linux-toradex.git/Documentation, branch v4.9.116

arm64: Add 'ssbd' command-line option

2018-07-22T12:27:41+00:00

commit a43ae4dfe56a01f5b98ba0cb2f784b6a43bafcc6 upstream.

On a system where the firmware implements ARCH_WORKAROUND_2,
it may be useful to either permanently enable or disable the
workaround for cases where the user decides that they'd rather
not get a trap overhead, and keep the mitigation permanently
on or off instead of switching it on exception entry/exit.

In any case, default to the mitigation being enabled.

Reviewed-by: Julien Grall 
Reviewed-by: Mark Rutland 
Acked-by: Will Deacon 
Signed-off-by: Marc Zyngier 
Signed-off-by: Catalin Marinas 
Signed-off-by: Marc Zyngier 
Signed-off-by: Greg Kroah-Hartman

lib/vsprintf: Remove atomic-unsafe support for %pCr

2018-07-03T09:23:06+00:00

commit 666902e42fd8344b923c02dc5b0f37948ff4f225 upstream.

"%pCr" formats the current rate of a clock, and calls clk_get_rate().
The latter obtains a mutex, hence it must not be called from atomic
context.

Remove support for this rarely-used format, as vsprintf() (and e.g.
printk()) must be callable from any context.

Any remaining out-of-tree users will start seeing the clock's name
printed instead of its rate.

Reported-by: Jia-Ju Bai 
Fixes: 900cca2944254edd ("lib/vsprintf: add %pC{,n,r} format specifiers for clocks")
Link: http://lkml.kernel.org/r/1527845302-12159-5-git-send-email-geert+renesas@glider.be
To: Jia-Ju Bai 
To: Jonathan Corbet 
To: Michael Turquette 
To: Stephen Boyd 
To: Zhang Rui 
To: Eduardo Valentin 
To: Eric Anholt 
To: Stefan Wahren 
To: Greg Kroah-Hartman 
Cc: Sergey Senozhatsky 
Cc: Petr Mladek 
Cc: Linus Torvalds 
Cc: Steven Rostedt 
Cc: linux-doc@vger.kernel.org
Cc: linux-clk@vger.kernel.org
Cc: linux-pm@vger.kernel.org
Cc: linux-serial@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: Geert Uytterhoeven 
Cc: stable@vger.kernel.org # 4.1+
Signed-off-by: Geert Uytterhoeven 
Signed-off-by: Petr Mladek 
Signed-off-by: Greg Kroah-Hartman

net: dsa: b53: Add BCM5389 support

2018-06-26T00:08:05+00:00

[ Upstream commit a95691bc54af1ac4b12c354f91e9cabf1cb068df ]

This patch adds support for the BCM5389 switch connected through MDIO.

Signed-off-by: Damien Thébault 
Reviewed-by: Florian Fainelli 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

netdev-FAQ: clarify DaveM's position for stable backports

2018-06-13T14:16:42+00:00

[ Upstream commit 75d4e704fa8d2cf33ff295e5b441317603d7f9fd ]

Per discussion with David at netconf 2018, let's clarify
DaveM's position of handling stable backports in netdev-FAQ.

This is important for people relying on upstream -stable
releases.

Cc: Greg Kroah-Hartman 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

dmaengine: mv_xor_v2: Fix clock resource by adding a register clock

2018-05-30T05:50:36+00:00

[ Upstream commit 3cd2c313f1d618f92d1294addc6c685c17065761 ]

On the CP110 components which are present on the Armada 7K/8K SoC we need
to explicitly enable the clock for the registers. However it is not
needed for the AP8xx component, that's why this clock is optional.

With this patch both clock have now a name, but in order to be backward
compatible, the name of the first clock is not used. It allows to still
use this clock with a device tree using the old binding.

Reviewed-by: Rob Herring 
Signed-off-by: Vinod Koul 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

dm thin: fix documentation relative to low water mark threshold

2018-05-30T05:50:20+00:00

[ Upstream commit 9b28a1102efc75d81298198166ead87d643a29ce ]

Fixes:
1. The use of "exceeds" when the opposite of exceeds, falls below,
was meant.
2. Properly speaking, a table can not exceed a threshold.

It emphasizes the important point, which is that it is the userspace
daemon's responsibility to check for low free space when a device
is resumed, since it won't get a special event indicating low free
space in that situation.

Signed-off-by: mulhern 
Signed-off-by: Mike Snitzer 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

Documentation/spec_ctrl: Do some minor cleanups

2018-05-22T14:58:02+00:00

commit dd0792699c4058e63c0715d9a7c2d40226fcdddc upstream

Fix some typos, improve formulations, end sentences with a fullstop.

Signed-off-by: Borislav Petkov 
Signed-off-by: Thomas Gleixner 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

x86/speculation: Make "seccomp" the default mode for Speculative Store Bypass

2018-05-22T14:58:02+00:00

commit f21b53b20c754021935ea43364dbf53778eeba32 upstream

Unless explicitly opted out of, anything running under seccomp will have
SSB mitigations enabled. Choosing the "prctl" mode will disable this.

[ tglx: Adjusted it to the new arch_seccomp_spec_mitigate() mechanism ]

Signed-off-by: Kees Cook 
Signed-off-by: Thomas Gleixner 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

prctl: Add force disable speculation

2018-05-22T14:58:01+00:00

commit 356e4bfff2c5489e016fdb925adbf12a1e3950ee upstream

For certain use cases it is desired to enforce mitigations so they cannot
be undone afterwards. That's important for loader stubs which want to
prevent a child from disabling the mitigation again. Will also be used for
seccomp(). The extra state preserving of the prctl state for SSB is a
preparatory step for EBPF dymanic speculation control.

Signed-off-by: Thomas Gleixner 
Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman

x86/speculation: Add prctl for Speculative Store Bypass mitigation

2018-05-22T14:58:01+00:00

commit a73ec77ee17ec556fe7f165d00314cb7c047b1ac upstream

Add prctl based control for Speculative Store Bypass mitigation and make it
the default mitigation for Intel and AMD.

Andi Kleen provided the following rationale (slightly redacted):

 There are multiple levels of impact of Speculative Store Bypass:

 1) JITed sandbox.
    It cannot invoke system calls, but can do PRIME+PROBE and may have call
    interfaces to other code

 2) Native code process.
    No protection inside the process at this level.

 3) Kernel.

 4) Between processes.

 The prctl tries to protect against case (1) doing attacks.

 If the untrusted code can do random system calls then control is already
 lost in a much worse way. So there needs to be system call protection in
 some way (using a JIT not allowing them or seccomp). Or rather if the
 process can subvert its environment somehow to do the prctl it can already
 execute arbitrary code, which is much worse than SSB.

 To put it differently, the point of the prctl is to not allow JITed code
 to read data it shouldn't read from its JITed sandbox. If it already has
 escaped its sandbox then it can already read everything it wants in its
 address space, and do much worse.

 The ability to control Speculative Store Bypass allows to enable the
 protection selectively without affecting overall system performance.

Based on an initial patch from Tim Chen. Completely rewritten.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Konrad Rzeszutek Wilk 

Signed-off-by: David Woodhouse 
Signed-off-by: Greg Kroah-Hartman