linux-stable.git/Documentation, branch linux-5.1.y

dt-bindings: allow up to four clocks for orion-mdio

2019-07-26T07:13:08+00:00

commit 80785f5a22e9073e2ded5958feb7f220e066d17b upstream.

Armada 8040 needs four clocks to be enabled for MDIO accesses to work.
Update the binding to allow the extra clock to be specified.

Cc: stable@vger.kernel.org
Fixes: 6d6a331f44a1 ("dt-bindings: allow up to three clocks for orion-mdio")
Reviewed-by: Andrew Lunn 
Signed-off-by: Josua Mayer 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

x86/atomic: Fix smp_mb__{before,after}_atomic()

2019-07-26T07:12:36+00:00

[ Upstream commit 69d927bba39517d0980462efc051875b7f4db185 ]

Recent probing at the Linux Kernel Memory Model uncovered a
'surprise'. Strongly ordered architectures where the atomic RmW
primitive implies full memory ordering and
smp_mb__{before,after}_atomic() are a simple barrier() (such as x86)
fail for:

	*x = 1;
	atomic_inc(u);
	smp_mb__after_atomic();
	r0 = *y;

Because, while the atomic_inc() implies memory order, it
(surprisingly) does not provide a compiler barrier. This then allows
the compiler to re-order like so:

	atomic_inc(u);
	*x = 1;
	smp_mb__after_atomic();
	r0 = *y;

Which the CPU is then allowed to re-order (under TSO rules) like:

	atomic_inc(u);
	r0 = *y;
	*x = 1;

And this very much was not intended. Therefore strengthen the atomic
RmW ops to include a compiler barrier.

NOTE: atomic_{or,and,xor} and the bitops already had the compiler
barrier.

Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

sched/fair: Fix "runnable_avg_yN_inv" not used warnings

2019-07-26T07:12:36+00:00

[ Upstream commit 509466b7d480bc5d22e90b9fbe6122ae0e2fbe39 ]

runnable_avg_yN_inv[] is only used in kernel/sched/pelt.c but was
included in several other places because they need other macros all
came from kernel/sched/sched-pelt.h which was generated by
Documentation/scheduler/sched-pelt. As the result, it causes compilation
a lot of warnings,

  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  kernel/sched/sched-pelt.h:4:18: warning: 'runnable_avg_yN_inv' defined but not used [-Wunused-const-variable=]
  ...

Silence it by appending the __maybe_unused attribute for it, so all
generated variables and macros can still be kept in the same file.

Signed-off-by: Qian Cai 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Link: https://lkml.kernel.org/r/1559596304-31581-1-git-send-email-cai@lca.pw
Signed-off-by: Ingo Molnar 
Signed-off-by: Sasha Levin

Documentation/admin: Remove the vsyscall=native documentation

2019-07-14T06:09:48+00:00

commit d974ffcfb7447db5f29a4b662a3eaf99a4e1109e upstream.

The vsyscall=native feature is gone -- remove the docs.

Fixes: 076ca272a14c ("x86/vsyscall/64: Drop "native" vsyscalls")
Signed-off-by: Andy Lutomirski 
Signed-off-by: Thomas Gleixner 
Acked-by: Kees Cook 
Cc: Florian Weimer 
Cc: Jann Horn 
Cc: stable@vger.kernel.org
Cc: Borislav Petkov 
Cc: Kernel Hardening 
Cc: Peter Zijlstra 
Link: https://lkml.kernel.org/r/d77c7105eb4c57c1a95a95b6a5b8ba194a18e764.1561610354.git.luto@kernel.org
Signed-off-by: Greg Kroah-Hartman

Documentation: Add section about CPU vulnerabilities for Spectre

2019-07-14T06:09:48+00:00

commit 6e88559470f581741bcd0f2794f9054814ac9740 upstream.

