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ff6d413b |
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12-Dec-2023 |
Kees Cook <keescook@chromium.org> |
kernfs: Convert kernfs_path_from_node_locked() from strlcpy() to strscpy() One of the last remaining users of strlcpy() in the kernel is kernfs_path_from_node_locked(), which passes back the problematic "length we _would_ have copied" return value to indicate truncation. Convert the chain of all callers to use the negative return value (some of which already doing this explicitly). All callers were already also checking for negative return values, so the risk to missed checks looks very low. In this analysis, it was found that cgroup1_release_agent() actually didn't handle the "too large" condition, so this is technically also a bug fix. :) Here's the chain of callers, and resolution identifying each one as now handling the correct return value: kernfs_path_from_node_locked() kernfs_path_from_node() pr_cont_kernfs_path() returns void kernfs_path() sysfs_warn_dup() return value ignored cgroup_path() blkg_path() bfq_bic_update_cgroup() return value ignored TRACE_IOCG_PATH() return value ignored TRACE_CGROUP_PATH() return value ignored perf_event_cgroup() return value ignored task_group_path() return value ignored damon_sysfs_memcg_path_eq() return value ignored get_mm_memcg_path() return value ignored lru_gen_seq_show() return value ignored cgroup_path_from_kernfs_id() return value ignored cgroup_show_path() already converted "too large" error to negative value cgroup_path_ns_locked() cgroup_path_ns() bpf_iter_cgroup_show_fdinfo() return value ignored cgroup1_release_agent() wasn't checking "too large" error proc_cgroup_show() already converted "too large" to negative value Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Waiman Long <longman@redhat.com> Cc: <cgroups@vger.kernel.org> Co-developed-by: Azeem Shaikh <azeemshaikh38@gmail.com> Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Link: https://lore.kernel.org/r/20231116192127.1558276-3-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20231212211741.164376-3-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
aecd408b |
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29-Oct-2023 |
Yafang Shao <laoar.shao@gmail.com> |
cgroup: Add a new helper for cgroup1 hierarchy A new helper is added for cgroup1 hierarchy: - task_get_cgroup1 Acquires the associated cgroup of a task within a specific cgroup1 hierarchy. The cgroup1 hierarchy is identified by its hierarchy ID. This helper function is added to facilitate the tracing of tasks within a particular container or cgroup dir in BPF programs. It's important to note that this helper is designed specifically for cgroup1 only. tj: Use irsqsave/restore as suggested by Hou Tao <houtao@huaweicloud.com>. Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Yafang Shao <laoar.shao@gmail.com> Cc: Hou Tao <houtao@huaweicloud.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
1ca0b605 |
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09-Oct-2023 |
Michal Koutný <mkoutny@suse.com> |
cgroup: Remove duplicates in cgroup v1 tasks file One PID may appear multiple times in a preloaded pidlist. (Possibly due to PID recycling but we have reports of the same task_struct appearing with different PIDs, thus possibly involving transfer of PID via de_thread().) Because v1 seq_file iterator uses PIDs as position, it leads to a message: > seq_file: buggy .next function kernfs_seq_next did not update position index Conservative and quick fix consists of removing duplicates from `tasks` file (as opposed to removing pidlists altogether). It doesn't affect correctness (it's sufficient to show a PID once), performance impact would be hidden by unconditional sorting of the pidlist already in place (asymptotically). Link: https://lore.kernel.org/r/20230823174804.23632-1-mkoutny@suse.com/ Suggested-by: Firo Yang <firo.yang@suse.com> Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: stable@vger.kernel.org
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#
e7e64a1b |
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07-Aug-2023 |
Miaohe Lin <linmiaohe@huawei.com> |
cgroup: clean up if condition in cgroup_pidlist_start() There's no need to use '<=' when knowing 'l->list[mid] != pid' already. No functional change intended. Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
c33080cd |
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17-May-2023 |
Azeem Shaikh <azeemshaikh38@gmail.com> |
cgroup: Replace all non-returning strlcpy with strscpy strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated [1]. In an effort to remove strlcpy() completely [2], replace strlcpy() here with strscpy(). No return values were used, so direct replacement is safe. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [2] https://github.com/KSPP/linux/issues/89 Signed-off-by: Azeem Shaikh <azeemshaikh38@gmail.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
ab1de7ea |
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17-May-2023 |
Qi Zheng <zhengqi.arch@bytedance.com> |
cgroup: fix missing cpus_read_{lock,unlock}() in cgroup_transfer_tasks() The commit 4f7e7236435c ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") fixed the deadlock between cgroup_threadgroup_rwsem and cpus_read_lock() by introducing cgroup_attach_{lock,unlock}() and removing cpus_read_{lock,unlock}() from cpuset_attach(). But cgroup_transfer_tasks() was missed and not handled, which will cause th following warning: WARNING: CPU: 0 PID: 589 at kernel/cpu.c:526 lockdep_assert_cpus_held+0x32/0x40 CPU: 0 PID: 589 Comm: kworker/1:4 Not tainted 6.4.0-rc2-next-20230517 #50 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.14.0-2 04/01/2014 Workqueue: events cpuset_hotplug_workfn RIP: 0010:lockdep_assert_cpus_held+0x32/0x40 <...> Call Trace: <TASK> cpuset_attach+0x40/0x240 cgroup_migrate_execute+0x452/0x5e0 ? _raw_spin_unlock_irq+0x28/0x40 cgroup_transfer_tasks+0x1f3/0x360 ? find_held_lock+0x32/0x90 ? cpuset_hotplug_workfn+0xc81/0xed0 cpuset_hotplug_workfn+0xcb1/0xed0 ? process_one_work+0x248/0x5b0 process_one_work+0x2b9/0x5b0 worker_thread+0x56/0x3b0 ? process_one_work+0x5b0/0x5b0 kthread+0xf1/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> So just use the cgroup_attach_{lock,unlock}() helper to fix it. Reported-by: Zhao Gongyi <zhaogongyi@bytedance.com> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Acked-by: Muchun Song <songmuchun@bytedance.com> Fixes: 05c7b7a92cc8 ("cgroup/cpuset: Fix a race between cpuset_attach() and cpu hotplug") Cc: stable@vger.kernel.org # v5.17+ Signed-off-by: Tejun Heo <tj@kernel.org>
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#
4cdb91b0 |
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03-Mar-2023 |
Kamalesh Babulal <kamalesh.babulal@oracle.com> |
cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers Replace mutex_[un]lock() with cgroup_[un]lock() wrappers to stay consistent across cgroup core and other subsystem code, while operating on the cgroup_mutex. Signed-off-by: Kamalesh Babulal <kamalesh.babulal@oracle.com> Acked-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
075b593f |
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25-Aug-2022 |
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
cgroup: Use cgroup_attach_{lock,unlock}() from cgroup_attach_task_all() No behavior changes; preparing for potential locking changes in future. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by:Mukesh Ojha <quic_mojha@quicinc.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
43626dad |
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25-Aug-2022 |
Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> |
cgroup: Add missing cpus_read_lock() to cgroup_attach_task_all() syzbot is hitting percpu_rwsem_assert_held(&cpu_hotplug_lock) warning at cpuset_attach() [1], for commit 4f7e7236435ca0ab ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") missed that cpuset_attach() is also called from cgroup_attach_task_all(). Add cpus_read_lock() like what cgroup_procs_write_start() does. Link: https://syzkaller.appspot.com/bug?extid=29d3a3b4d86c8136ad9e [1] Reported-by: syzbot <syzbot+29d3a3b4d86c8136ad9e@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Fixes: 4f7e7236435ca0ab ("cgroup: Fix threadgroup_rwsem <-> cpus_read_lock() deadlock") Signed-off-by: Tejun Heo <tj@kernel.org>
