review.tizen.org Git - platform/kernel/linux-rpi.git/log

s390/ftrace: Add -mfentry and -mnop-mcount support

Utilize -mfentry and -mnop-mcount gcc options together with
-mrecord-mcount to get compiler generated calls to the profiling functions
as nops which are compatible with current -mhotpatch=0,3 approach. At the
same time -mrecord-mcount enables __mcount_loc section generation by
the compiler which allows to avoid using scripts/recordmcount.pl script.

Link: http://lkml.kernel.org/r/patch-4.thread-aa7b8d.git-aa7b8dbf236f.your-ad-here.call-01533557518-ext-9465@work.hours
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Add -mcount-nop option support

-mcount-nop gcc option generates the calls to the profiling functions
as nops which allows to avoid patching mcount jump with NOP instructions
initially.

-mcount-nop gcc option will be activated if platform selects
HAVE_NOP_MCOUNT and gcc actually supports it.
In addition to that CC_USING_NOP_MCOUNT is defined and could be used by
architectures to adapt ftrace patching behavior.

Link: http://lkml.kernel.org/r/patch-3.thread-aa7b8d.git-e02ed2dc082b.your-ad-here.call-01533557518-ext-9465@work.hours
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Avoid calling cc-option -mrecord-mcount for every Makefile

Currently if CONFIG_FTRACE_MCOUNT_RECORD is enabled -mrecord-mcount
compiler flag support is tested for every Makefile.

Top 4 cc-option usages:
    511 -mrecord-mcount
     11  -fno-stack-protector
      9 -Wno-override-init
      2 -fsched-pressure

To address that move cc-option from scripts/Makefile.build to top Makefile
and export CC_USING_RECORD_MCOUNT to be used in original place.

While doing that also add -mrecord-mcount to CC_FLAGS_FTRACE (if gcc
actually supports it).

Link: http://lkml.kernel.org/r/patch-2.thread-aa7b8d.git-de935bace15a.your-ad-here.call-01533557518-ext-9465@work.hours
Acked-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Handle CC_FLAGS_FTRACE more accurately

CC_FLAGS_FTRACE is exported and later used to remove ftrace relevant
build flags from files which should be built without ftrace support.
For that reason add -mfentry to CC_FLAGS_FTRACE as well. That fixes
a problem with vdso32 build on s390, where -mfentry could not be used
together with -m31 flag.

At the same time flags like -pg and -mfentry are not relevant for asm
files, so avoid adding them to KBUILD_AFLAGS.

Introduce CC_FLAGS_USING instead of CC_USING_FENTRY to collect
-DCC_USING_FENTRY (and future alike) which are relevant for both
KBUILD_CFLAGS and KBUILD_AFLAGS.

Link: http://lkml.kernel.org/r/patch-1.thread-aa7b8d.git-42971afe87de.your-ad-here.call-01533557518-ext-9465@work.hours
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Uprobe: Additional argument arch_uprobe to uprobe_write_opcode()

Add addition argument 'arch_uprobe' to uprobe_write_opcode().
We need this in later set of patches.

Link: http://lkml.kernel.org/r/20180809041856.1547-3-ravi.bangoria@linux.ibm.com
Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Uprobes: Simplify uprobe_register() body

Simplify uprobe_register() function body and let __uprobe_register()
handle everything. Also move dependency functions around to avoid build
failures.

Link: http://lkml.kernel.org/r/20180809041856.1547-2-ravi.bangoria@linux.ibm.com
Reviewed-by: Song Liu <songliubraving@fb.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracepoints: Free early tracepoints after RCU is initialized

When enabling trace events via the kernel command line, I hit this warning:

WARNING: CPU: 0 PID: 13 at kernel/rcu/srcutree.c:236 check_init_srcu_struct+0xe/0x61
Modules linked in:
CPU: 0 PID: 13 Comm: watchdog/0 Not tainted 4.18.0-rc6-test+ #6
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
RIP: 0010:check_init_srcu_struct+0xe/0x61
Code: 48 c7 c6 ec 8a 65 b4 e8 ff 79 fe ff 48 89 df 31 f6 e8 f2 fa ff ff 5a
5b 41 5c 5d c3 0f 1f 44 00 00 83 3d 68 94 b8 01 01 75 02 <0f> 0b 48 8b 87 f0
0a 00 00 a8 03 74 45 55 48 89 e5 41 55 41 54 4c
RSP: 0000:ffff96eb9ea03e68 EFLAGS: 00010246
RAX: ffff96eb962b5b01 RBX: ffffffffb4a87420 RCX: 0000000000000001
RDX: ffffffffb3107969 RSI: ffff96eb962b5b40 RDI: ffffffffb4a87420
RBP: ffff96eb9ea03eb0 R08: ffffabbd00cd7f48 R09: 0000000000000000
R10: ffff96eb9ea03e68 R11: ffffffffb4a6eec0 R12: ffff96eb962b5b40
R13: ffff96eb9ea03ef8 R14: ffffffffb3107969 R15: ffffffffb3107948
FS: 0000000000000000(0000) GS:ffff96eb9ea00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff96eb13ab2000 CR3: 0000000192a1e001 CR4: 00000000001606f0
Call Trace:
<IRQ>
? __call_srcu+0x2d/0x290
? rcu_process_callbacks+0x26e/0x448
? allocate_probes+0x2b/0x2b
call_srcu+0x13/0x15
rcu_free_old_probes+0x1f/0x21
rcu_process_callbacks+0x2ed/0x448
__do_softirq+0x172/0x336
irq_exit+0x62/0xb2
smp_apic_timer_interrupt+0x161/0x19e
apic_timer_interrupt+0xf/0x20
</IRQ>

The problem is that the enabling of trace events before RCU is set up will
cause SRCU to give this warning. To avoid this, add a list to store probes
that need to be freed till after RCU is initialized, and then free them
then.

Link: http://lkml.kernel.org/r/20180810113554.1df28050@gandalf.local.home
Link: http://lkml.kernel.org/r/20180810123517.5e9714ad@gandalf.local.home
Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Fixes: e6753f23d961d ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

uprobes: Use synchronize_rcu() not synchronize_sched()

While debugging another bug, I was looking at all the synchronize*()
functions being used in kernel/trace, and noticed that trace_uprobes was
using synchronize_sched(), with a comment to synchronize with
{u,ret}_probe_trace_func(). When looking at those functions, the data is
protected with "rcu_read_lock()" and not with "rcu_read_lock_sched()". This
is using the wrong synchronize_*() function.

Link: http://lkml.kernel.org/r/20180809160553.469e1e32@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 70ed91c6ec7f8 ("tracing/uprobes: Support ftrace_event_file base multibuffer")
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Fix synchronizing to event changes with tracepoint_synchronize_unregister()

Now that some trace events can be protected by srcu_read_lock(tracepoint_srcu),
we need to make sure all locations that depend on this are also protected.
There were many places that did a synchronize_sched() thinking that it was
enough to protect againts access to trace events. This use to be the case,
but now that we use SRCU for _rcuidle() trace events, they may not be
protected by synchronize_sched(), as they may be called in paths that RCU is
not watching for preempt disable.

Fixes: e6753f23d961d ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ftrace: Remove unused pointer ftrace_swapper_pid

Pointer ftrace_swapper_pid is defined but is never used hence it is
redundant and can be removed. The use of this variable was removed
in commit 345ddcc882d8 ("ftrace: Have set_ftrace_pid use the bitmap
like events do").

Cleans up clang warning:
warning: 'ftrace_swapper_pid' defined but not used [-Wunused-const-variable=]

Link: http://lkml.kernel.org/r/20180809125609.13142-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: More reverting of "tracing: Centralize preemptirq tracepoints and unify their usage"

Joel Fernandes created a nice patch that cleaned up the duplicate hooks used
by lockdep and irqsoff latency tracer. It made both use tracepoints. But the
latency tracer is triggering warnings when using tracepoints to call into
the latency tracer's routines. Mainly, they can be called from NMI context.
If that happens, then the SRCU may not work properly because on some
architectures, SRCU is not safe to be called in both NMI and non-NMI
context.

This is a partial revert of the clean up patch c3bc8fd637a9 ("tracing:
Centralize preemptirq tracepoints and unify their usage") that adds back the
direct calls into the latency tracer. It also only calls the trace events
when not in NMI.

Link: http://lkml.kernel.org/r/20180809210654.622445925@goodmis.org
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Fixes: c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing/irqsoff: Handle preempt_count for different configs

I was hitting the following warning:

WARNING: CPU: 0 PID: 1 at kernel/trace/trace_irqsoff.c:631 tracer_hardirqs_off+0x15/0x2a

Modules linked in:
CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.18.0-rc6-test+ #13
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
EIP: tracer_hardirqs_off+0x15/0x2a
Code: ff 85 c0 74 0e 8b 45 00 8b 50 04 8b 45 04 e8 35 ff ff ff 5d c3 55 64 a1 cc 37 51 c1 a9 ff ff ff 7f 89 e5 53 89 d3 89 ca 75 02 <0f> 0b e8 90 fc ff ff 85 c0 74 07 89 d8 e8 0c ff ff ff 5b 5d c3 55
EAX: 80000000 EBX: c04337f0 ECX: c04338e3 EDX: c04338e3
ESI: c04337f0 EDI: c04338e3 EBP: f2aa1d68 ESP: f2aa1d64
DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00210046
CR0: 80050033 CR2: 00000000 CR3: 01668000 CR4: 001406f0
Call Trace:
trace_irq_disable_rcuidle+0x63/0x6c
trace_hardirqs_off+0x26/0x30
default_send_IPI_mask_allbutself_logical+0x31/0x93
default_send_IPI_allbutself+0x37/0x48
native_send_call_func_ipi+0x4d/0x6a
smp_call_function_many+0x165/0x19d
? add_nops+0x34/0x34
? trace_hardirqs_on_caller+0x2d/0x2d
? add_nops+0x34/0x34
smp_call_function+0x1f/0x23
on_each_cpu+0x15/0x43
? trace_hardirqs_on_caller+0x2d/0x2d
? trace_hardirqs_on_caller+0x2d/0x2d
? trace_irq_disable_rcuidle+0x1/0x6c
text_poke_bp+0xa0/0xc2
? trace_hardirqs_on_caller+0x2d/0x2d
arch_jump_label_transform+0xa7/0xcb
? trace_irq_disable_rcuidle+0x5/0x6c
__jump_label_update+0x3e/0x6d
jump_label_update+0x7d/0x81
static_key_slow_inc_cpuslocked+0x58/0x6d
static_key_slow_inc+0x19/0x20
tracepoint_probe_register_prio+0x19e/0x1d1
? start_critical_timings+0x1c/0x1c
tracepoint_probe_register+0xf/0x11
irqsoff_tracer_init+0x21/0xf2
tracer_init+0x16/0x1a
trace_selftest_startup_irqsoff+0x25/0xc4
run_tracer_selftest+0xca/0x131
register_tracer+0xd5/0x172
? trace_event_define_fields_preemptirq_template+0x45/0x45
init_irqsoff_tracer+0xd/0x11
do_one_initcall+0xab/0x1e8
? rcu_read_lock_sched_held+0x3d/0x44
? trace_initcall_level+0x52/0x86
kernel_init_freeable+0x195/0x21a
? rest_init+0xb4/0xb4
kernel_init+0xd/0xe4
ret_from_fork+0x2e/0x38

It is due to running a CONFIG_PREEMPT_VOLUNTARY kernel, which would trigger
this warning every time:

WARN_ON_ONCE(preempt_count());

Because on CONFIG_PREEMPT_VOLUNTARY, preempt_count() is always zero.

