Tejun Heo [Mon, 5 May 2014 16:37:30 +0000 (12:37 -0400)]
blkcg: use trylock on blkcg_pol_mutex in blkcg_reset_stats()
During the recent conversion of cgroup to kernfs, cgroup_tree_mutex
which nests above both the kernfs s_active protection and cgroup_mutex
is added to synchronize cgroup file type operations as cgroup_mutex
needed to be grabbed from some file operations and thus can't be put
above s_active protection.
While this arrangement mostly worked for cgroup, this triggered the
following lockdep warning.
======================================================
[ INFO: possible circular locking dependency detected ] 3.15.0-rc3-next-20140430-sasha-00016-g4e281fa-dirty #429 Tainted: G W
-------------------------------------------------------
trinity-c173/9024 is trying to acquire lock:
(blkcg_pol_mutex){+.+.+.}, at: blkcg_reset_stats (include/linux/spinlock.h:328 block/blk-cgroup.c:455)
but task is already holding lock:
(s_active#89){++++.+}, at: kernfs_fop_write (fs/kernfs/file.c:283)
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
This is a highly unlikely but valid circular dependency between "echo
1 > blkcg.reset_stats" and cfq module [un]loading. cgroup is going
through further locking update which will remove this complication but
for now let's use trylock on blkcg_pol_mutex and retry the file
operation if the trylock fails.
device_cgroup: check if exception removal is allowed
[PATCH v3 1/2] device_cgroup: check if exception removal is allowed
When the device cgroup hierarchy was introduced in bd2953ebbb53 - devcg: propagate local changes down the hierarchy
a specific case was overlooked. Consider the hierarchy bellow:
A default policy: ALLOW, exceptions will deny access
\
B default policy: ALLOW, exceptions will deny access
There's no need to verify when an new exception is added to B because
in this case exceptions will deny access to further devices, which is
always fine. Hierarchy in device cgroup only makes sure B won't have
more access than A.
But when an exception is removed (by writing devices.allow), it isn't
checked if the user is in fact removing an inherited exception from A,
thus giving more access to B.
This shouldn't be allowed and this patch fixes it by making sure to never allow
exceptions in this case to be removed if the exception is partially or fully
present on the parent.
v3: missing '*' in function description
v2: improved log message and formatting fixes
Tejun Heo [Sun, 4 May 2014 19:09:14 +0000 (15:09 -0400)]
cgroup, memcg: implement css->id and convert css_from_id() to use it
Until now, cgroup->id has been used to identify all the associated
csses and css_from_id() takes cgroup ID and returns the matching css
by looking up the cgroup and then dereferencing the css associated
with it; however, now that the lifetimes of cgroup and css are
separate, this is incorrect and breaks on the unified hierarchy when a
controller is disabled and enabled back again before the previous
instance is released.
This patch adds css->id which is a subsystem-unique ID and converts
css_from_id() to look up by the new css->id instead. memcg is the
only user of css_from_id() and also converted to use css->id instead.
For traditional hierarchies, this shouldn't make any functional
difference.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jianyu Zhan <nasa4836@gmail.com> Acked-by: Li Zefan <lizefan@huawei.com>
Tejun Heo [Sun, 4 May 2014 19:09:14 +0000 (15:09 -0400)]
cgroup: update init_css() into init_and_link_css()
init_css() takes the cgroup the new css belongs to as an argument and
initializes the new css's ->cgroup and ->parent pointers but doesn't
acquire the matching reference counts. After the previous patch,
create_css() puts init_css() and reference acquisition right next to
each other. Let's move reference acquistion into init_css() and
rename the function to init_and_link_css(). This makes sense and is
easier to follow. This makes the root csses to hold a reference on
cgrp_dfl_root.cgrp, which is harmless.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Tejun Heo [Sun, 4 May 2014 19:09:14 +0000 (15:09 -0400)]
cgroup: use RCU free in create_css() failure path
Currently, when create_css() fails in the middle, the half-initialized
css is freed by invoking cgroup_subsys->css_free() directly. This
patch updates the function so that it invokes RCU free path instead.
As the RCU free path puts the parent css and owning cgroup, their
references are now acquired right after a new css is successfully
allocated.
This doesn't make any visible difference now but is to enable
implementing css->id and RCU protected lookup by such IDs.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Tejun Heo [Sun, 4 May 2014 19:09:13 +0000 (15:09 -0400)]
cgroup: protect cgroup_root->cgroup_idr with a spinlock
Currently, cgroup_root->cgroup_idr is protected by cgroup_mutex, which
ends up requiring cgroup_put() to be invoked under sleepable context.
This is okay for now but is an unusual requirement and we'll soon add
css->id which will have the same problem but won't be able to simply
grab cgroup_mutex as removal will have to happen from css_release()
which can't sleep.
Introduce cgroup_idr_lock and idr_alloc/replace/remove() wrappers
which protects the idr operations with the lock and use them for
cgroup_root->cgroup_idr. cgroup_put() no longer needs to grab
cgroup_mutex and css_from_id() is updated to always require RCU read
lock instead of either RCU read lock or cgroup_mutex, which doesn't
affect the existing users.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Tejun Heo [Sun, 4 May 2014 19:09:13 +0000 (15:09 -0400)]
cgroup, memcg: allocate cgroup ID from 1
Currently, cgroup->id is allocated from 0, which is always assigned to
the root cgroup; unfortunately, memcg wants to use ID 0 to indicate
invalid IDs and ends up incrementing all IDs by one.
It's reasonable to reserve 0 for special purposes. This patch updates
cgroup core so that ID 0 is not used and the root cgroups get ID 1.
The ID incrementing is removed form memcg.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Li Zefan <lizefan@huawei.com>
Tejun Heo [Sun, 4 May 2014 19:09:13 +0000 (15:09 -0400)]
cgroup: make flags and subsys_masks unsigned int
There's no reason to use atomic bitops for cgroup_subsys_state->flags,
cgroup_root->flags and various subsys_masks. This patch updates those
to use bitwise and/or operations instead and converts them form
unsigned long to unsigned int.
This makes the fields occupy (marginally) smaller space and makes it
clear that they don't require atomicity.
This patch doesn't cause any behavior difference.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Joe Perches [Fri, 25 Apr 2014 22:28:03 +0000 (18:28 -0400)]
cgroup: Use more current logging style
Use pr_fmt and remove embedded prefixes.
Realign modified multi-line statements to open parenthesis.
Convert embedded function name to "%s: ", __func__
Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Tejun Heo <tj@kernel.org>
6612f05b88fa309c9 ("cgroup: unify pidlist and other file handling")
has removed the only user of cgroup_pidlist_seq_operations :
cgroup_pidlist_open().
cgroup: clean up obsolete comment for parse_cgroupfs_options()
1d5be6b287c8efc87 ("cgroup: move module ref handling into
rebind_subsystems()") makes parse_cgroupfs_options() no longer takes
refcounts on subsystems.
And unified hierachy makes parse_cgroupfs_options not need to call
with cgroup_mutex held to protect the cgroup_subsys[].
So this patch removes BUG_ON() and the comment. As the comment
doesn't contain useful information afterwards, the whole comment is
removed.
Unified hierarchy will be the new version of cgroup interface. This
patch adds Documentation/cgroups/unified-hierarchy.txt which describes
the design and rationales of unified hierarchy.
v2: Grammatical updates as per Randy Dunlap's review.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org>
cgroup: implement cgroup.populated for the default hierarchy
cgroup users often need a way to determine when a cgroup's
subhierarchy becomes empty so that it can be cleaned up. cgroup
currently provides release_agent for it; unfortunately, this mechanism
is riddled with issues.
* It delivers events by forking and execing a userland binary
specified as the release_agent. This is a long deprecated method of
notification delivery. It's extremely heavy, slow and cumbersome to
integrate with larger infrastructure.
* There is single monitoring point at the root. There's no way to
delegate management of a subtree.
