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2014-04-25cgroup: clean up obsolete comment for parse_cgroupfs_options()Jianyu Zhan
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. Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-04-25cgroup: add documentation about unified hierarchyTejun Heo
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>
2014-04-25cgroup: implement cgroup.populated for the default hierarchyTejun Heo
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>
2014-04-25Merge branch 'driver-core-next' of ↵Tejun Heo
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core into for-3.16 Pull in driver-core-next to receive kernfs_notify() updates which will be used by the planned "cgroup.populated" implementation. Signed-off-by: Tejun Heo <tj@kernel.org>
2014-04-25kobject: Make support for uevent_helper optional.Michael Marineau
Support for uevent_helper, aka hotplug, is not required on many systems these days but it can still be enabled via sysfs or sysctl. Reported-by: Darren Shepherd <darren.s.shepherd@gmail.com> Signed-off-by: Michael Marineau <mike@marineau.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-25kernfs: make kernfs_notify() trigger inotify events tooTejun Heo
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>
2014-04-25kernfs: implement kernfs_root->supers listTejun Heo
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. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-23cgroup: implement dynamic subtree controller enable/disable on the default ↵Tejun Heo
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>
2014-04-23cgroup: prepare migration path for unified hierarchyTejun Heo
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>
2014-04-23cgroup: update subsystem rebind restrictionsTejun Heo
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>
2014-04-23cgroup: add css_set->dfl_cgrpTejun Heo
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>
2014-04-23cgroup: allow cgroup creation and suppress automatic css creation in the ↵Tejun Heo
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>
2014-04-23cgroup: cgroup->subsys[] should be cleared after the css is offlinedTejun Heo
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>
2014-04-23cgroup: teach css_task_iter about effective cssesTejun Heo
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>
2014-04-23cgroup: reorganize css_task_iterTejun Heo
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>
2014-04-23cgroup: make css_next_child() skip missing cssesTejun Heo
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>
2014-04-23cgroup: implement cgroup->e_csets[]Tejun Heo
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>
2014-04-23cgroup: introduce effective cgroup_subsys_stateTejun Heo
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>
2014-04-23cgroup: update cgroup->subsys_mask to ->child_subsys_mask and restore ↵Tejun Heo
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>
2014-04-23cgroup: cgroup_apply_cftypes() shouldn't skip the default hierarhcyTejun Heo
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>
2014-04-21device_cgroup: rework device access check and exception checkingAristeu Rozanski
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. A simple test case: # mkdir new_group # cd new_group # echo $$ >tasks # echo "c 1:3 w" >devices.deny # echo >/dev/null # echo $? 0 This is a serious bug and was introduced on 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. Cc: cgroups@vger.kernel.org Cc: Tejun Heo <tj@kernel.org> Cc: Serge Hallyn <serge.hallyn@canonical.com> Cc: Li Zefan <lizefan@huawei.com> Cc: stable@vger.kernel.org Signed-off-by: Aristeu Rozanski <arozansk@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2014-04-20Linux 3.15-rc2Linus Torvalds
2014-04-20Merge branch 'fixes' of git://git.infradead.org/users/vkoul/slave-dmaLinus Torvalds
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
2014-04-20Merge tag 'iommu-fixes-v3.15-rc1' of ↵Linus Torvalds
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
2014-04-20Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf tooling fixes from Ingo Molnar: "Three small tooling fixes" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf tools: Improve error reporting perf tools: Adjust symbols in VDSO perf kvm: Fix 'Min time' counting in report command
2014-04-20Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar
git://git.kernel.org/pub/scm/linux/kernel/git/jolsa/perf into perf/urgent Pull perf/urgent fixes from Jiri Olsa: User visible changes: * Adjust symbols in VDSO to properly resolve its function names (Vladimir Nikulichev) * Improve error reporting for record session failure (Adrien BAK) * Fix 'Min time' counting in report command (Alexander Yarygin) Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-04-20perf tools: Improve error reportingAdrien BAK
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>
2014-04-20perf tools: Adjust symbols in VDSOVladimir Nikulichev
pert-report doesn't resolve function names in VDSO: $ perf report --stdio -g flat,0.0,15,callee --sort pid ... 8.76% 0x7fff6b1fe861 __gettimeofday ACE_OS::gettimeofday() ... In this case symbol values should be adjusted the same way as for executables, relocatable objects and prelinked libraries. After fix: $ perf report --stdio -g flat,0.0,15,callee --sort pid ... 8.76% __vdso_gettimeofday __gettimeofday ACE_OS::gettimeofday() 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>
2014-04-20perf kvm: Fix 'Min time' counting in report commandAlexander Yarygin
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: # perf kvm stat report Analyze events for all VCPUs: VM-EXIT Samples Samples% Time% Min Time Max Time Avg time [..] 0xB2 MSCH 12 0.07% 0.00% 0us 8us 7.31us ( +- 2.11% ) 0xB2 CHSC 12 0.07% 0.00% 0us 18us 9.39us ( +- 9.49% ) 0xB2 STPX 8 0.05% 0.00% 0us 2us 1.88us ( +- 7.18% ) 0xB2 STSI 7 0.04% 0.00% 0us 44us 16.49us ( +- 38.20% ) [..] 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: # perf kvm stat report Analyze events for all VCPUs: VM-EXIT Samples Samples% Time% Min Time Max Time Avg time [..] 0xB2 MSCH 12 0.07% 0.00% 6us 8us 7.31us ( +- 2.11% ) 0xB2 CHSC 12 0.07% 0.00% 7us 18us 9.39us ( +- 9.49% ) 0xB2 STPX 8 0.05% 0.00% 1us 2us 1.88us ( +- 7.18% ) 0xB2 STSI 7 0.04% 0.00% 1us 44us 16.49us ( +- 38.20% ) [..] Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: David Ahern <dsahern@gmail.com> Link: http://lkml.kernel.org/r/1397053319-2130-3-git-send-email-borntraeger@de.ibm.com [ Fixing the perf examples changelog output ] Signed-off-by: Jiri Olsa <jolsa@redhat.com>