This warning is to make sure preempt_count is set because
tracer_hardirqs_on() does a preempt_enable_notrace() to make the
preempt_trace() work properly, as being called by a trace event, the trace
event code disables preemption, and the tracer wants to know what the
preemption was before it was called.

Instead of enabling preemption like this, just record the preempt_count,
subtract PREEMPT_DISABLE_OFFSET from it (which is zero with !CONFIG_PREEMPT
set), and pass that value to the necessary functions, which should use the
passed in parameter instead of calling preempt_count() directly.

Fixes: da5b3ebb45277 ("tracing: irqsoff: Account for additional preempt_disable")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Partial revert of "tracing: Centralize preemptirq tracepoints and unify their usage"

Joel Fernandes created a nice patch that cleaned up the duplicate hooks used
by lockdep and irqsoff latency tracer. It made both use tracepoints. But it
caused lockdep to trigger several false positives. We have not figured out
why yet, but removing lockdep from using the trace event hooks and just call
its helper functions directly (like it use to), makes the problem go away.

This is a partial revert of the clean up patch c3bc8fd637a9 ("tracing:
Centralize preemptirq tracepoints and unify their usage") that adds direct
calls for lockdep, but also keeps most of the clean up done to get rid of
the horrible preprocessor if statements.

Link: http://lkml.kernel.org/r/20180806155058.5ee875f4@gandalf.local.home
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Fixes: c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: irqsoff: Account for additional preempt_disable

Recently we tried to make the preemptirqsoff tracer to use irqsoff
tracepoint probes. However this causes issues as reported by Masami:

[2.271078] Testing tracer preemptirqsoff: .. no entries found ..FAILED!
[2.381015] WARNING: CPU: 0 PID: 1 at /home/mhiramat/ksrc/linux/kernel/
trace/trace.c:1512 run_tracer_selftest+0xf3/0x154

This is due to the tracepoint code increasing the preempt nesting count
by calling an additional preempt_disable before calling into the
preemptoff tracer which messes up the preempt_count() check in
tracer_hardirqs_off.

To fix this, make the irqsoff tracer probes balance the additional outer
preempt_disable with a preempt_enable_notrace.

The other way to fix this is to just use SRCU for all tracepoints.
However we can't do that because we can't use NMIs from RCU context.

Link: http://lkml.kernel.org/r/20180806034049.67949-1-joel@joelfernandes.org
Fixes: c3bc8fd637a9 ("tracing: Centralize preemptirq tracepoints and unify their usage")
Fixes: e6753f23d961 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

trace: Use rcu_dereference_raw for hooks from trace-event subsystem

Since we switched to using SRCU for tracepoints used in the idle path,
we can no longer use rcu_dereference_sched for dereferencing points in
trace-event hooks.

Since tracepoints can now use either SRCU or sched-RCU, just use
rcu_dereference_raw for traceevents just like we're doing when
dereferencing the tracepoint table.

This prevents an RCU warning reported by Masami:

[  282.060593] WARNING: can't dereference registers at 00000000f3c7f62b
[  282.063200] =============================
[  282.064082] WARNING: suspicious RCU usage
[  282.064963] 4.18.0-rc6+ #15 Tainted: G        W
[  282.066048] -----------------------------
[  282.066923] /home/mhiramat/ksrc/linux/kernel/trace/trace_events.c:242
suspicious rcu_dereference_check() usage!
[  282.068974]
[  282.068974] other info that might help us debug this:
[  282.068974]
[  282.070770]
[  282.070770] RCU used illegally from idle CPU!
[  282.070770] rcu_scheduler_active = 2, debug_locks = 1
[  282.072938] RCU used illegally from extended quiescent state!
[  282.074183] no locks held by swapper/0/0.
[  282.075071]
[  282.075071] stack backtrace:
[  282.076121] CPU: 0 PID: 0 Comm: swapper/0 Tainted: G        W
[  282.077782] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)
[  282.079604] Call Trace:
[  282.080212]  <IRQ>
[  282.080755]  dump_stack+0x85/0xcb
[  282.081523]  trace_event_ignore_this_pid+0x66/0x70
[  282.082541]  trace_event_raw_event_preemptirq_template+0xa2/0xb0
[  282.083774]  ? interrupt_entry+0xc4/0xe0
[  282.084665]  ? trace_hardirqs_off_thunk+0x1a/0x1c
[  282.085669]  trace_hardirqs_off_caller+0x90/0xd0
[  282.086597]  trace_hardirqs_off_thunk+0x1a/0x1c
[  282.087433]  ? call_function_interrupt+0xa/0x20
[  282.088201]  interrupt_entry+0xc4/0xe0
[  282.088848]  ? call_function_interrupt+0xa/0x20
[  282.089579]  </IRQ>
[  282.090029]  ? native_safe_halt+0x2/0x10
[  282.090695]  ? default_idle+0x1f/0x160
[  282.091330]  ? default_idle_call+0x24/0x40
[  282.091997]  ? do_idle+0x210/0x250
[  282.092658]  ? cpu_startup_entry+0x6f/0x80
[  282.093338]  ? start_kernel+0x49d/0x4bd
[  282.093987]  ? secondary_startup_64+0xa5/0xb0

Link: http://lkml.kernel.org/r/20180803023407.225852-1-joel@joelfernandes.org
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Masami Hiramatsu <mhiramat@kernel.org>
Fixes: e6753f23d961 ("tracepoint: Make rcuidle tracepoint callers use SRCU")
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing/kprobes: Fix within_notrace_func() to check only notrace functions

Fix within_notrace_func() to check only notrace functions and to ignore the
kprobe-event which can not solve symbol addresses.

within_notrace_func() returns true if the given kprobe events probe point
seems to be out-of-range. But that is not the correct place to check for it,
it should be done in kprobes afterwards.

kprobe-events allow users to define a probe point on "currently unloaded
module" so that it can trace the event during module load. In this case, the
user will put a probe on a symbol which is not in kallsyms yet and it hits
the within_notrace_func(). As a result, kprobe-events always refuses if
user defines a probe on a "currenly unloaded module".

Fixes: commit 45408c4f9250 ("tracing: kprobes: Prohibit probing on notrace function")
Link: http://lkml.kernel.org/r/153319624799.29007.13604430345640129926.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ftrace: Use true and false for boolean values in ops_references_rec()

Return statements in functions returning bool should use true or false
instead of an integer value.

This code was detected with the help of Coccinelle.

Link: http://lkml.kernel.org/r/20180802010056.GA31012@embeddedor.com
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ring-buffer: Make ring_buffer_record_is_set_on() return bool

The value of ring_buffer_record_is_set_on() is either true or false, so have
its return value be bool.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ring-buffer: Make ring_buffer_record_is_on() return bool

The value of ring_buffer_record_is_on() is either true or false, so have its
return value be bool.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Make tracer_tracing_is_on() return bool

There's code that expects tracer_tracing_is_on() to be either true or false,
not some random number. Currently, it should only return one or zero, but
just in case, change its return value to bool, to enforce it.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Do a WARN_ON() if start_thread() in hwlat is called when thread exists

The start function of the hwlat tracer should never be called when the hwlat
thread already exists. If it is called, do a WARN_ON().

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ftrace: Add missing check for existing hwlat thread

The hwlat tracer uses a kernel thread to measure latencies. The function
that creates this kernel thread, start_kthread(), can be called when the
tracer is initialized and when the tracer is explicitly enabled.
start_kthread() does not check if there is an existing hwlat kernel
thread and will create a new one each time it is called.

This causes the reference to the previous thread to be lost. Without the
thread reference, the old kernel thread becomes unstoppable and
continues to use CPU time even after the hwlat tracer has been disabled.
This problem can be observed when a system is booted with tracing
enabled and the hwlat tracer is configured like this:

echo hwlat > current_tracer; echo 1 > tracing_on

Add the missing check for an existing kernel thread in start_kthread()
to prevent this problem. This function and the rest of the hwlat kernel
thread setup and teardown are already serialized because they are called
through the tracer core code with trace_type_lock held.

[
Note, this only fixes the symptom. The real fix was not to call
this function when tracing_on was already one. But this still makes
the code more robust, so we'll add it.
]

Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de
Signed-off-by: Erica Bugden <erica.bugden@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Do not call start/stop() functions when tracing_on does not change

Currently, when one echo's in 1 into tracing_on, the current tracer's
"start()" function is executed, even if tracing_on was already one. This can
lead to strange side effects. One being that if the hwlat tracer is enabled,
and someone does "echo 1 > tracing_on" into tracing_on, the hwlat tracer's
start() function is called again which will recreate another kernel thread,
and make it unable to remove the old one.