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#
6a010a49 |
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23-Jul-2022 |
Tejun Heo <tj@kernel.org> |
cgroup: Make !percpu threadgroup_rwsem operations optional 3942a9bd7b58 ("locking, rcu, cgroup: Avoid synchronize_sched() in __cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem because the impiled synchronize_rcu() on write locking was pushing up the latencies too much for android which constantly moves processes between cgroups. This makes the hotter paths - fork and exit - slower as they're always forced into the slow path. There is no reason to force this on everyone especially given that more common static usage pattern can now completely avoid write-locking the rwsem. Write-locking is elided when turning on and off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a cgroup without grabbing the rwsem. Restore the default percpu operations and introduce the mount option "favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need lower latencies for the dynamic operations. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Christian Brauner <brauner@kernel.org> Cc: Michal Koutn� <mkoutny@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: John Stultz <john.stultz@linaro.org> Cc: Dmitry Shmidt <dimitrysh@google.com> Cc: Oleg Nesterov <oleg@redhat.com>
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#
467a726b |
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17-Feb-2022 |
Michal Koutný <mkoutny@suse.com> |
cgroup-v1: Correct privileges check in release_agent writes The idea is to check: a) the owning user_ns of cgroup_ns, b) capabilities in init_user_ns. The commit 24f600856418 ("cgroup-v1: Require capabilities to set release_agent") got this wrong in the write handler of release_agent since it checked user_ns of the opener (may be different from the owning user_ns of cgroup_ns). Secondly, to avoid possibly confused deputy, the capability of the opener must be checked. Fixes: 24f600856418 ("cgroup-v1: Require capabilities to set release_agent") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/stable/20220216121142.GB30035@blackbody.suse.cz/ Signed-off-by: Michal Koutný <mkoutny@suse.com> Reviewed-by: Masami Ichikawa(CIP) <masami.ichikawa@cybertrust.co.jp> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
24f60085 |
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20-Jan-2022 |
Eric W. Biederman <ebiederm@xmission.com> |
cgroup-v1: Require capabilities to set release_agent The cgroup release_agent is called with call_usermodehelper. The function call_usermodehelper starts the release_agent with a full set fo capabilities. Therefore require capabilities when setting the release_agaent. Reported-by: Tabitha Sable <tabitha.c.sable@gmail.com> Tested-by: Tabitha Sable <tabitha.c.sable@gmail.com> Fixes: 81a6a5cdd2c5 ("Task Control Groups: automatic userspace notification of idle cgroups") Cc: stable@vger.kernel.org # v2.6.24+ Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
0d2b5955 |
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06-Jan-2022 |
Tejun Heo <tj@kernel.org> |
cgroup: Allocate cgroup_file_ctx for kernfs_open_file->priv of->priv is currently used by each interface file implementation to store private information. This patch collects the current two private data usages into struct cgroup_file_ctx which is allocated and freed by the common path. This allows generic private data which applies to multiple files, which will be used to in the following patch. Note that cgroup_procs iterator is now embedded as procs.iter in the new cgroup_file_ctx so that it doesn't need to be allocated and freed separately. v2: union dropped from cgroup_file_ctx and the procs iterator is embedded in cgroup_file_ctx as suggested by Linus. v3: Michal pointed out that cgroup1's procs pidlist uses of->priv too. Converted. Didn't change to embedded allocation as cgroup1 pidlists get stored for caching. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Michal Koutný <mkoutny@suse.com>
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#
1756d799 |
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06-Jan-2022 |
Tejun Heo <tj@kernel.org> |
cgroup: Use open-time credentials for process migraton perm checks cgroup process migration permission checks are performed at write time as whether a given operation is allowed or not is dependent on the content of the write - the PID. This currently uses current's credentials which is a potential security weakness as it may allow scenarios where a less privileged process tricks a more privileged one into writing into a fd that it created. This patch makes both cgroup2 and cgroup1 process migration interfaces to use the credentials saved at the time of open (file->f_cred) instead of current's. Reported-by: "Eric W. Biederman" <ebiederm@xmission.com> Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org> Fixes: 187fe84067bd ("cgroup: require write perm on common ancestor when moving processes on the default hierarchy") Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
822bc9ba |
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25-Oct-2021 |
Shakeel Butt <shakeelb@google.com> |
cgroup: no need for cgroup_mutex for /proc/cgroups On the real systems, the cgroups hierarchies are setup early and just once by the node controller, so, other than number of cgroups, all information in /proc/cgroups remain same for the system uptime. Let's remove the cgroup_mutex usage on reading /proc/cgroups. There is a chance of inconsistent number of cgroups for co-mounted cgroups while printing the information from /proc/cgroups but that is not a big issue. In addition /proc/cgroups is a v1 specific interface, so the dependency on it should reduce over time. The main motivation for removing the cgroup_mutex from /proc/cgroups is to reduce the avenues of its contention. On our fleet, we have observed buggy application hammering on /proc/cgroups and drastically slowing down the node controller on the system which have many negative consequences on other workloads running on the system. Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
bb758421 |
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25-Oct-2021 |
Shakeel Butt <shakeelb@google.com> |
cgroup: remove cgroup_mutex from cgroupstats_build The function cgroupstats_build extracts cgroup from the kernfs_node's priv pointer which is a RCU pointer. So, there is no need to grab cgroup_mutex. Just get the reference on the cgroup before using and remove the cgroup_mutex altogether. Signed-off-by: Shakeel Butt <shakeelb@google.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
00612703 |
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04-Oct-2021 |
Vishal Verma <vverma@digitalocean.com> |
cgroup: cgroup-v1: do not exclude cgrp_dfl_root Found an issue within cgroup_attach_task_all() fn which seem to exclude cgrp_dfl_root (cgroupv2) while attaching tasks to the given cgroup. This was noticed when the system was running qemu/kvm with kernel vhost helper threads. It appears that the vhost layer which uses cgroup_attach_task_all() fn to assign the vhost kthread to the right qemu cgroup works fine with cgroupv1 based configuration but not in cgroupv2. With cgroupv2, the vhost helper thread ends up just belonging to the root cgroup as is shown below: $ stat -fc %T /sys/fs/cgroup/ cgroup2fs $ sudo pgrep qemu 1916421 $ ps -eL | grep 1916421 1916421 1916421 ? 00:00:01 qemu-system-x86 1916421 1916431 ? 00:00:00 call_rcu 1916421 1916435 ? 00:00:00 IO mon_iothread 1916421 1916436 ? 00:00:34 CPU 0/KVM 1916421 1916439 ? 00:00:00 SPICE Worker 1916421 1916440 ? 00:00:00 vnc_worker 1916433 1916433 ? 00:00:00 vhost-1916421 1916437 1916437 ? 00:00:00 kvm-pit/1916421 $ cat /proc/1916421/cgroup 0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator $ cat /proc/1916439/cgroup 0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator $ cat /proc/1916433/cgroup 0::/ From above, it can be seen that the vhost kthread (PID: 1916433) doesn't seem to belong the qemu cgroup like other qemu PIDs. After applying this patch: $ pgrep qemu 1643 $ ps -eL | grep 1643 1643 1643 ? 00:00:00 qemu-system-x86 1643 1645 ? 00:00:00 call_rcu 1643 1648 ? 00:00:00 IO mon_iothread 1643 1649 ? 00:00:00 CPU 0/KVM 1643 1652 ? 00:00:00 SPICE Worker 1643 1653 ? 00:00:00 vnc_worker 1647 1647 ? 00:00:00 vhost-1643 1651 1651 ? 00:00:00 kvm-pit/1643 $ cat /proc/1647/cgroup 0::/machine.slice/machine-qemu\x2d18\x2dDroplet\x2d7572850.scope/emulator Suggested-by: Tejun Heo <tj@kernel.org> Signed-off-by: Vishal Verma <vverma@digitalocean.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