* The event isn't recursive. It triggers when a cgroup doesn't have
any tasks or child cgroups. Events for internal nodes trigger only
after all children are removed. This again makes it impossible to
delegate management of a subtree.
* Events are filtered from the kernel side. "notify_on_release" file
is used to subscribe to or suppress release event. This is
unnecessarily complicated and probably done this way because event
delivery itself was expensive.
This patch implements interface file "cgroup.populated" which can be
used to monitor whether the cgroup's subhierarchy has tasks in it or
not. Its value is 0 if there is no task in the cgroup and its
descendants; otherwise, 1, and kernfs_notify() notificaiton is
triggers when the value changes, which can be monitored through poll
and [di]notify.
This is a lot ligther and simpler and trivially allows delegating
management of subhierarchy - subhierarchy monitoring can block further
propgation simply by putting itself or another process in the root of
the subhierarchy and monitor events that it's interested in from there
without interfering with monitoring higher in the tree.
v2: Patch description updated as per Serge.
v3: "cgroup.subtree_populated" renamed to "cgroup.populated". The
subtree_ prefix was a bit confusing because
"cgroup.subtree_control" uses it to denote the tree rooted at the
cgroup sans the cgroup itself while the populated state includes
the cgroup itself.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com> Acked-by: Li Zefan <lizefan@huawei.com> Cc: Lennart Poettering <lennart@poettering.net>
kernfs: make kernfs_notify() trigger inotify events too
kernfs_notify() is used to indicate either new data is available or
the content of a file has changed. It currently only triggers poll
which may not be the most convenient to monitor especially when there
are a lot to monitor. Let's hook it up to fsnotify too so that the
events can be monitored via inotify too.
fsnotify_modify() requires file * but kernfs_notify() doesn't have any
specific file associated; however, we can walk all super_blocks
associated with a kernfs_root and as kernfs always associate one ino
with inode and one dentry with an inode, it's trivial to look up the
dentry associated with a given kernfs_node. As any active monitor
would pin dentry, just looking up existing dentry is enough. This
patch looks up the dentry associated with the specified kernfs_node
and generates events equivalent to fsnotify_modify().
Note that as fsnotify doesn't provide fsnotify_modify() equivalent
which can be called with dentry, kernfs_notify() directly calls
fsnotify_parent() and fsnotify(). It might be better to add a wrapper
in fsnotify.h instead.
Signed-off-by: Tejun Heo <tj@kernel.org> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Currently, there's no way to find out which super_blocks are
associated with a given kernfs_root. Let's implement it - the planned
inotify extension to kernfs_notify() needs it.
Make kernfs_super_info point back to the super_block and chain it at
kernfs_root->supers.
cgroup: implement dynamic subtree controller enable/disable on the default hierarchy
cgroup is switching away from multiple hierarchies and will use one
unified default hierarchy where controllers can be dynamically enabled
and disabled per subtree. The default hierarchy will serve as the
unified hierarchy to which all controllers are attached and a css on
the default hierarchy would need to also serve the tasks of descendant
cgroups which don't have the controller enabled - ie. the tree may be
collapsed from leaf towards root when viewed from specific
controllers. This has been implemented through effective css in the
previous patches.
This patch finally implements dynamic subtree controller
enable/disable on the default hierarchy via a new knob -
"cgroup.subtree_control" which controls which controllers are enabled
on the child cgroups. Let's assume a hierarchy like the following.
root - A - B - C
\ D
root's "cgroup.subtree_control" determines which controllers are
enabled on A. A's on B. B's on C and D. This coincides with the
fact that controllers on the immediate sub-level are used to
distribute the resources of the parent. In fact, it's natural to
assume that resource control knobs of a child belong to its parent.
Enabling a controller in "cgroup.subtree_control" declares that
distribution of the respective resources of the cgroup will be
controlled. Note that this means that controller enable states are
shared among siblings.
The default hierarchy has an extra restriction - only cgroups which
don't contain any task may have controllers enabled in
"cgroup.subtree_control". Combined with the other properties of the
default hierarchy, this guarantees that, from the view point of
controllers, tasks are only on the leaf cgroups. In other words, only
leaf csses may contain tasks. This rules out situations where child
cgroups compete against internal tasks of the parent, which is a
competition between two different types of entities without any clear
way to determine resource distribution between the two. Different
controllers handle it differently and all the implemented behaviors
are ambiguous, ad-hoc, cumbersome and/or just wrong. Having this
structural constraints imposed from cgroup core removes the burden
from controller implementations and enables showing one consistent
behavior across all controllers.
When a controller is enabled or disabled, css associations for the
controller in the subtrees of each child should be updated. After
enabling, the whole subtree of a child should point to the new css of
the child. After disabling, the whole subtree of a child should point
to the cgroup's css. This is implemented by first updating cgroup
states such that cgroup_e_css() result points to the appropriate css
and then invoking cgroup_update_dfl_csses() which migrates all tasks
in the affected subtrees to the self cgroup on the default hierarchy.
* When read, "cgroup.subtree_control" lists all the currently enabled
controllers on the children of the cgroup.
* White-space separated list of controller names prefixed with either
'+' or '-' can be written to "cgroup.subtree_control". The ones
prefixed with '+' are enabled on the controller and '-' disabled.
* A controller can be enabled iff the parent's
"cgroup.subtree_control" enables it and disabled iff no child's
"cgroup.subtree_control" has it enabled.
* If a cgroup has tasks, no controller can be enabled via
"cgroup.subtree_control". Likewise, if "cgroup.subtree_control" has
some controllers enabled, tasks can't be migrated into the cgroup.
* All controllers which aren't bound on other hierarchies are
automatically associated with the root cgroup of the default
hierarchy. All the controllers which are bound to the default
hierarchy are listed in the read-only file "cgroup.controllers" in
the root directory.
* "cgroup.controllers" in all non-root cgroups is read-only file whose
content is equal to that of "cgroup.subtree_control" of the parent.
This indicates which controllers can be used in the cgroup's
"cgroup.subtree_control".
This is still experimental and there are some holes, one of which is
that ->can_attach() failure during cgroup_update_dfl_csses() may leave
the cgroups in an undefined state. The issues will be addressed by
future patches.
v2: Non-root cgroups now also have "cgroup.controllers".
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
cgroup: prepare migration path for unified hierarchy
Unified hierarchy implementation would require re-migrating tasks onto
the same cgroup on the default hierarchy to reflect updated effective
csses. Update cgroup_migrate_prepare_dst() so that it accepts NULL as
the destination cgrp. When NULL is specified, the destination is
considered to be the cgroup on the default hierarchy associated with
each css_set.
After this change, the identity check in cgroup_migrate_add_src()
isn't sufficient for noop detection as the associated csses may change
without any cgroup association changing. The only way to tell whether
a migration is noop or not is testing whether the source and
destination csets are identical. The noop check in
cgroup_migrate_add_src() is removed and cset identity test is added to
cgroup_migreate_prepare_dst(). If it's detected that source and
destination csets are identical, the cset is removed removed from
@preloaded_csets and all the migration nodes are cleared which makes
cgroup_migrate() ignore the cset.
Also, make the function append the destination css_sets to
@preloaded_list so that destination css_sets always come after source
css_sets.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Because the default root couldn't have any non-root csses attached to
it, rebinding away from it was always allowed; however, the default
hierarchy will soon host the unified hierarchy and have non-root csses
so the rebind restrictions need to be updated accordingly.
Instead of special casing rebinding from the default hierarchy and
then checking whether the source hierarchy has children cgroups, which
implies non-root csses for !dfl hierarchies, simply check whether the
source hierarchy has non-root csses for the subsystem using
css_next_child().
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
To implement the unified hierarchy behavior, we'll need to be able to
determine the associated cgroup on the default hierarchy from css_set.
