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| SHA1 | ||
|---|---|---|
commit a713af394cf382a30dd28a1015cbe572f1b9ca75 upstream.
Because pids->limit can be changed concurrently (but we don't want to
take a lock because it would be needlessly expensive), use atomic64_ts
instead.
Fixes: commit
Aleksa Sarai
authored and
 Greg Kroah-Hartman
commited |
a1de70aa86 | |
commit c596687a008b579c503afb7a64fcacc7270fae9e upstream.
While adding handling for dying task group leaders c03cd7738a83
("cgroup: Include dying leaders with live threads in PROCS
iterations") added an inverted cset skip condition to
css_task_iter_advance_css_set(). It should skip cset if it's
completely empty but was incorrectly testing for the inverse condition
for the dying_tasks list. Fix it.
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: c03cd7738a83 ("cgroup: Include dying leaders with live threads in PROCS iterations")
Reported-by: syzbot+d4bba5ccd4f9a2a68681@syzkaller.appspotmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tejun Heo
authored and
Greg Kroah-Hartman
commited |
ebda41dd17 | |
commit cee0c33c546a93957a52ae9ab6bebadbee765ec5 upstream.
b636fd38dc40 ("cgroup: Implement css_task_iter_skip()") introduced
css_task_iter_skip() which is used to fix task iterations skipping
dying threadgroup leaders with live threads. Skipping is implemented
as a subportion of full advancing but css_task_iter_next() forgot to
fully advance a skipped iterator before determining the next task to
visit causing it to return invalid task pointers.
Fix it by making css_task_iter_next() fully advance the iterator if it
has been skipped since the previous iteration.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: syzbot
Link: http://lkml.kernel.org/r/00000000000097025d058a7fd785@google.com
Fixes: b636fd38dc40 ("cgroup: Implement css_task_iter_skip()")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tejun Heo
authored and
Greg Kroah-Hartman
commited |
0a9abd2778 | |
commit c03cd7738a83b13739f00546166969342c8ff014 upstream. CSS_TASK_ITER_PROCS currently iterates live group leaders; however, this means that a process with dying leader and live threads will be skipped. IOW, cgroup.procs might be empty while cgroup.threads isn't, which is confusing to say the least. Fix it by making cset track dying tasks and include dying leaders with live threads in PROCS iteration. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Topi Miettinen <toiwoton@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tejun Heo
authored and
Greg Kroah-Hartman
commited |
4340d175b8 | |
commit b636fd38dc40113f853337a7d2a6885ad23b8811 upstream. When a task is moved out of a cset, task iterators pointing to the task are advanced using the normal css_task_iter_advance() call. This is fine but we'll be tracking dying tasks on csets and thus moving tasks from cset->tasks to (to be added) cset->dying_tasks. When we remove a task from cset->tasks, if we advance the iterators, they may move over to the next cset before we had the chance to add the task back on the dying list, which can allow the task to escape iteration. This patch separates out skipping from advancing. Skipping only moves the affected iterators to the next pointer rather than fully advancing it and the following advancing will recognize that the cursor has already been moved forward and do the rest of advancing. This ensures that when a task moves from one list to another in its cset, as long as it moves in the right direction, it's always visible to iteration. This doesn't cause any visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tejun Heo
authored and
Greg Kroah-Hartman
commited |
370b9e6399 | |
[ Upstream commit d477f8c202d1f0d4791ab1263ca7657bbe5cf79e ] In the case that a process is constrained by taskset(1) (i.e. sched_setaffinity(2)) to a subset of available cpus, and all of those are subsequently offlined, the scheduler will set tsk->cpus_allowed to the current value of task_cs(tsk)->effective_cpus. This is done via a call to do_set_cpus_allowed() in the context of cpuset_cpus_allowed_fallback() made by the scheduler when this case is detected. This is the only call made to cpuset_cpus_allowed_fallback() in the latest mainline kernel. However, this is not sane behavior. I will demonstrate this on a system running the latest upstream kernel with the following initial configuration: # grep -i cpu /proc/$$/status Cpus_allowed: ffffffff,fffffff Cpus_allowed_list: 