo <tj@kernel.org>
arch/arm/mach-tegra/pm.c, kernel/power/console.c and mm/vmpressure.c
were somehow getting slab.h indirectly through cgroup.h which in turn
was getting it indirectly through xattr.h. A scheduled cgroup change
drops xattr.h inclusion from cgroup.h and breaks compilation of these
three files. Add explicit slab.h includes to the three files.
A pending cgroup patch depends on this change and it'd be great if
this can be routed through cgroup/for-3.14-fixes branch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Acked-by: Stephen Warren <swarren@wwwdotorg.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: linux-tegra@vger.kernel.org
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: linux-pm@vger.kernel.org
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: cgroups@vger.kernel.org
Pull timer/dynticks updates from Ingo Molnar:
"This tree contains misc dynticks updates: a fix and three cleanups"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/nohz: Fix overflow error in scheduler_tick_max_deferment()
nohz_full: fix code style issue of tick_nohz_full_stop_tick
nohz: Get timekeeping max deferment outside jiffies_lock
tick: Rename tick_check_idle() to tick_irq_enter()
Pull core debug changes from Ingo Molnar:
"This contains mostly kernel debugging related updates:
- make hung_task detection more configurable to distros
- add final bits for x86 UV NMI debugging, with related KGDB changes
- update the mailing-list of MAINTAINERS entries I'm involved with"
* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hung_task: Display every hung task warning
sysctl: Add neg_one as a standard constraint
x86/uv/nmi, kgdb/kdb: Fix UV NMI handler when KDB not configured
x86/uv/nmi: Fix Sparse warnings
kgdb/kdb: Fix no KDB config problem
MAINTAINERS: Restore "L: linux-kernel@vger.kernel.org" entries
After commit 9a46ad6d6d ("smp: make smp_call_function_many() use logic
similar to smp_call_function_single()"), cfd->cpumask is accessed only
in smp_call_function_many(). So there is no more need to copy it into
cfd->cpumask_ipi before putting csd into the list. The cpumask_ipi
field is obsolete and can be removed.
Signed-off-by: Roman Gushchin <klamm@yandex-team.ru>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Wang YanQing <udknight@gmail.com>
Cc: Xie XiuQi <xiexiuqi@huawei.com>
Cc: Shaohua Li <shli@fusionio.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Make smp_call_function_single and friends more efficient by using a
lockless list.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull core block IO changes from Jens Axboe:
"The major piece in here is the immutable bio_ve series from Kent, the
rest is fairly minor. It was supposed to go in last round, but
various issues pushed it to this release instead. The pull request
contains:
- Various smaller blk-mq fixes from different folks. Nothing major
here, just minor fixes and cleanups.
- Fix for a memory leak in the error path in the block ioctl code
from Christian Engelmayer.
- Header export fix from CaiZhiyong.
- Finally the immutable biovec changes from Kent Overstreet. This
enables some nice future work on making arbitrarily sized bios
possible, and splitting more efficient. Related fixes to immutable
bio_vecs:
- dm-cache immutable fixup from Mike Snitzer.
- btrfs immutable fixup from Muthu Kumar.
- bio-integrity fix from Nic Bellinger, which is also going to stable"
* 'for-3.14/core' of git://git.kernel.dk/linux-block: (44 commits)
xtensa: fixup simdisk driver to work with immutable bio_vecs
block/blk-mq-cpu.c: use hotcpu_notifier()
blk-mq: for_each_* macro correctness
block: Fix memory leak in rw_copy_check_uvector() handling
bio-integrity: Fix bio_integrity_verify segment start bug
block: remove unrelated header files and export symbol
blk-mq: uses page->list incorrectly
blk-mq: use __smp_call_function_single directly
btrfs: fix missing increment of bi_remaining
Revert "block: Warn and free bio if bi_end_io is not set"
block: Warn and free bio if bi_end_io is not set
blk-mq: fix initializing request's start time
block: blk-mq: don't export blk_mq_free_queue()
block: blk-mq: make blk_sync_queue support mq
block: blk-mq: support draining mq queue
dm cache: increment bi_remaining when bi_end_io is restored
block: fixup for generic bio chaining
block: Really silence spurious compiler warnings
block: Silence spurious compiler warnings
block: Kill bio_pair_split()
...