Let's add css_set->dfl_cgrp so that it can be accessed conveniently
and efficiently.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
cgroup: allow cgroup creation and suppress automatic css creation in the unified hierarchy
Now that effective css handling has been added and iterators updated
accordingly, it's safe to allow cgroup creation in the default
hierarchy. Unblock cgroup creation in the default hierarchy.
As the default hierarchy will implement explicit enabling and
disabling of controllers on each cgroup, suppress automatic css
enabling on cgroup creation.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
cgroup: cgroup->subsys[] should be cleared after the css is offlined
After a css finishes offlining, offline_css() mistakenly performs
RCU_INIT_POINTER(css->cgroup->subsys[ss->id], css) which just sets the
cgroup->subsys[] pointer to the current value. The intention was to
clear it after offline is complete, not reassign the same value.
Update it to assign NULL instead of the current value. This makes
cgroup_css() to return NULL once offline is complete. All the
existing users of the function either can handle NULL return already
or guarantee that the css doesn't get offlined.
While this is a bugfix, as css lifetime is currently tied to the
cgroup it belongs to, this bug doesn't cause any actual problems.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
Currently, css_task_iter iterates tasks associated with a css by
visiting each css_set associated with the owning cgroup and walking
tasks of each of them. This works fine for !unified hierarchies as
each cgroup has its own css for each associated subsystem on the
hierarchy; however, on the planned unified hierarchy, a cgroup may not
have csses associated and its tasks would be considered associated
with the matching css of the nearest ancestor which has the subsystem
enabled.
This means that on the default unified hierarchy, just walking all
tasks associated with a cgroup isn't enough to walk all tasks which
are associated with the specified css. If any of its children doesn't
have the matching css enabled, task iteration should also include all
tasks from the subtree. We already added cgroup->e_csets[] to list
all css_sets effectively associated with a given css and walk css_sets
on that list instead to achieve such iteration.
This patch updates css_task_iter iteration such that it walks css_sets
on cgroup->e_csets[] instead of cgroup->cset_links if iteration is
requested on an non-dummy css. Thanks to the previous iteration
update, this change can be achieved with the addition of
css_task_iter->ss and minimal updates to css_advance_task_iter() and
css_task_iter_start().
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
This patch reorganizes css_task_iter so that adding effective css
support is easier.
* s/->cset_link/->cset_pos/ and s/->task/->task_pos/ for consistency
* ->origin_css is used to determine whether the iteration reached the
last css_set. Replace it with explicit ->cset_head so that
css_advance_task_iter() doesn't have to know the termination
condition directly.
* css_task_iter_next() currently assumes that it's walking list of
cgrp_cset_link and reaches into the current cset through the current
link to determine the termination conditions for task walking. As
this won't always be true for effective css walking, add
->tasks_head and ->mg_tasks_head and use them to control task
walking so that css_task_iter_next() doesn't have to know how
css_sets are being walked.
This patch doesn't make any behavior changes. The iteration logic
stays unchanged after the patch.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
css_next_child() walks the children of the specified css. It does
this by finding the next cgroup and then returning the requested css.
On the default unified hierarchy, a cgroup may not have a css
associated with it even if the hierarchy has the subsystem enabled.
This patch updates css_next_child() so that it skips children without
the requested css associated.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
On the default unified hierarchy, a cgroup may be associated with
csses of its ancestors, which means that a css of a given cgroup may
be associated with css_sets of descendant cgroups. This means that we
can't walk all tasks associated with a css by iterating the css_sets
associated with the cgroup as there are css_sets which are pointing to
the css but linked on the descendants.
This patch adds per-subsystem list heads cgroup->e_csets[]. Any
css_set which is pointing to a css is linked to
css->cgroup->e_csets[$SUBSYS_ID] through
css_set->e_cset_node[$SUBSYS_ID]. The lists are protected by
css_set_rwsem and will allow us to walk all css_sets associated with a
given css so that we can find out all associated tasks.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
In the planned default unified hierarchy, controllers may get
dynamically attached to and detached from a cgroup and a cgroup may
not have csses for all the controllers associated with the hierarchy.
When a cgroup doesn't have its own css for a given controller, the css
of the nearest ancestor with the controller enabled will be used,
which is called the effective css. This patch introduces
cgroup_e_css() and for_each_e_css() to access the effective csses and
convert compare_css_sets(), find_existing_css_set() and
cgroup_migrate() to use the effective csses so that they can handle
cgroups with partial csses correctly.
This means that for two css_sets to be considered identical, they
should have both matching csses and cgroups. compare_css_sets()
already compares both, not for correctness but for optimization. As
this now becomes a matter of correctness, update the comments
accordingly.
For all !default hierarchies, cgroup_e_css() always equals
cgroup_css(), so this patch doesn't change behavior.
While at it, fix incorrect locking comment for for_each_css().
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
cgroup: update cgroup->subsys_mask to ->child_subsys_mask and restore cgroup_root->subsys_mask
944196278d3d ("cgroup: move ->subsys_mask from cgroupfs_root to
cgroup") moved ->subsys_mask from cgroup_root to cgroup to prepare for
the unified hierarhcy; however, it turns out that carrying the
subsys_mask of the children in the parent, instead of itself, is a lot
more natural. This patch restores cgroup_root->subsys_mask and morphs
cgroup->subsys_mask into cgroup->child_subsys_mask.
* Uses of root->cgrp.subsys_mask are restored to root->subsys_mask.
* Remove automatic setting and clearing of cgrp->subsys_mask and
instead just inherit ->child_subsys_mask from the parent during
cgroup creation. Note that this doesn't affect any current
behaviors.
* Undo __kill_css() separation.
Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
cgroup: cgroup_apply_cftypes() shouldn't skip the default hierarhcy
cgroup_apply_cftypes() skip creating or removing files if the
subsystem is attached to the default hierarchy, which led to missing
files in the root of the default hierarchy.
Skipping made sense when the default hierarchy was dummy; however, now
that the default hierarchy is full functional and planned to be used
as the unified hierarchy, it shouldn't be skipped over.
Reported-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Li Zefan <lizefan@huawei.com>
device_cgroup: rework device access check and exception checking
Whenever a device file is opened and checked against current device
cgroup rules, it uses the same function (may_access()) as when a new
exception rule is added by writing devices.{allow,deny}. And in both
cases, the algorithm is the same, doesn't matter the behavior.
First problem is having device access to be considered the same as rule
checking. Consider the following structure:
A (default behavior: allow, exceptions disallow access)
\
B (default behavior: allow, exceptions disallow access)
A new exception is added to B by writing devices.deny:
c 12:34 rw
When checking if that exception is allowed in may_access():
if (dev_cgroup->behavior == DEVCG_DEFAULT_ALLOW) {
if (behavior == DEVCG_DEFAULT_ALLOW) {
/* the exception will deny access to certain devices */
return true;
Which is ok, since B is not getting more privileges than A, it doesn't
matter and the rule is accepted
Now, consider it's a device file open check and the process belongs to
cgroup B. The access will be generated as:
behavior: allow
exception: c 12:34 rw
The very same chunk of code will allow it, even if there's an explicit
exception telling to do otherwise.
c39a2a3018f8 devcg: prepare may_access() for hierarchy support
To solve this problem, the device file open function was split from the
new exception check.
Second problem is how exceptions are processed by may_access(). The
first part of the said function tries to match fully with an existing
exception:
list_for_each_entry_rcu(ex, &dev_cgroup->exceptions, list) {
if ((refex->type & DEV_BLOCK) && !(ex->type & DEV_BLOCK))
continue;
if ((refex->type & DEV_CHAR) && !(ex->type & DEV_CHAR))
continue;
if (ex->major != ~0 && ex->major != refex->major)
continue;
if (ex->minor != ~0 && ex->minor != refex->minor)
continue;
if (refex->access & (~ex->access))
continue;
match = true;
break;
}
That means the new exception should be contained into an existing one to
be considered a match:
New exception Existing match? notes
b 12:34 rwm b 12:34 rwm yes
b 12:34 r b *:34 rw yes
b 12:34 rw b 12:34 w no extra "r"
b *:34 rw b 12:34 rw no too broad "*"
b *:34 rw b *:34 rwm yes
Which is fine in some cases. Consider:
A (default behavior: deny, exceptions allow access)
\
B (default behavior: deny, exceptions allow access)
In this case the full match makes sense, the new exception cannot add
more access than the parent allows
But this doesn't always work, consider:
A (default behavior: allow, exceptions disallow access)
\
B (default behavior: deny, exceptions allow access)
In this case, a new exception in B shouldn't match any of the exceptions
in A, after all you can't allow something that was forbidden by A. But
consider this scenario:
New exception Existing in A match? outcome
b 12:34 rw b 12:34 r no exception is accepted
Because the new exception has "w" as extra, it doesn't match, so it'll
be added to B's exception list.
