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Queued spinlock supports up to 4 levels of lock slowpath nesting -
user context, soft IRQ, hard IRQ and NMI. However, we are not sure how
often the nesting happens.
So add 3 more per-CPU stat counters to track the number of instances where
nesting index goes to 1, 2 and 3 respectively.
On a dual-socket 64-core 128-thread Zen server, the following were the
new stat counter values under different circumstances:
State slowpath index1 index2 index3
----- -------- ------ ------ -------
After bootup 1,012,150 82 0 0
After parallel build + perf-top 125,195,009 82 0 0
So the chance of having more than 2 levels of nesting is extremely low.
[ mingo: Minor changelog edits. ]
Signed-off-by: Waiman Long <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Paul E. McKenney <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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On x86 we cannot do fetch_or() with a single instruction and thus end up
using a cmpxchg loop, this reduces determinism. Replace the fetch_or()
with a composite operation: tas-pending + load.
Using two instructions of course opens a window we previously did not
have. Consider the scenario:
CPU0 CPU1 CPU2
1) lock
trylock -> (0,0,1)
2) lock
trylock /* fail */
3) unlock -> (0,0,0)
4) lock
trylock -> (0,0,1)
5) tas-pending -> (0,1,1)
load-val <- (0,1,0) from 3
6) clear-pending-set-locked -> (0,0,1)
FAIL: _2_ owners
where 5) is our new composite operation. When we consider each part of
the qspinlock state as a separate variable (as we can when
_Q_PENDING_BITS == 8) then the above is entirely possible, because
tas-pending will only RmW the pending byte, so the later load is able
to observe prior tail and lock state (but not earlier than its own
trylock, which operates on the whole word, due to coherence).
To avoid this we need 2 things:
- the load must come after the tas-pending (obviously, otherwise it
can trivially observe prior state).
- the tas-pending must be a full word RmW instruction, it cannot be an XCHGB for
example, such that we cannot observe other state prior to setting
pending.
On x86 we can realize this by using "LOCK BTS m32, r32" for
tas-pending followed by a regular load.
Note that observing later state is not a problem:
- if we fail to observe a later unlock, we'll simply spin-wait for
that store to become visible.
- if we observe a later xchg_tail(), there is no difference from that
xchg_tail() having taken place before the tas-pending.
Suggested-by: Will Deacon <[email protected]>
Reported-by: Thomas Gleixner <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Will Deacon <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: [email protected]
Cc: [email protected]
Fixes: 59fb586b4a07 ("locking/qspinlock: Remove unbounded cmpxchg() loop from locking slowpath")
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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While working my way through the code again; I felt the comments could
use help.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Will Deacon <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Flip the branch condition after atomic_fetch_or_acquire(_Q_PENDING_VAL)
such that we loose the indent. This also result in a more natural code
flow IMO.
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Acked-by: Will Deacon <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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unify jump-label work
Signed-off-by: Ingo Molnar <[email protected]>
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The comment and the code around the update_min_vruntime() call in
dequeue_entity() are not in agreement.
From commit:
b60205c7c558 ("sched/fair: Fix min_vruntime tracking")
I think that we want to update min_vruntime when a task is sleeping/migrating.
So, the check is inverted there - fix it.
Signed-off-by: Song Muchun <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Fixes: b60205c7c558 ("sched/fair: Fix min_vruntime tracking")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Remove the duplicated 'lock_class_ops' percpu array that is not used
anywhere.
Signed-off-by: Waiman Long <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Fixes: 8ca2b56cd7da ("locking/lockdep: Make class->ops a percpu counter and move it under CONFIG_DEBUG_LOCKDEP=y")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Daniel Borkmann says:
====================
pull-request: bpf-next 2018-10-16
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) Convert BPF sockmap and kTLS to both use a new sk_msg API and enable
sk_msg BPF integration for the latter, from Daniel and John.
2) Enable BPF syscall side to indicate for maps that they do not support
a map lookup operation as opposed to just missing key, from Prashant.
3) Add bpftool map create command which after map creation pins the
map into bpf fs for further processing, from Jakub.
4) Add bpftool support for attaching programs to maps allowing sock_map
and sock_hash to be used from bpftool, from John.
5) Improve syscall BPF map update/delete path for map-in-map types to
wait a RCU grace period for pending references to complete, from Daniel.
6) Couple of follow-up fixes for the BPF socket lookup to get it
enabled also when IPv6 is compiled as a module, from Joe.
7) Fix a generic-XDP bug to handle the case when the Ethernet header
was mangled and thus update skb's protocol and data, from Jesper.
8) Add a missing BTF header length check between header copies from
user space, from Wenwen.
9) Minor fixups in libbpf to use __u32 instead u32 types and include
proper perf_event.h uapi header instead of perf internal one, from Yonghong.
10) Allow to pass user-defined flags through EXTRA_CFLAGS and EXTRA_LDFLAGS
to bpftool's build, from Jiri.
11) BPF kselftest tweaks to add LWTUNNEL to config fragment and to install
with_addr.sh script from flow dissector selftest, from Anders.