2014-04-19coredump: fix va_list corruptionEric Dumazet
A va_list needs to be copied in case it needs to be used twice. Thanks to Hugh for debugging this issue, leading to various panics. Tested: lpq84:~# echo "|/foobar12345 %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h" >/proc/sys/kernel/core_pattern 'produce_core' is simply : main() { *(int *)0 = 1;} lpq84:~# ./produce_core Segmentation fault (core dumped) lpq84:~# dmesg | tail -1 [ 614.352947] Core dump to |/foobar12345 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 lpq84 (null) pipe failed Notice the last argument was replaced by a NULL (we were lucky enough to not crash, but do not try this on your production machine !) After fix : lpq83:~# echo "|/foobar12345 %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h %h" >/proc/sys/kernel/core_pattern lpq83:~# ./produce_core Segmentation fault lpq83:~# dmesg | tail -1 [ 740.800441] Core dump to |/foobar12345 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 lpq83 pipe failed Fixes: 5fe9d8ca21cc ("coredump: cn_vprintf() has no reason to call vsnprintf() twice") Signed-off-by: Eric Dumazet <edumazet@google.com> Diagnosed-by: Hugh Dickins <hughd@google.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: stable@vger.kernel.org # 3.11+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-19Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fix from Ingo Molnar: "This fixes the preemption-count imbalance crash reported by Owen Kibel" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mce: Fix CMCI preemption bugs
2014-04-19Merge branch 'sched-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Two fixes: - a SCHED_DEADLINE task selection fix - a sched/numa related lockdep splat fix" * 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched: Check for stop task appearance when balancing happens sched/numa: Fix task_numa_free() lockdep splat
2014-04-19Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Two kernel side fixes: - an Intel uncore PMU driver potential crash fix - a kprobes/perf-call-graph interaction fix" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU kprobes/x86: Fix page-fault handling logic
2014-04-19Merge branch 'drm-fixes' of git://people.freedesktop.org/~airlied/linuxLinus Torvalds
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 ...
2014-04-19Merge branch 'drm-next-3.15-wip' of ↵Dave Airlie
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
2014-04-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
Pull more networking fixes from David Miller: 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 ...
2014-04-18Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
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.
2014-04-18Merge tag 'char-misc-3.15-rc2' of ↵Linus Torvalds
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
2014-04-18Merge tag 'driver-core-3.15-rc2' of ↵Linus Torvalds
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
2014-04-18Merge tag 'staging-3.15-rc2' of ↵Linus Torvalds
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()
2014-04-18Merge tag 'tty-3.15-rc2' of ↵Linus Torvalds
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
2014-04-18Merge tag 'usb-3.15-rc2' of ↵Linus Torvalds
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
2014-04-18Merge branch 'akpm' (incoming from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "13 fixes" * 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()
2014-04-18thp: close race between split and zap huge pagesKirill A. Shutemov
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 BUG_ON(mapcount != page_mapcount(page)) // CRASH!!! page_remove_rmap(page) atomic_add_negative(-1, &page->_mapcount) 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). [1] https://lkml.kernel.org/g/<53440991.9090001@oracle.com> [2] https://lkml.kernel.org/g/<5310C56C.60709@oracle.com> Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Cc: Bob Liu <lliubbo@gmail.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Rik van Riel <riel@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Michel Lespinasse <walken@google.com> Cc: Dave Jones <davej@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> [3.13+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-18mm: fix new kernel-doc warning in filemap.cRandy Dunlap
Fix new kernel-doc warning in mm/filemap.c: Warning(mm/filemap.c:2600): Excess function parameter 'ppos' description in '__generic_file_aio_write' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-18mm: fix CONFIG_DEBUG_VM_RB descriptionDavidlohr Bueso
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. Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Aswin Chandramouleeswaran <aswin@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-18mm: use paravirt friendly ops for NUMA hinting ptesMel Gorman
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>
2014-04-18mips: export flush_icache_rangeKees Cook
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>
2014-04-18mm/hugetlb.c: add cond_resched_lock() in return_unused_surplus_pages()Mizuma, Masayoshi
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. Signed-off-by: Masayoshi Mizuma <m.mizuma@jp.fujitsu.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Aneesh Kumar <aneesh.kumar@linux.vnet.ibm.com> Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-18wait: explain the shadowing and type inconsistenciesPeter Zijlstra
Stick in a comment before someone else tries to fix the sparse warning this generates. Suggested-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/n/tip-o2ro6f3vkxklni0bc8f7m68s@git.kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>