Pull vfs updates from Al Viro:
"Assorted stuff; the biggest pile here is Christoph's ACL series. Plus
assorted cleanups and fixes all over the place...
There will be another pile later this week"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (43 commits)
__dentry_path() fixes
vfs: Remove second variable named error in __dentry_path
vfs: Is mounted should be testing mnt_ns for NULL or error.
Fix race when checking i_size on direct i/o read
hfsplus: remove can_set_xattr
nfsd: use get_acl and ->set_acl
fs: remove generic_acl
nfs: use generic posix ACL infrastructure for v3 Posix ACLs
gfs2: use generic posix ACL infrastructure
jfs: use generic posix ACL infrastructure
xfs: use generic posix ACL infrastructure
reiserfs: use generic posix ACL infrastructure
ocfs2: use generic posix ACL infrastructure
jffs2: use generic posix ACL infrastructure
hfsplus: use generic posix ACL infrastructure
f2fs: use generic posix ACL infrastructure
ext2/3/4: use generic posix ACL infrastructure
btrfs: use generic posix ACL infrastructure
fs: make posix_acl_create more useful
fs: make posix_acl_chmod more useful
...
Not all classes implement (or can implement) a useful get_rr_interval()
function, default to a 0 time-slice for them.
This fixes a crash reported by Tommi Rantala.
Reported-by: Tommi Rantala <tt.rantala@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Tommi Rantala <tt.rantala@gmail.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20140127105413.GC11314@laptop.programming.kicks-ass.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Add in Documentation/scheduler/ some hints about the design
choices, the usage and the future possible developments of the
sched_dl scheduling class and of the SCHED_DEADLINE policy.
Reviewed-by: Henrik Austad <henrik@austad.us>
Signed-off-by: Dario Faggioli <raistlin@linux.it>
Signed-off-by: Juri Lelli <juri.lelli@gmail.com>
[ Re-wrote sections 2 and 3. ]
Signed-off-by: Luca Abeni <luca.abeni@unitn.it>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1390821615-23247-1-git-send-email-juri.lelli@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Use a more current logging style.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Possible speed improvement of __do_softirq() by using ffs() instead of
using a while loop with an & 1 test then single bit shift.
Signed-off-by: Joe Perches <joe@perches.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
vsnprintf() may let 'r' larger than sizeof(buf), in this case, if 'r' is
also less than "vmcoreinfo_max_size - vmcoreinfo_size" (left size of
destination buffer), next memcpy() will read the unexpected addresses.
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
the new features added to 3.14.
The third patch is a minor bugfix to the trace_puts() functions that
will crash the system if a developer adds one before the tracing system
is setup. It also affects trace_printk() if it has no arguments, as
the code will convert it to a trace_puts() as well. Note, this bug
will not affect unmodified kernels, as trace_printk() and trace_puts()
should only be used by developers for testing.
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Merge tag 'trace-fixes-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"The first two patches fix the debugfs README file to reflect better
the new features added to 3.14.
The third patch is a minor bugfix to the trace_puts() functions that
will crash the system if a developer adds one before the tracing
system is setup. It also affects trace_printk() if it has no
arguments, as the code will convert it to a trace_puts() as well.
Note, this bug will not affect unmodified kernels, as trace_printk()
and trace_puts() should only be used by developers for testing"
* tag 'trace-fixes-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing: Check if tracing is enabled in trace_puts()
tracing: Fix formatting of trace README file
tracing/README: Add event file usage to tracing mini-HOWTO
Pull scheduler fixes from Ingo Molnar:
"A couple of regression fixes mostly hitting virtualized setups, but
also some bare metal systems"
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/x86/tsc: Initialize multiplier to 0
sched/clock: Fixup early initialization
sched/preempt/x86: Fix voluntary preempt for x86
Revert "sched: Fix sleep time double accounting in enqueue entity"
When khungtaskd detects hung tasks, it prints out
backtraces from a number of those tasks.