b4cc6196 |
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10-Aug-2021 |
Randy Dunlap <rdunlap@infradead.org> |
cgroup: cgroup-v1: clean up kernel-doc notation Fix kernel-doc warnings found in cgroup-v1.c: kernel/cgroup/cgroup-v1.c:55: warning: No description found for return value of 'cgroup_attach_task_all' kernel/cgroup/cgroup-v1.c:94: warning: expecting prototype for cgroup_trasnsfer_tasks(). Prototype was for cgroup_transfer_tasks() instead cgroup-v1.c:96: warning: No description found for return value of 'cgroup_transfer_tasks' kernel/cgroup/cgroup-v1.c:687: warning: No description found for return value of 'cgroupstats_build' Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: cgroups@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
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1e7107c5 |
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16-Jun-2021 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
cgroup1: fix leaked context root causing sporadic NULL deref in LTP Richard reported sporadic (roughly one in 10 or so) null dereferences and other strange behaviour for a set of automated LTP tests. Things like: BUG: kernel NULL pointer dereference, address: 0000000000000008 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 0 PID: 1516 Comm: umount Not tainted 5.10.0-yocto-standard #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014 RIP: 0010:kernfs_sop_show_path+0x1b/0x60 ...or these others: RIP: 0010:do_mkdirat+0x6a/0xf0 RIP: 0010:d_alloc_parallel+0x98/0x510 RIP: 0010:do_readlinkat+0x86/0x120 There were other less common instances of some kind of a general scribble but the common theme was mount and cgroup and a dubious dentry triggering the NULL dereference. I was only able to reproduce it under qemu by replicating Richard's setup as closely as possible - I never did get it to happen on bare metal, even while keeping everything else the same. In commit 71d883c37e8d ("cgroup_do_mount(): massage calling conventions") we see this as a part of the overall change: -------------- struct cgroup_subsys *ss; - struct dentry *dentry; [...] - dentry = cgroup_do_mount(&cgroup_fs_type, fc->sb_flags, root, - CGROUP_SUPER_MAGIC, ns); [...] - if (percpu_ref_is_dying(&root->cgrp.self.refcnt)) { - struct super_block *sb = dentry->d_sb; - dput(dentry); + ret = cgroup_do_mount(fc, CGROUP_SUPER_MAGIC, ns); + if (!ret && percpu_ref_is_dying(&root->cgrp.self.refcnt)) { + struct super_block *sb = fc->root->d_sb; + dput(fc->root); deactivate_locked_super(sb); msleep(10); return restart_syscall(); } -------------- In changing from the local "*dentry" variable to using fc->root, we now export/leave that dentry pointer in the file context after doing the dput() in the unlikely "is_dying" case. With LTP doing a crazy amount of back to back mount/unmount [testcases/bin/cgroup_regression_5_1.sh] the unlikely becomes slightly likely and then bad things happen. A fix would be to not leave the stale reference in fc->root as follows: -------------- dput(fc->root); + fc->root = NULL; deactivate_locked_super(sb); -------------- ...but then we are just open-coding a duplicate of fc_drop_locked() so we simply use that instead. Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Tejun Heo <tj@kernel.org> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: stable@vger.kernel.org # v5.1+ Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org> Fixes: 71d883c37e8d ("cgroup_do_mount(): massage calling conventions") Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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d1d488d8 |
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14-Jul-2021 |
Christian Brauner <christian.brauner@ubuntu.com> |
fs: add vfs_parse_fs_param_source() helper Add a simple helper that filesystems can use in their parameter parser to parse the "source" parameter. A few places open-coded this function and that already caused a bug in the cgroup v1 parser that we fixed. Let's make it harder to get this wrong by introducing a helper which performs all necessary checks. Link: https://syzkaller.appspot.com/bug?id=6312526aba5beae046fdae8f00399f87aab48b12 Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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3b046272 |
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14-Jul-2021 |
Christian Brauner <christian.brauner@ubuntu.com> |
cgroup: verify that source is a string The following sequence can be used to trigger a UAF: int fscontext_fd = fsopen("cgroup"); int fd_null = open("/dev/null, O_RDONLY); int fsconfig(fscontext_fd, FSCONFIG_SET_FD, "source", fd_null); close_range(3, ~0U, 0); The cgroup v1 specific fs parser expects a string for the "source" parameter. However, it is perfectly legitimate to e.g. specify a file descriptor for the "source" parameter. The fs parser doesn't know what a filesystem allows there. So it's a bug to assume that "source" is always of type fs_value_is_string when it can reasonably also be fs_value_is_file. This assumption in the cgroup code causes a UAF because struct fs_parameter uses a union for the actual value. Access to that union is guarded by the param->type member. Since the cgroup paramter parser didn't check param->type but unconditionally moved param->string into fc->source a close on the fscontext_fd would trigger a UAF during put_fs_context() which frees fc->source thereby freeing the file stashed in param->file causing a UAF during a close of the fd_null. Fix this by verifying that param->type is actually a string and report an error if not. In follow up patches I'll add a new generic helper that can be used here and by other filesystems instead of this error-prone copy-pasta fix. But fixing it in here first makes backporting a it to stable a lot easier. Fixes: 8d2451f4994f ("cgroup1: switch to option-by-option parsing") Reported-by: syzbot+283ce5a46486d6acdbaf@syzkaller.appspotmail.com Cc: Christoph Hellwig <hch@lst.de> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@kernel.org> Cc: syzkaller-bugs <syzkaller-bugs@googlegroups.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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2f064a59 |
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11-Jun-2021 |
Peter Zijlstra <peterz@infradead.org> |
sched: Change task_struct::state Change the type and name of task_struct::state. Drop the volatile and shrink it to an 'unsigned int'. Rename it in order to find all uses such that we can use READ_ONCE/WRITE_ONCE as appropriate. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com> Acked-by: Will Deacon <will@kernel.org> Acked-by: Daniel Thompson <daniel.thompson@linaro.org> Link: https://lore.kernel.org/r/20210611082838.550736351@infradead.org
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#
b7e24eb1 |
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09-Jun-2021 |
Alexander Kuznetsov <wwfq@yandex-team.ru> |
cgroup1: don't allow '\n' in renaming cgroup_mkdir() have restriction on newline usage in names: $ mkdir $'/sys/fs/cgroup/cpu/test\ntest2' mkdir: cannot create directory '/sys/fs/cgroup/cpu/test\ntest2': Invalid argument But in cgroup1_rename() such check is missed. This allows us to make /proc/<pid>/cgroup unparsable: $ mkdir /sys/fs/cgroup/cpu/test $ mv /sys/fs/cgroup/cpu/test $'/sys/fs/cgroup/cpu/test\ntest2' $ echo $$ > $'/sys/fs/cgroup/cpu/test\ntest2' $ cat /proc/self/cgroup 11:pids:/ 10:freezer:/ 9:hugetlb:/ 8:cpuset:/ 7:blkio:/user.slice 6:memory:/user.slice 5:net_cls,net_prio:/ 4:perf_event:/ 3:devices:/user.slice 2:cpu,cpuacct:/test test2 1:name=systemd:/ 0::/ Signed-off-by: Alexander Kuznetsov <wwfq@yandex-team.ru> Reported-by: Andrey Krasichkov <buglloc@yandex-team.ru> Acked-by: Dmitry Yakunin <zeil@yandex-team.ru> Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