0-63 (Where cpus 32-63 are provided via smt.) If we limit our current shell process to cpu2 only and then offline it and reonline it: # taskset -p 4 $$ pid 2272's current affinity mask: ffffffffffffffff pid 2272's new affinity mask: 4 # echo off > /sys/devices/system/cpu/cpu2/online # dmesg | tail -3 [ 2195.866089] process 2272 (bash) no longer affine to cpu2 [ 2195.872700] IRQ 114: no longer affine to CPU2 [ 2195.879128] smpboot: CPU 2 is now offline # echo on > /sys/devices/system/cpu/cpu2/online # dmesg | tail -1 [ 2617.043572] smpboot: Booting Node 0 Processor 2 APIC 0x4 We see that our current process now has an affinity mask containing every cpu available on the system _except_ the one we originally constrained it to: # grep -i cpu /proc/$$/status Cpus_allowed: ffffffff,fffffffb Cpus_allowed_list: 0-1,3-63 This is not sane behavior, as the scheduler can now not only place the process on previously forbidden cpus, it can't even schedule it on the cpu it was originally constrained to! Other cases result in even more exotic affinity masks. Take for instance a process with an affinity mask containing only cpus provided by smt at the moment that smt is toggled, in a configuration such as the following: # taskset -p f000000000 $$ # grep -i cpu /proc/$$/status Cpus_allowed: 000000f0,00000000 Cpus_allowed_list: 36-39 A double toggle of smt results in the following behavior: # echo off > /sys/devices/system/cpu/smt/control # echo on > /sys/devices/system/cpu/smt/control # grep -i cpus /proc/$$/status Cpus_allowed: ffffff00,ffffffff Cpus_allowed_list: 0-31,40-63 This is even less sane than the previous case, as the new affinity mask excludes all smt-provided cpus with ids less than those that were previously in the affinity mask, as well as those that were actually in the mask. With this patch applied, both of these cases end in the following state: # grep -i cpu /proc/$$/status Cpus_allowed: ffffffff,ffffffff Cpus_allowed_list: 0-63 The original policy is discarded. Though not ideal, it is the simplest way to restore sanity to this fallback case without reinventing the cpuset wheel that rolls down the kernel just fine in cgroup v2. A user who wishes for the previous affinity mask to be restored in this fallback case can use that mechanism instead. This patch modifies scheduler behavior by instead resetting the mask to task_cs(tsk)->cpus_allowed by default, and cpu_possible mask in legacy mode. I tested the cases above on both modes. Note that the scheduler uses this fallback mechanism if and only if _every_ other valid avenue has been traveled, and it is the last resort before calling BUG(). Suggested-by: Waiman Long <longman@redhat.com> Suggested-by: Phil Auld <pauld@redhat.com> Signed-off-by: Joel Savitz <jsavitz@redhat.com> Acked-by: Phil Auld <pauld@redhat.com> Acked-by: Waiman Long <longman@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
Joel Savitz
authored and
Greg Kroah-Hartman
commited |
b7747ecb82 | |
[ Upstream commit 4dcabece4c3a9f9522127be12cc12cc120399b2f ] The number of descendant cgroups and the number of dying descendant cgroups are currently synchronized using the cgroup_mutex. The number of descendant cgroups will be required by the cgroup v2 freezer, which will use it to determine if a cgroup is frozen (depending on total number of descendants and number of frozen descendants). It's not always acceptable to grab the cgroup_mutex, especially from quite hot paths (e.g. exit()). To avoid this, let's additionally synchronize these counters using the css_set_lock. So, it's safe to read these counters with either cgroup_mutex or css_set_lock locked, and for changing both locks should be acquired. Signed-off-by: Roman Gushchin <guro@fb.com> Signed-off-by: Tejun Heo <tj@kernel.org> Cc: kernel-team@fb.com Signed-off-by: Sasha Levin <sashal@kernel.org> 
Roman Gushchin
authored and
Greg Kroah-Hartman
commited |
4e4d5cea79 | |
[ Upstream commit 51bee5abeab2058ea5813c5615d6197a23dbf041 ]
The only user of cgroup_subsys->free() callback is pids_cgrp_subsys which
needs pids_free() to uncharge the pid.
However, ->free() is called from __put_task_struct()->cgroup_free() and this
is too late. Even the trivial program which does
for (;;) {
int pid = fork();
assert(pid >= 0);
if (pid)
wait(NULL);
else
exit(0);
}
can run out of limits because release_task()->call_rcu(delayed_put_task_struct)
implies an RCU gp after the task/pid goes away and before the final put().
