linux-stable.git/drivers/base/Kconfig, branch linux-4.9.y

sysfs/cpu: Add vulnerability folder

2018-01-17T08:38:57+00:00

commit 87590ce6e373d1a5401f6539f0c59ef92dd924a9 upstream.

As the meltdown/spectre problem affects several CPU architectures, it makes
sense to have common way to express whether a system is affected by a
particular vulnerability or not. If affected the way to express the
mitigation should be common as well.

Create /sys/devices/system/cpu/vulnerabilities folder and files for
meltdown, spectre_v1 and spectre_v2.

Allow architectures to override the show function.

Signed-off-by: Thomas Gleixner 
Reviewed-by: Greg Kroah-Hartman 
Reviewed-by: Konrad Rzeszutek Wilk 
Cc: Peter Zijlstra 
Cc: Will Deacon 
Cc: Dave Hansen 
Cc: Linus Torvalds 
Cc: Borislav Petkov 
Cc: David Woodhouse 
Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de
Signed-off-by: Greg Kroah-Hartman

driver core: Make Kconfig text for DEBUG_TEST_DRIVER_REMOVE stronger

2016-10-27T15:47:12+00:00

The current state of driver removal is not great.
CONFIG_DEBUG_TEST_DRIVER_REMOVE finds lots of errors. The help text
currently undersells exactly how many errors this option will find. Add
a bit more description to indicate this option shouldn't be turned on
unless you actually want to debug driver removal. The text can be
changed later when more drivers are fixed up.

Signed-off-by: Laura Abbott 
Signed-off-by: Greg Kroah-Hartman

driver core: add test of driver remove calls during probe

2016-08-31T13:13:55+00:00

In recent discussions on ksummit-discuss[1], it was suggested to do a
sequence of probe, remove, probe for testing driver remove paths. This
adds a kconfig option for said test.

[1] https://lists.linuxfoundation.org/pipermail/ksummit-discuss/2016-August/003459.html

Suggested-by: Arnd Bergmann 
Cc: Greg Kroah-Hartman 
Signed-off-by: Rob Herring 
Signed-off-by: Greg Kroah-Hartman

cma: make default CMA area size zero for x86

2014-12-11T01:41:06+00:00

This makes CMA memory area size zero for x86 in default configuration
(doesn't change on the other architectures).  If default CMA size is
zero, DMA_CMA is disabled.  It can be enabled by passing cma= to the
kernel.

This makes less impact on x86.  Because there is no mainline driver that
requires it for x86, and Peter Hurley reported the performance
regression, as this is trying to drive _all_ dma mapping allocations
through a _very_ small window.

Signed-off-by: Akinobu Mita 
Reported-by: Peter Hurley 
Cc: Peter Hurley 
Cc: Chuck Ebbert 
Cc: Jean Delvare 
Acked-by: Marek Szyprowski 
Cc: Konrad Rzeszutek Wilk 
Cc: David Woodhouse 
Cc: Don Dutile 
Cc: Thomas Gleixner 
Cc: Ingo Molnar 
Cc: "H. Peter Anvin" 
Cc: Andi Kleen 
Cc: Yinghai Lu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

tiny: rename ENABLE_DEV_COREDUMP to ALLOW_DEV_COREDUMP

2014-11-07T19:07:35+00:00

The ENABLE_DEV_COREDUMP option is misleading as it implies that
it gets the framework enabled, this isn't true it just allows it
to get enabled if a driver needs it.

Rename it to ALLOW_DEV_COREDUMP to better capture its semantics.

Signed-off-by: Johannes Berg 
Reviewed-by: Josh Triplett 
Acked-by: Aristeu Rozanski 
Signed-off-by: Greg Kroah-Hartman

tiny: reverse logic for DISABLE_DEV_COREDUMP

2014-11-07T19:07:35+00:00

It's desirable for allnconfig and tinyconfig targets to result in the
least amount of code possible. DISABLE_DEV_COREDUMP exists as a way to
switch off DEV_COREDUMP regardless if any drivers select
WANT_DEV_COREDUMP.