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#
08b2b6fd |
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24-May-2021 |
Zhen Lei <thunder.leizhen@huawei.com> |
cgroup: fix spelling mistakes Fix some spelling mistakes in comments: hierarhcy ==> hierarchy automtically ==> automatically overriden ==> overridden In absense of .. or ==> In absence of .. and assocaited ==> associated taget ==> target initate ==> initiate succeded ==> succeeded curremt ==> current udpated ==> updated Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
ffeee417 |
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12-Apr-2021 |
Chunguang Xu <brookxu@tencent.com> |
cgroup: use tsk->in_iowait instead of delayacct_is_task_waiting_on_io() If delayacct is disabled, then delayacct_is_task_waiting_on_io() always returns false, which causes the statistical value to be wrong. Perhaps tsk->in_iowait is better. Signed-off-by: Chunguang Xu <brookxu@tencent.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
61e960b0 |
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15-Jan-2021 |
Chen Zhou <chenzhou10@huawei.com> |
cgroup-v1: add disabled controller check in cgroup1_parse_param() When mounting a cgroup hierarchy with disabled controller in cgroup v1, all available controllers will be attached. For example, boot with cgroup_no_v1=cpu or cgroup_disable=cpu, and then mount with "mount -t cgroup -ocpu cpu /sys/fs/cgroup/cpu", then all enabled controllers will be attached except cpu. Fix this by adding disabled controller check in cgroup1_parse_param(). If the specified controller is disabled, just return error with information "Disabled controller xx" rather than attaching all the other enabled controllers. Fixes: f5dfb5315d34 ("cgroup: take options parsing into ->parse_monolithic()") Signed-off-by: Chen Zhou <chenzhou10@huawei.com> Reviewed-by: Zefan Li <lizefan.x@bytedance.com> Reviewed-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
2d18e54d |
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09-Dec-2020 |
Qinglang Miao <miaoqinglang@huawei.com> |
cgroup: Fix memory leak when parsing multiple source parameters A memory leak is found in cgroup1_parse_param() when multiple source parameters overwrite fc->source in the fs_context struct without free. unreferenced object 0xffff888100d930e0 (size 16): comm "mount", pid 520, jiffies 4303326831 (age 152.783s) hex dump (first 16 bytes): 74 65 73 74 6c 65 61 6b 00 00 00 00 00 00 00 00 testleak........ backtrace: [<000000003e5023ec>] kmemdup_nul+0x2d/0xa0 [<00000000377dbdaa>] vfs_parse_fs_string+0xc0/0x150 [<00000000cb2b4882>] generic_parse_monolithic+0x15a/0x1d0 [<000000000f750198>] path_mount+0xee1/0x1820 [<0000000004756de2>] do_mount+0xea/0x100 [<0000000094cafb0a>] __x64_sys_mount+0x14b/0x1f0 Fix this bug by permitting a single source parameter and rejecting with an error all subsequent ones. Fixes: 8d2451f4994f ("cgroup1: switch to option-by-option parsing") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Qinglang Miao <miaoqinglang@huawei.com> Reviewed-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
e7b20d97 |
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12-Mar-2020 |
Tejun Heo <tj@kernel.org> |
cgroup: Restructure release_agent_path handling cgrp->root->release_agent_path is protected by both cgroup_mutex and release_agent_path_lock and readers can hold either one. The dual-locking scheme was introduced while breaking a locking dependency issue around cgroup_mutex but doesn't make sense anymore given that the only remaining reader which uses cgroup_mutex is cgroup1_releaes_agent(). This patch updates cgroup1_release_agent() to use release_agent_path_lock so that release_agent_path is always protected only by release_agent_path_lock. While at it, convert strlen() based empty string checks to direct tests on the first character as suggested by Linus. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org>
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#
2e5383d7 |
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19-Feb-2020 |
Tycho Andersen <tycho@tycho.pizza> |
cgroup1: don't call release_agent when it is "" Older (and maybe current) versions of systemd set release_agent to "" when shutting down, but do not set notify_on_release to 0. Since 64e90a8acb85 ("Introduce STATIC_USERMODEHELPER to mediate call_usermodehelper()"), we filter out such calls when the user mode helper path is "". However, when used in conjunction with an actual (i.e. non "") STATIC_USERMODEHELPER, the path is never "", so the real usermode helper will be called with argv[0] == "". Let's avoid this by not invoking the release_agent when it is "". Signed-off-by: Tycho Andersen <tycho@tycho.ws> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
db8dd969 |
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30-Jan-2020 |
Vasily Averin <vvs@virtuozzo.com> |
cgroup-v1: cgroup_pidlist_next should update position index if seq_file .next fuction does not change position index, read after some lseek can generate unexpected output. # mount | grep cgroup # dd if=/mnt/cgroup.procs bs=1 # normal output ... 1294 1295 1296 1304 1382 584+0 records in 584+0 records out 584 bytes copied dd: /mnt/cgroup.procs: cannot skip to specified offset 83 <<< generates end of last line 1383 <<< ... and whole last line once again 0+1 records in 0+1 records out 8 bytes copied dd: /mnt/cgroup.procs: cannot skip to specified offset 1386 <<< generates last line anyway 0+1 records in 0+1 records out 5 bytes copied https://bugzilla.kernel.org/show_bug.cgi?id=206283 Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
58c025f0 |
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21-Dec-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup1: switch to use of errorfc() et.al. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
d7167b14 |
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07-Sep-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
fs_parse: fold fs_parameter_desc/fs_parameter_spec The former contains nothing but a pointer to an array of the latter... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
96cafb9c |
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06-Dec-2019 |
Eric Sandeen <sandeen@sandeen.net> |
fs_parser: remove fs_parameter_description name field Unused now. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
fbc2d168 |
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20-Dec-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
get rid of cg_invalf() pointless alias for invalf()... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
9a3284fa |
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03-Oct-2019 |
Michal Koutný <mkoutny@suse.com> |
cgroup: Optimize single thread migration There are reports of users who use thread migrations between cgroups and they report performance drop after d59cfc09c32a ("sched, cgroup: replace signal_struct->group_rwsem with a global percpu_rwsem"). The effect is pronounced on machines with more CPUs. The migration is affected by forking noise happening in the background, after the mentioned commit a migrating thread must wait for all (forking) processes on the system, not only of its threadgroup. There are several places that need to synchronize with migration: a) do_exit, b) de_thread, c) copy_process, d) cgroup_update_dfl_csses, e) parallel migration (cgroup_{proc,thread}s_write). In the case of self-migrating thread, we relax the synchronization on cgroup_threadgroup_rwsem to avoid the cost of waiting. d) and e) are excluded with cgroup_mutex, c) does not matter in case of single thread migration and the executing thread cannot exec(2) or exit(2) while it is writing into cgroup.threads. In case of do_exit because of signal delivery, we either exit before the migration or finish the migration (of not yet PF_EXITING thread) and die afterwards. This patch handles only the case of self-migration by writing "0" into cgroup.threads. For simplicity, we always take cgroup_threadgroup_rwsem with numeric PIDs. This change improves migration dependent workload performance similar to per-signal_struct state. Signed-off-by: Michal Koutný <mkoutny@suse.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