The same problem can happen during a file access check. Consider a
cgroup with allow as default behavior:
Access Exception match?
b 12:34 rw b 12:34 r no
In this case, the access didn't match any of the exceptions in the
cgroup, which is required since exceptions will disallow access.
To solve this problem, two new functions were created to match an
exception either fully or partially. In the example above, a partial
check will be performed and it'll produce a match since at least
"b 12:34 r" from "b 12:34 rw" access matches.
Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dma
Pull slave-dmaengine fixes from Vinod Koul:
"Back from long weekend here in India and now the time to send fixes
for slave dmaengine.
- Dan's fix of sirf xlate code
- Jean's fix for timberland
- edma fixes by Sekhar for SG handling and Yuan for changing init
call"
* 'fixes' of git://git.infradead.org/users/vkoul/slave-dma:
dma: fix eDMA driver as a subsys_initcall
dmaengine: sirf: off by one in of_dma_sirfsoc_xlate()
platform: Fix timberdale dependencies
dma: edma: fix incorrect SG list handling
Merge tag 'iommu-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull iommu fixes from Joerg Roedel:
"Fixes for regressions:
- fix wrong IOMMU enumeration causing some SCSI device drivers
initialization failures
- ARM-SMMU fixes for a panic condition and a wrong return value"
* tag 'iommu-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/arm-smmu: fix panic in arm_smmu_alloc_init_pte
iommu/arm-smmu: Return 0 on unmap failure
iommu/vt-d: fix bug in matching PCI devices with DRHD/RMRR descriptors
iommu/vt-d: Fix get_domain_for_dev() handling of upstream PCIe bridges
iommu/vt-d: fix memory leakage caused by commit ea8ea46
Adrien BAK [Fri, 18 Apr 2014 02:00:43 +0000 (11:00 +0900)]
perf tools: Improve error reporting
In the current version, when using perf record, if something goes
wrong in tools/perf/builtin-record.c:375
session = perf_session__new(file, false, NULL);
The error message:
"Not enough memory for reading per file header"
is issued. This error message seems to be outdated and is not very
helpful. This patch proposes to replace this error message by
"Perf session creation failed"
I believe this issue has been brought to lkml:
https://lkml.org/lkml/2014/2/24/458
although this patch only tackles a (small) part of the issue.
Additionnaly, this patch improves error reporting in
tools/perf/util/data.c open_file_write.
Currently, if the call to open fails, the user is unaware of it.
This patch logs the error, before returning the error code to
the caller.
Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Adrien BAK <adrien.bak@metascale.org> Link: http://lkml.kernel.org/r/1397786443.3093.4.camel@beast
[ Reorganize the changelog into paragraphs ]
[ Added empty line after fd declaration in open_file_write ] Signed-off-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Vladimir Nikulichev <nvs@tbricks.com> Tested-by: Namhyung Kim <namhyung@kernel.org> Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> Link: http://lkml.kernel.org/r/969812.163009436-sendEmail@nvs Signed-off-by: Jiri Olsa <jolsa@redhat.com>
perf kvm: Fix 'Min time' counting in report command
Every event in the perf-kvm has a 'stats' structure, which contains
max/min/average/etc times of handling this event.
The problem is that the 'perf-kvm stat report' command always shows
that 'min time' is 0us for every event. Example:
This happens because the 'stats' structure is not initialized and
stats->min equals to 0. Lets initialize the structure for every
event after its allocation using init_stats() function. This initializes
stats->min to -1 and makes 'Min time' statistics counting work:
Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linux
Pull drm fixes from Dave Airlie:
"Unfortunately this contains no easter eggs, its a bit larger than I'd
like, but I included a patch that just moves code from one file to
another and I'd like to avoid merge conflicts with that later, so it
makes it seem worse than it is,
Otherwise:
- radeon: fixes to use new microcode to stabilise some cards, use
some common displayport code, some runtime pm fixes, pll regression
fixes
- i915: fix for some context oopses, a warn in a used path, backlight
fixes
- nouveau: regression fix
- omap: a bunch of fixes"
* 'drm-fixes' of git://people.freedesktop.org/~airlied/linux: (51 commits)
drm: bochs: drop unused struct fields
drm: bochs: add power management support
drm: cirrus: add power management support
drm: Split out drm_probe_helper.c from drm_crtc_helper.c
drm/plane-helper: Don't fake-implement primary plane disabling
drm/ast: fix value check in cbr_scan2
drm/nouveau/bios: fix a bit shift error introduced by 457e77b
drm/radeon/ci: make sure mc ucode is loaded before checking the size
drm/radeon/si: make sure mc ucode is loaded before checking the size
drm/radeon: improve PLL params if we don't match exactly v2
drm/radeon: memory leak on bo reservation failure. v2
drm/radeon: fix VCE fence command
drm/radeon: re-enable mclk dpm on R7 260X asics
drm/radeon: add support for newer mc ucode on CI (v2)
drm/radeon: add support for newer mc ucode on SI (v2)
drm/radeon: apply more strict limits for PLL params v2
drm/radeon: update CI DPM powertune settings
drm/radeon: fix runpm handling on APUs (v4)
drm/radeon: disable mclk dpm on R7 260X
drm/tegra: Remove gratuitous pad field
...
Dave Airlie [Sat, 19 Apr 2014 01:16:02 +0000 (11:16 +1000)]
Merge branch 'drm-next-3.15-wip' of git://people.freedesktop.org/~deathsimple/linux into drm-next
Some i2c fixes over DisplayPort.
* 'drm-next-3.15-wip' of git://people.freedesktop.org/~deathsimple/linux:
drm/radeon: Improve vramlimit module param documentation
drm/radeon: fix audio pin counts for DCE6+ (v2)
drm/radeon/dp: switch to the common i2c over aux code
drm/dp/i2c: Update comments about common i2c over dp assumptions (v3)
drm/dp/i2c: send bare addresses to properly reset i2c connections (v4)
drm/radeon/dp: handle zero sized i2c over aux transactions (v2)
drm/i915: support address only i2c-over-aux transactions
drm/tegra: dp: Support address-only I2C-over-AUX transactions
1) Fix mlx4_en_netpoll implementation, it needs to schedule a NAPI
context, not synchronize it. From Chris Mason.
2) Ipv4 flow input interface should never be zero, it should be
LOOPBACK_IFINDEX instead. From Cong Wang and Julian Anastasov.
3) Properly configure MAC to PHY connection in mvneta devices, from
Thomas Petazzoni.
4) sys_recv should use SYSCALL_DEFINE. From Jan Glauber.
5) Tunnel driver ioctls do not use the correct namespace, fix from
Nicolas Dichtel.
6) Fix memory leak on seccomp filter attach, from Kees Cook.
7) Fix lockdep warning for nested vlans, from Ding Tianhong.
8) Crashes can happen in SCTP due to how the auth_enable value is
managed, fix from Vlad Yasevich.