Limiting the number of backtraces being printed
out can result in the user not seeing the information
necessary to debug the issue. The hung_task_warnings
sysctl controls this feature.
This patch makes it possible for hung_task_warnings
to accept a special value to print an unlimited
number of backtraces when khungtaskd detects hung
tasks.
The special value is -1. To use this value it is
necessary to change types from ulong to int.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: oleg@redhat.com
Link: http://lkml.kernel.org/r/1390239253-24030-3-git-send-email-atomlin@redhat.com
[ Build warning fix. ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
rcu_dereference_check_fdtable() looks very wrong,
1. rcu_my_thread_group_empty() was added by 844b9a8707 "vfs: fix
RCU-lockdep false positive due to /proc" but it doesn't really
fix the problem. A CLONE_THREAD (without CLONE_FILES) task can
hit the same race with get_files_struct().
And otoh rcu_my_thread_group_empty() can suppress the correct
warning if the caller is the CLONE_FILES (without CLONE_THREAD)
task.
2. files->count == 1 check is not really right too. Even if this
files_struct is not shared it is not safe to access it lockless
unless the caller is the owner.
Otoh, this check is sub-optimal. files->count == 0 always means
it is safe to use it lockless even if files != current->files,
but put_files_struct() has to take rcu_read_lock(). See the next
patch.
This patch removes the buggy checks and turns fcheck_files() into
__fcheck_files() which uses rcu_dereference_raw(), the "unshared"
callers, fget_light() and fget_raw_light(), can use it to avoid
the warning from RCU-lockdep.
fcheck_files() is trivially reimplemented as rcu_lockdep_assert()
plus __fcheck_files().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add neg_one to the list of standard constraints - will be used by the next patch.
Signed-off-by: Aaron Tomlin <atomlin@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: David Rientjes <rientjes@google.com>
Cc: oleg@redhat.com
Link: http://lkml.kernel.org/r/1390239253-24030-2-git-send-email-atomlin@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Some code added to the debug_core module had KDB dependencies
that it shouldn't have. Move the KDB dependent REASON back to
the caller to remove the dependency in the debug core code.
Update the call from the UV NMI handler to conform to the new
interface.
Signed-off-by: Mike Travis <travis@sgi.com>
Reviewed-by: Hedi Berriche <hedi@sgi.com>
Cc: Russ Anderson <rja@sgi.com>
Cc: Jason Wessel <jason.wessel@windriver.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Link: http://lkml.kernel.org/r/20140114162551.318251993@asylum.americas.sgi.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
- ACPI core changes to make it create a struct acpi_device object for every
device represented in the ACPI tables during all namespace scans regardless
of the current status of that device. In accordance with this, ACPI hotplug
operations will not delete those objects, unless the underlying ACPI tables
go away.
- On top of the above, new sysfs attribute for ACPI device objects allowing
user space to check device status by triggering the execution of _STA for
its ACPI object. From Srinivas Pandruvada.
- ACPI core hotplug changes reducing code duplication, integrating the
PCI root hotplug with the core and reworking container hotplug.
- ACPI core simplifications making it use ACPI_COMPANION() in the code
"glueing" ACPI device objects to "physical" devices.
- ACPICA update to upstream version 20131218. This adds support for the
DBG2 and PCCT tables to ACPICA, fixes some bugs and improves debug
facilities. From Bob Moore, Lv Zheng and Betty Dall.
- Init code change to carry out the early ACPI initialization earlier.
That should allow us to use ACPI during the timekeeping initialization
and possibly to simplify the EFI initialization too. From Chun-Yi Lee.
- Clenups of the inclusions of ACPI headers in many places all over from
Lv Zheng and Rashika Kheria (work in progress).
