| Age | Commit message (Collapse) | Author |
|---|
|
Add wq_barrier->task and worker_pool->manager to keep track of the
flushing task and pool manager respectively. These are purely
informational and will be used to implement sysrq dump of workqueues.
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
The workqueues list is protected by wq_pool_mutex and a workqueue and
its subordinate data structures are freed directly on destruction. We
want to add the ability dump workqueues from a sysrq callback which
requires walking all workqueues without grabbing wq_pool_mutex. This
patch makes freeing of workqueues RCU protected and makes the
workqueues list walkable while holding RCU read lock.
Note that pool_workqueues and pools are already sched-RCU protected.
For consistency, workqueues are also protected with sched-RCU.
While at it, reverse the workqueues list so that a workqueue which is
created earlier comes before. The order of the list isn't significant
functionally but this makes the planned sysrq dump list system
workqueues first.
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
We want the mei fixes in here as well.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
This resolves a merge issue in drivers/tty/serial/8250/8250_pci.c
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty
Pull tty/serial fixes from Greg KH:
"Here are some tty and serial driver fixes for 4.0-rc3.
Along with the atime fix that you know about, here are some other
serial driver bugfixes as well. Most notable is a wait_until_sent
bugfix that was traced back to being around since before 2.6.12 that
Johan has fixed up.
All have been in linux-next successfully"
* tag 'tty-4.0-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
TTY: fix tty_wait_until_sent maximum timeout
TTY: fix tty_wait_until_sent on 64-bit machines
USB: serial: fix infinite wait_until_sent timeout
TTY: bfin_jtag_comm: remove incorrect wait_until_sent operation
net: irda: fix wait_until_sent poll timeout
serial: uapi: Declare all userspace-visible io types
serial: core: Fix iotype userspace breakage
serial: sprd: Fix missing spin_unlock in sprd_handle_irq()
console: Fix console name size mismatch
tty: fix up atime/mtime mess, take four
serial: 8250_dw: Fix get_mctrl behaviour
serial:8250:8250_pci: delete unneeded quirk entries
serial:8250:8250_pci: fix redundant entry report for WCH_CH352_2S
Change email address for 8250_pci
serial: 8250: Revert "tty: serial: 8250_core: read only RX if there is something in the FIFO"
Revert "tty/serial: of_serial: add DT alias ID handling"
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 fixes from Catalin Marinas:
"arm64 and generic kernel/module.c (acked by Rusty) fixes for
CONFIG_DEBUG_SET_MODULE_RONX"
* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
kernel/module.c: Update debug alignment after symtable generation
arm64: Don't use is_module_addr in setting page attributes
|
|
Ming reported soft lockups occurring when running xfstest due to
the following tip:locking/core commit:
b3fd4f03ca0b ("locking/rwsem: Avoid deceiving lock spinners")
When doing optimistic spinning in rwsem, threads should stop
spinning when the lock owner is not running. While a thread is
spinning on owner, if the owner reschedules, owner->on_cpu
returns false and we stop spinning.
However, this commit essentially caused the check to get
ignored because when we break out of the spin loop due to
!on_cpu, we continue spinning if sem->owner != NULL.
This patch fixes this by making sure we stop spinning if the
owner is not running. Furthermore, just like with mutexes,
refactor the code such that we don't have separate checks for
owner_running(). This makes it more straightforward in terms of
why we exit the spin on owner loop and we would also avoid
needing to "guess" why we broke out of the loop to make this
more readable.
Reported-and-tested-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jason Low <jason.low2@hp.com>
Acked-by: Davidlohr Bueso <dave@stgolabs.net>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Jones <davej@codemonkey.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sasha Levin <sasha.levin@oracle.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Link: http://lkml.kernel.org/r/1425714331.2475.388.camel@j-VirtualBox
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Before register_console() calls the setup() method of the matched
console, the registering console index is already equal to the index
from the console command line; ie. newcon->index == c->index.
This change is also required to support extensible console matching;
(the command line index may have no relation to the console index
assigned by the console-defined match() function).
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
Fengguang reported, that on openrisc and avr32 architectures, we
get the following linker errors on *_defconfig builds that have
no bpf syscall support:
net/built-in.o:(.rodata+0x1cd0): undefined reference to `bpf_map_lookup_elem_proto'
net/built-in.o:(.rodata+0x1cd4): undefined reference to `bpf_map_update_elem_proto'
net/built-in.o:(.rodata+0x1cd8): undefined reference to `bpf_map_delete_elem_proto'
Fix it up by providing built-in weak definitions of the symbols,
so they can be overridden when the syscall is enabled. I think
the issue might be that gcc is not able to optimize all that away.