9) Wireless fixes from John W Linville and co.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (45 commits)
net: sctp: cache auth_enable per endpoint
tg3: update rx_jumbo_pending ring param only when jumbo frames are enabled
vlan: Fix lockdep warning when vlan dev handle notification
seccomp: fix memory leak on filter attach
isdn: icn: buffer overflow in icn_command()
ip6_tunnel: use the right netns in ioctl handler
sit: use the right netns in ioctl handler
ip_tunnel: use the right netns in ioctl handler
net: use SYSCALL_DEFINEx for sys_recv
net: mdio-gpio: Add support for separate MDI and MDO gpio pins
net: mdio-gpio: Add support for active low gpio pins
net: mdio-gpio: Use devm_ functions where possible
ipv4, route: pass 0 instead of LOOPBACK_IFINDEX to fib_validate_source()
ipv4, fib: pass LOOPBACK_IFINDEX instead of 0 to flowi4_iif
mlx4_en: don't use napi_synchronize inside mlx4_en_netpoll
net: mvneta: properly configure the MAC <-> PHY connection in all situations
net: phy: add minimal support for QSGMII PHY
sfc:On MCDI timeout, issue an FLR (and mark MCDI to fail-fast)
mwifiex: fix hung task on command timeout
mwifiex: process event before command response
...
Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6
Pull cifs fixes from Steve French:
"A set of 5 small cifs fixes"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
cif: fix dead code
cifs: fix error handling cifs_user_readv
fs: cifs: remove unused variable.
Return correct error on query of xattr on file with empty xattrs
cifs: Wait for writebacks to complete before attempting write.
Merge tag 'char-misc-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver fixes from Greg KH:
"Here are a few driver fixes for char/misc drivers that resolve
reported issues.
All have been in linux-next successfully for a few days"
* tag 'char-misc-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
Drivers: hv: vmbus: Negotiate version 3.0 when running on ws2012r2 hosts
Tools: hv: Handle the case when the target file exists correctly
vme_tsi148: Utilize to_pci_dev() macro
vme_tsi148: Fix PCI address mapping assumption
vme_tsi148: Fix typo in tsi148_slave_get()
w1: avoid recursive device_add
w1: fix netlink refcnt leak on error path
misc: Grammar s/addition/additional/
drivers: mcb: fix memory leak in chameleon_parse_cells() error path
mei: ignore client writing state during cb completion
mei: me: do not load the driver if the FW doesn't support MEI interface
GenWQE: Increase driver version number
GenWQE: Fix multithreading problems
GenWQE: Ensure rc is not returning an uninitialized value
GenWQE: Add wmb before DDCB is started
GenWQE: Enable access to VPD flash area
Merge tag 'driver-core-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core fixes from Greg KH:
"Here are some driver core fixes for 3.15-rc2. Also in here are some
documentation updates, as well as an API removal that had to wait for
after -rc1 due to the cleanups coming into you from multiple developer
trees (this one and the PPC tree.)
All have been in linux next successfully"
* tag 'driver-core-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core:
drivers/base/dd.c incorrect pr_debug() parameters
Documentation: Update stable address in Chinese and Japanese translations
topology: Fix compilation warning when not in SMP
Chinese: add translation of io_ordering.txt
stable_kernel_rules: spelling/word usage
sysfs, driver-core: remove unused {sysfs|device}_schedule_callback_owner()
kernfs: protect lazy kernfs_iattrs allocation with mutex
fs: Don't return 0 from get_anon_bdev
Merge tag 'staging-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging
Pull staging driver fixes from Greg KH:
"Here are a few staging driver fixes for issues that have been reported
for 3.15-rc2.
Also dominating the diffstat for the pull request is the removal of
the rtl8187se driver. It's no longer needed in staging as a "real"
driver for this hardware is now merged in the tree in the "correct"
location in drivers/net/
All of these patches have been tested in linux-next"
* tag 'staging-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging:
staging: r8188eu: Fix case where ethtype was never obtained and always be checked against 0
staging: r8712u: Fix case where ethtype was never obtained and always be checked against 0
staging: r8188eu: Calling rtw_get_stainfo() with a NULL sta_addr will return NULL
staging: comedi: fix circular locking dependency in comedi_mmap()
staging: r8723au: Add missing initialization of change_inx in sort algorithm
Staging: unisys: use after free in list_for_each()
staging: unisys: use after free in error messages
staging: speakup: fix misuse of kstrtol() in handle_goto()
staging: goldfish: Call free_irq in error path
staging: delete rtl8187se wireless driver
staging: rtl8723au: Fix buffer overflow in rtw_get_wfd_ie()
staging: gs_fpgaboot: remove __TIMESTAMP__ macro
staging: vme: fix memory leak in vme_user_probe()
staging: fpgaboot: clean up Makefile
staging/usbip: fix store_attach() sscanf return value check
staging/usbip: userspace - fix usbipd SIGSEGV from refresh_exported_devices()
staging: rtl8188eu: remove spaces, correct counts to unbreak P2P ioctls
staging/rtl8821ae: Fix OOM handling in _rtl_init_deferred_work()
Merge tag 'tty-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial driver fixes from Greg KH:
"Here are a number of small tty/serial driver fixes for 3.15-rc2. Also
in here are some Documentation file removals for drivers that we
removed a long time ago, no need to keep it around any longer.
All of these have been in linux-next for a bit"
* tag 'tty-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
Revert "serial: 8250, disable "too much work" messages"
serial: amba-pl011: fix regression, causing an Oops on rmmod
tty: Fix help text of SYNCLINK_CS
tty: fix memleak in alloc_pid
ttyprintk: Allow built as a module
ttyprintk: Fix wrong tty_unregister_driver() call in the error path
serial: 8250, disable "too much work" messages
Documentation/serial: Delete obsolete driver documentation
serial: omap: Fix missing pm_runtime_resume handling by simplifying code
serial_core: Fix pm imbalance on unbind
serial: pl011: change Rx burst size to half of trigger level
serial: timberdale: Depend on X86_32
serial: st-asc: Fix SysRq char handling
Revert "serial: clps711x: Give a chance to perform useful tasks during wait loop"
serial_core: Fix conditional start_tx on ring buffer not empty
serial: efm32: use $vendor,$device scheme for compatible string
serial: omap: free the wakeup settings in remove
Merge tag 'usb-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
Pull USB fixes from Greg KH:
"Here are a number of tiny USB fixes and new device ids for 3.15-rc2.
Nothing major, just issues some people have reported.
All of these have been in linux-next"
* tag 'usb-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
uas: fix deadlocky memory allocations
uas: fix error handling during scsi_scan()
uas: fix GFP_NOIO under spinlock
uwb: adds missing error handling
USB: cdc-acm: Remove Motorola/Telit H24 serial interfaces from ACM driver
USB: ohci-jz4740: FEAT_POWER is a port feature, not a hub feature
USB: ohci-jz4740: Fix uninitialized variable warning
USB: EHCI: tegra: set txfill_tuning
usb: ehci-platform: Return immediately from suspend if ehci_suspend fails
usb: ehci-exynos: Return immediately from suspend if ehci_suspend fails
USB: fix crash during hotplug of PCI USB controller card
USB: cdc-acm: fix double usb_autopm_put_interface() in acm_port_activate()
usb: usb-common: fix typo for usb_state_string
USB: usb_wwan: fix handling of missing bulk endpoints
USB: pl2303: add ids for Hewlett-Packard HP POS pole displays
USB: cp210x: Add 8281 (Nanotec Plug & Drive)
usb: option driver, add support for Telit UE910v2
Revert "USB: serial: add usbid for dell wwan card to sierra.c"
USB: serial: ftdi_sio: add id for Brainboxes serial cards
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
thp: close race between split and zap huge pages
mm: fix new kernel-doc warning in filemap.c
mm: fix CONFIG_DEBUG_VM_RB description
mm: use paravirt friendly ops for NUMA hinting ptes
mips: export flush_icache_range
mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()
wait: explain the shadowing and type inconsistencies
Shiraz has moved
Documentation/vm/numa_memory_policy.txt: fix wrong document in numa_memory_policy.txt
powerpc/mm: fix ".__node_distance" undefined
kernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()
init/Kconfig: move the trusted keyring config option to general setup
vmscan: reclaim_clean_pages_from_list() must use mod_zone_page_state()
Sasha Levin has reported two THP BUGs[1][2]. I believe both of them
have the same root cause. Let's look to them one by one.