Test-case:
mkdir -p /tmp/CG
mount -t cgroup2 none /tmp/CG
echo '+pids' > /tmp/CG/cgroup.subtree_control
mkdir /tmp/CG/PID
echo 2 > /tmp/CG/PID/pids.max
perl -e 'while ($p = fork) { wait; } $p // die "fork failed: $!\n"' &
echo $! > /tmp/CG/PID/cgroup.procs
Without this patch the forking process fails soon after migration.
Rename cgroup_subsys->free() to cgroup_subsys->release() and move the callsite
into the new helper, cgroup_release(), called by release_task() which actually
frees the pid(s).
Reported-by: Herton R. Krzesinski <hkrzesin@redhat.com>
Reported-by: Jan Stancek <jstancek@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Oleg Nesterov
authored and
Greg Kroah-Hartman
commited |
d0bc74c563 | |
[ Upstream commit b4ff1b44bcd384d22fcbac6ebaf9cc0d33debe50 ] cgroup_rstat_cpu_pop_updated() is used to traverse the updated cgroups on flush. While it was only visiting updated ones in the subtree, it was visiting @root unconditionally. We can easily check whether @root is updated or not by looking at its ->updated_next just as with the cgroups in the subtree. * Remove the unnecessary cgroup_parent() test. The system root cgroup is never updated and thus its ->updated_next is always NULL. No need to test whether cgroup_parent() exists in addition to ->updated_next. * Terminate traverse if ->updated_next is NULL. This can only happen for subtree @root and there's no reason to visit it if it's not marked updated. This reduces cpu consumption when reading a lot of rstat backed files. In a micro benchmark reading stat from ~1600 cgroups, the sys time was lowered by >40%. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Tejun Heo
authored and
Greg Kroah-Hartman
commited |
a74ebf047e | |
commit 399504e21a10be16dd1408ba0147367d9d82a10c upstream.
same story as with last May fixes in sysfs (
Al Viro
authored and
Greg Kroah-Hartman
commited |
7a8b048430 | |
[ Upstream commit e250d91d65750a0c0c62483ac4f9f357e7317617 ]
This fixes the case where all mount options specified are consumed by an
LSM and all that's left is an empty string. In this case cgroupfs should
accept the string and not fail.
How to reproduce (with SELinux enabled):
# umount /sys/fs/cgroup/unified
# mount -o context=system_u:object_r:cgroup_t:s0 -t cgroup2 cgroup2 /sys/fs/cgroup/unified
mount: /sys/fs/cgroup/unified: wrong fs type, bad option, bad superblock on cgroup2, missing codepage or helper program, or other error.
# dmesg | tail -n 1
[ 31.575952] cgroup: cgroup2: unknown option ""
Fixes:
Ondrej Mosnacek
authored and
Greg Kroah-Hartman
commited |
4b5abffd63 | |
commit e9d81a1bc2c48ea9782e3e8b53875f419766ef47 upstream.
CSS_TASK_ITER_PROCS implements process-only iteration by making
css_task_iter_advance() skip tasks which aren't threadgroup leaders;
however, when an iteration is started css_task_iter_start() calls the
inner helper function css_task_iter_advance_css_set() instead of
css_task_iter_advance(). As the helper doesn't have the skip logic,
when the first task to visit is a non-leader thread, it doesn't get
skipped correctly as shown in the following example.
# ps -L 2030
PID LWP TTY STAT TIME COMMAND
2030 2030 pts/0 Sl+ 0:00 ./test-thread
2030 2031 pts/0 Sl+ 0:00 ./test-thread
# mkdir -p /sys/fs/cgroup/x/a/b
# echo threaded > /sys/fs/cgroup/x/a/cgroup.type
# echo threaded > /sys/fs/cgroup/x/a/b/cgroup.type
# echo 2030 > /sys/fs/cgroup/x/a/cgroup.procs
# cat /sys/fs/cgroup/x/a/cgroup.threads
2030
2031
# cat /sys/fs/cgroup/x/cgroup.procs
2030
# echo 2030 > /sys/fs/cgroup/x/a/b/cgroup.threads
# cat /sys/fs/cgroup/x/cgroup.procs
2031
2030
The last read of cgroup.procs is incorrectly showing non-leader 2031
in cgroup.procs output.