This patch fixes the linker errors for me, tested with Fengguang's
make.cross [1] script.
[1] https://git.kernel.org/cgit/linux/kernel/git/wfg/lkp-tests.git/plain/sbin/make.cross
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Fixes: d4052c4aea0c ("ebpf: remove CONFIG_BPF_SYSCALL ifdefs in socket filter code")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
commit 6ae9200f2cab7 ("enlarge console.name") increased the storage
for the console name to 16 bytes, but not the corresponding
struct console_cmdline::name storage. Console names longer than
8 bytes cause read beyond end-of-string and failure to match
console; I'm not sure if there are other unexpected consequences.
Cc: <stable@vger.kernel.org> # 2.6.22+
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching
Pull livepatching fix from Jiri Kosina:
"Fix an RCU unlock misplacement in live patching infrastructure, from
Peter Zijlstra"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching:
livepatch: fix RCU usage in klp_find_external_symbol()
|
|
When CONFIG_DEBUG_SET_MODULE_RONX is enabled, the sizes of
module sections are aligned up so appropriate permissions can
be applied. Adjusting for the symbol table may cause them to
become unaligned. Make sure to re-align the sizes afterward.
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Acked-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
|
|
* irq-pm:
genirq / PM: describe IRQF_COND_SUSPEND
tty: serial: atmel: rework interrupt and wakeup handling
watchdog: at91sam9: request the irq with IRQF_NO_SUSPEND
clk: at91: implement suspend/resume for the PMC irqchip
rtc: at91rm9200: rework wakeup and interrupt handling
rtc: at91sam9: rework wakeup and interrupt handling
PM / wakeup: export pm_system_wakeup symbol
genirq / PM: Add flag for shared NO_SUSPEND interrupt lines
genirq / PM: better describe IRQF_NO_SUSPEND semantics
|
|
* suspend-to-idle:
cpuidle / sleep: Use broadcast timer for states that stop local timer
cpuidle: Clean up fallback handling in cpuidle_idle_call()
cpuidle / sleep: Do sanity checks in cpuidle_enter_freeze() too
idle / sleep: Avoid excessive disabling and enabling interrupts
|
|
Commit 381063133246 (PM / sleep: Re-implement suspend-to-idle handling)
overlooked the fact that entering some sufficiently deep idle states
by CPUs may cause their local timers to stop and in those cases it
is necessary to switch over to a broadcast timer prior to entering
the idle state. If the cpuidle driver in use does not provide
the new ->enter_freeze callback for any of the idle states, that
problem affects suspend-to-idle too, but it is not taken into account
after the changes made by commit 381063133246.
Fix that by changing the definition of cpuidle_enter_freeze() and
re-arranging of the code in cpuidle_idle_call(), so the former does
not call cpuidle_enter() any more and the fallback case is handled
by cpuidle_idle_call() directly.
Fixes: 381063133246 (PM / sleep: Re-implement suspend-to-idle handling)
Reported-and-tested-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
|
|
changes
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
PREEMPT_NONE
cancel[_delayed]_work_sync() are implemented using
__cancel_work_timer() which grabs the PENDING bit using
try_to_grab_pending() and then flushes the work item with PENDING set
to prevent the on-going execution of the work item from requeueing
itself.
try_to_grab_pending() can always grab PENDING bit without blocking
except when someone else is doing the above flushing during
cancelation. In that case, try_to_grab_pending() returns -ENOENT. In
this case, __cancel_work_timer() currently invokes flush_work(). The
assumption is that the completion of the work item is what the other
canceling task would be waiting for too and thus waiting for the same
condition and retrying should allow forward progress without excessive
busy looping
Unfortunately, this doesn't work if preemption is disabled or the
latter task has real time priority. Let's say task A just got woken
up from flush_work() by the completion of the target work item. If,
before task A starts executing, task B gets scheduled and invokes
__cancel_work_timer() on the same work item, its try_to_grab_pending()
will return -ENOENT as the work item is still being canceled by task A
and flush_work() will also immediately return false as the work item
is no longer executing. This puts task B in a busy loop possibly
preventing task A from executing and clearing the canceling state on
the work item leading to a hang.
task A task B worker
executing work
__cancel_work_timer()
try_to_grab_pending()
set work CANCELING
flush_work()
block for work completion
completion, wakes up A
__cancel_work_timer()
while (forever) {
try_to_grab_pending()
-ENOENT as work is being canceled
flush_work()
false as work is no longer executing
}
This patch removes the possible hang by updating __cancel_work_timer()
to explicitly wait for clearing of CANCELING rather than invoking
flush_work() after try_to_grab_pending() fails with -ENOENT.
