| Age | Commit message (Collapse) | Author | Files | Lines |
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Because the rcu_cblist_empty() just samples the ->head pointer, and
because the rcu_cblist structure is quite straightforward, it makes
sense to open-code rcu_cblist_empty(p) as !p->head, cutting out a
level of indirection. This commit makes this change.
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
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This commit creates a new kernel/rcu/rcu_segcblist.c file that
contains non-trivial segcblist functions. Trivial functions
remain as static inline functions in kernel/rcu/rcu_segcblist.h
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
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Linus noticed that the <linux/rcu_segcblist.h> has huge inline functions
which should not be inline at all.
As a first step in cleaning this up, move them all to kernel/rcu/ and
only keep an absolute minimum of data type defines in the header:
before: -rw-r--r-- 1 mingo mingo 22284 May 2 10:25 include/linux/rcu_segcblist.h
after: -rw-r--r-- 1 mingo mingo 3180 May 2 10:22 include/linux/rcu_segcblist.h
More can be done, such as uninlining the large functions, which inlining
is unjustified even if it's an RCU internal matter.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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The default value for the kernel boot parameter srcutree.exp_holdoff
is 50 microseconds, which is too long for good Tree SRCU performance
(compared to Classic SRCU) on the workloads tested by Mike Galbraith.
This commit therefore sets the default value to 25 microseconds, which
shows excellent results in Mike's testing.
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
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On small systems, in the absence of readers, expedited SRCU grace
periods can complete in less than a microsecond. This means that an
eight-CPU system can have all CPUs doing synchronize_srcu() in a tight
loop and almost always expedite. This might actually be desirable in
some situations, but in general it is a good way to needlessly burn
CPU cycles. And in those situations where it is desirable, your friend
is the function synchronize_srcu_expedited().
For other situations, this commit adds a kernel parameter that specifies
a holdoff between completing the last SRCU grace period and auto-expediting
the next. If the next grace period starts before the holdoff expires,
auto-expediting is disabled. The holdoff is 50 microseconds by default,
and can be tuned to the desired number of nanoseconds. A value of zero
disables auto-expediting.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
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Classic SRCU in effect expedites the first synchronize_srcu() when SRCU
is idle, and Mike Galbraith demonstrated that some use cases do in fact
rely on this behavior. In particular, Mike showed that Steven Rostedt's
hotplug stress script takes 55 seconds with Classic SRCU and more than
16 -minutes- when running Tree SRCU. Assuming that each Tree SRCU's call
to synchronize_srcu() takes four milliseconds, this implies that Steven's
test invokes synchronize_srcu() in isolation, but more than once per
200 microseconds. Mike used ftrace to demonstrate that the time between
successive calls to synchronize_srcu() ranged from 118 to 342 microseconds,
with one outlier at 80 milliseconds. This data clearly indicates that
Tree SRCU needs to expedite the first invocation of synchronize_srcu()
during an SRCU idle period.
This commit therefor introduces a srcu_might_be_idle() function that
probabilistically checks whether or not SRCU is idle. This function is
used by synchronize_rcu() as an additional criterion in deciding whether
or not to expedite.
(Hat trick to Peter Zijlstra for his earlier suggestion that this might
in fact be a problem. Which for all I know might have motivated Mike to
look into it.)
Reported-by: Mike Galbraith <efault@gmx.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
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Commit f60d231a87c5 ("srcu: Crude control of expedited grace periods")
introduced a per-srcu_struct atomic counter to track outstanding
requests for grace periods. This works, but represents a memory-contention
bottleneck. This commit therefore uses the srcu_node combining tree
to remove this bottleneck.
This commit adds new ->srcu_gp_seq_needed_exp fields to the
srcu_data, srcu_node, and srcu_struct structures, which track the
farthest-in-the-future grace period that must be expedited, which in
turn requires that all nearer-term grace periods also be expedited.
Requests for expediting start with the srcu_data structure, run up
through the srcu_node tree, and end at the srcu_struct structure.
Note that it may be necessary to expedite a grace period that just
now started, and this is handled by a new srcu_funnel_exp_start()
function, which is invoked when the grace period itself is already
in its way, but when that grace period was not marked as expedited.
A new srcu_get_delay() function returns zero if there is at least one
expedited SRCU grace period in flight, or SRCU_INTERVAL otherwise.