====================
Signed-off-by: David S. Miller <[email protected]>
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Add a generic sk_msg layer, and convert current sockmap and later
kTLS over to make use of it. While sk_buff handles network packet
representation from netdevice up to socket, sk_msg handles data
representation from application to socket layer.
This means that sk_msg framework spans across ULP users in the
kernel, and enables features such as introspection or filtering
of data with the help of BPF programs that operate on this data
structure.
Latter becomes in particular useful for kTLS where data encryption
is deferred into the kernel, and as such enabling the kernel to
perform L7 introspection and policy based on BPF for TLS connections
where the record is being encrypted after BPF has run and came to
a verdict. In order to get there, first step is to transform open
coding of scatter-gather list handling into a common core framework
that subsystems can use.
The code itself has been split and refactored into three bigger
pieces: i) the generic sk_msg API which deals with managing the
scatter gather ring, providing helpers for walking and mangling,
transferring application data from user space into it, and preparing
it for BPF pre/post-processing, ii) the plain sock map itself
where sockets can be attached to or detached from; these bits
are independent of i) which can now be used also without sock
map, and iii) the integration with plain TCP as one protocol
to be used for processing L7 application data (later this could
e.g. also be extended to other protocols like UDP). The semantics
are the same with the old sock map code and therefore no change
of user facing behavior or APIs. While pursuing this work it
also helped finding a number of bugs in the old sockmap code
that we've fixed already in earlier commits. The test_sockmap
kselftest suite passes through fine as well.
Joint work with John.
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: John Fastabend <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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In order to prepare sockmap logic to be used in combination with kTLS
we need to detangle it from ULP, and further split it in later commits
into a generic API.
Joint work with John.
Signed-off-by: Daniel Borkmann <[email protected]>
Signed-off-by: John Fastabend <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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Daniel Borkmann says:
====================
pull-request: bpf 2018-10-14
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix xsk map update and delete operation to not call synchronize_net()
but to piggy back on SOCK_RCU_FREE for sockets instead as we are not
allowed to sleep under RCU, from Björn.
2) Do not change RLIMIT_MEMLOCK in reuseport_bpf selftest if the process
already has unlimited RLIMIT_MEMLOCK, from Eric.
====================
Signed-off-by: David S. Miller <[email protected]>
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Conflicts were easy to resolve using immediate context mostly,
except the cls_u32.c one where I simply too the entire HEAD
chunk.
Signed-off-by: David S. Miller <[email protected]>
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The map-in-map frequently serves as a mechanism for atomic
snapshotting of state that a BPF program might record. The current
implementation is dangerous to use in this way, however, since
userspace has no way of knowing when all programs that might have
retrieved the "old" value of the map may have completed.
This change ensures that map update operations on map-in-map map types
always wait for all references to the old map to drop before returning
to userspace.
Signed-off-by: Daniel Colascione <[email protected]>
Reviewed-by: Joel Fernandes (Google) <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input
Dmitry writes:
"Input updates for v4.19-rc7
- we added a few scheduling points into various input interfaces to
ensure that large writes will not cause RCU stalls
- fixed configuring PS/2 keyboards as wakeup devices on newer
platforms
- added a new Xbox gamepad ID."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input:
Input: uinput - add a schedule point in uinput_inject_events()
Input: evdev - add a schedule point in evdev_write()
Input: mousedev - add a schedule point in mousedev_write()
Input: i8042 - enable keyboard wakeups by default when s2idle is used
Input: xpad - add support for Xbox1 PDP Camo series gamepad
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The way we calculate logbuf free space percentage overflows signed
integer:
int free;
free = __LOG_BUF_LEN - log_next_idx;
pr_info("early log buf free: %u(%u%%)\n",
free, (free * 100) / __LOG_BUF_LEN);
We support LOG_BUF_LEN of up to 1<<25 bytes. Since setup_log_buf() is
called during early init, logbuf is mostly empty, so
__LOG_BUF_LEN - log_next_idx
is close to 1<<25. Thus when we multiply it by 100, we overflow signed
integer value range: 100 is 2^6 + 2^5 + 2^2.
Example, booting with LOG_BUF_LEN 1<<25 and log_buf_len=2G
boot param:
[ 0.075317] log_buf_len: -2147483648 bytes
[ 0.075319] early log buf free: 33549896(-28%)
Make "free" unsigned integer and use appropriate printk() specifier.
Link: http://lkml.kernel.org/r/[email protected]
To: Steven Rostedt <[email protected]>
Cc: [email protected]
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
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We have a proper 'overflow' check which tells us that we need to
split up existing cont buffer in separate records:
if (cont.len + len > sizeof(cont.buf))
cont_flush();
At the same time we also have one extra flush: "if cont buffer is
80% full then split it up" in cont_add():
if (cont.len > (sizeof(cont.buf) * 80) / 100)
cont_flush();
This looks to be redundant, since the existing "overflow" check
should work just fine, so remove this 80% check and wait for either
a normal cont termination \n, for preliminary flush due to
possible buffer overflow or for preliminary flush due to cont race.