This can be fixed by updating css_task_iter_advance() to handle the
first advance and css_task_iters_tart() to call
css_task_iter_advance() instead of the inner helper. After the fix,
the same commands result in the following (correct) result:
# ps -L 2062
PID LWP TTY STAT TIME COMMAND
2062 2062 pts/0 Sl+ 0:00 ./test-thread
2062 2063 pts/0 Sl+ 0:00 ./test-thread
# mkdir -p /sys/fs/cgroup/x/a/b
# echo threaded > /sys/fs/cgroup/x/a/cgroup.type
# echo threaded > /sys/fs/cgroup/x/a/b/cgroup.type
# echo 2062 > /sys/fs/cgroup/x/a/cgroup.procs
# cat /sys/fs/cgroup/x/a/cgroup.threads
2062
2063
# cat /sys/fs/cgroup/x/cgroup.procs
2062
# echo 2062 > /sys/fs/cgroup/x/a/b/cgroup.threads
# cat /sys/fs/cgroup/x/cgroup.procs
2062
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Fixes:
Tejun Heo
authored and
Greg Kroah-Hartman
commited |
8a2fbdd5b0 | |
A cgroup which is already a threaded domain may be converted into a
threaded cgroup if the prerequisite conditions are met. When this
happens, all threaded descendant should also have their ->dom_cgrp
updated to the new threaded domain cgroup. Unfortunately, this
propagation was missing leading to the following failure.
# cd /sys/fs/cgroup/unified
# cat cgroup.subtree_control # show that no controllers are enabled
# mkdir -p mycgrp/a/b/c
# echo threaded > mycgrp/a/b/cgroup.type
At this point, the hierarchy looks as follows:
mycgrp [d]
a [dt]
b [t]
c [inv]
Now let's make node "a" threaded (and thus "mycgrp" s made "domain threaded"):
# echo threaded > mycgrp/a/cgroup.type
By this point, we now have a hierarchy that looks as follows:
mycgrp [dt]
a [t]
b [t]
c [inv]
But, when we try to convert the node "c" from "domain invalid" to
"threaded", we get ENOTSUP on the write():
# echo threaded > mycgrp/a/b/c/cgroup.type
sh: echo: write error: Operation not supported
This patch fixes the problem by
* Moving the opencoded ->dom_cgrp save and restoration in
cgroup_enable_threaded() into cgroup_{save|restore}_control() so
that mulitple cgroups can be handled.
* Updating all threaded descendants' ->dom_cgrp to point to the new
dom_cgrp when enabling threaded mode.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: "Michael Kerrisk (man-pages)" <mtk.manpages@gmail.com>
Reported-by: Amin Jamali <ajamali@pivotal.io>
Reported-by: Joao De Almeida Pereira <jpereira@pivotal.io>
Link: https://lore.kernel.org/r/CAKgNAkhHYCMn74TCNiMJ=ccLd7DcmXSbvw3CbZ1YREeG7iJM5g@mail.gmail.com
Fixes:
Tejun Heo
commited |
479adb89a9 | |
Pull cgroup updates from Tejun Heo: "Just one commit from Steven to take out spin lock from trace event handlers" * 'for-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup/tracing: Move taking of spin lock out of trace event handlers 
Linus Torvalds
commited |
596766102a | |
This change allows creating kernfs files and directories with arbitrary uid/gid instead of always using GLOBAL_ROOT_UID/GID by extending kernfs_create_dir_ns() and kernfs_create_file_ns() with uid/gid arguments. The "simple" kernfs_create_file() and kernfs_create_dir() are left alone and always create objects belonging to the global root. When creating symlinks ownership (uid/gid) is taken from the target kernfs object. Co-Developed-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Tyler Hicks <tyhicks@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
Dmitry Torokhov
authored and
 David S. Miller
commited |
488dee96bb | |
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> 
Steven Rostedt (VMware)
authored and
Tejun Heo
commited |
e4f8d81c73 | |
As we move stuff around, some doc references are broken. Fix some of them via this script: ./scripts/documentation-file-ref-check --fix Manually checked if the produced result is valid, removing a few false-positives. Acked-by: Takashi Iwai <tiwai@suse.de> Acked-by: Masami Hiramatsu <mhiramat@kernel.org> Acked-by: Stephen Boyd <sboyd@kernel.org> Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com> Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org> Reviewed-by: Coly Li <colyli@suse.de> Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Acked-by: Jonathan Corbet <corbet@lwn.net> 
Mauro Carvalho Chehab
commited |
5fb94e9ca3 | |
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>
Kees Cook
commited |
42bc47b353 | |
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>
Kees Cook
commited |
6da2ec5605 | |
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
- Introduce overflow test module (Rasmus, Kees)
- Introduce saturating size helper functions (Matthew, Kees)
- Treewide use of struct_size() for allocators (Kees)
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Merge tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull overflow updates from Kees Cook:
"This adds the new overflow checking helpers and adds them to the
2-factor argument allocators. And this adds the saturating size
helpers and does a treewide replacement for the struct_size() usage.