653a23ca |
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06-Aug-2019 |
Marc Koderer <marc@koderer.com> |
Use kvmalloc in cgroups-v1 Instead of using its own logic for k-/vmalloc rely on kvmalloc which is actually doing quite the same. Signed-off-by: Marc Koderer <marc@koderer.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
457c8996 |
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19-May-2019 |
Thomas Gleixner <tglx@linutronix.de> |
treewide: Add SPDX license identifier for missed files Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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#
aade7f9e |
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19-Apr-2019 |
Roman Gushchin <guro@fb.com> |
cgroup: implement __cgroup_task_count() helper The helper is identical to the existing cgroup_task_count() except it doesn't take the css_set_lock by itself, assuming that the caller does. Also, move cgroup_task_count() implementation into kernel/cgroup/cgroup.c, as there is nothing specific to cgroup v1. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: kernel-team@fb.com
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#
06a2ae56 |
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01-Nov-2018 |
David Howells <dhowells@redhat.com> |
vfs: Add some logging to the core users of the fs_context log Add some logging to the core users of the fs_context log so that information can be extracted from them as to the reason for failure. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
cca8f327 |
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17-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup: store a reference to cgroup_ns into cgroup_fs_context ... and trim cgroup_do_mount() arguments (renaming it to cgroup_do_get_tree()) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
6678889f |
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17-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
71d883c3 |
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17-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup_do_mount(): massage calling conventions pass it fs_context instead of fs_type/flags/root triple, have it return int instead of dentry and make it deal with setting fc->root. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
cf6299b1 |
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17-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup: stash cgroup_root reference into cgroup_fs_context Note that this reference is *NOT* contributing to refcount of cgroup_root in question and is valid only until cgroup_do_mount() returns. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
8d2451f4 |
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16-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup1: switch to option-by-option parsing [dhowells should be the author - it's carved out of his patch] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
f5dfb531 |
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16-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup: take options parsing into ->parse_monolithic() Store the results in cgroup_fs_context. There's a nasty twist caused by the enabling/disabling subsystems - we can't do the checks sensitive to that until cgroup_mutex gets grabbed. Frankly, these checks are complete bullshit (e.g. all,none combination is accepted if all subsystems are disabled; so's cpusets,none and all,cpusets when cpusets is disabled, etc.), but touching that would be a userland-visible behaviour change ;-/ So we do parsing in ->parse_monolithic() and have the consistency checks done in check_cgroupfs_options(), with the latter called (on already parsed options) from cgroup1_get_tree() and cgroup1_reconfigure(). Freeing the strdup'ed strings is done from fs_context destructor, which somewhat simplifies the life for cgroup1_{get_tree,reconfigure}(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
7feeef58 |
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16-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup: fold cgroup1_mount() into cgroup1_get_tree() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
90129625 |
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04-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup: start switching to fs_context Unfortunately, cgroup is tangled into kernfs infrastructure. To avoid converting all kernfs-based filesystems at once, we need to untangle the remount part of things, instead of having it go through kernfs_sop_remount_fs(). Fortunately, it's not hard to do. This commit just gets cgroup/cgroup1 to use fs_context to deliver options on mount and remount paths. Parsing those is going to be done in the next commits; for now we do pretty much what legacy case does. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
35ac1184 |
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11-Jan-2019 |
Al Viro <viro@zeniv.linux.org.uk> |
cgroup: saner refcounting for cgroup_root * make the reference from superblock to cgroup_root counting - do cgroup_put() in cgroup_kill_sb() whether we'd done percpu_ref_kill() or not; matching grab is done when we allocate a new root. That gives the same refcounting rules for all callers of cgroup_do_mount() - a reference to cgroup_root has been grabbed by caller and it either is transferred to new superblock or dropped. * have cgroup_kill_sb() treat an already killed refcount as "just don't bother killing it, then". * after successful cgroup_do_mount() have cgroup1_mount() recheck if we'd raced with mount/umount from somebody else and cgroup_root got killed. In that case we drop the superblock and bugger off with -ERESTARTSYS, same as if we'd found it in the list already dying. * don't bother with delayed initialization of refcount - it's unreliable and not needed. No need to prevent attempts to bump the refcount if we find cgroup_root of another mount in progress - sget will reuse an existing superblock just fine and if the other sb manages to die before we get there, we'll catch that immediately after cgroup_do_mount(). * don't bother with kernfs_pin_sb() - no need for doing that either. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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#
3fc9c12d |
|
28-Dec-2018 |
Tejun Heo <tj@kernel.org> |
cgroup: Add named hierarchy disabling to cgroup_no_v1 boot param It can be useful to inhibit all cgroup1 hierarchies especially during transition and for debugging. cgroup_no_v1 can block hierarchies with controllers which leaves out the named hierarchies. Expand it to cover the named hierarchies so that "cgroup_no_v1=all,named" disables all cgroup1 hierarchies. Signed-off-by: Tejun Heo <tj@kernel.org> Suggested-by: Marcin Pawlowski <mpawlowski@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
e4f8d81c |
|
09-Jul-2018 |
Steven Rostedt (VMware) <rostedt@goodmis.org> |
cgroup/tracing: Move taking of spin lock out of trace event handlers It is unwise to take spin locks from the handlers of trace events. Mainly, because they can introduce lockups, because it introduces locks in places that are normally not tested. Worse yet, because trace events are tucked away in the include/trace/events/ directory, locks that are taken there are forgotten about. As a general rule, I tell people never to take any locks in a trace event handler. Several cgroup trace event handlers call cgroup_path() which eventually takes the kernfs_rename_lock spinlock. This injects the spinlock in the code without people realizing it. It also can cause issues for the PREEMPT_RT patch, as the spinlock becomes a mutex, and the trace event handlers are called with preemption disabled. By moving the calculation of the cgroup_path() out of the trace event handlers and into a macro (surrounded by a trace_cgroup_##type##_enabled()), then we could place the cgroup_path into a string, and pass that to the trace event. Not only does this remove the taking of the spinlock out of the trace event handler, but it also means that the cgroup_path() only needs to be called once (it is currently called twice, once to get the length to reserver the buffer for, and once again to get the path itself. Now it only needs to be done once. Reported-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