Link: http://lkml.kernel.org/r/[email protected]
To: Steven Rostedt <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: LKML <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
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Prior to commit 5c2992ee7fd8a29 ("printk: remove console flushing special
cases for partial buffered lines") we would do console_cont_flush()
for each pr_cont() to print cont fragments, so console_unlock() would
actually print data:
pr_cont();
console_lock();
console_unlock()
console_cont_flush(); // print cont fragment
...
pr_cont();
console_lock();
console_unlock()
console_cont_flush(); // print cont fragment
We don't do console_cont_flush() anymore, so when we do pr_cont()
console_unlock() does nothing (unless we flushed the cont buffer):
pr_cont();
console_lock();
console_unlock(); // noop
...
pr_cont();
console_lock();
console_unlock(); // noop
...
pr_cont();
cont_flush();
console_lock();
console_unlock(); // print data
We also wakeup klogd purposelessly for pr_cont() output - un-flushed
cont buffer is not stored in log_buf; there is nothing to pull.
Thus we can console_lock()/console_unlock()/wake_up_klogd() only when
we know that we log_store()-ed a message and there is something to
print to the consoles/syslog.
Link: http://lkml.kernel.org/r/[email protected]
To: Steven Rostedt <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: LKML <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: Petr Mladek <[email protected]>
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Since commit 5c2992ee7fd8a29 ("printk: remove console flushing special
cases for partial buffered lines") we don't print cont fragments
to the consoles; cont lines are now proper log_buf entries and
there is no "consecutive continuation flag" anymore: we either
have 'c' entries that mark continuation lines without fragments;
or '-' entries that mark normal logbuf entries. There are no '+'
entries anymore.
However, we still have a small leftover - presence of ext_console
drivers disables kernel cont support and we flush each pr_cont()
and store it as a separate log_buf entry. Previously, it worked
because msg_print_ext_header() had that "an optional external merge
of the records" functionality:
if (msg->flags & LOG_CONT)
cont = (prev_flags & LOG_CONT) ? '+' : 'c';
We don't do this as of now, so keep kernel cont always enabled.
Note from pmladek:
The original purpose was to get full information including
the metadata and dictionary via extended console drivers,
see commit 6fe29354befe4c46e ("printk: implement support
for extended console drivers").
The dictionary probably was the most important part but
it was actually lost:
static void cont_flush(void)
{
[...]
log_store(cont.facility, cont.level, cont.flags, cont.ts_nsec,
NULL, 0, cont.buf, cont.len);
Nobody noticed because the only dictionary user is dev_printk()
and dev_cont() is _not_ defined.
Link: http://lkml.kernel.org/r/[email protected]
To: Steven Rostedt <[email protected]>
Cc: Andrew Morton <[email protected]>
Cc: Dmitriy Vyukov <[email protected]>
Cc: Tetsuo Handa <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: LKML <[email protected]>
Cc: Sergey Senozhatsky <[email protected]>
Signed-off-by: Sergey Senozhatsky <[email protected]>
[[email protected]: Updated commit message]
Signed-off-by: Petr Mladek <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Tejun writes:
"cgroup fixes for v4.19-rc7
One cgroup2 threaded mode fix for v4.19-rc7. While threaded mode
isn't used widely (yet) and the bug requires somewhat convoluted
sequence of operations, it causes a userland visible malfunction -
EINVAL on a valid attempt to enable threaded mode. This pull request
contains the fix"
* 'for-4.19-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
cgroup: Fix dom_cgrp propagation when enabling threaded mode
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With a very low cpu.cfs_quota_us setting, such as the minimum of 1000,
distribute_cfs_runtime may not empty the throttled_list before it runs
out of runtime to distribute. In that case, due to the change from
c06f04c7048 to put throttled entries at the head of the list, later entries
on the list will starve. Essentially, the same X processes will get pulled
off the list, given CPU time and then, when expired, get put back on the
head of the list where distribute_cfs_runtime will give runtime to the same
set of processes leaving the rest.
Fix the issue by setting a bit in struct cfs_bandwidth when
distribute_cfs_runtime is running, so that the code in throttle_cfs_rq can
decide to put the throttled entry on the tail or the head of the list. The
bit is set/cleared by the callers of distribute_cfs_runtime while they hold
cfs_bandwidth->lock.