- New helper for ACPI _DSM execution and rework of the code in drivers
that uses _DSM to execute it via the new helper. From Jiang Liu.
- New Win8 OSI blacklist entries from Takashi Iwai.
- Assorted ACPI fixes and cleanups from Al Stone, Emil Goode, Hanjun Guo,
Lan Tianyu, Masanari Iida, Oliver Neukum, Prarit Bhargava, Rashika Kheria,
Tang Chen, Zhang Rui.
- intel_pstate driver updates, including proper Baytrail support, from
Dirk Brandewie and intel_pstate documentation from Ramkumar Ramachandra.
- Generic CPU boost ("turbo") support for cpufreq from Lukasz Majewski.
- powernow-k6 cpufreq driver fixes from Mikulas Patocka.
- cpufreq core fixes and cleanups from Viresh Kumar, Jane Li, Mark Brown.
- Assorted cpufreq drivers fixes and cleanups from Anson Huang, John Tobias,
Paul Bolle, Paul Walmsley, Sachin Kamat, Shawn Guo, Viresh Kumar.
- cpuidle cleanups from Bartlomiej Zolnierkiewicz.
- Support for hibernation APM events from Bin Shi.
- Hibernation fix to avoid bringing up nonboot CPUs with ACPI EC disabled
during thaw transitions from Bjørn Mork.
- PM core fixes and cleanups from Ben Dooks, Leonardo Potenza, Ulf Hansson.
- PNP subsystem fixes and cleanups from Dmitry Torokhov, Levente Kurusa,
Rashika Kheria.
- New tool for profiling system suspend from Todd E Brandt and a cpupower
tool cleanup from One Thousand Gnomes.
/
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Merge tag 'pm+acpi-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management updates from Rafael Wysocki:
"As far as the number of commits goes, the top spot belongs to ACPI
this time with cpufreq in the second position and a handful of PM
core, PNP and cpuidle updates. They are fixes and cleanups mostly, as
usual, with a couple of new features in the mix.
The most visible change is probably that we will create struct
acpi_device objects (visible in sysfs) for all devices represented in
the ACPI tables regardless of their status and there will be a new
sysfs attribute under those objects allowing user space to check that
status via _STA.
Consequently, ACPI device eject or generally hot-removal will not
delete those objects, unless the table containing the corresponding
namespace nodes is unloaded, which is extremely rare. Also ACPI
container hotplug will be handled quite a bit differently and cpufreq
will support CPU boost ("turbo") generically and not only in the
acpi-cpufreq driver.
Specifics:
- ACPI core changes to make it create a struct acpi_device object for
every device represented in the ACPI tables during all namespace
scans regardless of the current status of that device. In
accordance with this, ACPI hotplug operations will not delete those
objects, unless the underlying ACPI tables go away.
- On top of the above, new sysfs attribute for ACPI device objects
allowing user space to check device status by triggering the
execution of _STA for its ACPI object. From Srinivas Pandruvada.
- ACPI core hotplug changes reducing code duplication, integrating
the PCI root hotplug with the core and reworking container hotplug.
- ACPI core simplifications making it use ACPI_COMPANION() in the
code "glueing" ACPI device objects to "physical" devices.
- ACPICA update to upstream version 20131218. This adds support for
the DBG2 and PCCT tables to ACPICA, fixes some bugs and improves
debug facilities. From Bob Moore, Lv Zheng and Betty Dall.
- Init code change to carry out the early ACPI initialization
earlier. That should allow us to use ACPI during the timekeeping
initialization and possibly to simplify the EFI initialization too.
From Chun-Yi Lee.
- Clenups of the inclusions of ACPI headers in many places all over
from Lv Zheng and Rashika Kheria (work in progress).
- New helper for ACPI _DSM execution and rework of the code in
drivers that uses _DSM to execute it via the new helper. From
Jiang Liu.
- New Win8 OSI blacklist entries from Takashi Iwai.