The first bug[1] is "kernel BUG at mm/huge_memory.c:1829!". It's
BUG_ON(mapcount != page_mapcount(page)) in __split_huge_page(). From my
testing I see that page_mapcount() is higher than mapcount here.
I think it happens due to race between zap_huge_pmd() and
page_check_address_pmd(). page_check_address_pmd() misses PMD which is
under zap:
CPU0 CPU1
zap_huge_pmd()
pmdp_get_and_clear()
__split_huge_page()
anon_vma_interval_tree_foreach()
__split_huge_page_splitting()
page_check_address_pmd()
mm_find_pmd()
/*
* We check if PMD present without taking ptl: no
* serialization against zap_huge_pmd(). We miss this PMD,
* it's not accounted to 'mapcount' in __split_huge_page().
*/
pmd_present(pmd) == 0
The second bug[2] is "kernel BUG at mm/huge_memory.c:1371!".
It's VM_BUG_ON_PAGE(!PageHead(page), page) in zap_huge_pmd().
This happens in similar way:
CPU0 CPU1
zap_huge_pmd()
pmdp_get_and_clear()
page_remove_rmap(page)
atomic_add_negative(-1, &page->_mapcount)
__split_huge_page()
anon_vma_interval_tree_foreach()
__split_huge_page_splitting()
page_check_address_pmd()
mm_find_pmd()
pmd_present(pmd) == 0 /* The same comment as above */
/*
* No crash this time since we already decremented page->_mapcount in
* zap_huge_pmd().
*/
BUG_ON(mapcount != page_mapcount(page))
/*
* We split the compound page here into small pages without
* serialization against zap_huge_pmd()
*/
__split_huge_page_refcount()
VM_BUG_ON_PAGE(!PageHead(page), page); // CRASH!!!
So my understanding the problem is pmd_present() check in mm_find_pmd()
without taking page table lock.
The bug was introduced by me commit with commit 117b0791ac42. Sorry for
that. :(
Let's open code mm_find_pmd() in page_check_address_pmd() and do the
check under page table lock.
Note that __page_check_address() does the same for PTE entires
if sync != 0.
I've stress tested split and zap code paths for 36+ hours by now and
don't see crashes with the patch applied. Before it took <20 min to
trigger the first bug and few hours for second one (if we ignore
first).
This appears to be a copy/paste error. Update the description to
reflect extra rbtree debug and checks for the config option instead of
duplicating CONFIG_DEBUG_VM.
mm: use paravirt friendly ops for NUMA hinting ptes
David Vrabel identified a regression when using automatic NUMA balancing
under Xen whereby page table entries were getting corrupted due to the
use of native PTE operations. Quoting him
Xen PV guest page tables require that their entries use machine
addresses if the preset bit (_PAGE_PRESENT) is set, and (for
successful migration) non-present PTEs must use pseudo-physical
addresses. This is because on migration MFNs in present PTEs are
translated to PFNs (canonicalised) so they may be translated back
to the new MFN in the destination domain (uncanonicalised).
pte_mknonnuma(), pmd_mknonnuma(), pte_mknuma() and pmd_mknuma()
set and clear the _PAGE_PRESENT bit using pte_set_flags(),
pte_clear_flags(), etc.
In a Xen PV guest, these functions must translate MFNs to PFNs
when clearing _PAGE_PRESENT and translate PFNs to MFNs when setting
_PAGE_PRESENT.
His suggested fix converted p[te|md]_[set|clear]_flags to using
paravirt-friendly ops but this is overkill. He suggested an alternative
of using p[te|md]_modify in the NUMA page table operations but this is
does more work than necessary and would require looking up a VMA for
protections.
This patch modifies the NUMA page table operations to use paravirt
friendly operations to set/clear the flags of interest. Unfortunately
this will take a performance hit when updating the PTEs on
CONFIG_PARAVIRT but I do not see a way around it that does not break
Xen.
Signed-off-by: Mel Gorman <mgorman@suse.de> Acked-by: David Vrabel <david.vrabel@citrix.com> Tested-by: David Vrabel <david.vrabel@citrix.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Anvin <hpa@zytor.com> Cc: Fengguang Wu <fengguang.wu@intel.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Steven Noonan <steven@uplinklabs.net> Cc: Rik van Riel <riel@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: Cyrill Gorcunov <gorcunov@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The lkdtm module performs tests against executable memory ranges, so it
needs to flush the icache for proper behaviors. Other architectures
already export this, so do the same for MIPS.
[akpm@linux-foundation.org: relocate export sites] Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Sanjay Lal <sanjayl@kymasys.com> Cc: John Crispin <blogic@openwrt.org> Cc: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()
soft lockup in freeing gigantic hugepage fixed in commit 55f67141a892 "mm:
hugetlb: fix softlockup when a large number of hugepages are freed." can
happen in return_unused_surplus_pages(), so let's fix it.
Documentation/vm/numa_memory_policy.txt: fix wrong document in numa_memory_policy.txt
In document numa_memory_policy.txt, the following examples for flag
MPOL_F_RELATIVE_NODES are incorrect.
For example, consider a task that is attached to a cpuset with
mems 2-5 that sets an Interleave policy over the same set with
MPOL_F_RELATIVE_NODES. If the cpuset's mems change to 3-7, the
interleave now occurs over nodes 3,5-6. If the cpuset's mems
then change to 0,2-3,5, then the interleave occurs over nodes
0,3,5.
According to the comment of the patch adding flag MPOL_F_RELATIVE_NODES,
the nodemasks the user specifies should be considered relative to the
current task's mems_allowed.
(https://lkml.org/lkml/2008/2/29/428)
And according to numa_memory_policy.txt, if the user's nodemask includes
nodes that are outside the range of the new set of allowed nodes, then
the remap wraps around to the beginning of the nodemask and, if not
already set, sets the node in the mempolicy nodemask.
So in the example, if the user specifies 2-5, for a task whose
mems_allowed is 3-7, the nodemasks should be remapped the third, fourth,
fifth, sixth node in mems_allowed. like the following:
mems_allowed: 3 4 5 6 7
relative index: 0 1 2 3 4
5
So the nodemasks should be remapped to 3,5-7, but not 3,5-6.
And for a task whose mems_allowed is 0,2-3,5, the nodemasks should be
remapped to 0,2-3,5, but not 0,3,5.
mems_allowed: 0 2 3 5
relative index: 0 1 2 3
4 5
Signed-off-by: Tang Chen <tangchen@cn.fujitsu.com> Cc: Randy Dunlap <rdunlap@infradead.org> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Andrew Morton [Fri, 18 Apr 2014 22:07:12 +0000 (15:07 -0700)]
kernel/watchdog.c:touch_softlockup_watchdog(): use raw_cpu_write()
Fix:
BUG: using __this_cpu_write() in preemptible [00000000] code: systemd-udevd/497
caller is __this_cpu_preempt_check+0x13/0x20
CPU: 3 PID: 497 Comm: systemd-udevd Tainted: G W 3.15.0-rc1 #9
Hardware name: Hewlett-Packard HP EliteBook 8470p/179B, BIOS 68ICF Ver. F.02 04/27/2012
Call Trace:
check_preemption_disabled+0xe1/0xf0
__this_cpu_preempt_check+0x13/0x20
touch_nmi_watchdog+0x28/0x40
Reported-by: Luis Henriques <luis.henriques@canonical.com> Tested-by: Luis Henriques <luis.henriques@canonical.com> Cc: Eric Piel <eric.piel@tremplin-utc.net> Cc: Robert Moore <robert.moore@intel.com> Cc: Lv Zheng <lv.zheng@intel.com> Cc: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com> Cc: Len Brown <lenb@kernel.org> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Peter Foley [Fri, 18 Apr 2014 22:07:11 +0000 (15:07 -0700)]
init/Kconfig: move the trusted keyring config option to general setup
The SYSTEM_TRUSTED_KEYRING config option is not in any menu, causing it
to show up in the toplevel of the kernel configuration. Fix this by
moving it under the General Setup menu.