This is easy to reproduce with a handful of CPU consumers. I use 'crash' on
the live system. In some cases you can simply look at the throttled list and
see the later entries are not changing:
crash> list cfs_rq.throttled_list -H 0xffff90b54f6ade40 -s cfs_rq.runtime_remaining | paste - - | awk '{print $1" "$4}' | pr -t -n3
1 ffff90b56cb2d200 -976050
2 ffff90b56cb2cc00 -484925
3 ffff90b56cb2bc00 -658814
4 ffff90b56cb2ba00 -275365
5 ffff90b166a45600 -135138
6 ffff90b56cb2da00 -282505
7 ffff90b56cb2e000 -148065
8 ffff90b56cb2fa00 -872591
9 ffff90b56cb2c000 -84687
10 ffff90b56cb2f000 -87237
11 ffff90b166a40a00 -164582
crash> list cfs_rq.throttled_list -H 0xffff90b54f6ade40 -s cfs_rq.runtime_remaining | paste - - | awk '{print $1" "$4}' | pr -t -n3
1 ffff90b56cb2d200 -994147
2 ffff90b56cb2cc00 -306051
3 ffff90b56cb2bc00 -961321
4 ffff90b56cb2ba00 -24490
5 ffff90b166a45600 -135138
6 ffff90b56cb2da00 -282505
7 ffff90b56cb2e000 -148065
8 ffff90b56cb2fa00 -872591
9 ffff90b56cb2c000 -84687
10 ffff90b56cb2f000 -87237
11 ffff90b166a40a00 -164582
Sometimes it is easier to see by finding a process getting starved and looking
at the sched_info:
crash> task ffff8eb765994500 sched_info
PID: 7800 TASK: ffff8eb765994500 CPU: 16 COMMAND: "cputest"
sched_info = {
pcount = 8,
run_delay = 697094208,
last_arrival = 240260125039,
last_queued = 240260327513
},
crash> task ffff8eb765994500 sched_info
PID: 7800 TASK: ffff8eb765994500 CPU: 16 COMMAND: "cputest"
sched_info = {
pcount = 8,
run_delay = 697094208,
last_arrival = 240260125039,
last_queued = 240260327513
},
Signed-off-by: Phil Auld <[email protected]>
Reviewed-by: Ben Segall <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Fixes: c06f04c70489 ("sched: Fix potential near-infinite distribute_cfs_runtime() loop")
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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The XSKMAP update and delete functions called synchronize_net(), which
can sleep. It is not allowed to sleep during an RCU read section.
Instead we need to make sure that the sock sk_destruct (xsk_destruct)
function is asynchronously called after an RCU grace period. Setting
the SOCK_RCU_FREE flag for XDP sockets takes care of this.
Fixes: fbfc504a24f5 ("bpf: introduce new bpf AF_XDP map type BPF_MAP_TYPE_XSKMAP")
Reported-by: Eric Dumazet <[email protected]>
Signed-off-by: Björn Töpel <[email protected]>
Acked-by: Song Liu <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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While fixing an out of bounds array access in known_siginfo_layout
reported by the kernel test robot it became apparent that the same bug
exists in siginfo_layout and affects copy_siginfo_from_user32.
The straight forward fix that makes guards against making this mistake
in the future and should keep the code size small is to just take an
unsigned signal number instead of a signed signal number, as I did to
fix known_siginfo_layout.
Cc: [email protected]
Fixes: cc731525f26a ("signal: Remove kernel interal si_code magic")
Signed-off-by: "Eric W. Biederman" <[email protected]>
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The bounds checks in known_siginfo_layout only guards against positive
numbers that are too large, large negative can slip through and
can cause out of bounds accesses.
Ordinarily this is not a concern because early in signal processing
the signal number is filtered with valid_signal which ensures it
is a small positive signal number, but copy_siginfo_from_user
is called before this check is performed.
[ 73.031126] BUG: unable to handle kernel paging request at ffffffff6281bcb6
[ 73.032038] PGD 3014067 P4D 3014067 PUD 0
[ 73.032565] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC PTI
[ 73.033287] CPU: 0 PID: 732 Comm: trinity-c3 Tainted: G W T 4.19.0-rc1-00077-g4ce5f9c #1
[ 73.034423] RIP: 0010:copy_siginfo_from_user+0x4d/0xd0
[ 73.034908] Code: 00 8b 53 08 81 fa 80 00 00 00 0f 84 90 00 00 00 85 d2 7e 2d 48 63 0b 83 f9 1f 7f 1c 8d 71 ff bf d8 04 01 50 48 0f a3 f7 73 0e <0f> b6 8c 09 20 bb 81 82 39 ca 7f 15 eb 68 31 c0 83 fa 06 7f 0c eb
[ 73.036665] RSP: 0018:ffff88001b8f7e20 EFLAGS: 00010297
[ 73.037160] RAX: 0000000000000000 RBX: ffff88001b8f7e90 RCX: fffffffff00000cb
[ 73.037865] RDX: 0000000000000001 RSI: 00000000f00000ca RDI: 00000000500104d8
[ 73.038546] RBP: ffff88001b8f7e80 R08: 0000000000000000 R09: 0000000000000000
[ 73.039201] R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000008
[ 73.039874] R13: 00000000000002dc R14: 0000000000000000 R15: 0000000000000000
[ 73.040613] FS: 000000000104a880(0000) GS:ffff88001f000000(0000) knlGS:0000000000000000
[ 73.041649] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 73.042405] CR2: ffffffff6281bcb6 CR3: 000000001cb52003 CR4: 00000000001606b0
[ 73.043351] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 73.044286] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600
[ 73.045221] Call Trace:
[ 73.045556] __x64_sys_rt_tgsigqueueinfo+0x34/0xa0
[ 73.046199] do_syscall_64+0x1a4/0x390
[ 73.046708] ? vtime_user_enter+0x61/0x80
[ 73.047242] ? __context_tracking_enter+0x4e/0x60
[ 73.047714] ? __context_tracking_enter+0x4e/0x60
[ 73.048278] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Therefore fix known_siginfo_layout to take an unsigned signal number
instead of a signed signal number. All valid signal numbers are small
positive numbers so they will not be affected, but invalid negative
signal numbers will now become large positive signal numbers and will
not be used as indices into the sig_sicodes array.