- Assorted ACPI fixes and cleanups from Al Stone, Emil Goode, Hanjun
Guo, Lan Tianyu, Masanari Iida, Oliver Neukum, Prarit Bhargava,
Rashika Kheria, Tang Chen, Zhang Rui.
- intel_pstate driver updates, including proper Baytrail support,
from Dirk Brandewie and intel_pstate documentation from Ramkumar
Ramachandra.
- Generic CPU boost ("turbo") support for cpufreq from Lukasz
Majewski.
- powernow-k6 cpufreq driver fixes from Mikulas Patocka.
- cpufreq core fixes and cleanups from Viresh Kumar, Jane Li, Mark
Brown.
- Assorted cpufreq drivers fixes and cleanups from Anson Huang, John
Tobias, Paul Bolle, Paul Walmsley, Sachin Kamat, Shawn Guo, Viresh
Kumar.
- cpuidle cleanups from Bartlomiej Zolnierkiewicz.
- Support for hibernation APM events from Bin Shi.
- Hibernation fix to avoid bringing up nonboot CPUs with ACPI EC
disabled during thaw transitions from Bjørn Mork.
- PM core fixes and cleanups from Ben Dooks, Leonardo Potenza, Ulf
Hansson.
- PNP subsystem fixes and cleanups from Dmitry Torokhov, Levente
Kurusa, Rashika Kheria.
- New tool for profiling system suspend from Todd E Brandt and a
cpupower tool cleanup from One Thousand Gnomes"
* tag 'pm+acpi-3.14-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (153 commits)
thermal: exynos: boost: Automatic enable/disable of BOOST feature (at Exynos4412)
cpufreq: exynos4x12: Change L0 driver data to CPUFREQ_BOOST_FREQ
Documentation: cpufreq / boost: Update BOOST documentation
cpufreq: exynos: Extend Exynos cpufreq driver to support boost
cpufreq / boost: Kconfig: Support for software-managed BOOST
acpi-cpufreq: Adjust the code to use the common boost attribute
cpufreq: Add boost frequency support in core
intel_pstate: Add trace point to report internal state.
cpufreq: introduce cpufreq_generic_get() routine
ARM: SA1100: Create dummy clk_get_rate() to avoid build failures
cpufreq: stats: create sysfs entries when cpufreq_stats is a module
cpufreq: stats: free table and remove sysfs entry in a single routine
cpufreq: stats: remove hotplug notifiers
cpufreq: stats: handle cpufreq_unregister_driver() and suspend/resume properly
cpufreq: speedstep: remove unused speedstep_get_state
platform: introduce OF style 'modalias' support for platform bus
PM / tools: new tool for suspend/resume performance optimization
ACPI: fix module autoloading for ACPI enumerated devices
ACPI: add module autoloading support for ACPI enumerated devices
ACPI: fix create_modalias() return value handling
...
Merge second patch-bomb from Andrew Morton:
- various misc bits
- the rest of MM
- add generic fixmap.h, use it
- backlight updates
- dynamic_debug updates
- printk() updates
- checkpatch updates
- binfmt_elf
- ramfs
- init/
- autofs4
- drivers/rtc
- nilfs
- hfsplus
- Documentation/
- coredump
- procfs
- fork
- exec
- kexec
- kdump
- partitions
- rapidio
- rbtree
- userns
- memstick
- w1
- decompressors
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (197 commits)
lib/decompress_unlz4.c: always set an error return code on failures
romfs: fix returm err while getting inode in fill_super
drivers/w1/masters/w1-gpio.c: add strong pullup emulation
drivers/memstick/host/rtsx_pci_ms.c: fix ms card data transfer bug
userns: relax the posix_acl_valid() checks
arch/sh/kernel/dwarf.c: use rbtree postorder iteration helper instead of solution using repeated rb_erase()
fs-ext3-use-rbtree-postorder-iteration-helper-instead-of-opencoding-fix
fs/ext3: use rbtree postorder iteration helper instead of opencoding
fs/jffs2: use rbtree postorder iteration helper instead of opencoding
fs/ext4: use rbtree postorder iteration helper instead of opencoding
fs/ubifs: use rbtree postorder iteration helper instead of opencoding
net/netfilter/ipset/ip_set_hash_netiface.c: use rbtree postorder iteration instead of opencoding
rbtree/test: test rbtree_postorder_for_each_entry_safe()
rbtree/test: move rb_node to the middle of the test struct
rapidio: add modular rapidio core build into powerpc and mips branches
partitions/efi: complete documentation of gpt kernel param purpose
kdump: add /sys/kernel/vmcoreinfo ABI documentation
kdump: fix exported size of vmcoreinfo note
kexec: add sysctl to disable kexec_load
fs/exec.c: call arch_pick_mmap_layout() only once
...