This function is used to calculate delays: Normal grace periods
are allowed to extend in order to cover more requests with a given
grace-period computation, which decreases per-request overhead.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
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In the past, SRCU was simple enough that there was little point in
making the rcutorture writer stall messages print the SRCU grace-period
number state. With the advent of Tree SRCU, this has changed. This
commit therefore makes Classic, Tiny, and Tree SRCU report this state
to rcutorture as needed.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
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The current Tree SRCU implementation schedules a workqueue for every
srcu_data covered by a given leaf srcu_node structure having callbacks,
even if only one of those srcu_data structures actually contains
callbacks. This is clearly inefficient for workloads that don't feature
callbacks everywhere all the time. This commit therefore adds an array
of masks that are used by the leaf srcu_node structures to track exactly
which srcu_data structures contain callbacks.
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Mike Galbraith <efault@gmx.de>
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SRCU is optional, and included only if there is a "select SRCU" in effect.
However, we now have Tiny SRCU, so this commit defaults CONFIG_SRCU=y.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
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If the CONFIG_SRCU option is not selected, for example, when building
arch/tile allnoconfig, the following build errors appear:
kernel/rcu/tree.o: In function `srcu_online_cpu':
tree.c:(.text+0x4248): multiple definition of `srcu_online_cpu'
kernel/rcu/srcutree.o:srcutree.c:(.text+0x2120): first defined here
kernel/rcu/tree.o: In function `srcu_offline_cpu':
tree.c:(.text+0x4250): multiple definition of `srcu_offline_cpu'
kernel/rcu/srcutree.o:srcutree.c:(.text+0x2160): first defined here
The corresponding .config file shows CONFIG_TREE_SRCU=y, but no sign
of CONFIG_SRCU, which fatally confuses SRCU's #ifdefs, resulting in
the above errors. The reason this occurs is the folowing line in
init/Kconfig's definition for TREE_SRCU:
default y if !TINY_RCU && !CLASSIC_SRCU
If CONFIG_CLASSIC_SRCU=n, as it will be in for allnoconfig, and if
CONFIG_SMP=y, then we will get CONFIG_TREE_SRCU=y but no CONFIG_SRCU,
as seen in the .config file, and which will result in the above errors.
This error did not show up during rcutorture testing because rcutorture
forces CONFIG_SRCU=y, as it must to prevent build errors in rcutorture.c.
This commit therefore conditions TREE_SRCU (and TINY_SRCU, while it is
at it) with SRCU, like this:
default y if SRCU && !TINY_RCU && !CLASSIC_SRCU
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Reported-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Link: http://lkml.kernel.org/r/20170423162205.GP3956@linux.vnet.ibm.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Reducing real_num_tx_queues needs to be in sync with skb queue_mapping
otherwise skbs with queue_mapping greater than real_num_tx_queues
can be sent to the underlying driver and can result in kernel panic.
One such event is running netconsole and enabling VF on the same
device. Or running netconsole and changing number of tx queues via
ethtool on same device.
e.g.
Unable to handle kernel NULL pointer dereference
tsk->{mm,active_mm}->context = 0000000000001525
tsk->{mm,active_mm}->pgd = fff800130ff9a000
\|/ ____ \|/
"@'/ .. \`@"
/_| \__/ |_\
\__U_/
kworker/48:1(475): Oops [#1]
CPU: 48 PID: 475 Comm: kworker/48:1 Tainted: G OE
4.11.0-rc3-davem-net+ #7
Workqueue: events queue_process
task: fff80013113299c0 task.stack: fff800131132c000
TSTATE: 0000004480e01600 TPC: 00000000103f9e3c TNPC: 00000000103f9e40 Y:
00000000 Tainted: G OE
TPC: <ixgbe_xmit_frame_ring+0x7c/0x6c0 [ixgbe]>
g0: 0000000000000000 g1: 0000000000003fff g2: 0000000000000000 g3:
0000000000000001
g4: fff80013113299c0 g5: fff8001fa6808000 g6: fff800131132c000 g7:
00000000000000c0
o0: fff8001fa760c460 o1: fff8001311329a50 o2: fff8001fa7607504 o3:
0000000000000003
o4: fff8001f96e63a40 o5: fff8001311d77ec0 sp: fff800131132f0e1 ret_pc:
000000000049ed94
RPC: <set_next_entity+0x34/0xb80>
l0: 0000000000000000 l1: 0000000000000800 l2: 0000000000000000 l3:
0000000000000000
l4: 000b2aa30e34b10d l5: 0000000000000000 l6: 0000000000000000 l7:
fff8001fa7605028
i0: fff80013111a8a00 i1: fff80013155a0780 i2: 0000000000000000 i3:
0000000000000000
i4: 0000000000000000 i5: 0000000000100000 i6: fff800131132f1a1 i7:
00000000103fa4b0
I7: <ixgbe_xmit_frame+0x30/0xa0 [ixgbe]>
Call Trace:
[00000000103fa4b0] ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
[0000000000998c74] netpoll_start_xmit+0xf4/0x200
[0000000000998e10] queue_process+0x90/0x160
[0000000000485fa8] process_one_work+0x188/0x480
[0000000000486410] worker_thread+0x170/0x4c0
[000000000048c6b8] kthread+0xd8/0x120
[0000000000406064] ret_from_fork+0x1c/0x2c
[0000000000000000] (null)
Disabling lock debugging due to kernel taint
Caller[00000000103fa4b0]: ixgbe_xmit_frame+0x30/0xa0 [ixgbe]
Caller[0000000000998c74]: netpoll_start_xmit+0xf4/0x200
Caller[0000000000998e10]: queue_process+0x90/0x160
Caller[0000000000485fa8]: process_one_work+0x188/0x480
Caller[0000000000486410]: worker_thread+0x170/0x4c0
Caller[000000000048c6b8]: kthread+0xd8/0x120
Caller[0000000000406064]: ret_from_fork+0x1c/0x2c
Caller[0000000000000000]: (null)
Signed-off-by: Tushar Dave <tushar.n.dave@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Andrey Konovalov reported a BUG caused by the ip6mr code which is caused
because we call unregister_netdevice_many for a device that is already
being destroyed. In IPv4's ipmr that has been resolved by two commits
long time ago by introducing the "notify" parameter to the delete
function and avoiding the unregister when called from a notifier, so
let's do the same for ip6mr.