Making the signal number unsigned makes it difficult for similar mistakes to
happen in the future.
Fixes: 4ce5f9c9e754 ("signal: Use a smaller struct siginfo in the kernel")
Inspired-by: Sean Christopherson <[email protected]>
Reported-by: kernel test robot <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>
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can_stop_idle_tick() checks cpu_online() twice. The first check leaves the
function when the CPU is not online, so the second check it
redundant. Remove it.
Signed-off-by: Peng Hao <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
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Return ERR_PTR(-EOPNOTSUPP) from map_lookup_elem() methods of below
map types:
- BPF_MAP_TYPE_PROG_ARRAY
- BPF_MAP_TYPE_STACK_TRACE
- BPF_MAP_TYPE_XSKMAP
- BPF_MAP_TYPE_SOCKMAP/BPF_MAP_TYPE_SOCKHASH
Signed-off-by: Prashant Bhole <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Acked-by: Song Liu <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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The error value returned by map_lookup_elem doesn't differentiate
whether lookup was failed because of invalid key or lookup is not
supported.
Lets add handling for -EOPNOTSUPP return value of map_lookup_elem()
method of map, with expectation from map's implementation that it
should return -EOPNOTSUPP if lookup is not supported.
The errno for bpf syscall for BPF_MAP_LOOKUP_ELEM command will be set
to EOPNOTSUPP if map lookup is not supported.
Signed-off-by: Prashant Bhole <[email protected]>
Acked-by: Alexei Starovoitov <[email protected]>
Acked-by: Song Liu <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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In btf_parse_hdr(), the length of the btf data header is firstly copied
from the user space to 'hdr_len' and checked to see whether it is larger
than 'btf_data_size'. If yes, an error code EINVAL is returned. Otherwise,
the whole header is copied again from the user space to 'btf->hdr'.
However, after the second copy, there is no check between
'btf->hdr->hdr_len' and 'hdr_len' to confirm that the two copies get the
same value. Given that the btf data is in the user space, a malicious user
can race to change the data between the two copies. By doing so, the user
can provide malicious data to the kernel and cause undefined behavior.
This patch adds a necessary check after the second copy, to make sure
'btf->hdr->hdr_len' has the same value as 'hdr_len'. Otherwise, an error
code EINVAL will be returned.
Signed-off-by: Wenwen Wang <[email protected]>
Acked-by: Song Liu <[email protected]>
Signed-off-by: Alexei Starovoitov <[email protected]>
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- Drop BUG_ON()s and do normal error handling instead, in
find_next_iomem_res().
- Align function arguments on opening braces.
- Get rid of local var sibling_only in find_next_iomem_res().
- Shorten unnecessarily long first_level_children_only arg name.
Signed-off-by: Borislav Petkov <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Bjorn Helgaas <[email protected]>
CC: Brijesh Singh <[email protected]>
CC: Dan Williams <[email protected]>
CC: H. Peter Anvin <[email protected]>
CC: Lianbo Jiang <[email protected]>
CC: Takashi Iwai <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Tom Lendacky <[email protected]>
CC: Vivek Goyal <[email protected]>
CC: Yaowei Bai <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
Link: <new submission>
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Previously find_next_iomem_res() used "*res" as both an input parameter for
the range to search and the type of resource to search for, and an output
parameter for the resource we found, which makes the interface confusing.
The current callers use find_next_iomem_res() incorrectly because they
allocate a single struct resource and use it for repeated calls to
find_next_iomem_res(). When find_next_iomem_res() returns a resource, it
overwrites the start, end, flags, and desc members of the struct. If we
call find_next_iomem_res() again, we must update or restore these fields.
The previous code restored res.start and res.end, but not res.flags or
res.desc.
Since the callers did not restore res.flags, if they searched for flags
IORESOURCE_MEM | IORESOURCE_BUSY and found a resource with flags
IORESOURCE_MEM | IORESOURCE_BUSY | IORESOURCE_SYSRAM, the next search would
incorrectly skip resources unless they were also marked as
IORESOURCE_SYSRAM.
Fix this by restructuring the interface so it takes explicit "start, end,
flags" parameters and uses "*res" only as an output parameter.
Based on a patch by Lianbo Jiang <[email protected]>.
[ bp: While at it:
- make comments kernel-doc style.
-
Originally-by: http://lore.kernel.org/lkml/[email protected]
Signed-off-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Brijesh Singh <[email protected]>
CC: Dan Williams <[email protected]>
CC: H. Peter Anvin <[email protected]>
CC: Lianbo Jiang <[email protected]>
CC: Takashi Iwai <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Tom Lendacky <[email protected]>
CC: Vivek Goyal <[email protected]>
CC: Yaowei Bai <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: x86-ml <[email protected]>
Link: http://lkml.kernel.org/r/153805812916.1157.177580438135143788.stgit@bhelgaas-glaptop.roam.corp.google.com
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find_next_iomem_res() finds an iomem resource that covers part of a range
described by "start, end". All callers expect that range to be inclusive,
i.e., both start and end are included, but find_next_iomem_res() doesn't
handle the end address correctly.