Additionally this adds the overflow testing modules to make sure
everything works.
I'm still working on the treewide replacements for allocators with
"simple" multiplied arguments:
*alloc(a * b, ...) -> *alloc_array(a, b, ...)
and
*zalloc(a * b, ...) -> *calloc(a, b, ...)
as well as the more complex cases, but that's separable from this
portion of the series. I expect to have the rest sent before -rc1
closes; there are a lot of messy cases to clean up.
Summary:
- Introduce arithmetic overflow test helper functions (Rasmus)
- Use overflow helpers in 2-factor allocators (Kees, Rasmus)
- Introduce overflow test module (Rasmus, Kees)
- Introduce saturating size helper functions (Matthew, Kees)
- Treewide use of struct_size() for allocators (Kees)"
* tag 'overflow-v4.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
treewide: Use struct_size() for devm_kmalloc() and friends
treewide: Use struct_size() for vmalloc()-family
treewide: Use struct_size() for kmalloc()-family
device: Use overflow helpers for devm_kmalloc()
mm: Use overflow helpers in kvmalloc()
mm: Use overflow helpers in kmalloc_array*()
test_overflow: Add memory allocation overflow tests
overflow.h: Add allocation size calculation helpers
test_overflow: Report test failures
test_overflow: macrofy some more, do more tests for free
lib: add runtime test of check_*_overflow functions
compiler.h: enable builtin overflow checkers and add fallback code
Linus Torvalds
commited |
2857676045 | |
One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:
struct foo {
int stuff;
void *entry[];
};
instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);
Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:
instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);
This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:
// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
// sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@
- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)
// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@
- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)
// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@
- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)
Signed-off-by: Kees Cook <keescook@chromium.org>
Kees Cook
commited |
acafe7e302 | |
Pull cgroup updates from Tejun Heo: - For cpustat, cgroup has a percpu hierarchical stat mechanism which propagates up the hierarchy lazily. This contains commits to factor out and generalize the mechanism so that it can be used for other cgroup stats too. The original intention was to update memcg stats to use it but memcg went for a different approach, so still the only user is cpustat. The factoring out and generalization still make sense and it's likely that this can be used for other purposes in the future. - cgroup uses kernfs_notify() (which uses fsnotify()) to inform user space of certain events. A rate limiting mechanism is added. - Other misc changes. * 'for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: css_set_lock should nest inside tasklist_lock rdmacg: Convert to use match_string() helper cgroup: Make cgroup_rstat_updated() ready for root cgroup usage cgroup: Add memory barriers to plug cgroup_rstat_updated() race window cgroup: Add cgroup_subsys->css_rstat_flush() cgroup: Replace cgroup_rstat_mutex with a spinlock cgroup: Factor out and expose cgroup_rstat_*() interface functions cgroup: Reorganize kernel/cgroup/rstat.c cgroup: Distinguish base resource stat implementation from rstat cgroup: Rename stat to rstat cgroup: Rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c cgroup: Limit event generation frequency cgroup: Explicitly remove core interface files
Linus Torvalds
commited |
9f25a8da42 | |
cgroup_enable_task_cg_lists() incorrectly nests non-irq-safe tasklist_lock inside irq-safe css_set_lock triggering the following lockdep warning. WARNING: possible irq lock inversion dependency detected 4.17.0-rc1-00027-gb37d049 #6 Not tainted -------------------------------------------------------- systemd/1 just changed the state of lock: 00000000fe57773b (css_set_lock){..-.}, at: cgroup_free+0xf2/0x12a but this lock took another, SOFTIRQ-unsafe lock in the past: (tasklist_lock){.+.+} and interrupts could create inverse lock ordering between them. other info that might help us debug this: Possible interrupt unsafe locking scenario: CPU0 CPU1 ---- ---- lock(tasklist_lock); local_irq_disable(); lock(css_set_lock); lock(tasklist_lock); <Interrupt> lock(css_set_lock); *** DEADLOCK *** The condition is highly unlikely to actually happen especially given that the path is executed only once per boot. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Boqun Feng <boqun.feng@gmail.com>
Tejun Heo
commited |
d8742e2290 | |
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>
Christoph Hellwig
commited |
3f3942aca6 | |