The trace from Andrey:
------------[ cut here ]------------
kernel BUG at net/core/dev.c:6813!
invalid opcode: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 1 PID: 1165 Comm: kworker/u4:3 Not tainted 4.11.0-rc7+ #251
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs
01/01/2011
Workqueue: netns cleanup_net
task: ffff880069208000 task.stack: ffff8800692d8000
RIP: 0010:rollback_registered_many+0x348/0xeb0 net/core/dev.c:6813
RSP: 0018:ffff8800692de7f0 EFLAGS: 00010297
RAX: ffff880069208000 RBX: 0000000000000002 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88006af90569
RBP: ffff8800692de9f0 R08: ffff8800692dec60 R09: 0000000000000000
R10: 0000000000000006 R11: 0000000000000000 R12: ffff88006af90070
R13: ffff8800692debf0 R14: dffffc0000000000 R15: ffff88006af90000
FS: 0000000000000000(0000) GS:ffff88006cb00000(0000)
knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe7e897d870 CR3: 00000000657e7000 CR4: 00000000000006e0
Call Trace:
unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
unregister_netdevice_many+0xc8/0x120 net/core/dev.c:7880
ip6mr_device_event+0x362/0x3f0 net/ipv6/ip6mr.c:1346
notifier_call_chain+0x145/0x2f0 kernel/notifier.c:93
__raw_notifier_call_chain kernel/notifier.c:394
raw_notifier_call_chain+0x2d/0x40 kernel/notifier.c:401
call_netdevice_notifiers_info+0x51/0x90 net/core/dev.c:1647
call_netdevice_notifiers net/core/dev.c:1663
rollback_registered_many+0x919/0xeb0 net/core/dev.c:6841
unregister_netdevice_many.part.105+0x87/0x440 net/core/dev.c:7881
unregister_netdevice_many net/core/dev.c:7880
default_device_exit_batch+0x4fa/0x640 net/core/dev.c:8333
ops_exit_list.isra.4+0x100/0x150 net/core/net_namespace.c:144
cleanup_net+0x5a8/0xb40 net/core/net_namespace.c:463
process_one_work+0xc04/0x1c10 kernel/workqueue.c:2097
worker_thread+0x223/0x19c0 kernel/workqueue.c:2231
kthread+0x35e/0x430 kernel/kthread.c:231
ret_from_fork+0x31/0x40 arch/x86/entry/entry_64.S:430
Code: 3c 32 00 0f 85 70 0b 00 00 48 b8 00 02 00 00 00 00 ad de 49 89
47 78 e9 93 fe ff ff 49 8d 57 70 49 8d 5f 78 eb 9e e8 88 7a 14 fe <0f>
0b 48 8b 9d 28 fe ff ff e8 7a 7a 14 fe 48 b8 00 00 00 00 00
RIP: rollback_registered_many+0x348/0xeb0 RSP: ffff8800692de7f0
---[ end trace e0b29c57e9b3292c ]---
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add various related files that have been missing under
BPF entry covering essential parts of its infrastructure
and also add myself as co-maintainer.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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If skb_pad() fails then it frees the skb so we should check for errors.
Fixes: bdabad3e363d ("net: Add Qualcomm IPC router")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Maps of per-cpu type have their value element size adjusted to 8 if it
is specified smaller during various map operations.
This makes test_maps as a 32-bit binary fail, in fact the kernel
writes past the end of the value's array on the user's stack.