If it finds an iomem resource that contains exactly the end address, it
skips it, e.g., if "start, end" is [0x0-0x10000] and there happens to be an
iomem resource [mem 0x10000-0x10000] (the single byte at 0x10000), we skip
it:
find_next_iomem_res(...)
{
start = 0x0;
end = 0x10000;
for (p = next_resource(...)) {
# p->start = 0x10000;
# p->end = 0x10000;
# we *should* return this resource, but this condition is false:
if ((p->end >= start) && (p->start < end))
break;
Adjust find_next_iomem_res() so it allows a resource that includes the
single byte at the end of the range. This is a corner case that we
probably don't see in practice.
Fixes: 58c1b5b07907 ("[PATCH] memory hotadd fixes: find_next_system_ram catch range fix")
Signed-off-by: Bjorn Helgaas <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
CC: Andrew Morton <[email protected]>
CC: Brijesh Singh <[email protected]>
CC: Dan Williams <[email protected]>
CC: H. Peter Anvin <[email protected]>
CC: Lianbo Jiang <[email protected]>
CC: Takashi Iwai <[email protected]>
CC: Thomas Gleixner <[email protected]>
CC: Tom Lendacky <[email protected]>
CC: Vivek Goyal <[email protected]>
CC: Yaowei Bai <[email protected]>
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: [email protected]
CC: x86-ml <[email protected]>
Link: http://lkml.kernel.org/r/153805812254.1157.16736368485811773752.stgit@bhelgaas-glaptop.roam.corp.google.com
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Introduce a variant of on_each_cpu_cond that iterates only over the
CPUs in a cpumask, in order to avoid making callbacks for every single
CPU in the system when we only need to test a subset.
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Rik van Riel <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
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The code in on_each_cpu_cond sets CPUs in a locally allocated bitmask,
which should never be used by other CPUs simultaneously. There is no
need to use locked memory accesses to set the bits in this bitmap.
Switch to __cpumask_set_cpu.
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Suggested-by: Peter Zijlstra <[email protected]>
Signed-off-by: Rik van Riel <[email protected]>
Reviewed-by: Andy Lutomirski <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
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Respect the DMA_ATTR_NO_WARN flags for allocations in dma-direct.
Signed-off-by: Christoph Hellwig <[email protected]>
Acked-by: Robin Murphy <[email protected]>
|
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The current printk() is ready to handle log buffer size up to 2G.
Give an explicit error for users who want to use larger log buffer.
Also fix printk formatting to show the 2G as a positive number.
Link: http://lkml.kernel.org/r/[email protected]
Cc: [email protected]
Cc: [email protected]
Suggested-by: Sergey Senozhatsky <[email protected]>
Signed-off-by: He Zhe <[email protected]>
Reviewed-by: Sergey Senozhatsky <[email protected]>
[pmladek: Fixed to the really safe limit 2GB.]
Signed-off-by: Petr Mladek <[email protected]>
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lockdep_assert_held() is better suited for checking locking requirements,
since it won't get confused when the lock is held by some other task. This
is also a step towards possibly removing spin_is_locked().
Signed-off-by: Lance Roy <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Darren Hart <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
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CONFIG_DEBUG_LOCKDEP=y
A sizable portion of the CPU cycles spent on the __lock_acquire() is used
up by the atomic increment of the class->ops stat counter. By taking it out
from the lock_class structure and changing it to a per-cpu per-lock-class
counter, we can reduce the amount of cacheline contention on the class
structure when multiple CPUs are trying to acquire locks of the same
class simultaneously.
To limit the increase in memory consumption because of the percpu nature
of that counter, it is now put back under the CONFIG_DEBUG_LOCKDEP
config option. So the memory consumption increase will only occur if
CONFIG_DEBUG_LOCKDEP is defined. The lock_class structure, however,
is reduced in size by 16 bytes on 64-bit archs after ops removal and
a minor restructuring of the fields.
This patch also fixes a bug in the increment code as the counter is of
the 'unsigned long' type, but atomic_inc() was used to increment it.
Signed-off-by: Waiman Long <[email protected]>
Acked-by: Peter Zijlstra <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Will Deacon <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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Alexei Starovoitov says:
====================
pull-request: bpf-next 2018-10-08
The following pull-request contains BPF updates for your *net-next* tree.
The main changes are:
1) sk_lookup_[tcp|udp] and sk_release helpers from Joe Stringer which allow
BPF programs to perform lookups for sockets in a network namespace. This would
allow programs to determine early on in processing whether the stack is
expecting to receive the packet, and perform some action (eg drop,
forward somewhere) based on this information.
2) per-cpu cgroup local storage from Roman Gushchin.