Link: http://lkml.kernel.org/g/20150206171156.GA8942@axis.com
v3: bit_waitqueue() can't be used for work items defined in vmalloc
area. Switched to custom wake function which matches the target
work item and exclusive wait and wakeup.
v2: v1 used wake_up() on bit_waitqueue() which leads to NULL deref if
the target bit waitqueue has wait_bit_queue's on it. Use
DEFINE_WAIT_BIT() and __wake_up_bit() instead. Reported by Tomeu
Vizoso.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Rabin Vincent <rabin.vincent@axis.com>
Cc: Tomeu Vizoso <tomeu.vizoso@gmail.com>
Cc: stable@vger.kernel.org
Tested-by: Jesper Nilsson <jesper.nilsson@axis.com>
Tested-by: Rabin Vincent <rabin.vincent@axis.com>
|
|
klp_find_object_module() is called from both the klp register and enable
paths. Only the call from the register path is necessary because the
module notifier will let us know if the patched module gets loaded or
unloaded.
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
|
|
It currently is required that all users of NO_SUSPEND interrupt
lines pass the IRQF_NO_SUSPEND flag when requesting the IRQ or the
WARN_ON_ONCE() in irq_pm_install_action() will trigger. That is
done to warn about situations in which unprepared interrupt handlers
may be run unnecessarily for suspended devices and may attempt to
access those devices by mistake. However, it may cause drivers
that have no technical reasons for using IRQF_NO_SUSPEND to set
that flag just because they happen to share the interrupt line
with something like a timer.
Moreover, the generic handling of wakeup interrupts introduced by
commit 9ce7a25849e8 (genirq: Simplify wakeup mechanism) only works
for IRQs without any NO_SUSPEND users, so the drivers of wakeup
devices needing to use shared NO_SUSPEND interrupt lines for
signaling system wakeup generally have to detect wakeup in their
interrupt handlers. Thus if they happen to share an interrupt line
with a NO_SUSPEND user, they also need to request that their
interrupt handlers be run after suspend_device_irqs().
In both cases the reason for using IRQF_NO_SUSPEND is not because
the driver in question has a genuine need to run its interrupt
handler after suspend_device_irqs(), but because it happens to
share the line with some other NO_SUSPEND user. Otherwise, the
driver would do without IRQF_NO_SUSPEND just fine.
To make it possible to specify that condition explicitly, introduce
a new IRQ action handler flag for shared IRQs, IRQF_COND_SUSPEND,
that, when set, will indicate to the IRQ core that the interrupt
user is generally fine with suspending the IRQ, but it also can
tolerate handler invocations after suspend_device_irqs() and, in
particular, it is capable of detecting system wakeup and triggering
it as appropriate from its interrupt handler.
That will allow us to work around a problem with a shared timer
interrupt line on at91 platforms.
Link: http://marc.info/?l=linux-kernel&m=142252777602084&w=2
Link: http://marc.info/?t=142252775300011&r=1&w=2
Link: https://lkml.org/lkml/2014/12/15/552
Reported-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
|
|
more changes
|
|
Conflicts:
drivers/net/ethernet/rocker/rocker.c
The rocker commit was two overlapping changes, one to rename
the ->vport member to ->pport, and another making the bitmask
expression use '1ULL' instead of plain '1'.
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Because invoke_cpu_core() checks whether the current CPU is online,
there is no need for __call_rcu_core() to redundantly check it.
There should not be any performance degradation because the called
function is visible to the compiler. This commit therefore removes
the redundant check.