To be quite honest, I think the kernel should reject creation of a
per-cpu map that doesn't have a value size of at least 8 if that's
what the kernel is going to silently adjust to later.
If the user passed something smaller, it is a sizeof() calcualtion
based upon the type they will actually use (just like in this testcase
code) in later calls to the map operations.
Fixes: df570f577231 ("samples/bpf: unit test for BPF_MAP_TYPE_PERCPU_ARRAY")
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
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Andrey reported a fault in the IPv6 route code:
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN
Modules linked in:
CPU: 1 PID: 4035 Comm: a.out Not tainted 4.11.0-rc7+ #250
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
task: ffff880069809600 task.stack: ffff880062dc8000
RIP: 0010:ip6_rt_cache_alloc+0xa6/0x560 net/ipv6/route.c:975
RSP: 0018:ffff880062dced30 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffff8800670561c0 RCX: 0000000000000006
RDX: 0000000000000003 RSI: ffff880062dcfb28 RDI: 0000000000000018
RBP: ffff880062dced68 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff880062dcfb28 R14: dffffc0000000000 R15: 0000000000000000
FS: 00007feebe37e7c0(0000) GS:ffff88006cb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000205a0fe4 CR3: 000000006b5c9000 CR4: 00000000000006e0
Call Trace:
ip6_pol_route+0x1512/0x1f20 net/ipv6/route.c:1128
ip6_pol_route_output+0x4c/0x60 net/ipv6/route.c:1212
...
Andrey's syzkaller program passes rtmsg.rtmsg_flags with the RTF_PCPU bit
set. Flags passed to the kernel are blindly copied to the allocated
rt6_info by ip6_route_info_create making a newly inserted route appear
as though it is a per-cpu route. ip6_rt_cache_alloc sees the flag set
and expects rt->dst.from to be set - which it is not since it is not
really a per-cpu copy. The subsequent call to __ip6_dst_alloc then
generates the fault.
Fix by checking for the flag and failing with EINVAL.
Fixes: d52d3997f843f ("ipv6: Create percpu rt6_info")
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David Ahern <dsa@cumulusnetworks.com>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Tested-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Commit 07b26c9454a2 ("gso: Support partial splitting at the frag_list
pointer") assumes that all SKBs in a frag_list (except maybe the last
one) contain the same amount of GSO payload.
This assumption is not always correct, resulting in the following
warning message in the log:
skb_segment: too many frags
For example, mlx5 driver in Striding RQ mode creates some RX SKBs with
one frag, and some with 2 frags.
After GRO, the frag_list SKBs end up having different amounts of payload.
If this frag_list SKB is then forwarded, the aforementioned assumption
is violated.
Validate the assumption, and fall back to software GSO if it not true.
Change-Id: Ia03983f4a47b6534dd987d7a2aad96d54d46d212
Fixes: 07b26c9454a2 ("gso: Support partial splitting at the frag_list pointer")
Signed-off-by: Ilan Tayari <ilant@mellanox.com>
Signed-off-by: Ilya Lesokhin <ilyal@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We can use skb_cow_head() to properly deal with clones,
especially the ones coming from TCP stack that allow their head being
modified. This avoids a copy.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: 4a476bd6d1d9 ("usbnet: New driver for QinHeng CH9200 devices")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Matthew Garrett <mjg59@srcf.ucam.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Cc: Woojung Huh <woojung.huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: cc28a20e77b2 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We need to ensure there is enough headroom to push extra header,
but we also need to check if we are allowed to change headers.
skb_cow_head() is the proper helper to deal with this.
Fixes: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: James Hughes <james.hughes@raspberrypi.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The icmpv6_param_prob() function already does a kfree_skb(),
this patch removes the duplicate one.
Fixes: 1ababeba4a21f3dba3da3523c670b207fb2feb62 ("ipv6: implement dataplane support for rthdr type 4 (Segment Routing Header)")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
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We want people to report bugs to the netdev list.
Signed-off-by: David S. Miller <davem@davemloft.net>
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Currently, a call to schedule() acts as a Tasks RCU quiescent state
only if a context switch actually takes place. However, just the
call to schedule() guarantees that the calling task has moved off of
whatever tracing trampoline that it might have been one previously.
This commit therefore plumbs schedule()'s "preempt" parameter into
rcu_note_context_switch(), which then records the Tasks RCU quiescent
state, but only if this call to schedule() was -not- due to a preemption.
To avoid adding overhead to the common-case context-switch path,
this commit hides the rcu_note_context_switch() check under an existing
non-common-case check.