Link: http://lkml.kernel.org/r/1533120354-22923-1-git-send-email-erica.bugden@linutronix.de
Cc: stable@vger.kernel.org
Fixes: 2df8f8a6a897e ("tracing: Fix regression with irqsoff tracer and tracing_on file")
Reported-by: Erica Bugden <erica.bugden@linutronix.de>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracefs: Annotate tracefs_ops with __ro_after_init

tracefs_ops is initialized inside tracefs_create_instance_dir and not
modified after. tracefs_create_instance_dir allows for initialization
only once, and is called from create_trace_instances(marked __init),
which is called from tracer_init_tracefs(marked __init). Also, mark
tracefs_create_instance_dir as __init.

Link: http://lkml.kernel.org/r/20180725171901.4468-1-zsm@chromium.org
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Zubin Mithra <zsm@chromium.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Centralize preemptirq tracepoints and unify their usage

This patch detaches the preemptirq tracepoints from the tracers and
keeps it separate.

Advantages:
* Lockdep and irqsoff event can now run in parallel since they no longer
have their own calls.

* This unifies the usecase of adding hooks to an irqsoff and irqson
event, and a preemptoff and preempton event.
  3 users of the events exist:
  - Lockdep
  - irqsoff and preemptoff tracers
  - irqs and preempt trace events

The unification cleans up several ifdefs and makes the code in preempt
tracer and irqsoff tracers simpler. It gets rid of all the horrific
ifdeferry around PROVE_LOCKING and makes configuration of the different
users of the tracepoints more easy and understandable. It also gets rid
of the time_* function calls from the lockdep hooks used to call into
the preemptirq tracer which is not needed anymore. The negative delta in
lines of code in this patch is quite large too.

In the patch we introduce a new CONFIG option PREEMPTIRQ_TRACEPOINTS
as a single point for registering probes onto the tracepoints. With
this,
the web of config options for preempt/irq toggle tracepoints and its
users becomes:

PREEMPT_TRACER   PREEMPTIRQ_EVENTS  IRQSOFF_TRACER PROVE_LOCKING
       |                 |     \         |           |
       \    (selects)    /      \        \ (selects) /
      TRACE_PREEMPT_TOGGLE       ----> TRACE_IRQFLAGS
                      \                  /
                       \ (depends on)   /
                     PREEMPTIRQ_TRACEPOINTS

Other than the performance tests mentioned in the previous patch, I also
ran the locking API test suite. I verified that all tests cases are
passing.

I also injected issues by not registering lockdep probes onto the
tracepoints and I see failures to confirm that the probes are indeed
working.

This series + lockdep probes not registered (just to inject errors):
[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:FAILED|FAILED|  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:FAILED|FAILED|  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |

With this series + lockdep probes registered, all locking tests pass:

[    0.000000]      hard-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]      soft-irqs-on + irq-safe-A/21:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]        sirq-safe-A => hirqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/12:  ok  |  ok  |  ok  |
[    0.000000]          hard-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]          soft-safe-A + irqs-on/21:  ok  |  ok  |  ok  |
[    0.000000]     hard-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |
[    0.000000]     soft-safe-A + unsafe-B #1/123:  ok  |  ok  |  ok  |

Link: http://lkml.kernel.org/r/20180730222423.196630-4-joel@joelfernandes.org
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracepoint: Make rcuidle tracepoint callers use SRCU

In recent tests with IRQ on/off tracepoints, a large performance
overhead ~10% is noticed when running hackbench. This is root caused to
calls to rcu_irq_enter_irqson and rcu_irq_exit_irqson from the
tracepoint code. Following a long discussion on the list [1] about this,
we concluded that srcu is a better alternative for use during rcu idle.
Although it does involve extra barriers, its lighter than the sched-rcu
version which has to do additional RCU calls to notify RCU idle about
entry into RCU sections.

In this patch, we change the underlying implementation of the
trace_*_rcuidle API to use SRCU. This has shown to improve performance
alot for the high frequency irq enable/disable tracepoints.

Test: Tested idle and preempt/irq tracepoints.

Here are some performance numbers:

With a run of the following 30 times on a single core x86 Qemu instance
with 1GB memory:
hackbench -g 4 -f 2 -l 3000

Completion times in seconds. CONFIG_PROVE_LOCKING=y.

No patches (without this series)
Mean: 3.048
Median: 3.025
Std Dev: 0.064

With Lockdep using irq tracepoints with RCU implementation:
Mean: 3.451   (-11.66 %)
Median: 3.447 (-12.22%)
Std Dev: 0.049

With Lockdep using irq tracepoints with SRCU implementation (this series):
Mean: 3.020   (I would consider the improvement against the "without
       this series" case as just noise).
Median: 3.013
Std Dev: 0.033

[1] https://patchwork.kernel.org/patch/10344297/

[remove rcu_read_lock_sched_notrace as its the equivalent of
preempt_disable_notrace and is unnecessary to call in tracepoint code]
Link: http://lkml.kernel.org/r/20180730222423.196630-3-joel@joelfernandes.org
Cleaned-up-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
[ Simplified WARN_ON_ONCE() ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

lockdep: Use this_cpu_ptr instead of get_cpu_var stats

get_cpu_var disables preemption which has the potential to call into the
preemption disable trace points causing some complications. There's also
no need to disable preemption in uses of get_lock_stats anyway since
preempt is already disabled. So lets simplify the code.

Link: http://lkml.kernel.org/r/20180730222423.196630-2-joel@joelfernandes.org
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

selftests/ftrace: Fix kprobe string testcase to not probe notrace function

Fix kprobe string argument testcase to not probe notrace
function. Instead, it probes tracefs function which must
be available with ftrace.

Link: http://lkml.kernel.org/r/153294607107.32740.1664854684396589624.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

selftest/ftrace: Move kprobe selftest function to separate compile unit

Move selftest function to its own compile unit so it can be compiled
with the ftrace cflags (CC_FLAGS_FTRACE) allowing it to be probed
during the ftrace startup tests.

Link: http://lkml.kernel.org/r/153294604271.32740.16490677128630177030.stgit@devbox
Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: kprobes: Prohibit probing on notrace function

Prohibit kprobe-events probing on notrace functions. Since probing on a
notrace function can cause a recursive event call. In most cases those are just
skipped, but in some cases it falls into an infinite recursive call.

This protection can be disabled by the kconfig
CONFIG_KPROBE_EVENTS_ON_NOTRACE=y, but it is highly recommended to keep it
"n" for normal kernel builds. Note that this is only available if "kprobes on
ftrace" has been implemented on the target arch and CONFIG_KPROBES_ON_FTRACE=y.

Link: http://lkml.kernel.org/r/153294601436.32740.10557881188933661239.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Tested-by: Francis Deslauriers <francis.deslauriers@efficios.com>
[ Slight grammar and spelling fixes ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: preemptirq_delay_run() can be static

Automatically found by kbuild test robot.

Fixes: ffdc73a3b2ad ("lib: Add module for testing preemptoff/irqsoff latency tracers")
Signed-off-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing/kprobes: Simplify the logic of enable_trace_kprobe()

The function enable_trace_kprobe() performs slightly differently if the file
parameter is passed in as NULL on non-NULL. Instead of checking file twice,
move the code between the two tests into a static inline helper function to
make the code easier to follow.

Link: http://lkml.kernel.org/r/20180725224728.7b1d5db2@vmware.local.home
Link: http://lkml.kernel.org/r/20180726121152.4dd54330@gandalf.local.home
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Remove orphaned function ftrace_nr_registered_ops()

Remove ftrace_nr_registered_ops() because it is no longer used.

ftrace_nr_registered_ops() has been introduced by commit ea701f11da44
("ftrace: Add selftest to test function trace recursion protection"), but
its caller has been removed by commit 05cbbf643b8e ("tracing: Fix selftest
function recursion accounting"). So it is not called anymore.

Link: http://lkml.kernel.org/r/153260907227.12474.5234899025934963683.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Remove orphaned function using_ftrace_ops_list_func().

Remove using_ftrace_ops_list_func() since it is no longer used.

Using ftrace_ops_list_func() has been introduced by commit 7eea4fce0246
("tracing/stack_trace: Skip 4 instead of 3 when using ftrace_ops_list_func")
as a helper function, but its caller has been removed by commit 72ac426a5bb0
("tracing: Clean up stack tracing and fix fentry updates"). So it is not
called anymore.

Link: http://lkml.kernel.org/r/153260904427.12474.9952096317439329851.stgit@devbox
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Make unregister_trigger() static

Nothing uses unregister_trigger() outside of trace_events_trigger.c file,
thus it should be static. Not sure why this was ever converted, because
its counter part, register_trigger(), was always static.

Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kselftests: Add tests for the preemptoff and irqsoff tracers

Here we add unit tests for the preemptoff and irqsoff tracer by using a
kernel module introduced previously to trigger long preempt or irq
disabled sections in the kernel.

Link: http://lkml.kernel.org/r/20180711063540.91101-3-joel@joelfernandes.org
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

lib: Add module for testing preemptoff/irqsoff latency tracers

Here we introduce a test module for introducing a long preempt or irq
disable delay in the kernel which the preemptoff or irqsoff tracers can
detect. This module is to be used only for test purposes and is default
disabled.

Following is the expected output (only briefly shown) that can be parsed
to verify that the tracers are working correctly. We will use this from
the kselftests in future patches.