42bc47b3 |
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12-Jun-2018 |
Kees Cook <keescook@chromium.org> |
treewide: Use array_size() in vmalloc() The vmalloc() function has no 2-factor argument form, so multiplication factors need to be wrapped in array_size(). This patch replaces cases of: vmalloc(a * b) with: vmalloc(array_size(a, b)) as well as handling cases of: vmalloc(a * b * c) with: vmalloc(array3_size(a, b, c)) This does, however, attempt to ignore constant size factors like: vmalloc(4 * 1024) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( vmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | vmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( vmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | vmalloc( - sizeof(u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | vmalloc( - sizeof(char) * COUNT + COUNT , ...) | vmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( vmalloc( - sizeof(TYPE) * (COUNT_ID) + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_ID + array_size(COUNT_ID, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT_CONST + array_size(COUNT_CONST, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT_ID) + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_ID + array_size(COUNT_ID, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT_CONST) + array_size(COUNT_CONST, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT_CONST + array_size(COUNT_CONST, sizeof(THING)) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ vmalloc( - SIZE * COUNT + array_size(COUNT, SIZE) , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( vmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | vmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( vmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | vmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( vmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | vmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( vmalloc(C1 * C2 * C3, ...) | vmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants. @@ expression E1, E2; constant C1, C2; @@ ( vmalloc(C1 * C2, ...) | vmalloc( - E1 * E2 + array_size(E1, E2) , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
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#
6da2ec56 |
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12-Jun-2018 |
Kees Cook <keescook@chromium.org> |
treewide: kmalloc() -> kmalloc_array() The kmalloc() function has a 2-factor argument form, kmalloc_array(). This patch replaces cases of: kmalloc(a * b, gfp) with: kmalloc_array(a * b, gfp) as well as handling cases of: kmalloc(a * b * c, gfp) with: kmalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kmalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kmalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The tools/ directory was manually excluded, since it has its own implementation of kmalloc(). The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kmalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kmalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kmalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kmalloc( - sizeof(u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kmalloc( - sizeof(char) * COUNT + COUNT , ...) | kmalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kmalloc + kmalloc_array ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kmalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kmalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kmalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kmalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kmalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kmalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kmalloc(C1 * C2 * C3, ...) | kmalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kmalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kmalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kmalloc(sizeof(THING) * C2, ...) | kmalloc(sizeof(TYPE) * C2, ...) | kmalloc(C1 * C2 * C3, ...) | kmalloc(C1 * C2, ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kmalloc + kmalloc_array ( - (E1) * E2 + E1, E2 , ...) | - kmalloc + kmalloc_array ( - (E1) * (E2) + E1, E2 , ...) | - kmalloc + kmalloc_array ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
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3f3942ac |
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15-May-2018 |
Christoph Hellwig <hch@lst.de> |
proc: introduce proc_create_single{,_data} Variants of proc_create{,_data} that directly take a seq_file show callback and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig <hch@lst.de>
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#
116d2f74 |
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18-Dec-2017 |
Prateek Sood <prsood@codeaurora.org> |
cgroup: Fix deadlock in cpu hotplug path Deadlock during cgroup migration from cpu hotplug path when a task T is being moved from source to destination cgroup. kworker/0:0 cpuset_hotplug_workfn() cpuset_hotplug_update_tasks() hotplug_update_tasks_legacy() remove_tasks_in_empty_cpuset() cgroup_transfer_tasks() // stuck in iterator loop cgroup_migrate() cgroup_migrate_add_task() In cgroup_migrate_add_task() it checks for PF_EXITING flag of task T. Task T will not migrate to destination cgroup. css_task_iter_start() will keep pointing to task T in loop waiting for task T cg_list node to be removed. Task T do_exit() exit_signals() // sets PF_EXITING exit_task_namespaces() switch_task_namespaces() free_nsproxy() put_mnt_ns() drop_collected_mounts() namespace_unlock() synchronize_rcu() _synchronize_rcu_expedited() schedule_work() // on cpu0 low priority worker pool wait_event() // waiting for work item to execute Task T inserted a work item in the worklist of cpu0 low priority worker pool. It is waiting for expedited grace period work item to execute. This work item will only be executed once kworker/0:0 complete execution of cpuset_hotplug_workfn(). kworker/0:0 ==> Task T ==>kworker/0:0 In case of PF_EXITING task being migrated from source to destination cgroup, migrate next available task in source cgroup. Signed-off-by: Prateek Sood <prsood@codeaurora.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
e1cba4b8 |
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17-Aug-2017 |
Waiman Long <longman@redhat.com> |
cgroup: Add mount flag to enable cpuset to use v2 behavior in v1 cgroup A new mount option "cpuset_v2_mode" is added to the v1 cgroupfs filesystem to enable cpuset controller to use v2 behavior in a v1 cgroup. This mount option applies only to cpuset controller and have no effect on other controllers. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
8cfd8147 |
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21-Jul-2017 |
Tejun Heo <tj@kernel.org> |