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
|
|
Although Tree SRCU does reduce delays when there is at least one
synchronize_srcu_expedited() invocation pending, srcu_schedule_cbs_snp()
still waits for SRCU_INTERVAL before invoking callbacks. Since
synchronize_srcu_expedited() now posts a callback and waits for
that callback to do a wakeup, this destroys the expedited nature of
synchronize_srcu_expedited(). This destruction became apparent to
Marc Zyngier in the guise of a guest-OS bootup slowdown from five
seconds to no fewer than forty seconds.
This commit therefore invokes callbacks immediately at the end of the
grace period when there is at least one synchronize_srcu_expedited()
invocation pending. This brought Marc's guest-OS bootup times back
into the realm of reason.
Reported-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Marc Zyngier <marc.zyngier@arm.com>
|
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Peter Zijlstra proposed using SRCU to reduce mmap_sem contention [1,2],
however, there are workloads that could result in a high volume of
concurrent invocations of call_srcu(), which with current SRCU would
result in excessive lock contention on the srcu_struct structure's
->queue_lock, which protects SRCU's callback lists. This commit therefore
moves SRCU to per-CPU callback lists, thus greatly reducing contention.
Because a given SRCU instance no longer has a single centralized callback
list, starting grace periods and invoking callbacks are both more complex
than in the single-list Classic SRCU implementation. Starting grace
periods and handling callbacks are now handled using an srcu_node tree
that is in some ways similar to the rcu_node trees used by RCU-bh,
RCU-preempt, and RCU-sched (for example, the srcu_node tree shape is
controlled by exactly the same Kconfig options and boot parameters that
control the shape of the rcu_node tree).
In addition, the old per-CPU srcu_array structure is now named srcu_data
and contains an rcu_segcblist structure named ->srcu_cblist for its
callbacks (and a spinlock to protect this). The srcu_struct gets
an srcu_gp_seq that is used to associate callback segments with the
corresponding completion-time grace-period number. These completion-time
grace-period numbers are propagated up the srcu_node tree so that the
grace-period workqueue handler can determine whether additional grace
periods are needed on the one hand and where to look for callbacks that
are ready to be invoked.
The srcu_barrier() function must now wait on all instances of the per-CPU
->srcu_cblist. Because each ->srcu_cblist is protected by ->lock,
srcu_barrier() can remotely add the needed callbacks. In theory,
it could also remotely start grace periods, but in practice doing so
is complex and racy. And interestingly enough, it is never necessary
for srcu_barrier() to start a grace period because srcu_barrier() only
enqueues a callback when a callback is already present--and it turns out
that a grace period has to have already been started for this pre-existing
callback. Furthermore, it is only the callback that srcu_barrier()
needs to wait on, not any particular grace period. Therefore, a new
rcu_segcblist_entrain() function enqueues the srcu_barrier() function's
callback into the same segment occupied by the last pre-existing callback
in the list. The special case where all the pre-existing callbacks are
on a different list (because they are in the process of being invoked)
is handled by enqueuing srcu_barrier()'s callback into the RCU_DONE_TAIL
segment, relying on the done-callbacks check that takes place after all
callbacks are inovked.
Note that the readers use the same algorithm as before. Note that there
is a separate srcu_idx that tells the readers what counter to increment.
This unfortunately cannot be combined with srcu_gp_seq because they
need to be incremented at different times.
This commit introduces some ugly #ifdefs in rcutorture. These will go
away when I feel good enough about Tree SRCU to ditch Classic SRCU.
Some crude performance comparisons, courtesy of a quickly hacked rcuperf
asynchronous-grace-period capability:
Callback Queuing Overhead
-------------------------
# CPUS Classic SRCU Tree SRCU
------ ------------ ---------
2 0.349 us 0.342 us
16 31.66 us 0.4 us
41 --------- 0.417 us
The times are the 90th percentiles, a statistic that was chosen to reject
the overheads of the occasional srcu_barrier() call needed to avoid OOMing
the test machine. The rcuperf test hangs when running Classic SRCU at 41
CPUs, hence the line of dashes. Despite the hacks to both the rcuperf code
and that statistics, this is a convincing demonstration of Tree SRCU's
performance and scalability advantages.
[1] https://lwn.net/Articles/309030/
[2] https://patchwork.kernel.org/patch/5108281/
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
[ paulmck: Fix initialization if synchronize_srcu_expedited() called first. ]
|
|
Parallelizing SRCU callback handling will increase the size of
srcu_struct, which will move the kvm structure's kvm_arch field out
of reach of powerpc's current assembly code, which will result in the
following sort of build error:
arch/powerpc/kvm/book3s_hv_rmhandlers.S:617: Error: operand out of range (0x000000000000b328 is not between 0xffffffffffff8000 and 0x0000000000007fff)
This commit moves the srcu_struct fields in the kvm structure to follow
the kvm_arch field, which will allow powerpc's assembly code to continue
to be able to reach the kvm_arch field.