Signed-off-by: Yao Dongdong <yaodongdong@huawei.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
The very similar functions rcu_force_quiescent_state(),
rcu_bh_force_quiescent_state(), and rcu_sched_force_quiescent_state()
are supposed to be together, but have drifted apart. This commit
restores rcu_sched_force_quiescent_state() to its rightful place.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
This commit gets rid of some inline #ifdefs by replacing them with
IS_ENABLED.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
If an RCU read-side critical section occurs within an interrupt handler
or a softirq handler, it cannot have been preempted. Therefore, there is
a check in rcu_read_unlock_special() checking for this error. However,
when this check triggers, it lacks diagnostic information. This commit
therefore moves rcu_read_unlock()'s lockdep annotation to follow the
call to __rcu_read_unlock() and changes rcu_read_unlock_special()'s
WARN_ON_ONCE() to an lockdep_rcu_suspicious() in order to locate where
the offending RCU read-side critical section began. In addition, the
value of the ->rcu_read_unlock_special field is printed.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
This commit uses IS_ENABLED() to remove the #ifdef from the
rcu_init_levelspread() functions. No effect on executable code.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
Because callbacks can now be posted quite early in boot, move the
early boot callback tests to precede RCU initialization.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
When a CPU is first determined to be a no-CBs CPUs, this commit causes
any early boot callbacks to be moved to the no-CBs callback list,
allowing them to be invoked.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
The wrapper already calls the appropriate free
function, use it instead of spinning our own.
Signed-off-by: Bandan Das <bsd@redhat.com>
Acked-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
While one must hold RCU-sched (aka. preempt_disable) for find_symbol()
one must equally hold it over the use of the object returned.
The moment you release the RCU-sched read lock, the object can be dead
and gone.
[jkosina@suse.cz: change subject line to be aligned with other patches]
Cc: Seth Jennings <sjenning@redhat.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Miroslav Benes <mbenes@suse.cz>
Cc: Petr Mladek <pmladek@suse.cz>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
|
|
This reverts commit 74390aa55678 ("perf: Remove the extra validity check
on nr_pages")
nr_pages equals to number of pages - 1 in perf_mmap. So nr_pages = 0 is
valid.
So the nr_pages != 0 && !is_power_of_2(nr_pages) are all
needed for checking. Otherwise, for example, perf test 6 failed.
# perf test 6
6: x86 rdpmc test :Error:
mmap() syscall returned with (Invalid argument)
FAILED!
Signed-off-by: Kan Liang <kan.liang@intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Kaixu Xia <xiakaixu@huawei.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1425280466-7830-1-git-send-email-kan.liang@intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
|
|
Move the fallback code path in cpuidle_idle_call() to the end of the
function to avoid jumping to a label in an if () branch.
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
Currently, we call cgroup_subsys->bind only on unmount, remount, and
when creating a new root on mount. Since the default hierarchy root is
created in cgroup_init, we will not call cgroup_subsys->bind if the
default hierarchy is freshly mounted. As a result, some controllers will
behave incorrectly (most notably, the "memory" controller will not
enable hierarchy support). Fix this by calling cgroup_subsys->bind right
after initializing a cgroup subsystem.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
The cpuset.sched_relax_domain_level can control how far we do
immediate load balancing on a system. However, it was found on recent
kernels that echo'ing a value into cpuset.sched_relax_domain_level
did not reduce any immediate load balancing.
The reason this occurred was because the update_domain_attr_tree() traversal
did not update for the "top_cpuset". This resulted in nothing being changed
when modifying the sched_relax_domain_level parameter.
This patch is able to address that problem by having update_domain_attr_tree()
allow updates for the root in the cpuset traversal.
Fixes: fc560a26acce ("cpuset: replace cpuset->stack_list with cpuset_for_each_descendant_pre()")
Cc: <stable@vger.kernel.org> # 3.9+
Signed-off-by: Jason Low <jason.low2@hp.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Serge Hallyn <serge.hallyn@canonical.com>
|
|
When we clear cpuset.cpus, cpuset.effective_cpus won't be cleared:
# mount -t cgroup -o cpuset xxx /mnt
# mkdir /mnt/tmp
# echo 0 > /mnt/tmp/cpuset.cpus
# echo > /mnt/tmp/cpuset.cpus
# cat cpuset.cpus
# cat cpuset.effective_cpus
0-15
And a kernel warning in update_cpumasks_hier() is triggered:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 4028 at kernel/cpuset.c:894 update_cpumasks_hier+0x471/0x650()
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Serge Hallyn <serge.hallyn@canonical.com>
|
|
If clone_children is enabled, effective masks won't be initialized
due to the bug:
# mount -t cgroup -o cpuset xxx /mnt
# echo 1 > cgroup.clone_children
# mkdir /mnt/tmp
# cat /mnt/tmp/
# cat cpuset.effective_cpus
# cat cpuset.cpus
0-15
And then this cpuset won't constrain the tasks in it.
Either the bug or the fix has no effect on unified hierarchy, as
there's no clone_chidren flag there any more.