cgroup: implement cgroup v2 thread support This patch implements cgroup v2 thread support. The goal of the thread mode is supporting hierarchical accounting and control at thread granularity while staying inside the resource domain model which allows coordination across different resource controllers and handling of anonymous resource consumptions. A cgroup is always created as a domain and can be made threaded by writing to the "cgroup.type" file. When a cgroup becomes threaded, it becomes a member of a threaded subtree which is anchored at the closest ancestor which isn't threaded. The threads of the processes which are in a threaded subtree can be placed anywhere without being restricted by process granularity or no-internal-process constraint. Note that the threads aren't allowed to escape to a different threaded subtree. To be used inside a threaded subtree, a controller should explicitly support threaded mode and be able to handle internal competition in the way which is appropriate for the resource. The root of a threaded subtree, the nearest ancestor which isn't threaded, is called the threaded domain and serves as the resource domain for the whole subtree. This is the last cgroup where domain controllers are operational and where all the domain-level resource consumptions in the subtree are accounted. This allows threaded controllers to operate at thread granularity when requested while staying inside the scope of system-level resource distribution. As the root cgroup is exempt from the no-internal-process constraint, it can serve as both a threaded domain and a parent to normal cgroups, so, unlike non-root cgroups, the root cgroup can have both domain and threaded children. Internally, in a threaded subtree, each css_set has its ->dom_cset pointing to a matching css_set which belongs to the threaded domain. This ensures that thread root level cgroup_subsys_state for all threaded controllers are readily accessible for domain-level operations. This patch enables threaded mode for the pids and perf_events controllers. Neither has to worry about domain-level resource consumptions and it's enough to simply set the flag. For more details on the interface and behavior of the thread mode, please refer to the section 2-2-2 in Documentation/cgroup-v2.txt added by this patch. v5: - Dropped silly no-op ->dom_cgrp init from cgroup_create(). Spotted by Waiman. - Documentation updated as suggested by Waiman. - cgroup.type content slightly reformatted. - Mark the debug controller threaded. v4: - Updated to the general idea of marking specific cgroups domain/threaded as suggested by PeterZ. v3: - Dropped "join" and always make mixed children join the parent's threaded subtree. v2: - After discussions with Waiman, support for mixed thread mode is added. This should address the issue that Peter pointed out where any nesting should be avoided for thread subtrees while coexisting with other domain cgroups. - Enabling / disabling thread mode now piggy backs on the existing control mask update mechanism. - Bug fixes and cleanup. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Waiman Long <longman@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org>
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#
bc2fb7ed |
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15-May-2017 |
Tejun Heo <tj@kernel.org> |
cgroup: add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS css_task_iter currently always walks all tasks. With the scheduled cgroup v2 thread support, the iterator would need to handle multiple types of iteration. As a preparation, add @flags to css_task_iter_start() and implement CSS_TASK_ITER_PROCS. If the flag is not specified, it walks all tasks as before. When asserted, the iterator only walks the group leaders. For now, the only user of the flag is cgroup v2 "cgroup.procs" file which no longer needs to skip non-leader tasks in cgroup_procs_next(). Note that cgroup v1 "cgroup.procs" can't use the group leader walk as v1 "cgroup.procs" doesn't mean "list all thread group leaders in the cgroup" but "list all thread group id's with any threads in the cgroup". While at it, update cgroup_procs_show() to use task_pid_vnr() instead of task_tgid_vnr(). As the iteration guarantees that the function only sees group leaders, this doesn't change the output and will allow sharing the function for thread iteration. Signed-off-by: Tejun Heo <tj@kernel.org>
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#
715c809d |
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15-May-2017 |
Tejun Heo <tj@kernel.org> |
cgroup: reorganize cgroup.procs / task write path Currently, writes "cgroup.procs" and "cgroup.tasks" files are all handled by __cgroup_procs_write() on both v1 and v2. This patch reoragnizes the write path so that there are common helper functions that different write paths use. While this somewhat increases LOC, the different paths are no longer intertwined and each path has more flexibility to implement different behaviors which will be necessary for the planned v2 thread support. v3: - Restructured so that cgroup_procs_write_permission() takes @src_cgrp and @dst_cgrp. v2: - Rolled in Waiman's task reference count fix. - Updated on top of nsdelegate changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Waiman Long <longman@redhat.com>
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#
a28f8f5e |
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13-Jun-2017 |
Waiman Long <longman@redhat.com> |
cgroup: Move debug cgroup to its own file The debug cgroup currently resides within cgroup-v1.c and is enabled only for v1 cgroup. To enable the debug cgroup also for v2, it makes sense to put the code into its own file as it will no longer be v1 specific. There is no change to the debug cgroup specific code. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
73a7242a |
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13-Jun-2017 |
Waiman Long <longman@redhat.com> |
cgroup: Keep accurate count of tasks in each css_set The reference count in the css_set data structure was used as a proxy of the number of tasks attached to that css_set. However, that count is actually not an accurate measure especially with thread mode support. So a new variable nr_tasks is added to the css_set to keep track of the actual task count. This new variable is protected by the css_set_lock. Functions that require the actual task count are updated to use the new variable. tj: s/task_count/nr_tasks/ for consistency with cgroup_root->nr_cgrps. Refreshed on top of cgroup/for-v4.13 which dropped on css_set_populated() -> nr_tasks conversion. Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
9732adc5 |
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18-Apr-2017 |
Zefan Li <lizefan@huawei.com> |
cgroup: avoid attaching a cgroup root to two different superblocks, take 2 Commit bfb0b80db5f9 ("cgroup: avoid attaching a cgroup root to two different superblocks") is broken. Now we try to fix the race by delaying the initialization of cgroup root refcnt until a superblock has been allocated. Reported-by: Dmitry Vyukov <dvyukov@google.com> Reported-by: Andrei Vagin <avagin@virtuozzo.com> Tested-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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330c4186 |
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16-Apr-2017 |
Tejun Heo <tj@kernel.org> |
Revert "cgroup: avoid attaching a cgroup root to two different superblocks" This reverts commit bfb0b80db5f9dca5ac0a5fd0edb765ee555e5a8e. Andrei reports CRIU test hangs with the patch applied. The bug fixed by the patch isn't too likely to trigger in actual uses. Revert the patch for now. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Andrei Vagin <avagin@virtuozzo.com> Link: http://lkml.kernel.org/r/20170414232737.GC20350@outlook.office365.com
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#
bfb0b80d |
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07-Apr-2017 |
Zefan Li <lizefan@huawei.com> |
cgroup: avoid attaching a cgroup root to two different superblocks Run this: touch file0 for ((; ;)) { mount -t cpuset xxx file0 } And this concurrently: touch file1 for ((; ;)) { mount -t cpuset xxx file1 } We'll trigger a warning like this: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 4675 at lib/percpu-refcount.c:317 percpu_ref_kill_and_confirm+0x92/0xb0 percpu_ref_kill_and_confirm called more than once on css_release! CPU: 1 PID: 4675 Comm: mount Not tainted 4.11.0-rc5+ #5 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 Call Trace: dump_stack+0x63/0x84 __warn+0xd1/0xf0 warn_slowpath_fmt+0x5f/0x80 percpu_ref_kill_and_confirm+0x92/0xb0 cgroup_kill_sb+0x95/0xb0 deactivate_locked_super+0x43/0x70 deactivate_super+0x46/0x60 ... ---[ end trace a79f61c2a2633700 ]--- Here's a race: Thread A Thread B cgroup1_mount() # alloc a new cgroup root cgroup_setup_root() cgroup1_mount() # no sb yet, returns NULL kernfs_pin_sb() # but succeeds in getting the refcnt, # so re-use cgroup root percpu_ref_tryget_live() # alloc sb with cgroup root cgroup_do_mount() cgroup_kill_sb() # alloc another sb with same root cgroup_do_mount() cgroup_kill_sb() We end up using the same cgroup root for two different superblocks, so percpu_ref_kill() will be called twice on the same root when the two superblocks are destroyed. We should fix to make sure the superblock pinning is really successful. Cc: stable@vger.kernel.org # 3.16+ Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Zefan Li <lizefan@huawei.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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#