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reported-by: Michael Ellerman <michaele@au1.ibm.com>
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Suggested-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Michael Ellerman <mpe@ellerman.id.au>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
[ paulmck: Moved this commit to precede SRCU callback parallelization,
and reworded the commit log into future tense, all in the name of
bisectability. ]
|
|
Commit 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn
based migration") moved the dec_node_page_state() call (along with the
page_is_file_cache() call) to after putback_lru_page().
But page_is_file_cache() can change after putback_lru_page() is called,
so it should be called before putback_lru_page(), as it was before that
patch, to prevent NR_ISOLATE_* stats from going negative.
Without this fix, non-CONFIG_SMP kernels end up hanging in the
while(too_many_isolated()) { congestion_wait() } loop in
shrink_active_list() due to the negative stats.
Mem-Info:
active_anon:32567 inactive_anon:121 isolated_anon:1
active_file:6066 inactive_file:6639 isolated_file:4294967295
^^^^^^^^^^
unevictable:0 dirty:115 writeback:0 unstable:0
slab_reclaimable:2086 slab_unreclaimable:3167
mapped:3398 shmem:18366 pagetables:1145 bounce:0
free:1798 free_pcp:13 free_cma:0
Fixes: 6afcf8ef0ca0 ("mm, compaction: fix NR_ISOLATED_* stats for pfn based migration")
Link: http://lkml.kernel.org/r/1492683865-27549-1-git-send-email-rabin.vincent@axis.com
Signed-off-by: Rabin Vincent <rabinv@axis.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Ming Ling <ming.ling@spreadtrum.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
This reverts commit 374ad05ab64.
While the patch worked great for userspace allocations, the fact that
softirq loses the per-cpu allocator caused problems. It needs to be
redone taking into account that a separate list is needed for hard/soft
IRQs or alternatively find a cheap way of detecting reentry due to an
interrupt. Both are possible but sufficiently tricky that it shouldn't
be rushed.
Jesper had one method for allowing softirqs but reported that the cost
was high enough that it performed similarly to a plain revert. His
figures for netperf TCP_STREAM were as follows
Baseline v4.10.0 : 60316 Mbit/s
Current 4.11.0-rc6: 47491 Mbit/s
Jesper's patch : 60662 Mbit/s
This patch : 60106 Mbit/s
As this is a regression, I wish to revert to noirq allocator for now and
go back to the drawing board.
Link: http://lkml.kernel.org/r/20170415145350.ixy7vtrzdzve57mh@techsingularity.net
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Reported-by: Tariq Toukan <ttoukan.linux@gmail.com>
Acked-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
If we have a scheduler attached, blk_mq_tag_to_rq() on the
scheduled tags will return NULL if a request is no longer
in flight. This is different than using the normal tags,
where it will always return the fixed request. Check for
this condition for polling, in case we happen to enter
polling for a completed request.
The request address remains valid, so this check and return
should be perfectly safe.
Fixes: bd166ef183c2 ("blk-mq-sched: add framework for MQ capable IO schedulers")
Tested-by: Stephen Bates <sbates@raithlin.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
|
|
There's a report that it malfunctions with APST on.
See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
|
|
I got a couple more reports: the Samsung APST issues appears to
affect multiple 950-series devices in Dell XPS 15 9550 and Precision
5510 laptops. Change the quirk: rather than blacklisting the
firmware on the first problematic SSD that was reported, disable
APST on all 144d:a802 devices if they're installed in the two
affected Dell models. While we're at it, disable only the deepest
sleep state instead of all of them -- the reporters say that this is
sufficient to fix the problem.
(I have a device that appears to be entirely identical to one of the
affected devices, but I have a different Dell laptop, so it's not
the case that all Samsung devices with firmware BXW75D0Q are broken
under all circumstances.)
Samsung engineers have an affected system, and hopefully they'll
give us a better workaround some time soon. In the mean time, this
should minimize regressions.
See https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1678184
Cc: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Signed-off-by: Jens Axboe <axboe@fb.com>
|
|
Policing filters do not use the TCA_ACT_* enum and the tb[]
nlattr array in tcf_action_init_1() doesn't get filled for
them so we should not try to look for a TCA_ACT_COOKIE
attribute in the then uninitialized array.
The error handling in cookie allocation then calls
tcf_hash_release() leading to invalid memory access later
on.
Additionally, if cookie allocation fails after an already
existing non-policing filter has successfully been changed,
tcf_action_release() should not be called, also we would
have to roll back the changes in the error handling, so
instead we now allocate the cookie early and assign it on
success at the end.