Signed-off-by: Peter Foley <pefoley2@pefoley.com> Cc: David Howells <dhowells@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
What happens while auth_enable=0 in that case is, that
ep->auth_hmacs is initialized to NULL in sctp_auth_init_hmacs()
when endpoint is being created.
After that point, if an admin switches over to auth_enable=1,
the machine can crash due to NULL pointer dereference during
reception of an INIT chunk. When we enter sctp_process_init()
via sctp_sf_do_5_1B_init() in order to respond to an INIT chunk,
the INIT verification succeeds and while we walk and process
all INIT params via sctp_process_param() we find that
net->sctp.auth_enable is set, therefore do not fall through,
but invoke sctp_auth_asoc_set_default_hmac() instead, and thus,
dereference what we have set to NULL during endpoint
initialization phase.
The fix is to make auth_enable immutable by caching its value
during endpoint initialization, so that its original value is
being carried along until destruction. The bug seems to originate
from the very first days.
Fix in joint work with Daniel Borkmann.
Reported-by: Joshua Kinard <kumba@gentoo.org> Signed-off-by: Vlad Yasevich <vyasevic@redhat.com> Signed-off-by: Daniel Borkmann <dborkman@redhat.com> Acked-by: Neil Horman <nhorman@tuxdriver.com> Tested-by: Joshua Kinard <kumba@gentoo.org> Signed-off-by: David S. Miller <davem@davemloft.net>
Please pull this batch of fixes intended for the 3.15 stream...
For the mac80211 bits, Johannes says:
"We have a fix from Chun-Yeow to not look at management frame bitrates
that are typically really low, two fixes from Felix for AP_VLAN
interfaces, a fix from Ido to disable SMPS settings when a monitor
interface is enabled, a radar detection fix from Michał and a fix from
myself for a very old remain-on-channel bug."
For the iwlwifi bits, Emmanuel says:
"I have new device IDs and a new firmware API. These are the trivial
ones. The less trivial ones are Johannes's fix that delays the
enablement of an interrupt coalescing hardware until after association
- this fixes a few connection problems seen in the field. Eyal has a
bunch of rate control fixes. I decided to add these for 3.15 because
they fix some disconnection and packet loss scenarios which were
reported by the field. I also have a fix for a memory leak that
happens only with a very new NIC."
Along with those...
Amitkumar Karwar fixes a couple of problems relating to driver/firmware
interactions in mwifiex.
Christian Engelmayer avoids a couple of potential memory leaks in
the new rsi driver.
Eliad Peller provides a wl18xx mailbox alignment fix for problems
when using new firmware.
Frederic Danis adds a couple of missing debugging strings to the
cw1200 driver.
Geert Uytterhoeven adds a variable initialization inside of the
rsi driver.
Luciano Coelho patches the wlcore code to ignore dummy packet events
in PLT mode in order to work around a firmware bug.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Ivan Vecera [Thu, 17 Apr 2014 12:51:08 +0000 (14:51 +0200)]
tg3: update rx_jumbo_pending ring param only when jumbo frames are enabled
The patch fixes a problem with dropped jumbo frames after usage of
'ethtool -G ... rx'.
Scenario:
1. ip link set eth0 up
2. ethtool -G eth0 rx N # <- This zeroes rx-jumbo
3. ip link set mtu 9000 dev eth0
The ethtool command set rx_jumbo_pending to zero so any received jumbo
packets are dropped and you need to use 'ethtool -G eth0 rx-jumbo N'
to workaround the issue.
The patch changes the logic so rx_jumbo_pending value is changed only if
jumbo frames are enabled (MTU > 1500).
Signed-off-by: Ivan Vecera <ivecera@redhat.com> Acked-by: Michael Chan <mchan@broadcom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
The reason is that all of the addr_lock_key for vlan dev have the same class,
so if we change the status for vlan dev, the vlan dev and its real dev will
hold the same class of addr_lock_key together, so the warning happened.
we should distinguish the lock depth for vlan dev and its real dev.
v1->v2: Convert the vlan_netdev_addr_lock_key to an array of eight elements, which
could support to add 8 vlan id on a same vlan dev, I think it is enough for current
scene, because a netdev's name is limited to IFNAMSIZ which could not hold 8 vlan id,
and the vlan dev would not meet the same class key with its real dev.
The new function vlan_dev_get_lockdep_subkey() will return the subkey and make the vlan
dev could get a suitable class key.
v2->v3: According David's suggestion, I use the subclass to distinguish the lock key for vlan dev
and its real dev, but it make no sense, because the difference for subclass in the
lock_class_key doesn't mean that the difference class for lock_key, so I use lock_depth
to distinguish the different depth for every vlan dev, the same depth of the vlan dev
could have the same lock_class_key, I import the MAX_LOCK_DEPTH from the include/linux/sched.h,
I think it is enough here, the lockdep should never exceed that value.
v3->v4: Add a huge array of locking keys will waste static kernel memory and is not a appropriate method,
we could use _nested() variants to fix the problem, calculate the depth for every vlan dev,
and use the depth as the subclass for addr_lock_key.
Signed-off-by: Ding Tianhong <dingtianhong@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Merge tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband
Pull infiniband/rdma updates from Roland Dreier:
- mostly cxgb4 fixes unblocked by the merge of some prerequisites via
the net tree
- drop deprecated MSI-X API use.
- a couple other miscellaneous things.
* tag 'rdma-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/roland/infiniband:
RDMA/cxgb4: Fix over-dereference when terminating
RDMA/cxgb4: Use uninitialized_var()
RDMA/cxgb4: Add missing debug stats
RDMA/cxgb4: Initialize reserved fields in a FW work request
RDMA/cxgb4: Use pr_warn_ratelimited
RDMA/cxgb4: Max fastreg depth depends on DSGL support
RDMA/cxgb4: SQ flush fix
RDMA/cxgb4: rmb() after reading valid gen bit
RDMA/cxgb4: Endpoint timeout fixes
RDMA/cxgb4: Use the BAR2/WC path for kernel QPs and T5 devices
IB/mlx5: Add block multicast loopback support
IB/mthca: Use pci_enable_msix_exact() instead of pci_enable_msix()
IB/qib: Use pci_enable_msix_range() instead of pci_enable_msix()
Commit 93ea02bb8435 ("arch: Clean up asm/barrier.h implementations")
wired generic barrier.h for ARC, but failed to delete the existing file.
In 3.15, due to rcupdate.h updates, this causes a build breakage on ARC:
CC arch/arc/kernel/asm-offsets.s
In file included from include/linux/sched.h:45:0,
from arch/arc/kernel/asm-offsets.c:9:
include/linux/rculist.h: In function __list_add_rcu:
include/linux/rculist.h:54:2: error: implicit declaration of function smp_store_release [-Werror=implicit-function-declaration]
rcu_assign_pointer(list_next_rcu(prev), new);
^
Merge tag 'pci-v3.15-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI updates from Bjorn Helgaas:
"These are fixes for a powerpc NULL pointer dereference, an OF
interrupt mapping issue on some of the new host bridges, and a
DesignWare iATU issue.