The new helper returns index of the matching string in an array. We are going to use it here. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
Andy Shevchenko
authored and
Tejun Heo
commited |
cc659e76f3 | |
cgroup_rstat_updated() ensures that the cgroup's rstat is linked to the parent. If there's no parent, it never gets linked and the function ends up grabbing and releasing the cgroup_rstat_lock each time for no reason which can be expensive. This hasn't been a problem till now because nobody was calling the function for the root cgroup but rstat is gonna be exposed to controllers and use cases, so let's get ready. Make cgroup_rstat_updated() an no-op for the root cgroup. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
c43c5ea75f | |
cgroup_rstat_updated() has a small race window where an updated signaling can race with flush and could be lost till the next update. This wasn't a problem for the existing usages, but we plan to use rstat to track counters which need to be accurate. This patch plugs the race window by synchronizing cgroup_rstat_updated() and flush path with memory barriers around cgroup_rstat_cpu->updated_next pointer. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
9a9e97b2f1 | |
This patch adds cgroup_subsys->css_rstat_flush(). If a subsystem has this callback, its csses are linked on cgrp->css_rstat_list and rstat will call the function whenever the associated cgroup is flushed. Flush is also performed when such csses are released so that residual counts aren't lost. Combined with the rstat API previous patches factored out, this allows controllers to plug into rstat to manage their statistics in a scalable way. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
8f53470bab | |
Currently, rstat flush path is protected with a mutex which is fine as all the existing users are from interface file show path. However, rstat is being generalized for use by controllers and flushing from atomic contexts will be necessary. This patch replaces cgroup_rstat_mutex with a spinlock and adds a irq-safe flush function - cgroup_rstat_flush_irqsafe(). Explicit yield handling is added to the flush path so that other flush functions can yield to other threads and flushers. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
0fa294fb19 | |
cgroup_rstat is being generalized so that controllers can use it too. This patch factors out and exposes the following interface functions. * cgroup_rstat_updated(): Renamed from cgroup_rstat_cpu_updated() for consistency. * cgroup_rstat_flush_hold/release(): Factored out from base stat implementation. * cgroup_rstat_flush(): Verbatim expose. While at it, drop assert on cgroup_rstat_mutex in cgroup_base_stat_flush() as it crosses layers and make a minor comment update. v2: Added EXPORT_SYMBOL_GPL(cgroup_rstat_updated) to fix a build bug. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
6162cef0f7 | |
Currently, rstat.c has rstat and base stat implementations intermixed. Collect base stat implementation at the end of the file. Also, reorder the prototypes. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
a17556f8d9 | |
Base resource stat accounts universial (not specific to any controller) resource consumptions on top of rstat. Currently, its implementation is intermixed with rstat implementation making the code confusing to follow. This patch clarifies the distintion by doing the followings. * Encapsulate base resource stat counters, currently only cputime, in struct cgroup_base_stat. * Move prev_cputime into struct cgroup and initialize it with cgroup. * Rename the related functions so that they start with cgroup_base_stat. * Prefix the related variables and field names with b. This patch doesn't make any functional changes. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
d4ff749b5e | |
stat is too generic a name and ends up causing subtle confusions. It'll be made generic so that controllers can plug into it, which will make the problem worse. Let's rename it to something more specific - cgroup_rstat for cgroup recursive stat. This patch does the following renames. No other changes. * cpu_stat -> rstat_cpu * stat -> rstat * ?cstat -> ?rstatc Note that the renames are selective. The unrenamed are the ones which implement basic resource statistics on top of rstat. This will be further cleaned up in the following patches. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
c58632b363 | |
stat is too generic a name and ends up causing subtle confusions. It'll be made generic so that controllers can plug into it, which will make the problem worse. Let's rename it to something more specific - cgroup_rstat for cgroup recursive stat. First, rename kernel/cgroup/stat.c to kernel/cgroup/rstat.c. No content changes. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
a5c2b93f79 | |