For the preemptoff tracer:

echo preemptoff > /d/tracing/current_tracer
sleep 1
insmod ./preemptirq_delay_test.ko test_mode=preempt delay=500000
sleep 1
bash-4.3# cat /d/tracing/trace
preempt -1066    2...2    0us@: preemptirq_delay_run <-preemptirq_delay_run
preempt -1066    2...2 500002us : preemptirq_delay_run <-preemptirq_delay_run
preempt -1066    2...2 500004us : tracer_preempt_on <-preemptirq_delay_run
preempt -1066    2...2 500012us : <stack trace>
=> kthread
=> ret_from_fork

For the irqsoff tracer:

echo irqsoff > /d/tracing/current_tracer
sleep 1
insmod ./preemptirq_delay_test.ko test_mode=irq delay=500000
sleep 1
bash-4.3# cat /d/tracing/trace
irq dis -1069    1d..1    0us@: preemptirq_delay_run
irq dis -1069    1d..1 500001us : preemptirq_delay_run
irq dis -1069    1d..1 500002us : tracer_hardirqs_on <-preemptirq_delay_run
irq dis -1069    1d..1 500005us : <stack trace>
=> ret_from_fork

Link: http://lkml.kernel.org/r/20180712213611.GA8743@joelaf.mtv.corp.google.com
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Byungchul Park <byungchul.park@lge.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Julia Cartwright <julia@ni.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Thomas Glexiner <tglx@linutronix.de>
Cc: Todd Kjos <tkjos@google.com>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
[ Erick is a co-developer of this commit ]
Signed-off-by: Erick Reyes <erickreyes@google.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing/irqsoff: Split reset into separate functions

Split reset functions into seperate functions in preparation
of future patches that need to do tracer specific reset.

Link: http://lkml.kernel.org/r/20180628182149.226164-4-joel@joelfernandes.org
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

srcu: Add notrace variant of srcu_dereference

In the last patch in this series, we are making lockdep register hooks
onto the irq_{disable,enable} tracepoints. These tracepoints use the
_rcuidle tracepoint variant. In this series we switch the _rcuidle
tracepoint callers to use SRCU instead of sched-RCU. Inorder to
dereference the pointer to the probe functions, we could call
srcu_dereference, however this API will call back into lockdep to check
if the lock is held *before* the lockdep probe hooks have a chance to
run and annotate the IRQ enabled/disabled state.

For this reason we need a notrace variant of srcu_dereference since
otherwise we get lockdep splats. This patch adds the needed
srcu_dereference_notrace variant.

Link: http://lkml.kernel.org/r/20180628182149.226164-3-joel@joelfernandes.org
Reviewed-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

srcu: Add notrace variants of srcu_read_{lock,unlock}

This is needed for a future tracepoint patch that uses srcu, and to make
sure it doesn't call into lockdep.

tracepoint code already calls notrace variants for rcu_read_lock_sched
so this patch does the same for srcu which will be used in a later
patch. Keeps it consistent with rcu-sched.

[Joel: Added commit message]
Link: http://lkml.kernel.org/r/20180628182149.226164-2-joel@joelfernandes.org
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Paul McKenney <paulmck@linux.vnet.ibm.com>
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

kthread, tracing: Don't expose half-written comm when creating kthreads

There is a window for racing when printing directly to task->comm,
allowing other threads to see a non-terminated string. The vsnprintf
function fills the buffer, counts the truncated chars, then finally
writes the \0 at the end.

creator                     other
vsnprintf:
  fill (not terminated)
  count the rest            trace_sched_waking(p):
  ...                         memcpy(comm, p->comm, TASK_COMM_LEN)
  write \0

The consequences depend on how 'other' uses the string. In our case,
it was copied into the tracing system's saved cmdlines, a buffer of
adjacent TASK_COMM_LEN-byte buffers (note the 'n' where 0 should be):

crash-arm64> x/1024s savedcmd->saved_cmdlines | grep 'evenk'
0xffffffd5b3818640:     "irq/497-pwr_evenkworker/u16:12"

...and a strcpy out of there would cause stack corruption:

[224761.522292] Kernel panic - not syncing: stack-protector:
    Kernel stack is corrupted in: ffffff9bf9783c78

crash-arm64> kbt | grep 'comm\|trace_print_context'
#6  0xffffff9bf9783c78 in trace_print_context+0x18c(+396)
      comm (char [16]) =  "irq/497-pwr_even"

crash-arm64> rd 0xffffffd4d0e17d14 8
ffffffd4d0e17d14:  2f71726900000000 5f7277702d373934   ....irq/497-pwr_
ffffffd4d0e17d24:  726f776b6e657665 3a3631752f72656b   evenkworker/u16:
ffffffd4d0e17d34:  f9780248ff003231 cede60e0ffffff9b   12..H.x......`..
ffffffd4d0e17d44:  cede60c8ffffffd4 00000fffffffffd4   .....`..........

The workaround in e09e28671 (use strlcpy in __trace_find_cmdline) was
likely needed because of this same bug.

Solved by vsnprintf:ing to a local buffer, then using set_task_comm().
This way, there won't be a window where comm is not terminated.

Link: http://lkml.kernel.org/r/20180726071539.188015-1-snild@sony.com
Cc: stable@vger.kernel.org
Fixes: bc0c38d139ec7 ("ftrace: latency tracer infrastructure")
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Snild Dolkow <snild@sony.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Quiet gcc warning about maybe unused link variable

Commit 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on
enable_trace_kprobe() failure") added an if statement that depends on another
if statement that gcc doesn't see will initialize the "link" variable and
gives the warning:

"warning: 'link' may be used uninitialized in this function"

It is really a false positive, but to quiet the warning, and also to make
sure that it never actually is used uninitialized, initialize the "link"
variable to NULL and add an if (!WARN_ON_ONCE(!link)) where the compiler
thinks it could be used uninitialized.

Cc: stable@vger.kernel.org
Fixes: 57ea2a34adf4 ("tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure")
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Fix possible double free in event_enable_trigger_func()

There was a case that triggered a double free in event_trigger_callback()
due to the called reg() function freeing the trigger_data and then it
getting freed again by the error return by the caller. The solution there
was to up the trigger_data ref count.

Code inspection found that event_enable_trigger_func() has the same issue,
but is not as easy to trigger (requires harder to trigger failures). It
needs to be solved slightly different as it needs more to clean up when the
reg() function fails.

Link: http://lkml.kernel.org/r/20180725124008.7008e586@gandalf.local.home
Cc: stable@vger.kernel.org
Fixes: 7862ad1846e99 ("tracing: Add 'enable_event' and 'disable_event' event trigger commands")
Reivewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing/kprobes: Fix trace_probe flags on enable_trace_kprobe() failure

If enable_trace_kprobe fails to enable the probe in enable_k(ret)probe
it returns an error, but does not unset the tp flags it set previously.
This results in a probe being considered enabled and failures like being
unable to remove the probe through kprobe_events file since probes_open()
expects every probe to be disabled.

Link: http://lkml.kernel.org/r/20180725102826.8300-1-asavkov@redhat.com
Link: http://lkml.kernel.org/r/20180725142038.4765-1-asavkov@redhat.com
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 41a7dd420c57 ("tracing/kprobes: Support ftrace_event_file base multibuffer")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

selftests/ftrace: Add snapshot and tracing_on test case

Add a testcase for checking snapshot and tracing_on
relationship. This ensures that the snapshotting doesn't
affect current tracing on/off settings.

Link: http://lkml.kernel.org/r/153149932412.11274.15289227592627901488.stgit@devbox
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

ring_buffer: tracing: Inherit the tracing setting to next ring buffer

Maintain the tracing on/off setting of the ring_buffer when switching
to the trace buffer snapshot.

Taking a snapshot is done by swapping the backup ring buffer
(max_tr_buffer). But since the tracing on/off setting is defined
by the ring buffer, when swapping it, the tracing on/off setting
can also be changed. This causes a strange result like below:

  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 0 > tracing_on
  /sys/kernel/debug/tracing # cat tracing_on
  0
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  1
  /sys/kernel/debug/tracing # echo 1 > snapshot
  /sys/kernel/debug/tracing # cat tracing_on
  0

We don't touch tracing_on, but snapshot changes tracing_on
setting each time. This is an anomaly, because user doesn't know
that each "ring_buffer" stores its own tracing-enable state and
the snapshot is done by swapping ring buffers.

Link: http://lkml.kernel.org/r/153149929558.11274.11730609978254724394.stgit@devbox
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Tom Zanussi <tom.zanussi@linux.intel.com>
Cc: Hiraku Toyooka <hiraku.toyooka@cybertrust.co.jp>
Cc: stable@vger.kernel.org
Fixes: debdd57f5145 ("tracing: Make a snapshot feature available from userspace")
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
[ Updated commit log and comment in the code ]
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tracing: Fix double free of event_trigger_data

Running the following:

# cd /sys/kernel/debug/tracing
# echo 500000 > buffer_size_kb
[ Or some other number that takes up most of memory ]
# echo snapshot > events/sched/sched_switch/trigger

Triggers the following bug:

------------[ cut here ]------------
kernel BUG at mm/slub.c:296!
invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
CPU: 6 PID: 6878 Comm: bash Not tainted 4.18.0-rc6-test+ #1066
Hardware name: Hewlett-Packard HP Compaq Pro 6300 SFF/339A, BIOS K01 v03.03 07/14/2016
RIP: 0010:kfree+0x16c/0x180
Code: 05 41 0f b6 72 51 5b 5d 41 5c 4c 89 d7 e9 ac b3 f8 ff 48 89 d9 48 89 da 41 b8 01 00 00 00 5b 5d 41 5c 4c 89 d6 e9 f4 f3 ff ff <0f> 0b 0f 0b 48 8b 3d d9 d8 f9 00 e9 c1 fe ff ff 0f 1f 40 00 0f 1f
RSP: 0018:ffffb654436d3d88 EFLAGS: 00010246
RAX: ffff91a9d50f3d80 RBX: ffff91a9d50f3d80 RCX: ffff91a9d50f3d80
RDX: 00000000000006a4 RSI: ffff91a9de5a60e0 RDI: ffff91a9d9803500
RBP: ffffffff8d267c80 R08: 00000000000260e0 R09: ffffffff8c1a56be
R10: fffff0d404543cc0 R11: 0000000000000389 R12: ffffffff8c1a56be
R13: ffff91a9d9930e18 R14: ffff91a98c0c2890 R15: ffffffff8d267d00
FS:  00007f363ea64700(0000) GS:ffff91a9de580000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c1cacc8e10 CR3: 00000000d9b46003 CR4: 00000000001606e0
Call Trace:
  event_trigger_callback+0xee/0x1d0
  event_trigger_write+0xfc/0x1a0
  __vfs_write+0x33/0x190
  ? handle_mm_fault+0x115/0x230
  ? _cond_resched+0x16/0x40
  vfs_write+0xb0/0x190
  ksys_write+0x52/0xc0
  do_syscall_64+0x5a/0x160
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f363e16ab50
Code: 73 01 c3 48 8b 0d 38 83 2c 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 79 db 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e e3 01 00 48 89 04 24
RSP: 002b:00007fff9a4c6378 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f363e16ab50
RDX: 0000000000000009 RSI: 000055c1cacc8e10 RDI: 0000000000000001
RBP: 000055c1cacc8e10 R08: 00007f363e435740 R09: 00007f363ea64700
R10: 0000000000000073 R11: 0000000000000246 R12: 0000000000000009
R13: 0000000000000001 R14: 00007f363e4345e0 R15: 00007f363e4303c0
Modules linked in: ip6table_filter ip6_tables snd_hda_codec_hdmi snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hwdep snd_hda_core snd_seq snd_seq_device i915 snd_pcm snd_timer i2c_i801 snd soundcore i2c_algo_bit drm_kms_helper
86_pkg_temp_thermal video kvm_intel kvm irqbypass wmi e1000e
---[ end trace d301afa879ddfa25 ]---

The cause is because the register_snapshot_trigger() call failed to
allocate the snapshot buffer, and then called unregister_trigger()
which freed the data that was passed to it. Then on return to the
function that called register_snapshot_trigger(), as it sees it
failed to register, it frees the trigger_data again and causes
a double free.