Reported-by: Christian Brauner <christianvanbrauner@gmail.com>
Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com>
Cc: <stable@vger.kernel.org> # 3.17+
Signed-off-by: Zefan Li <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Tested-by: Serge Hallyn <serge.hallyn@canonical.com>
|
|
It looks like clockevents_unbind is being exported by mistake as:
- it is static;
- it is not listed in include/linux/clockchips.h;
- EXPORT_SYMBOL_GPL(clockevents_unbind) follows clockevents_unbind_device()
implementation.
I think clockevents_unbind_device should be exported instead. This is going to
be used to teardown Hyper-V clockevent devices on module unload.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Ingo Molnar:
"An rtmutex deadlock path fixlet"
* 'locking-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rtmutex: Set state back to running on error
|
|
This work extends the "classic" BPF programmable tc classifier by
extending its scope also to native eBPF code!
This allows for user space to implement own custom, 'safe' C like
classifiers (or whatever other frontend language LLVM et al may
provide in future), that can then be compiled with the LLVM eBPF
backend to an eBPF elf file. The result of this can be loaded into
the kernel via iproute2's tc. In the kernel, they can be JITed on
major archs and thus run in native performance.
Simple, minimal toy example to demonstrate the workflow:
#include <linux/ip.h>
#include <linux/if_ether.h>
#include <linux/bpf.h>
#include "tc_bpf_api.h"
__section("classify")
int cls_main(struct sk_buff *skb)
{
return (0x800 << 16) | load_byte(skb, ETH_HLEN + __builtin_offsetof(struct iphdr, tos));
}
char __license[] __section("license") = "GPL";
The classifier can then be compiled into eBPF opcodes and loaded
via tc, for example:
clang -O2 -emit-llvm -c cls.c -o - | llc -march=bpf -filetype=obj -o cls.o
tc filter add dev em1 parent 1: bpf cls.o [...]
As it has been demonstrated, the scope can even reach up to a fully
fledged flow dissector (similarly as in samples/bpf/sockex2_kern.c).
For tc, maps are allowed to be used, but from kernel context only,
in other words, eBPF code can keep state across filter invocations.
In future, we perhaps may reattach from a different application to
those maps e.g., to read out collected statistics/state.
Similarly as in socket filters, we may extend functionality for eBPF
classifiers over time depending on the use cases. For that purpose,
cls_bpf programs are using BPF_PROG_TYPE_SCHED_CLS program type, so
we can allow additional functions/accessors (e.g. an ABI compatible
offset translation to skb fields/metadata). For an initial cls_bpf
support, we allow the same set of helper functions as eBPF socket
filters, but we could diverge at some point in time w/o problem.
I was wondering whether cls_bpf and act_bpf could share C programs,
I can imagine that at some point, we introduce i) further common
handlers for both (or even beyond their scope), and/or if truly needed
ii) some restricted function space for each of them. Both can be
abstracted easily through struct bpf_verifier_ops in future.
The context of cls_bpf versus act_bpf is slightly different though:
a cls_bpf program will return a specific classid whereas act_bpf a
drop/non-drop return code, latter may also in future mangle skbs.
That said, we can surely have a "classify" and "action" section in
a single object file, or considered mentioned constraint add a
possibility of a shared section.
The workflow for getting native eBPF running from tc [1] is as
follows: for f_bpf, I've added a slightly modified ELF parser code
from Alexei's kernel sample, which reads out the LLVM compiled
object, sets up maps (and dynamically fixes up map fds) if any, and
loads the eBPF instructions all centrally through the bpf syscall.
The resulting fd from the loaded program itself is being passed down
to cls_bpf, which looks up struct bpf_prog from the fd store, and
holds reference, so that it stays available also after tc program
lifetime. On tc filter destruction, it will then drop its reference.
Moreover, I've also added the optional possibility to annotate an
eBPF filter with a name (e.g. path to object file, or something
else if preferred) so that when tc dumps currently installed filters,
some more context can be given to an admin for a given instance (as
opposed to just the file descriptor number).
Last but not least, bpf_prog_get() and bpf_prog_put() needed to be
exported, so that eBPF can be used from cls_bpf built as a module.
Thanks to 60a3b2253c41 ("net: bpf: make eBPF interpreter images
read-only") I think this is of no concern since anything wanting to
alter eBPF opcode after verification stage would crash the kernel.