CVE-2017-7979
Fixes: 1045ba77a596 ("net sched actions: Add support for user cookies")
Signed-off-by: Wolfgang Bumiller <w.bumiller@proxmox.com>
Acked-by: Jamal Hadi Salim <jhs@mojatatu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Change ieee_setpfc() callback implementation to populate traffic class
count with the user provided value.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
qed_dcbnl_get_dcbx() API uses kmalloc in GFT_KERNEL mode. The API gets
invoked in the interrupt context by qed_dcbnl_getdcbx callback. Need
to invoke this kmalloc in atomic mode.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
PFC error-mask value is not supported by MFW, but this bit could be
set in the pfc bit-map of the operational parameters if remote device
supports it. These operational parameters are used as basis for
populating the dcbx config parameters. User provided configs will be
applied on top of these parameters and then send them to MFW when
requested. Driver need to clear the error-mask bit before sending the
config parameters to MFW.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Some adapters may not publish the max_tc value. Populate the default
value for max_tc field in case the mfw didn't provide one.
Signed-off-by: Sudarsana Reddy Kalluru <Sudarsana.Kalluru@cavium.com>
Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
The driver was failing to check that the SKB wasn't cloned
before adding checksum data.
Replace existing handling to extend/copy the header buffer
with skb_cow_head.
Signed-off-by: James Hughes <james.hughes@raspberrypi.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Acked-by: Woojung Huh <Woojung.Huh@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Mugunthan V N, who was reviewing TI's CPSW driver patches is
not working for TI anymore and wont be reviewing patches for
that driver.
Drop Mugunthan as the maintiainer for this driver.
Grygorii continues to be a reviewer. Dave Miller applies the
patches directly and adding a maintainer is actually
misleading since get_maintainer.pl script stops suggesting
that Dave Miller be copied.
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This patch is prompted by a static checker warning about a potential
use after free. The concern is that netif_rx_ni() can free "skb" and we
call it twice.
When I look at the commit that added this, it looks like some stray
lines were added accidentally. It doesn't make sense to me that we
would recieve the same data two times. I asked the author but never
recieved a response.
I can't test this code, but I'm pretty sure my patch is correct.
Fixes: 4b063258ab93 ("dp83640: Delay scheduled work.")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Stefan Sørensen <stefan.sorensen@spectralink.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
This patch fixes an out-of-bounds access in seg6_validate_srh() when the
trailing data is less than sizeof(struct sr6_tlv).
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: David Lebrun <david.lebrun@uclouvain.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
'psock_fanout' has been failing since commit 4d7b9dc1f36a9 ("tools:
psock_lib: harden socket filter used by psock tests"). That commit
changed the CBPF filter to examine the full ethernet frame, and was
tested on 'psock_tpacket' which uses SOCK_RAW. But 'psock_fanout' was
also using this same CBPF in two places, for filtering and fanout, on a
SOCK_DGRAM socket.
Change 'psock_fanout' to use SOCK_RAW so that the CBPF program used with
SO_ATTACH_FILTER can examine the entire frame. Create a new CBPF
program for use with PACKET_FANOUT_DATA which ignores the header, as it
cannot see the ethernet header.
Tested: Ran tools/testing/selftests/net/psock_{fanout,tpacket} 10 times,
and they all passed.
Fixes: 4d7b9dc1f36a9 ("tools: psock_lib: harden socket filter used by psock tests")
Signed-off-by: 'Mike Maloney <maloneykernel@gmail.com>'
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
AP/AP_VLAN modes don't accept any real 802.11 multicast data
frames, but since they do need to accept broadcast management
frames the same is currently permitted for data frames. This
opens a security problem because such frames would be decrypted
with the GTK, and could even contain unicast L3 frames.
Since the spec says that ToDS frames must always have the BSSID
as the RA (addr1), reject any other data frames.
The problem was originally reported in "Predicting, Decrypting,
and Abusing WPA2/802.11 Group Keys" at usenix
https://www.usenix.org/conference/usenixsecurity16/technical-sessions/presentation/vanhoef
and brought to my attention by Jouni.
Cc: stable@vger.kernel.org
Reported-by: Jouni Malinen <j@w1.fi>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
--
Dave, I didn't want to send you a new pull request for a single
commit yet again - can you apply this one patch as is?
Signed-off-by: David S. Miller <davem@davemloft.net>
|
|
Currently for DDR50 card, it need tuning in default. We meet tuning fail
issue for DDR50 card and some data CRC error when DDR50 sd card works.
This is because the default pad I/O drive strength can't make sure DDR50
card work stable. So increase the pad I/O drive strength for DDR50 card,
and use pins_100mhz.