Add documentation for Spectre vulnerability and the mitigation mechanisms:

- Explain the problem and risks
- Document the mitigation mechanisms
- Document the command line controls
- Document the sysfs files

Co-developed-by: Andi Kleen 
Signed-off-by: Andi Kleen 
Co-developed-by: Tim Chen 
Signed-off-by: Tim Chen 
Reviewed-by: Randy Dunlap 
Reviewed-by: Thomas Gleixner 
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Corbet 
Signed-off-by: Greg Kroah-Hartman

qmi_wwan: extend permitted QMAP mux_id value range

2019-07-14T06:09:44+00:00

[ Upstream commit 36815b416fa48766ac5a98e4b2dc3ebc5887222e ]

Permit mux_id values up to 254 to be used in qmimux_register_device()
for compatibility with ip(8) and the rmnet driver.

Fixes: c6adf77953bc ("net: usb: qmi_wwan: add qmap mux protocol support")
Cc: Daniele Palmas 
Signed-off-by: Reinhard Speyerer 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

dt-bindings: can: mcp251x: add mcp25625 support

2019-07-14T06:09:38+00:00

[ Upstream commit 0df82dcd55832a99363ab7f9fab954fcacdac3ae ]

Fully compatible with mcp2515, the mcp25625 have integrated transceiver.

This patch add the mcp25625 to the device tree bindings documentation.

Signed-off-by: Sean Nyekjaer 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

futex: Update comments and docs about return values of arch futex code

2019-07-03T11:13:44+00:00

commit 427503519739e779c0db8afe876c1b33f3ac60ae upstream.

The architecture implementations of 'arch_futex_atomic_op_inuser()' and
'futex_atomic_cmpxchg_inatomic()' are permitted to return only -EFAULT,
-EAGAIN or -ENOSYS in the case of failure.

Update the comments in the asm-generic/ implementation and also a stray
reference in the robust futex documentation.

Signed-off-by: Will Deacon 
Signed-off-by: Greg Kroah-Hartman

tcp: add tcp_min_snd_mss sysctl

2019-06-17T17:50:37+00:00

commit 5f3e2bf008c2221478101ee72f5cb4654b9fc363 upstream.

Some TCP peers announce a very small MSS option in their SYN and/or
SYN/ACK messages.

This forces the stack to send packets with a very high network/cpu
overhead.

Linux has enforced a minimal value of 48. Since this value includes
the size of TCP options, and that the options can consume up to 40
bytes, this means that each segment can include only 8 bytes of payload.

In some cases, it can be useful to increase the minimal value
to a saner value.

We still let the default to 48 (TCP_MIN_SND_MSS), for compatibility
reasons.

Note that TCP_MAXSEG socket option enforces a minimal value
of (TCP_MIN_MSS). David Miller increased this minimal value
in commit c39508d6f118 ("tcp: Make TCP_MAXSEG minimum more correct.")
from 64 to 88.

We might in the future merge TCP_MIN_SND_MSS and TCP_MIN_MSS.

CVE-2019-11479 -- tcp mss hardcoded to 48

Signed-off-by: Eric Dumazet 
Suggested-by: Jonathan Looney 
Acked-by: Neal Cardwell 
Cc: Yuchung Cheng 
Cc: Tyler Hicks 
Cc: Bruce Curtis 
Cc: Jonathan Lemon 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

Input: goodix - add GT5663 CTP support

2019-06-15T09:53:03+00:00

[ Upstream commit a5f50c501321249d67611353dde6d68d48c5b959 ]

GT5663 is capacitive touch controller with customized smart
wakeup gestures.

Add support for it by adding compatible and supported chip data.

The chip data on GT5663 is similar to GT1151, like
- config data register has 0x8050 address
- config data register max len is 240
- config data checksum has 16-bit

Signed-off-by: Jagan Teki 
Reviewed-by: Rob Herring 
Signed-off-by: Dmitry Torokhov 
Signed-off-by: Sasha Levin