Per-cpu cgroup local storage is very similar to simple cgroup storage
except all the data is per-cpu. The main goal of per-cpu variant is to
implement super fast counters (e.g. packet counters), which don't require
neither lookups, neither atomic operations in a fast path.
The example of these hybrid counters is in selftests/bpf/netcnt_prog.c
3) allow HW offload of programs with BPF-to-BPF function calls from Quentin Monnet
4) support more than 64-byte key/value in HW offloaded BPF maps from Jakub Kicinski
5) rename of libbpf interfaces from Andrey Ignatov.
libbpf is maturing as a library and should follow good practices in
library design and implementation to play well with other libraries.
This patch set brings consistent naming convention to global symbols.
6) relicense libbpf as LGPL-2.1 OR BSD-2-Clause from Alexei Starovoitov
to let Apache2 projects use libbpf
7) various AF_XDP fixes from Björn and Magnus
====================
Signed-off-by: David S. Miller <[email protected]>
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Fix a grammar mistake in <linux/interrupt.h>.
[ mingo: While at it also fix another similar error in another comment as well. ]
Signed-off-by: Geert Uytterhoeven <[email protected]>
Cc: Jiri Kosina <[email protected]>
Cc: Linus Torvalds <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Link: http://lkml.kernel.org/r/20181008111726.26286-1-geert%[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
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What we are doing here isn't quite obvious, so add a comment explaining
it.
Signed-off-by: Christoph Hellwig <[email protected]>
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Now that there is at least one driver supporting BPF-to-BPF function
calls, lift the restriction, in the verifier, on hardware offload of
eBPF programs containing such calls. But prevent jit_subprogs(), still
in the verifier, from being run for offloaded programs.
Signed-off-by: Quentin Monnet <[email protected]>
Reviewed-by: Jiong Wang <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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In preparation for BPF-to-BPF calls in offloaded programs, add a new
function attribute to the struct bpf_prog_offload_ops so that drivers
supporting eBPF offload can hook at the end of program verification, and
potentially extract information collected by the verifier.
Implement a minimal callback (returning 0) in the drivers providing the
structs, namely netdevsim and nfp.
This will be useful in the nfp driver, in later commits, to extract the
number of subprograms as well as the stack depth for those subprograms.
Signed-off-by: Quentin Monnet <[email protected]>
Reviewed-by: Jiong Wang <[email protected]>
Reviewed-by: Jakub Kicinski <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
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I recently debugged a DMA mapping oops where a driver was trying to map
a buffer returned from request_firmware() with dma_map_single(). Memory
returned from request_firmware() is mapped into the vmalloc region and
this isn't a valid region to map with dma_map_single() per the DMA
documentation's "What memory is DMA'able?" section.
Unfortunately, we don't really check that in the DMA debugging code, so
enabling DMA debugging doesn't help catch this problem. Let's add a new
DMA debug function to check for a vmalloc address or an invalid virtual
address and print a warning if this happens. This makes it a little
easier to debug these sorts of problems, instead of seeing odd behavior
or crashes when drivers attempt to map the vmalloc space for DMA.
Cc: Marek Szyprowski <[email protected]>
Reviewed-by: Robin Murphy <[email protected]>
Signed-off-by: Stephen Boyd <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
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Andrei Vagin <[email protected]> reported:
> Accoding to the man page, the user should not set si_signo, it has to be set
> by kernel.
>
> $ man 2 rt_sigqueueinfo
>
> The uinfo argument specifies the data to accompany the signal. This
> argument is a pointer to a structure of type siginfo_t, described in
> sigaction(2) (and defined by including <sigaction.h>). The caller
> should set the following fields in this structure:
>
> si_code
> This must be one of the SI_* codes in the Linux kernel source
> file include/asm-generic/siginfo.h, with the restriction that
> the code must be negative (i.e., cannot be SI_USER, which is
> used by the kernel to indicate a signal sent by kill(2)) and
> cannot (since Linux 2.6.39) be SI_TKILL (which is used by the
> kernel to indicate a signal sent using tgkill(2)).
>
> si_pid This should be set to a process ID, typically the process ID of
> the sender.
>
> si_uid This should be set to a user ID, typically the real user ID of
> the sender.
>
> si_value
> This field contains the user data to accompany the signal. For
> more information, see the description of the last (union sigval)
> argument of sigqueue(3).
>
> Internally, the kernel sets the si_signo field to the value specified
> in sig, so that the receiver of the signal can also obtain the signal
> number via that field.
>
> On Tue, Sep 25, 2018 at 07:19:02PM +0200, Eric W. Biederman wrote:
>>
>> If there is some application that calls sigqueueinfo directly that has
>> a problem with this added sanity check we can revisit this when we see
>> what kind of crazy that application is doing.
>
>
> I already know two "applications" ;)
>
> https://github.com/torvalds/linux/blob/master/tools/testing/selftests/ptrace/peeksiginfo.c
> https://github.com/checkpoint-restore/criu/blob/master/test/zdtm/static/sigpending.c
>
> Disclaimer: I'm the author of both of them.
Looking at the kernel code the historical behavior has alwasy been to prefer
the signal number passed in by the kernel.