This fixes DDR50 card support for IMX since DDR50 tuning was enabled from
commit 9faac7b95ea4 ("mmc: sdhci: enable tuning for DDR50")
Tested-and-reported-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Haibo Chen <haibo.chen@nxp.com>
Cc: stable@vger.kernel.org # v4.4+
Acked-by: Dong Aisheng <aisheng.dong@nxp.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
|
|
It apears that devices designed around Wacom's G11 chipset (e.g. Lenovo
ThinkPad Yoga 260, Lenovo ThinkPad X1 Yoga, Dell XPS 12 9250, Dell Venue
8 Pro 5855, etc.) suffer from a common issue in their HID descriptors.
The logical maximum is not updated for the "Contact Identifier" usage,
leaving it as just "1" despite these devices being capable of tracking
far more touches.
Commit 60a221869803 began ignoring usages with out-of-range values,
causing problems for devices based on this chipset. Touches after
the first will have an out-of-range Contact Identifier, and ignoring
that usage will cause the kernel to incorrectly slot each finger's
events (along with all the knock-on userspace effects that entails).
This commit checks for these buggy descriptors and updates the maximum
where required. Prior chipsets have used "255" as the maximum (and the
G11, at least, doesn't seem to actually use IDs outside the range of
1..CONTACTMAX) so continue using this value.
Cc: stable@vger.kernel.org
Fixes: 60a221869803 ("HID: wacom: generic: add support for touchring")
Signed-off-by: Jason Gerecke <jason.gerecke@wacom.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
|
|
I noticed that reading the snapshot file when it is empty no longer gives a
status. It suppose to show the status of the snapshot buffer as well as how
to allocate and use it. For example:
># cat snapshot
# tracer: nop
#
#
# * Snapshot is allocated *
#
# Snapshot commands:
# echo 0 > snapshot : Clears and frees snapshot buffer
# echo 1 > snapshot : Allocates snapshot buffer, if not already allocated.
# Takes a snapshot of the main buffer.
# echo 2 > snapshot : Clears snapshot buffer (but does not allocate or free)
# (Doesn't have to be '2' works with any number that
# is not a '0' or '1')
But instead it just showed an empty buffer:
># cat snapshot
# tracer: nop
#
# entries-in-buffer/entries-written: 0/0 #P:4
#
# _-----=> irqs-off
# / _----=> need-resched
# | / _---=> hardirq/softirq
# || / _--=> preempt-depth
# ||| / delay
# TASK-PID CPU# |||| TIMESTAMP FUNCTION
# | | | |||| | |
What happened was that it was using the ring_buffer_iter_empty() function to
see if it was empty, and if it was, it showed the status. But that function
was returning false when it was empty. The reason was that the iter header
page was on the reader page, and the reader page was empty, but so was the
buffer itself. The check only tested to see if the iter was on the commit
page, but the commit page was no longer pointing to the reader page, but as
all pages were empty, the buffer is also.
Cc: stable@vger.kernel.org
Fixes: 651e22f2701b ("ring-buffer: Always reset iterator to reader page")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
|
|
Andrey reported a use-after-free in __ns_get_path():
spin_lock include/linux/spinlock.h:299 [inline]
lockref_get_not_dead+0x19/0x80 lib/lockref.c:179
__ns_get_path+0x197/0x860 fs/nsfs.c:66
open_related_ns+0xda/0x200 fs/nsfs.c:143
sock_ioctl+0x39d/0x440 net/socket.c:1001
vfs_ioctl fs/ioctl.c:45 [inline]
do_vfs_ioctl+0x1bf/0x1780 fs/ioctl.c:685
SYSC_ioctl fs/ioctl.c:700 [inline]
SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
We are under rcu read lock protection at that point:
rcu_read_lock();
d = atomic_long_read(&ns->stashed);
if (!d)
goto slow;
dentry = (struct dentry *)d;
if (!lockref_get_not_dead(&dentry->d_lockref))
goto slow;
rcu_read_unlock();
but don't use a proper RCU API on the free path, therefore a parallel
__d_free() could free it at the same time. We need to mark the stashed
dentry with DCACHE_RCUACCESS so that __d_free() will be called after all
readers leave RCU.
Fixes: e149ed2b805f ("take the targets of /proc/*/ns/* symlinks to separate fs")
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
Paul E. McKenney
Ingo Molnar
Tushar Dave
Nikolay Aleksandrov
Daniel Borkmann
Dan Carpenter
David Miller
David Ahern
Ilan Tayari
Eric Dumazet
David Lebrun
Rabin Vincent
Mel Gorman
Jens Axboe
Andy Lutomirski
Wolfgang Bumiller
sudarsana.kalluru@cavium.com
James Hughes
Sekhar Nori
Mike Maloney
Johannes Berg
Haibo Chen
Jason Gerecke
Steven Rostedt (VMware)
Cong Wang