4b9502e6 |
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08-Mar-2017 |
Elena Reshetova <elena.reshetova@intel.com> |
kernel: convert css_set.refcount from atomic_t to refcount_t refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
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b6a6759d |
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25-Feb-2017 |
Kees Cook <keescook@chromium.org> |
cgroups: censor kernel pointer in debug files As found in grsecurity, this avoids exposing a kernel pointer through the cgroup debug entries. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Tejun Heo <tj@kernel.org>
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50ff9d13 |
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05-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h> It's not used by any of the scheduler methods, but <linux/sched/task_stack.h> needs it to pick up STACK_END_MAGIC. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
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56cd6973 |
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06-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Move the task_lock()/unlock() APIs to <linux/sched/task.h> The task_lock()/task_unlock() APIs are not realated to core scheduling, they are task lifetime APIs, i.e. they belong into <linux/sched/task.h>. Move them. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
c3edc401 |
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02-Feb-2017 |
Ingo Molnar <mingo@kernel.org> |
sched/headers: Move task_struct::signal and task_struct::sighand types and accessors into <linux/sched/signal.h> task_struct::signal and task_struct::sighand are pointers, which would normally make it straightforward to not define those types in sched.h. That is not so, because the types are accompanied by a myriad of APIs (macros and inline functions) that dereference them. Split the types and the APIs out of sched.h and move them into a new header, <linux/sched/signal.h>. With this change sched.h does not know about 'struct signal' and 'struct sighand' anymore, trying to put accessors into sched.h as a test fails the following way: ./include/linux/sched.h: In function ‘test_signal_types’: ./include/linux/sched.h:2461:18: error: dereferencing pointer to incomplete type ‘struct signal_struct’ ^ This reduces the size and complexity of sched.h significantly. Update all headers and .c code that relied on getting the signal handling functionality from <linux/sched.h> to include <linux/sched/signal.h>. The list of affected files in the preparatory patch was partly generated by grepping for the APIs, and partly by doing coverage build testing, both all[yes|mod|def|no]config builds on 64-bit and 32-bit x86, and an array of cross-architecture builds. Nevertheless some (trivial) build breakage is still expected related to rare Kconfig combinations and in-flight patches to various kernel code, but most of it should be handled by this patch. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
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#
bfc2cf6f |
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15-Jan-2017 |
Tejun Heo <tj@kernel.org> |
cgroup: call subsys->*attach() only for subsystems which are actually affected by migration Currently, subsys->*attach() callbacks are called for all subsystems which are attached to the hierarchy on which the migration is taking place. With cgroup_migrate_prepare_dst() filtering out identity migrations, v1 hierarchies can avoid spurious ->*attach() callback invocations where the source and destination csses are identical; however, this isn't enough on v2 as only a subset of the attached controllers can be affected on controller enable/disable. While spurious ->*attach() invocations aren't critically broken, they're unnecessary overhead and can lead to temporary overcharges on certain controllers. Fix it by tracking which subsystems are affected by a migration and invoking ->*attach() callbacks only on those subsystems. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com>
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#
e595cd70 |
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15-Jan-2017 |
Tejun Heo <tj@kernel.org> |
cgroup: track migration context in cgroup_mgctx cgroup migration is performed in four steps - css_set preloading, addition of target tasks, actual migration, and clean up. A list named preloaded_csets is used to track the preloading. This is a bit too restricted and the code is already depending on the subtlety that all source css_sets appear before destination ones. Let's create struct cgroup_mgctx which keeps track of everything during migration. Currently, it has separate preload lists for source and destination csets and also embeds cgroup_taskset which is used during the actual migration. This moves struct cgroup_taskset definition to cgroup-internal.h. This patch doesn't cause any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Zefan Li <lizefan@huawei.com>
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#
e0aed7c7 |
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27-Dec-2016 |
Tejun Heo <tj@kernel.org> |
cgroup: fix RCU related sparse warnings kn->priv which is a void * is used as a RCU pointer by cgroup. When dereferencing it, it was passing kn->priv to rcu_derefreence() without casting it into a RCU pointer triggering address space mismatch warning from sparse. Fix them. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Fengguang Wu <fengguang.wu@intel.com> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
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#
d62beb7f |
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27-Dec-2016 |
Tejun Heo <tj@kernel.org> |
cgroup: rename functions for consistency Now that v1 functions are separated out, rename some functions for consistency. cgroup_dfl_base_files -> cgroup_base_files cgroup_legacy_base_files -> cgroup1_base_files cgroup_ssid_no_v1() -> cgroup1_ssid_disabled() cgroup_pidlist_destroy_all -> cgroup1_pidlist_destroy_all() cgroup_release_agent() -> cgroup1_release_agent() check_for_release() -> cgroup1_check_for_release() Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
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#
1592c9b2 |
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27-Dec-2016 |
Tejun Heo <tj@kernel.org> |
cgroup: move v1 mount functions to kernel/cgroup/cgroup-v1.c Now that the v1 mount code is split into separate functions, move them to kernel/cgroup/cgroup-v1.c along with the mount option handling code. As this puts all v1-only kernfs_syscall_ops in cgroup-v1.c, move cgroup1_kf_syscall_ops to cgroup-v1.c too. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
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#
fa069904 |
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27-Dec-2016 |
Tejun Heo <tj@kernel.org> |
cgroup: separate out cgroup1_kf_syscall_ops Currently, cgroup_kf_syscall_ops is shared by v1 and v2 and the specific methods test the version and take different actions. Split out v1 functions and put them in cgroup1_kf_syscall_ops and remove the now unnecessary explicit branches in specific methods. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
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0a268dbd |
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27-Dec-2016 |
Tejun Heo <tj@kernel.org> |
cgroup: move cgroup v1 specific code to kernel/cgroup/cgroup-v1.c cgroup.c is getting too unwieldy. Let's move out cgroup v1 specific code along with the debug controller into kernel/cgroup/cgroup-v1.c. v2: cgroup_mutex and css_set_lock made available in cgroup-internal.h regardless of CONFIG_PROVE_RCU. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Acked-by: Zefan Li <lizefan@huawei.com>
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