[1] http://git.breakpoint.cc/cgit/dborkman/iproute2.git/log/?h=ebpf
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
is_gpl_compatible and prog_type should be moved directly into bpf_prog
as they stay immutable during bpf_prog's lifetime, are core attributes
and they can be locked as read-only later on via bpf_prog_select_runtime().
With a bit of rearranging, this also allows us to shrink bpf_prog_aux
to exactly 1 cacheline.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
As discussed recently and at netconf/netdev01, we want to prevent making
bpf_verifier_ops registration available for modules, but have them at a
controlled place inside the kernel instead.
The reason for this is, that out-of-tree modules can go crazy and define
and register any verfifier ops they want, doing all sorts of crap, even
bypassing available GPLed eBPF helper functions. We don't want to offer
such a shiny playground, of course, but keep strict control to ourselves
inside the core kernel.
This also encourages us to design eBPF user helpers carefully and
generically, so they can be shared among various subsystems using eBPF.
For the eBPF traffic classifier (cls_bpf), it's a good start to share
the same helper facilities as we currently do in eBPF for socket filters.
That way, we have BPF_PROG_TYPE_SCHED_CLS look like it's own type, thus
one day if there's a good reason to diverge the set of helper functions
from the set available to socket filters, we keep ABI compatibility.
In future, we could place all bpf_prog_type_list at a central place,
perhaps.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
We can move bpf_map_ops and bpf_verifier_ops and other structs into ro
section, bpf_map_type_list and bpf_prog_type_list into read mostly.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Now that we have BPF_PROG_TYPE_SOCKET_FILTER up and running, we can
remove the test stubs which were added to get the verifier suite up.
We can just let the test cases probe under socket filter type instead.
In the fill/spill test case, we cannot (yet) access fields from the
context (skb), but we may adapt that test case in future.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@plumgrid.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The "usual" path is:
- rt_mutex_slowlock()
- set_current_state()
- task_blocks_on_rt_mutex() (ret 0)
- __rt_mutex_slowlock()
- sleep or not but do return with __set_current_state(TASK_RUNNING)
- back to caller.
In the early error case where task_blocks_on_rt_mutex() return
-EDEADLK we never change the task's state back to RUNNING. I
assume this is intended. Without this change after ww_mutex
using rt_mutex the selftest passes but later I get plenty of:
| bad: scheduling from the idle thread!
backtraces.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Maarten Lankhorst <maarten.lankhorst@canonical.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Fixes: afffc6c1805d ("locking/rtmutex: Optimize setting task running after being blocked")
Link: http://lkml.kernel.org/r/1425056229-22326-4-git-send-email-bigeasy@linutronix.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
|
|
Disabling interrupts at the end of cpuidle_enter_freeze() is not
useful, because its caller, cpuidle_idle_call(), re-enables them
right away after invoking it.
To avoid that unnecessary back and forth dance with interrupts,
make cpuidle_enter_freeze() enable interrupts after calling
enter_freeze_proper() and drop the local_irq_disable() at its
end, so that all of the code paths in it end up with interrupts
enabled. Then, cpuidle_idle_call() will not need to re-enable
interrupts after calling cpuidle_enter_freeze() any more, because
the latter will return with interrupts enabled, in analogy with
cpuidle_enter().
Reported-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
|
|
There's a uname workaround for broken userspace which can't handle kernel
versions of 3.x. Update it for 4.x.
Signed-off-by: Jon DeVree <nuxi@vault24.org>
Cc: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
If the RCU grace-period kthread invoking rcu_sysidle_check_cpu()
happens to be running on the tick_do_timer_cpu initially,
then rcu_bind_gp_kthread() won't bind it. This kthread might
then migrate before invoking rcu_gp_fqs(), which will trigger the
WARN_ON_ONCE() in rcu_sysidle_check_cpu(). This commit therefore makes
rcu_bind_gp_kthread() do the binding even if the kthread is currently
on the same CPU. Because this incurs added overhead, this commit also
causes each RCU grace-period kthread to invoke rcu_bind_gp_kthread()
once at boot rather than at the beginning of each grace period.
And as long as rcu_bind_gp_kthread() is being modified, this commit
eliminates its #ifdef.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
The standard code path accommodates a condition when no
RCU callbacks are ready to invoke. Since size of the code
is a priority for tiny RCU, remove the fast path.
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
When the ->curtail and ->donetail pointers differ, ->rcucblist
always points to the beginning of the current list and thus
cannot be NULL. Therefore, the check ->rcucblist != NULL is
redundant and this commit removes it.
Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