By calling event_trigger_init() on the trigger_data (which only ups
the reference counter for it), and then event_trigger_free() afterward,
the trigger_data would not get freed by the registering trigger function
as it would only up and lower the ref count for it. If the register
trigger function fails, then the event_trigger_free() called after it
will free the trigger data normally.

Link: http://lkml.kernel.org/r/20180724191331.738eb819@gandalf.local.home
Cc: stable@vger.kerne.org
Fixes: 93e31ffbf417 ("tracing: Add 'snapshot' event trigger command")
Reported-by: Masami Hiramatsu <mhiramat@kernel.org>
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Linux 4.18-rc6

Merge tag 'nvme-for-4.18' of git://git.infradead.org/nvme

Pull NVMe fixes from Christoph Hellwig:

- fix a regression in 4.18 that causes a memory leak on probe failure
   (Keith Bush)

- fix a deadlock in the passthrough ioctl code (Scott Bauer)

- don't enable AENs if not supported (Weiping Zhang)

- fix an old regression in metadata handling in the passthrough ioctl
   code (Roland Dreier)

* tag 'nvme-for-4.18' of git://git.infradead.org/nvme:
  nvme: fix handling of metadata_len for NVME_IOCTL_IO_CMD
  nvme: don't enable AEN if not supported
  nvme: ensure forward progress during Admin passthru
  nvme-pci: fix memory leak on probe failure

Merge branch 'fixes' of git://git./linux/kernel/git/viro/vfs

Pull vfs fixes from Al Viro:
"Fix several places that screw up cleanups after failures halfway
  through opening a file (one open-coding filp_clone_open() and getting
  it wrong, two misusing alloc_file()). That part is -stable fodder from
  the 'work.open' branch.

  And Christoph's regression fix for uapi breakage in aio series;
  include/uapi/linux/aio_abi.h shouldn't be pulling in the kernel
  definition of sigset_t, the reason for doing so in the first place had
  been bogus - there's no need to expose struct __aio_sigset in
  aio_abi.h at all"

* 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  aio: don't expose __aio_sigset in uapi
  ocxlflash_getfile(): fix double-iput() on alloc_file() failures
  cxl_getfile(): fix double-iput() on alloc_file() failures
  drm_mode_create_lease_ioctl(): fix open-coded filp_clone_open()

alpha: fix osf_wait4() breakage

kernel_wait4() expects a userland address for status - it's only
rusage that goes as a kernel one (and needs a copyout afterwards)

[ Also, fix the prototype of kernel_wait4() to have that __user
annotation - Linus ]

Fixes: 92ebce5ac55d ("osf_wait4: switch to kernel_wait4()")
Cc: stable@kernel.org # v4.13+
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'armsoc-fixes' of git://git./linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Olof Johansson:

- Fix interrupt type on ethernet switch for i.MX-based RDU2

- GPC on i.MX exposed too large a register window which resulted in
   userspace being able to crash the machine.

- Fixup of bad merge resolution moving GPIO DT nodes under pinctrl on
   droid4.

* tag 'armsoc-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: dts: imx6: RDU2: fix irq type for mv88e6xxx switch
  soc: imx: gpc: restrict register range for regmap access
  ARM: dts: omap4-droid4: fix dts w.r.t. pwm

Merge branch 'x86-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 fix from Ingo Molnar:
"A single fix for a MCE-polling regression, which prevented the
disabling of polling"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/MCE: Remove min interval polling limitation

Merge branch 'x86-pti-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull x86 pti fixes from Ingo Molnar:
"An APM fix, and a BTS hardware-tracing fix related to PTI changes"

* 'x86-pti-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/apm: Don't access __preempt_count with zeroed fs
x86/events/intel/ds: Fix bts_interrupt_threshold alignment

Merge branch 'sched-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
"Two fixes: a stop-machine preemption fix and a SCHED_DEADLINE fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Fix switched_from_dl() warning
stop_machine: Disable preemption when waking two stopper threads

Merge branch 'core-urgent-for-linus' of git://git./linux/kernel/git/tip/tip

Pull core kernel fixes from Ingo Molnar:
"This is mostly the copy_to_user_mcsafe() related fixes from Dan
  Williams, and an ORC fix for Clang"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/asm/memcpy_mcsafe: Fix copy_to_user_mcsafe() exception handling
  lib/iov_iter: Fix pipe handling in _copy_to_iter_mcsafe()
  lib/iov_iter: Document _copy_to_iter_flushcache()
  lib/iov_iter: Document _copy_to_iter_mcsafe()
  objtool: Use '.strtab' if '.shstrtab' doesn't exist, to support ORC tables on Clang

Merge tag 'powerpc-4.18-4' of git://git./linux/kernel/git/powerpc/linux

Pull powerpc fixes from Michael Ellerman:
"Two regression fixes, one for xmon disassembly formatting and the
  other to fix the E500 build.

  Two commits to fix a potential security issue in the VFIO code under
  obscure circumstances.

  And finally a fix to the Power9 idle code to restore SPRG3, which is
  user visible and used for sched_getcpu().

  Thanks to: Alexey Kardashevskiy, David Gibson. Gautham R. Shenoy,
  James Clarke"

* tag 'powerpc-4.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  powerpc/powernv: Fix save/restore of SPRG3 on entry/exit from stop (idle)
  powerpc/Makefile: Assemble with -me500 when building for E500
  KVM: PPC: Check if IOMMU page is contained in the pinned physical page
  vfio/spapr: Use IOMMU pageshift rather than pagesize
  powerpc/xmon: Fix disassembly since printf changes

Merge tag 'for-4.18-rc5-tag' of git://git./linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
"A fix of a corruption regarding fsync and clone, under some very
  specific conditions explained in the patch.

  The fix is marked for stable 3.16+ so I'd like to get it merged now
  given the impact"

* tag 'for-4.18-rc5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix file data corruption after cloning a range and fsync

mm: make vm_area_alloc() initialize core fields

Like vm_area_dup(), it initializes the anon_vma_chain head, and the
basic mm pointer.

The rest of the fields end up being different for different users,
although the plan is to also initialize the 'vm_ops' field to a dummy
entry.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: make vm_area_dup() actually copy the old vma data

.. and re-initialize th eanon_vma_chain head.

This removes some boiler-plate from the users, and also makes it clear
why it didn't need use the 'zalloc()' version.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm: use helper functions for allocating and freeing vm_area structs

The vm_area_struct is one of the most fundamental memory management
objects, but the management of it is entirely open-coded evertwhere,
ranging from allocation and freeing (using kmem_cache_[z]alloc and
kmem_cache_free) to initializing all the fields.

We want to unify this in order to end up having some unified
initialization of the vmas, and the first step to this is to at least
have basic allocation functions.

Right now those functions are literally just wrappers around the
kmem_cache_*() calls.  This is a purely mechanical conversion:

    # new vma:
    kmem_cache_zalloc(vm_area_cachep, GFP_KERNEL) -> vm_area_alloc()

    # copy old vma
    kmem_cache_alloc(vm_area_cachep, GFP_KERNEL) -> vm_area_dup(old)

    # free vma
    kmem_cache_free(vm_area_cachep, vma) -> vm_area_free(vma)

to the point where the old vma passed in to the vm_area_dup() function
isn't even used yet (because I've left all the old manual initialization
alone).

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge branch 'akpm' (patches from Andrew)

Merge fixes from Andrew Morton:
"5 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm: memcg: fix use after free in mem_cgroup_iter()
  mm/huge_memory.c: fix data loss when splitting a file pmd
  fat: fix memory allocation failure handling of match_strdup()
  MAINTAINERS: Peter has moved
  mm/memblock: add missing include <linux/bootmem.h>

mm: memcg: fix use after free in mem_cgroup_iter()

It was reported that a kernel crash happened in mem_cgroup_iter(), which
can be triggered if the legacy cgroup-v1 non-hierarchical mode is used.

Unable to handle kernel paging request at virtual address 6b6b6b6b6b6b8f
......
Call trace:
  mem_cgroup_iter+0x2e0/0x6d4
  shrink_zone+0x8c/0x324
  balance_pgdat+0x450/0x640
  kswapd+0x130/0x4b8
  kthread+0xe8/0xfc
  ret_from_fork+0x10/0x20

  mem_cgroup_iter():
      ......
      if (css_tryget(css))    <-- crash here
    break;
      ......

The crashing reason is that mem_cgroup_iter() uses the memcg object whose
pointer is stored in iter->position, which has been freed before and
filled with POISON_FREE(0x6b).

And the root cause of the use-after-free issue is that
invalidate_reclaim_iterators() fails to reset the value of iter->position
to NULL when the css of the memcg is released in non- hierarchical mode.