So sigh. Implmenet __copy_siginfo_from_user and __copy_siginfo_from_user32 to
take that signal number and prefer it. The user of ptrace will still
use copy_siginfo_from_user and copy_siginfo_from_user32 as they do not and
never have had a signal number there.
Luckily this change has never made it farther than linux-next.
Fixes: e75dc036c445 ("signal: Fail sigqueueinfo if si_signo != sig")
Reported-by: Andrei Vagin <[email protected]>
Tested-by: Andrei Vagin <[email protected]>
Signed-off-by: "Eric W. Biederman" <[email protected]>
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Signed-off-by: Ingo Molnar <[email protected]>
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When SME is enabled in the first kernel, it needs to allocate decrypted
pages for kdump because when the kdump kernel boots, these pages need to
be accessed decrypted in the initial boot stage, before SME is enabled.
[ bp: clean up text. ]
Signed-off-by: Lianbo Jiang <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Tom Lendacky <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
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Dave writes:
"Networking fixes:
1) Fix truncation of 32-bit right shift in bpf, from Jann Horn.
2) Fix memory leak in wireless wext compat, from Stefan Seyfried.
3) Use after free in cfg80211's reg_process_hint(), from Yu Zhao.
4) Need to cancel pending work when unbinding in smsc75xx otherwise
we oops, also from Yu Zhao.
5) Don't allow enslaving a team device to itself, from Ido Schimmel.
6) Fix backwards compat with older userspace for rtnetlink FDB dumps.
From Mauricio Faria.
7) Add validation of tc policy netlink attributes, from David Ahern.
8) Fix RCU locking in rawv6_send_hdrinc(), from Wei Wang."
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
net: mvpp2: Extract the correct ethtype from the skb for tx csum offload
ipv6: take rcu lock in rawv6_send_hdrinc()
net: sched: Add policy validation for tc attributes
rtnetlink: fix rtnl_fdb_dump() for ndmsg header
yam: fix a missing-check bug
net: bpfilter: Fix type cast and pointer warnings
net: cxgb3_main: fix a missing-check bug
bpf: 32-bit RSH verification must truncate input before the ALU op
net: phy: phylink: fix SFP interface autodetection
be2net: don't flip hw_features when VXLANs are added/deleted
net/packet: fix packet drop as of virtio gso
net: dsa: b53: Keep CPU port as tagged in all VLANs
openvswitch: load NAT helper
bnxt_en: get the reduced max_irqs by the ones used by RDMA
bnxt_en: free hwrm resources, if driver probe fails.
bnxt_en: Fix enables field in HWRM_QUEUE_COS2BW_CFG request
bnxt_en: Fix VNIC reservations on the PF.
team: Forbid enslaving team device to itself
net/usb: cancel pending work when unbinding smsc75xx
mlxsw: spectrum: Delete RIF when VLAN device is removed
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Ingo writes:
"perf fixes:
- fix a CPU#0 hot unplug bug and a PCI enumeration bug in the x86 Intel uncore PMU driver
- fix a CPU event enumeration bug in the x86 AMD PMU driver
- fix a perf ring-buffer corruption bug when using tracepoints
- fix a PMU unregister locking bug"
* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/amd/uncore: Set ThreadMask and SliceMask for L3 Cache perf events
perf/x86/intel/uncore: Fix PCI BDF address of M3UPI on SKX
perf/ring_buffer: Prevent concurent ring buffer access
perf/x86/intel/uncore: Use boot_cpu_data.phys_proc_id instead of hardcorded physical package ID 0
perf/core: Fix perf_pmu_unregister() locking
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Ingo writes:
"scheduler fixes:
These fixes address a rather involved performance regression between
v4.17->v4.19 in the sched/numa auto-balancing code. Since distros
really need this fix we accelerated it to sched/urgent for a faster
upstream merge.
NUMA scheduling and balancing performance is now largely back to
v4.17 levels, without reintroducing the NUMA placement bugs that
v4.18 and v4.19 fixed.
Many thanks to Srikar Dronamraju, Mel Gorman and Jirka Hladky, for
reporting, testing, re-testing and solving this rather complex set of
bugs."
* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/numa: Migrate pages to local nodes quicker early in the lifetime of a task
mm, sched/numa: Remove rate-limiting of automatic NUMA balancing migration
sched/numa: Avoid task migration for small NUMA improvement
mm/migrate: Use spin_trylock() while resetting rate limit
sched/numa: Limit the conditions where scan period is reset
sched/numa: Reset scan rate whenever task moves across nodes
sched/numa: Pass destination CPU as a parameter to migrate_task_rq
sched/numa: Stop multiple tasks from moving to the CPU at the same time
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Daniel Borkmann says:
====================
pull-request: bpf 2018-10-05
The following pull-request contains BPF updates for your *net* tree.
The main changes are:
1) Fix to truncate input on ALU operations in 32 bit mode, from Jann.
2) Fixes for cgroup local storage to reject reserved flags on element
update and rejection of map allocation with zero-sized value, from Roman.
====================
Signed-off-by: David S. Miller <[email protected]>
|