".events" files generate file modified event to notify userland of possible new events. Some of the events can be quite bursty (e.g. memory high event) and generating notification each time is costly and pointless. This patch implements a event rate limit mechanism. If a new notification is requested before 10ms has passed since the previous notification, the new notification is delayed till then. As this only delays from the second notification on in a given close cluster of notifications, userland reactions to notifications shouldn't be delayed at all in most cases while avoiding notification storms. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
b12e358328 | |
The "cgroup." core interface files bypass the usual interface removal path and get removed recursively along with the cgroup itself. While this works now, the subtle discrepancy gets in the way of implementing common mechanisms. This patch updates cgroup core interface file handling so that it's consistent with controller interface files. When added, the css is marked CSS_VISIBLE and they're explicitly removed before the cgroup is destroyed. This doesn't cause user-visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
5faaf05f29 | |
Pull workqueue updates from Tejun Heo: "rcu_work addition and a couple trivial changes" * 'for-4.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: remove the comment about the old manager_arb mutex workqueue: fix the comments of nr_idle fs/aio: Use rcu_work instead of explicit rcu and work item cgroup: Use rcu_work instead of explicit rcu and work item RCU, workqueue: Implement rcu_work
Linus Torvalds
commited |
d92cd810e6 | |
Workqueue now has rcu_work. Use it instead of open-coding rcu -> work item bouncing. Signed-off-by: Tejun Heo <tj@kernel.org>
Tejun Heo
commited |
8f36aaec9c | |
A domain cgroup isn't allowed to be turned threaded if its subtree is
populated or domain controllers are enabled. cgroup_enable_threaded()
depended on cgroup_can_be_thread_root() test to enforce this rule. A
parent which has populated domain descendants or have domain
controllers enabled can't become a thread root, so the above rules are
enforced automatically.
However, for the root cgroup which can host mixed domain and threaded
children, cgroup_can_be_thread_root() doesn't check any of those
conditions and thus first level cgroups ends up escaping those rules.
This patch fixes the bug by adding explicit checks for those rules in
cgroup_enable_threaded().
Reported-by: Michael Kerrisk (man-pages) <mtk.manpages@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes:
Tejun Heo
commited |
d1897c9538 | |
Make current_cpuset_is_being_rebound return bool due to this particular function only using either one or zero as its return value. No functional change. Link: http://lkml.kernel.org/r/1513266622-15860-4-git-send-email-baiyaowei@cmss.chinamobile.com Signed-off-by: Yaowei Bai <baiyaowei@cmss.chinamobile.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> 
Yaowei Bai
authored and
Linus Torvalds
commited |
77ef80c65a | |
Tejun Heo
commited |
08a77676f9 | |
Make cgroup.threads file delegatable. The behavior of cgroup.threads should follow the behavior of cgroup.procs. Signed-off-by: Roman Gushchin <guro@fb.com> Discovered-by: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Tejun Heo <tj@kernel.org>
Roman Gushchin
authored and
Tejun Heo
commited |
4f58424da3 | |
While teaching css_task_iter to handle skipping over tasks which aren't group leaders,
Tejun Heo
commited |
74d0833c65 | |
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>
Prateek Sood
authored and
Tejun Heo
commited |
116d2f7496 | |
As long as cft->name is guaranteed to be NUL-terminated, using strlcpy() would work just as well and avoid that warning, so the change below could be folded into that commit. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Tejun Heo <tj@kernel.org> 
Arnd Bergmann
authored and
Tejun Heo
commited |
50034ed496 | |
cgroup root name and file name have max length limit, we should avoid copying longer name than that to the name. tj: minor update to $SUBJ. Signed-off-by: Ma Shimiao <mashimiao.fnst@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
Ma Shimiao
authored and
Tejun Heo
commited |
e7fd37ba12 | |
This reverts commit
Tejun Heo
commited |
bdfbbda90a | |
This reverts commit
Tejun Heo
commited |
11db855c3d | |
Lockdep complains that the stats update is trying to register a non-static
key. This is because u64_stats are using a seqlock on 32bit arches, which
needs to be initialized before usage.
Fixes:
Lucas Stach
authored and
Tejun Heo
commited |
52cf373c37 | |
This macro `task_css_set` verifies that the caller is inside proper critical section if the kernel set CONFIG_PROVE_RCU=y. Signed-off-by: Wang Long <wanglong19@meituan.com> Signed-off-by: Tejun Heo <tj@kernel.org> 
Wang Long
authored and
Tejun Heo
commited |
ddf7005f32 |