Link: http://lkml.kernel.org/r/1531994807-25639-1-git-send-email-jing.xia@unisoc.com
Fixes: 6df38689e0e9 ("mm: memcontrol: fix possible memcg leak due to interrupted reclaim")
Signed-off-by: Jing Xia <jing.xia.mail@gmail.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: <chunyan.zhang@unisoc.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/huge_memory.c: fix data loss when splitting a file pmd

__split_huge_pmd_locked() must check if the cleared huge pmd was dirty,
and propagate that to PageDirty: otherwise, data may be lost when a huge
tmpfs page is modified then split then reclaimed.

How has this taken so long to be noticed? Because there was no problem
when the huge page is written by a write system call (shmem_write_end()
calls set_page_dirty()), nor when the page is allocated for a write fault
(fault_dirty_shared_page() calls set_page_dirty()); but when allocated for
a read fault (which MAP_POPULATE simulates), no set_page_dirty().

Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1807111741430.1106@eggly.anvils
Fixes: d21b9e57c74c ("thp: handle file pages in split_huge_pmd()")
Signed-off-by: Hugh Dickins <hughd@google.com>
Reported-by: Ashwin Chaugule <ashwinch@google.com>
Reviewed-by: Yang Shi <yang.shi@linux.alibaba.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: <stable@vger.kernel.org> [4.8+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fat: fix memory allocation failure handling of match_strdup()

In parse_options(), if match_strdup() failed, parse_options() leaves
opts->iocharset in unexpected state (i.e. still pointing the freed
string). And this can be the cause of double free.

To fix, this initialize opts->iocharset always when freeing.

Link: http://lkml.kernel.org/r/8736wp9dzc.fsf@mail.parknet.co.jp
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Reported-by: syzbot+90b8e10515ae88228a92@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

MAINTAINERS: Peter has moved

Update my E-mail address in the MAINTAINERS file.

Link: http://lkml.kernel.org/r/20180710144702.1308-1-peter.senna@gmail.com
Signed-off-by: Peter Senna Tschudin <peter.senna@gmail.com>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.co.uk>
Acked-by: Martyn Welch <martyn.welch@collabora.co.uk>
Cc: David S. Miller <davem@davemloft.net>
Cc: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Martin Donnelly <martin.donnelly@ge.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

mm/memblock: add missing include <linux/bootmem.h>

Commit 26f09e9b3a06 ("mm/memblock: add memblock memory allocation apis")
introduced two new function definitions:

  memblock_virt_alloc_try_nid_nopanic()
  memblock_virt_alloc_try_nid()

and commit ea1f5f3712af ("mm: define memblock_virt_alloc_try_nid_raw")
introduced the following function definition:

  memblock_virt_alloc_try_nid_raw()

This commit adds an include of header file <linux/bootmem.h> to provide
the missing function prototypes.  This silences the following gcc warning
(W=1):

  mm/memblock.c:1334:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_raw' [-Wmissing-prototypes]
  mm/memblock.c:1371:15: warning: no previous prototype for `memblock_virt_alloc_try_nid_nopanic' [-Wmissing-prototypes]
  mm/memblock.c:1407:15: warning: no previous prototype for `memblock_virt_alloc_try_nid' [-Wmissing-prototypes]

Also adds #ifdef blockers to prevent compilation failure on mips/ia64
where CONFIG_NO_BOOTMEM=n as could be seen in commit commit 6cc22dc08a24
("revert "mm/memblock: add missing include <linux/bootmem.h>"").

Because Makefile already does:

  obj-$(CONFIG_HAVE_MEMBLOCK) += memblock.o

The #ifdef has been simplified from:

  #if defined(CONFIG_HAVE_MEMBLOCK) && defined(CONFIG_NO_BOOTMEM)

to simply:

  #if defined(CONFIG_NO_BOOTMEM)

Link: http://lkml.kernel.org/r/20180626184422.24974-1-malat@debian.org
Signed-off-by: Mathieu Malaterre <malat@debian.org>
Suggested-by: Tony Luck <tony.luck@intel.com>
Suggested-by: Michal Hocko <mhocko@kernel.org>
Acked-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Merge tag 'vfio-v4.18-rc6' of git://github.com/awilliam/linux-vfio

Pull VFIO fix from Alex Williamson:
"Harden potential Spectre v1 issue (Gustavo A. R. Silva)"

* tag 'vfio-v4.18-rc6' of git://github.com/awilliam/linux-vfio:
vfio/pci: Fix potential Spectre v1

Merge tag 'for-4.18/dm-fixes-2' of git://git./linux/kernel/git/device-mapper/linux-dm

Pull device mapper fix from Mike Snitzer:
"Fix DM writecache target to allow an optional offset to the start of
  the data and metadata area.

  This allows userspace tools (e.g. LVM2) to place a header and metadata
  at the front of the writecache device for its use"

* tag 'for-4.18/dm-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm:
  dm writecache: support optional offset for start of device

Merge tag 'imx-fixes-4.18-4' of git://git./linux/kernel/git/shawnguo/linux into fixes

i.MX fixes for 4.18, round 4:
- A fix for i.MX6 RDU2 board on the wrong IRQ type of Marvell switch,
   which might result in a race condition in the interrupt handler and
   cause the OS to miss all future events.

* tag 'imx-fixes-4.18-4' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  ARM: dts: imx6: RDU2: fix irq type for mv88e6xxx switch

Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'scsi-fixes' of git://git./linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
"A set of 8 obvious fixes.

  Three (2 qla2xxx and the cxlflash oopses) are regressions, two from
  4.17 and one from the merge window. The hpsa change is user visible,
  but it fixes an error users have complained about"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: cxlflash: fix assignment of the backend operations
  scsi: qedi: Send driver state to MFW
  scsi: qedf: Send the driver state to MFW
  scsi: hpsa: correct enclosure sas address
  scsi: sd_zbc: Fix variable type and bogus comment
  scsi: qla2xxx: Fix NULL pointer dereference for fcport search
  scsi: qla2xxx: Fix kernel crash due to late workqueue allocation
  scsi: qla2xxx: Fix inconsistent DMA mem alloc/free

Merge tag 'iommu-fixes-v4.18-rc5' of git://git./linux/kernel/git/joro/iommu

Pull IOMMU fix from Joerg Roedel:
"Only one revert, for an an Intel VT-d patch that caused issues with
the i915 GPU driver"

* tag 'iommu-fixes-v4.18-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
Revert "iommu/vt-d: Clean up pasid quirk for pre-production devices"

Merge tag 'platform-drivers-x86-v4.18-2' of git://git.infradead.org/linux-platform-drivers-x86

Pull x86 platform driver fixes from Andy Shevchenko:
"The Dell laptop ACPI video brightness control is now back after fixing
a regression brought by SMM refactoring"

* tag 'platform-drivers-x86-v4.18-2' of git://git.infradead.org/linux-platform-drivers-x86:
platform/x86: dell-laptop: Fix backlight detection

Merge tag 'arc-4.18-rc6' of git://git./linux/kernel/git/vgupta/arc

Pull ARC fixes from Vineet Gupta:
"ARC is back after radio silence in 4.17:

   - Fix CONFIG_SWAP [Alexey]

   - Robustify cmpxchg emulation for systems w/o atomics [Alexey /
     PeterZ]

   - Allow mprotext(PROT_EXEC) for stack mappings [Vineet]

   - HSDK platform enable PCIe, APG GPIO [Gustavo]

   - miscll other fixes, config updates etc"

* tag 'arc-4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: [plat-hsdk]: Save accl reg pair by default
  ARC: mm: allow mprotect to make stack mappings executable
  ARC: Fix CONFIG_SWAP
  ARC: [arcompact] entry.S: minor code movement
  ARC: configs: Remove CONFIG_INITRAMFS_SOURCE from defconfigs
  ARC: configs: remove no longer needed CONFIG_DEVPTS_MULTIPLE_INSTANCES
  ARC: Improve cmpxchg syscall implementation
  ARC: [plat-hsdk]: Configure APB GPIO controller on ARC HSDK platform
  ARC: [plat-hsdk] Add PCIe support
  ARC: Enable machine_desc->init_per_cpu for !CONFIG_SMP
  ARC: Explicitly add -mmedium-calls to CFLAGS

Merge tag 'nds32-for-linus-4.18' of git://git./linux/kernel/git/greentime/linux

Pull nds32 updates from Greentime Hu:
"Bug fixes and build ixes for nds32"

* tag 'nds32-for-linus-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/greentime/linux:
  nds32: fix build error "relocation truncated to fit: R_NDS32_25_PCREL_RELA" when make allyesconfig
  nds32: To simplify the implementation of update_mmu_cache()
  nds32: Fix the dts pointer is not passed correctly issue.
  nds32: To implement these icache invalidation APIs since nds32 cores don't snoop data cache. This issue is found by Guo Ren. Based on the Documentation/core-api/cachetlb.rst and it says:
  nds32: Fix build error caused by configuration flag rename
  nds32: define __NDS32_E[BL]__ for sparse

Merge tag 'pm-4.18-rc6' of git://git./linux/kernel/git/rafael/linux-pm

Pull power management fix from Rafael Wysocki:
"Fix a relatively old initialization issue in intel_pstate causing the
  pcc-cpufreq driver to be used instead of it on some HP Proliant
  systems.

  This turned into a functional regression during the 4.17 cycle,
  because pcc-cpufreq is a scalability disaster and that was amplified
  by the idle loop rework done at that time (Rafael Wysocki).

* tag 'pm-4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  cpufreq: intel_pstate: Register when ACPI PCCH is present

Merge tag 'acpi-4.18-rc6' of git://git./linux/kernel/git/rafael/linux-pm

Pull ACPI fix from Rafael Wysocki:
"Extend the recently added suspend-to-idle quirk for Thinkpad X1 Carbon
  6th to other systems from that familiy which turned out to need it too
  (Robin Johnson)"

* tag 'acpi-4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  ACPI / EC: Use ec_no_wakeup on more Thinkpad X1 Carbon 6th systems

nvme: fix handling of metadata_len for NVME_IOCTL_IO_CMD

The old code in nvme_user_cmd() passed the userspace virtual address
from nvme_passthru_cmd.metadata as the length of the metadata buffer
as well as the address to nvme_submit_user_cmd().