Pull audit update from Eric Paris:
"Again we stayed pretty well contained inside the audit system.
Venturing out was fixing a couple of function prototypes which were
inconsistent (didn't hurt anything, but we used the same value as an
int, uint, u32, and I think even a long in a couple of places).
We also made a couple of minor changes to when a couple of LSMs called
the audit system. We hoped to add aarch64 audit support this go
round, but it wasn't ready.
I'm disappearing on vacation on Thursday. I should have internet
access, but it'll be spotty. If anything goes wrong please be sure to
cc rgb@redhat.com. He'll make fixing things his top priority"
* git://git.infradead.org/users/eparis/audit: (50 commits)
audit: whitespace fix in kernel-parameters.txt
audit: fix location of __net_initdata for audit_net_ops
audit: remove pr_info for every network namespace
audit: Modify a set of system calls in audit class definitions
audit: Convert int limit uses to u32
audit: Use more current logging style
audit: Use hex_byte_pack_upper
audit: correct a type mismatch in audit_syscall_exit()
audit: reorder AUDIT_TTY_SET arguments
audit: rework AUDIT_TTY_SET to only grab spin_lock once
audit: remove needless switch in AUDIT_SET
audit: use define's for audit version
audit: documentation of audit= kernel parameter
audit: wait_for_auditd rework for readability
audit: update MAINTAINERS
audit: log task info on feature change
audit: fix incorrect set of audit_sock
audit: print error message when fail to create audit socket
audit: fix dangling keywords in audit_log_set_loginuid() output
audit: log on errors from filter user rules
...
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>
For general-purpose (i.e. distro) kernel builds it makes sense to build
with CONFIG_KEXEC to allow end users to choose what kind of things they
want to do with kexec. However, in the face of trying to lock down a
system with such a kernel, there needs to be a way to disable kexec_load
(much like module loading can be disabled). Without this, it is too easy
for the root user to modify kernel memory even when CONFIG_STRICT_DEVMEM
and modules_disabled are set. With this change, it is still possible to
load an image for use later, then disable kexec_load so the image (or lack
of image) can't be altered.
The intention is for using this in environments where "perfect"
enforcement is hard. Without a verified boot, along with verified
modules, and along with verified kexec, this is trying to give a system a
better chance to defend itself (or at least grow the window of
discoverability) against attack in the face of a privilege escalation.
In my mind, I consider several boot scenarios:
1) Verified boot of read-only verified root fs loading fd-based
verification of kexec images.
2) Secure boot of writable root fs loading signed kexec images.
3) Regular boot loading kexec (e.g. kcrash) image early and locking it.
4) Regular boot with no control of kexec image at all.
1 and 2 don't exist yet, but will soon once the verified kexec series has
landed. 4 is the state of things now. The gap between 2 and 4 is too
large, so this change creates scenario 3, a middle-ground above 4 when 2
and 1 are not possible for a system.
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Rik van Riel <riel@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We can kill either task->did_exec or PF_FORKNOEXEC, they are mutually
exclusive. The patch kills ->did_exec because it has a single user.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Kees Cook <keescook@chromium.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