* tag 'pci-v3.15-fixes-1' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: tegra: Use new OF interrupt mapping when possible
PCI: rcar: Use new OF interrupt mapping when possible
PCI: designware: Use new OF interrupt mapping when possible
PCI: designware: Fix iATU programming for cfg1, io and mem viewport
PCI: designware: Fix comment for setting number of lanes
powerpc/PCI: Fix NULL dereference in sys_pciconfig_iobase() list traversal
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
Pull HID fixes from Jiri Kosina:
- fix for merge window mismerge in hid-sony, from Frank Praznik
- fix for Surface Type/Touch Cover 2 device, from Benjamin Tissoires
- quirk for ThinkPad Helix sensor hub from Stephen Chandler Paul
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
HID: core: do not scan constant input report
Revert "HID: microsoft: Add ID's for Surface Type/Touch Cover 2"
HID: sensor-hub: add sensor hub quirk for ThinkPad Helix
HID: sony: Fix cancel_work_sync mismerge
Merge tag 'sound-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"Just a copule of HD-audio device/codec-specific quirks, and a trivial
replacement of udelay() with mdelay() in the old es18xx driver code.
All should be safe to apply"
* tag 'sound-3.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: hda/realtek - Add headset Mic support for Dell machine
ALSA: hda - add headset mic detect quirk for a Dell laptop
ALSA: es18xx driver should use udelay error
ALSA: hda/realtek - Add support of ALC288 codec
Merge tag 'dt-fixes-for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux
Pull devicetree fixes from Rob Herring:
- fix error handling in of_update_property
- fix section mismatch warnings in __reserved_mem_check_root
- add empty of_find_node_by_path for !OF builds
- add various missing binding documentation
* tag 'dt-fixes-for-3.15' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
of: add empty of_find_node_by_path() for !OF
of: Clean up of_update_property
DT: add vendor prefix for EBV Elektronik
of: Fix the section mismatch warnings.
of: Add vendor prefix for Digi International Inc.
DT: I2C: Add trivial bindings used by kirkwood boards
DT: Vendor: Add prefixes used by Kirkwood devices
DT: bindings: add missing Marvell Kirkwood SoC documentation
dt-bindings: add vendor-prefix for Newhaven Display
of: add vendor prefix for I2SE GmbH
of: add vendor prefix for ISEE 2007 S.L.
Merge tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs
Pull xfs bug fixes from Dave Chinner:
"The fixes are for data corruption issues, memory corruption and
regressions for changes merged in -rc1.
Data corruption fixes:
- fix a bunch of delayed allocation state mismatches
- fix collapse/zero range bugs
- fix a direct IO block mapping bug @ EOF
Other fixes:
- fix a use after free on metadata IO error
- fix a use after free on IO error during unmount
- fix an incorrect error sign on direct IO write errors
- add missing O_TMPFILE inode security context initialisation"
* tag 'xfs-for-linus-3.15-rc2' of git://oss.sgi.com/xfs/xfs:
xfs: fix tmpfile/selinux deadlock and initialize security
xfs: fix buffer use after free on IO error
xfs: wrong error sign conversion during failed DIO writes
xfs: unmount does not wait for shutdown during unmount
xfs: collapse range is delalloc challenged
xfs: don't map ranges that span EOF for direct IO
xfs: zeroing space needs to punch delalloc blocks
xfs: xfs_vm_write_end truncates too much on failure
xfs: write failure beyond EOF truncates too much data
xfs: kill buffers over failed write ranges properly
Merge tag 'trace-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fixes from Steven Rostedt:
"This contains two fixes.
The first is to remove a duplication of creating debugfs files that
already exist and causes an error report to be printed due to the
failure of the second creation.
The second is a memory leak fix that was introduced in 3.14"
* tag 'trace-fixes-v3.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/uprobes: Fix uprobe_cpu_buffer memory leak
tracing: Do not try to recreated toplevel set_ftrace_* files
Alexander Shiyan [Wed, 16 Apr 2014 06:49:20 +0000 (10:49 +0400)]
of: add empty of_find_node_by_path() for !OF
Add an empty version of of_find_node_by_path().
This fixes following build error for asoc tree:
sound/soc/fsl/fsl_ssi.c: In function 'fsl_ssi_probe':
sound/soc/fsl/fsl_ssi.c:1471:2: error: implicit declaration of function 'of_find_node_by_path' [-Werror=implicit-function-declaration]
sprop = of_get_property(of_find_node_by_path("/"), "compatible", NULL);
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Alexander Shiyan <shc_work@mail.ru> Signed-off-by: Rob Herring <robh@kernel.org>
perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU
CPUs which should support the RAPL counters according to
Family/Model/Stepping may still issue #GP when attempting to access
the RAPL MSRs. This may happen when Linux is running under KVM and
we are passing-through host F/M/S data, for example. Use rdmsrl_safe
to first access the RAPL_POWER_UNIT MSR; if this fails, do not
attempt to use this PMU.
Signed-off-by: Venkatesh Srinivas <venkateshs@google.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com Cc: zheng.z.yan@intel.com Cc: eranian@google.com Cc: ak@linux.intel.com Cc: linux-kernel@vger.kernel.org
[ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
Daniel Vetter [Thu, 10 Apr 2014 08:51:11 +0000 (10:51 +0200)]
drm: Split out drm_probe_helper.c from drm_crtc_helper.c
This is leftover stuff from my previous doc round which I kinda wanted
to do but didn't yet due to rebase hell.
The modeset helpers and the probing helpers a independent and e.g.
i915 uses the probing stuff but has its own modeset infrastructure. It
hence makes to split this up. While at it add a DOC: comment for the
probing libraray.
It would be rather neat to pull some of the DocBook documenting these
two helpers into in-line DOC: comments. But unfortunately kerneldoc
doesn't support markdown or something similar to make nice-looking
documentation, so the current state is better.
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Dave Airlie <airlied@redhat.com>
After thinking about this topic a bit more I've reached the conclusion
that implementing this doesn't make sense:
- The locking is all wrong: set_config(NULL) will also unlink encoders
and connectors, but those links are protected with the mode_config
mutex. In the ->disable_plane callback we only hold all modeset
locks, but eventually we want to switch to just grabbing the
per-crtc (and maybe per-plane) locks as needed, maybe based on
ww_mutexes. Having a callback which absolutely needs all modeset
locks is bad for this conversion.
Note that the same isn't true for the provided ->update_plane since
we've audited the crtc helpers to make sure that not encoder or
connector links are changed.
- There's no way to re-enable the plane with an ->update_plane: The
connectors/encoder links are lost and so we can't re-enable the
CRTC. Even without that issue the driver might have reassigned some
shared resources (as opposed to e.g. DPMS off, where drivers are not
allowed to do that to make sure the CRTC can be enabled again).
- The semantics don't make much sense: Userspace asked to scan out
black (or some other color if the driver supports a background
color), not that the screen be disabled.
- Implementing proper primary plane support (i.e. actually disabling
the primary plane without disabling the CRTC) is really simple, at
least if all the hw needs is flipping a bit. The big task is
auditing all the interactions with other ioctls when the CRTC is on
but there's no primary plane (e.g. pageflips). And some of that work
still needs to be done.
Cc: Matt Roper <matthew.d.roper@intel.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch> Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Reviewed-by: Matt Roper <matthew.d.roper@intel.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
Sergei Antonov [Tue, 15 Apr 2014 21:18:37 +0000 (23:18 +0200)]
drm/nouveau/bios: fix a bit shift error introduced by 457e77b
Commit 457e77b26428ab4a24998eecfb99f27fa4195397 added two checks applied to a
value received from nv_rd32(bios, 0x619f04). But after this new piece of code
is executed, the addr local variable does not hold the same value it used to
hold before the commit. Here is what is was assigned in the original code:
(u64)(nv_rd32(bios, 0x619f04) & 0xffffff00) << 8
in the committed code it ends up with this value:
(u64)(nv_rd32(bios, 0x619f04) >> 8) << 8
These expressions are obviously not equivalent.
My Nvidia video card does not show anything on the display when I boot a
kernel containing this commit.
The patch fixes the code so that the new checks are still done, but the
side effect of an incorrect addr value is gone.
Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Dave Airlie <airlied@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Sergei Antonov <saproj@gmail.com> Signed-off-by: Dave Airlie <airlied@redhat.com>
projects / karo-tx-linux.git / log