Fixes: 63263d60 ("nvme: Use metadata for passthrough commands")
Signed-off-by: Roland Dreier <roland@purestorage.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

platform/x86: dell-laptop: Fix backlight detection

Fix return code check for "max brightness" ACPI call.

The Dell laptop ACPI video brightness control is not present on dell
laptops anymore, but was present in older kernel versions.

The code that checks the return value is incorrect since the SMM
refactoring.

The old code was:
  if (buffer->output[0] == 0)

Which was changed to:
  ret = dell_send_request(...)
  if (ret)

However, dell_send_request() will return 0 if buffer->output[0] == 0,
so we must change the check to:
  if (ret == 0)

This issue was found on a Dell M4800 laptop, and the fix tested on it
as well.

Fixes: 549b4930f057 ("dell-smbios: Introduce dispatcher for SMM calls")
Signed-off-by: Damien Thébault <damien@dtbo.net>
Tested-by: Damien Thébault <damien@dtbo.net>
Reviewed-by: Pali Rohár <pali.rohar@gmail.com>
Reviewed-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Revert "iommu/vt-d: Clean up pasid quirk for pre-production devices"

This reverts commit ab96746aaa344fb720a198245a837e266fad3b62.

The commit ab96746aaa34 ("iommu/vt-d: Clean up pasid quirk for
pre-production devices") triggers ECS mode on some platforms
which have broken ECS support. As the result, graphic device
will be inoperable on boot.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107017

Cc: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>

Merge tag 'drm-fixes-2018-07-20' of git://anongit.freedesktop.org/drm/drm

Pull drm fixes from Dave Airlie:
"Just two sets of driver fixes this week to follow up on the set from
  earlier in the week and hopefully get me realigned schedule wise.

  amdgpu:
   - ACP fix for boards with multiple I2S instances
   - DP fix for CZ, vega
   - hybrid laptop fixes
   - Resume regression fix

  nouveau:
   - large memory systems and Pascal fix
   - MST race fixes
   - runtime PM fix"

* tag 'drm-fixes-2018-07-20' of git://anongit.freedesktop.org/drm/drm:
  drm/nouveau/fb/gp100-: disable address remapper
  drm/amd/amdgpu: creating two I2S instances for stoney/cz (v2)
  drm/amdgpu: add another ATPX quirk for TOPAZ
  drm/amd/display: Fix DP HBR2 Eye Diagram Pattern on Carrizo
  drm/amdgpu: Make sure IB tests flushed after IP resume
  drm/nouveau: Set DRIVER_ATOMIC cap earlier to fix debugfs
  drm/nouveau: Remove bogus crtc check in pmops_runtime_idle
  drm/nouveau/drm/nouveau: Fix runtime PM leak in nv50_disp_atomic_commit()
  drm/nouveau: Avoid looping through fake MST connectors
  drm/nouveau: Use drm_connector_list_iter_* for iterating connectors
  drm/nouveau/gem: off by one bugs in nouveau_gem_pushbuf_reloc_apply()
  drm/nouveau/kms/nv50-: ensure window updates are submitted when flushing mst disables

ARM: dts: imx6: RDU2: fix irq type for mv88e6xxx switch

The Marvell switches report their interrupts in a level sensitive way.
When using edge sensitive detection a race condition in the interrupt
handler of the swich might result in the OS to miss all future events
which might make the switch non-functional.

The problem is that both mv88e6xxx_g2_irq_thread_fn() and
mv88e6xxx_g1_irq_thread_work() sample the irq cause register
(MV88E6XXX_G2_INT_SRC and MV88E6XXX_G1_STS respectively) once and then
handle the observed sources. If after sampling but before all observed
irq sources are handled a new irq source gets active this is not noticed
by the handler which returns unsuspecting, but the interrupt line stays
active which prevents the edge detector to kick in.

All device trees but imx6qdl-zii-rdu2 get this right (most of them by
not specifying an interrupt parent). So fix imx6qdl-zii-rdu2
accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: f64992d1a916 ("ARM: dts: imx6: RDU2: Add Switch interrupts")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Merge branch 'linux-4.18' of git://github.com/skeggsb/linux into drm-fixes

- fix problem with pascal and large memory systems
- fix a bunch of MST problems
- fix a runtime PM interaction with MST

Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/CACAvsv79O8deSts2fxJ_oS6=q8yA+OgwBSEpp5R=BQBmWa+oyg@mail.gmail.com

Merge branch 'drm-fixes-4.18' of git://people.freedesktop.org/~agd5f/linux into drm-fixes

Fixes for 4.18. The ACP patch is a bit bigger than I would like
at this point, but it should have gone in long ago, it just fell
through the cracks. The others are pretty small and straight-forward.
- ACP fix for boards with 2 I2S instances
- DP fix for CZ, vega
- Fix for a hybrid graphics laptop
- Fix a resume regression

Signed-off-by: Dave Airlie <airlied@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180718162603.2747-1-alexander.deucher@amd.com

Merge tag 'imx-fixes-4.18-3' of git://git./linux/kernel/git/shawnguo/linux into fixes

i.MX fixes for 4.18, round 3:
- Restrict GPC driver on register range that is accessible by regmap,
   so that we can avoid user space from triggering imprecise external
   abort exception.

* tag 'imx-fixes-4.18-3' of git://git.kernel.org/pub/scm/linux/kernel/git/shawnguo/linux:
  soc: imx: gpc: restrict register range for regmap access

Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'omap-for-v4.18/fixes-rc5-signed' of git://git./linux/kernel/git/tmlind/linux-omap into fixes

One omap dts mismerge fix

The dts patch for droid4 PWM vibrator has added gpio6 entries to the wrong
node. Let's fix it with a note that there seems to be also other GPIO PWM
issues to fix still to get the PWM vibrator working. So this can wait for
v4.19 merge cycle if necessary.

* tag 'omap-for-v4.18/fixes-rc5-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap:
ARM: dts: omap4-droid4: fix dts w.r.t. pwm

Signed-off-by: Olof Johansson <olof@lixom.net>

Merge tag 'pci-v4.18-fixes-3' of git://git./linux/kernel/git/helgaas/pci

Pull PCI fixes from Bjorn Helgaas:

- Fix crashes that happen when PHY drivers are left disabled in the V3
   Semiconductor, MediaTek, Faraday, Aardvark, DesignWare, Versatile,
   and X-Gene host controller drivers (Sergei Shtylyov)

- Fix a NULL pointer dereference in the endpoint library configfs
   support (Kishon Vijay Abraham I)

- Fix a race condition in Hyper-V IRQ handling (Dexuan Cui)

* tag 'pci-v4.18-fixes-3' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
  PCI: v3-semi: Fix I/O space page leak
  PCI: mediatek: Fix I/O space page leak
  PCI: faraday: Fix I/O space page leak
  PCI: aardvark: Fix I/O space page leak
  PCI: designware: Fix I/O space page leak
  PCI: versatile: Fix I/O space page leak
  PCI: xgene: Fix I/O space page leak
  PCI: OF: Fix I/O space page leak
  PCI: endpoint: Fix NULL pointer dereference error when CONFIGFS is disabled
  PCI: hv: Disable/enable IRQs rather than BH in hv_compose_msi_msg()

ARCv2: [plat-hsdk]: Save accl reg pair by default

This manifsted as strace segfaulting on HSDK because gcc was targetting
the accumulator registers as GPRs, which kernek was not saving/restoring
by default.

Cc: stable@vger.kernel.org #4.14+
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

Merge tag 'sound-4.18-rc6' of git://git./linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
"A rawmidi race fix and three trivial HD-audio quirks"

* tag 'sound-4.18-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: hda/realtek - Yet another Clevo P950 quirk entry
  ALSA: rawmidi: Change resized buffers atomically
  ALSA: hda/realtek - Add Panasonic CF-SZ6 headset jack quirk
  ALSA: hda: add mute led support for HP ProBook 455 G5

ACPI / EC: Use ec_no_wakeup on more Thinkpad X1 Carbon 6th systems

The ec_no_wakeup matcher added for Thinkpad X1 Carbon 6th gen systems
beyond matched only a single DMI model (20KGS3JF01), that didn't cover
my laptop (20KH002JUS). Change to match based on DMI product family to
cover all X1 6th gen systems.

Signed-off-by: Robin H. Johnson <robbat2@gentoo.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Merge branch 'linus' of git://git./linux/kernel/git/herbert/crypto-2.6

Pull crypto fix from Herbert Xu:
"This fixes an allocation error-path bug in af_alg discovered by
syzkaller"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
crypto: af_alg - Initialize sg_num_bytes in error code path

Btrfs: fix file data corruption after cloning a range and fsync

When we clone a range into a file we can end up dropping existing
extent maps (or trimming them) and replacing them with new ones if the
range to be cloned overlaps with a range in the destination inode.
When that happens we add the new extent maps to the list of modified
extents in the inode's extent map tree, so that a "fast" fsync (the flag
BTRFS_INODE_NEEDS_FULL_SYNC not set in the inode) will see the extent maps
and log corresponding extent items. However, at the end of range cloning
operation we do truncate all the pages in the affected range (in order to
ensure future reads will not get stale data). Sometimes this truncation
will release the corresponding extent maps besides the pages from the page
cache. If this happens, then a "fast" fsync operation will miss logging
some extent items, because it relies exclusively on the extent maps being
present in the inode's extent tree, leading to data loss/corruption if
the fsync ends up using the same transaction used by the clone operation
(that transaction was not committed in the meanwhile). An extent map is
released through the callback btrfs_invalidatepage(), which gets called by
truncate_inode_pages_range(), and it calls __btrfs_releasepage(). The
later ends up calling try_release_extent_mapping() which will release the
extent map if some conditions are met, like the file size being greater
than 16Mb, gfp flags allow blocking and the range not being locked (which
is the case during the clone operation) nor being the extent map flagged
as pinned (also the case for cloning).

The following example, turned into a test for fstests, reproduces the
issue:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ xfs_io -f -c "pwrite -S 0x18 9000K 6908K" /mnt/foo
  $ xfs_io -f -c "pwrite -S 0x20 2572K 156K" /mnt/bar

  $ xfs_io -c "fsync" /mnt/bar
  # reflink destination offset corresponds to the size of file bar,
  # 2728Kb minus 4Kb.
  $ xfs_io -c ""reflink ${SCRATCH_MNT}/foo 0 2724K 15908K" /mnt/bar
  $ xfs_io -c "fsync" /mnt/bar

  $ md5sum /mnt/bar
  95a95813a8c2abc9aa75a6c2914a077e  /mnt/bar

  <power fail>

  $ mount /dev/sdb /mnt
  $ md5sum /mnt/bar
  207fd8d0b161be8a84b945f0df8d5f8d  /mnt/bar
  # digest should be 95a95813a8c2abc9aa75a6c2914a077e like before the
  # power failure

In the above example, the destination offset of the clone operation
corresponds to the size of the "bar" file minus 4Kb. So during the clone
operation, the extent map covering the range from 2572Kb to 2728Kb gets
trimmed so that it ends at offset 2724Kb, and a new extent map covering
the range from 2724Kb to 11724Kb is created. So at the end of the clone
operation when we ask to truncate the pages in the range from 2724Kb to
2724Kb + 15908Kb, the page invalidation callback ends up removing the new
extent map (through try_release_extent_mapping()) when the page at offset
2724Kb is passed to that callback.

Fix this by setting the bit BTRFS_INODE_NEEDS_FULL_SYNC whenever an extent
map is removed at try_release_extent_mapping(), forcing the next fsync to
search for modified extents in the fs/subvolume tree instead of relying on
the presence of extent maps in memory. This way we can continue doing a
"fast" fsync if the destination range of a clone operation does not
overlap with an existing range or if any of the criteria necessary to
remove an extent map at try_release_extent_mapping() is not met (file
size not bigger then 16Mb or gfp flags do not allow blocking).

CC: stable@vger.kernel.org # 3.16+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

drm/nouveau/fb/gp100-: disable address remapper

This was causing problems on a system with a large amount of RAM, where
display push buffers were being fetched incorrectly when placed in high
system memory addresses.

While this commit will resolve the issue on that particular system, the
issue will be avoided completely with another patch to more fully solve
problems with display and large amounts of system memory on Pascal.

It's still probably a good idea to disable this to prevent weird issues
in the future.

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

Merge git://git./linux/kernel/git/davem/net

Pull networking fixes from David Miller:
"Lots of fixes, here goes:

   1) NULL deref in qtnfmac, from Gustavo A. R. Silva.

   2) Kernel oops when fw download fails in rtlwifi, from Ping-Ke Shih.

   3) Lost completion messages in AF_XDP, from Magnus Karlsson.

   4) Correct bogus self-assignment in rhashtable, from Rishabh
      Bhatnagar.

   5) Fix regression in ipv6 route append handling, from David Ahern.

   6) Fix masking in __set_phy_supported(), from Heiner Kallweit.

   7) Missing module owner set in x_tables icmp, from Florian Westphal.

   8) liquidio's timeouts are HZ dependent, fix from Nicholas Mc Guire.

   9) Link setting fixes for sh_eth and ravb, from Vladimir Zapolskiy.

  10) Fix NULL deref when using chains in act_csum, from Davide Caratti.

  11) XDP_REDIRECT needs to check if the interface is up and whether the
      MTU is sufficient. From Toshiaki Makita.

  12) Net diag can do a double free when killing TCP_NEW_SYN_RECV
      connections, from Lorenzo Colitti.

  13) nf_defrag in ipv6 can unnecessarily hold onto dst entries for a
      full minute, delaying device unregister. From Eric Dumazet.

  14) Update MAC entries in the correct order in ixgbe, from Alexander
      Duyck.

  15) Don't leave partial mangles bpf program in jit_subprogs, from
      Daniel Borkmann.

  16) Fix pfmemalloc SKB state propagation, from Stefano Brivio.

  17) Fix ACK handling in DCTCP congestion control, from Yuchung Cheng.

  18) Use after free in tun XDP_TX, from Toshiaki Makita.

  19) Stale ipv6 header pointer in ipv6 gre code, from Prashant Bhole.

  20) Don't reuse remainder of RX page when XDP is set in mlx4, from
      Saeed Mahameed.

  21) Fix window probe handling of TCP rapair sockets, from Stefan
      Baranoff.

  22) Missing socket locking in smc_ioctl(), from Ursula Braun.

  23) IPV6_ILA needs DST_CACHE, from Arnd Bergmann.

  24) Spectre v1 fix in cxgb3, from Gustavo A. R. Silva.

  25) Two spots in ipv6 do a rol32() on a hash value but ignore the
      result. Fixes from Colin Ian King"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (176 commits)
  tcp: identify cryptic messages as TCP seq # bugs
  ptp: fix missing break in switch
  hv_netvsc: Fix napi reschedule while receive completion is busy
  MAINTAINERS: Drop inactive Vitaly Bordug's email
  net: cavium: Add fine-granular dependencies on PCI
  net: qca_spi: Fix log level if probe fails
  net: qca_spi: Make sure the QCA7000 reset is triggered
  net: qca_spi: Avoid packet drop during initial sync
  ipv6: fix useless rol32 call on hash
  ipv6: sr: fix useless rol32 call on hash
  net: sched: Using NULL instead of plain integer
  net: usb: asix: replace mii_nway_restart in resume path
  net: cxgb3_main: fix potential Spectre v1
  lib/rhashtable: consider param->min_size when setting initial table size
  net/smc: reset recv timeout after clc handshake
  net/smc: add error handling for get_user()
  net/smc: optimize consumer cursor updates
  net/nfc: Avoid stalls when nfc_alloc_send_skb() returned NULL.
  ipv6: ila: select CONFIG_DST_CACHE
  net: usb: rtl8150: demote allmulti message to dev_dbg()
  ...

soc: imx: gpc: restrict register range for regmap access

GPC registers are NOT continuous, some registers are
reserved and accessing them from userspace will trigger
external abort, add regmap register access table to
avoid below abort:

root@imx6slevk:~# cat /sys/kernel/debug/regmap/20dc000.gpc/registers
[  108.480477] Unhandled fault: imprecise external abort (0x1406) at 0xb6db5004
[  108.487985] pgd = 42b54bfd
[  108.490741] [b6db5004] *pgd=ba1b7831
[  108.494386] Internal error: : 1406 [#1] SMP ARM
[  108.498943] Modules linked in:
[  108.502043] CPU: 0 PID: 389 Comm: cat Not tainted 4.18.0-rc1-00074-gc9f1f60-dirty #482
[  108.509982] Hardware name: Freescale i.MX6 SoloLite (Device Tree)
[  108.516123] PC is at regmap_mmio_read32le+0x20/0x24
[  108.521031] LR is at regmap_mmio_read+0x40/0x60
[  108.525586] pc : [<c059cf74>]    lr : [<c059d1ac>]    psr: 20060093
[  108.531875] sp : eccf1d98  ip : eccf1da8  fp : eccf1da4
[  108.537122] r10: ec2d3800  r9 : eccf1f60  r8 : ecfc0000
[  108.542370] r7 : eccf1e2c  r6 : eccf1e2c  r5 : 00000028  r4 : ec338e00
[  108.548920] r3 : 00000000  r2 : eccf1e2c  r1 : f0980028  r0 : 00000000
[  108.555474] Flags: nzCv  IRQs off  FIQs on  Mode SVC_32  ISA ARM  Segment none
[  108.562720] Control: 10c5387d  Table: acf4004a  DAC: 00000051
[  108.568491] Process cat (pid: 389, stack limit = 0xd4318a65)
[  108.574174] Stack: (0xeccf1d98 to 0xeccf2000)

Fixes: 721cabf6c660 ("soc: imx: move PGC handling to a new GPC driver")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

Merge tag 'devicetree-fixes-for-4.18' of git://git./linux/kernel/git/robh/linux

Pull DeviceTree fixes from Rob Herring:

- Fix phandle cache to work with overlays

- Correct the default clock-frequency for QCom geni-i2c

- Binding doc quote and spelling fixes

* tag 'devicetree-fixes-for-4.18' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: overlay: update phandle cache on overlay apply and remove
  dt-bindings: Fix unbalanced quotation marks
  dt-bindings: soc: qcom: Fix default clock-freq for qcom,geni-i2c
  dt-bindings: w1-gpio: Remove unneeded unit address
  Documentation: devicetree: tilcdc: fix spelling mistake "suppors" -> "supports"

tcp: identify cryptic messages as TCP seq # bugs

Attempt to make cryptic TCP seq number error messages clearer by
(1) identifying the source of the message as "TCP", (2) identifying the
errors as "seq # bug", and (3) grouping the field identifiers and values
by separating them with commas.

E.g., the following message is changed from:

recvmsg bug 2: copied 73BCB6CD seq 70F17CBE rcvnxt 73BCB9AA fl 0
WARNING: CPU: 2 PID: 1501 at /linux/net/ipv4/tcp.c:1881 tcp_recvmsg+0x649/0xb90

to:

TCP recvmsg seq # bug 2: copied 73BCB6CD, seq 70F17CBE, rcvnxt 73BCB9AA, fl 0
WARNING: CPU: 2 PID: 1501 at /linux/net/ipv4/tcp.c:2011 tcp_recvmsg+0x694/0xba0

Suggested-by: 積丹尼 Dan Jacobson <jidanni@jidanni.org>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

ptp: fix missing break in switch

It seems that a *break* is missing in order to avoid falling through
to the default case. Otherwise, checking *chan* makes no sense.

Fixes: 72df7a7244c0 ("ptp: Allow reassigning calibration pin function")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Acked-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

hv_netvsc: Fix napi reschedule while receive completion is busy

If out ring is full temporarily and receive completion cannot go out,
we may still need to reschedule napi if certain conditions are met.
Otherwise the napi poll might be stopped forever, and cause network
disconnect.

Fixes: 7426b1a51803 ("netvsc: optimize receive completions")
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

MAINTAINERS: Drop inactive Vitaly Bordug's email

The Vitaly Bordug's email bounces ("ru.mvista.com: Name or service not
known") and there was no activity (ack, review, sign) since 2009.

Cc: Vitaly Bordug <vitb@kernel.crashing.org>
Cc: Pantelis Antoniou <pantelis.antoniou@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>