This patch renames the option to ENABLE_DEV_COREDUMP and setting it to
'n' (as in allnconfig or tinyconfig) will effectively disable device
coredump.

Cc: Josh Triplett 
Reviewed-by: Josh Triplett 
Signed-off-by: Aristeu Rozanski 
Reviewed-by: Johannes Berg 
Acked-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

CMA: document cma=0

2014-10-10T02:26:02+00:00

It isn't obvious that CMA can be disabled on the kernel's command line, so
document it.

Signed-off-by: Jean Delvare 
Cc: Joonsoo Kim 
Cc: Greg Kroah-Hartman 
Cc: Akinobu Mita 
Cc: Chuck Ebbert 
Cc: Marek Szyprowski 
Cc: Konrad Rzeszutek Wilk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

device coredump: add new device coredump class

2014-09-24T05:53:15+00:00

Many devices run firmware and/or complex hardware, and most of that
can have bugs. When it misbehaves, however, it is often much harder
to debug than software running on the host.

Introduce a "device coredump" mechanism to allow dumping internal
device/firmware state through a generalized mechanism. As devices
are different and information needed can vary accordingly, this
doesn't prescribe a file format - it just provides mechanism to
get data to be able to capture it in a generalized way (e.g. in
distributions.)

The dumped data will be readable in sysfs in the virtual device's
data file under /sys/class/devcoredump/devcd*/. Writing to it will
free the data and remove the device, as does a 5-minute timeout.

Note that generalized capturing of such data may result in privacy
issues, so users generally need to be involved. In order to allow
certain users/system integrators/... to disable the feature at all,
introduce a Kconfig option to override the drivers that would like
to have the feature.

For now, this provides two ways of dumping data:
 1) with a vmalloc'ed area, that is then given to the subsystem
    and freed after retrieval or timeout
 2) with a generalized reader/free function method

We could/should add more options, e.g. a list of pages, since the
vmalloc area is very limited on some architectures.

Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

CMA: generalize CMA reserved area management functionality

2014-08-07T01:01:16+00:00

Currently, there are two users on CMA functionality, one is the DMA
subsystem and the other is the KVM on powerpc.  They have their own code
to manage CMA reserved area even if they looks really similar.  From my
guess, it is caused by some needs on bitmap management.  KVM side wants
to maintain bitmap not for 1 page, but for more size.  Eventually it use
bitmap where one bit represents 64 pages.

When I implement CMA related patches, I should change those two places
to apply my change and it seem to be painful to me.  I want to change
this situation and reduce future code management overhead through this
patch.

This change could also help developer who want to use CMA in their new
feature development, since they can use CMA easily without copying &
pasting this reserved area management code.

In previous patches, we have prepared some features to generalize CMA
reserved area management and now it's time to do it.  This patch moves
core functions to mm/cma.c and change DMA APIs to use these functions.

There is no functional change in DMA APIs.

Signed-off-by: Joonsoo Kim 
Acked-by: Michal Nazarewicz 
Acked-by: Zhang Yanfei 
Acked-by: Minchan Kim 
Reviewed-by: Aneesh Kumar K.V 
Cc: Alexander Graf 
Cc: Aneesh Kumar K.V 
Cc: Gleb Natapov 
Acked-by: Marek Szyprowski 
Tested-by: Marek Szyprowski 
Cc: Paolo Bonzini 
Cc: Benjamin Herrenschmidt 
Cc: Paul Mackerras 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

firmware loader: allow disabling of udev as firmware loader

2014-07-08T22:24:39+00:00

[The patch was originally proposed by Tom Gundersen, and rewritten
 afterwards by me; most of changelogs below borrowed from Tom's
 original patch -- tiwai]

Currently (at least) the dell-rbu driver selects FW_LOADER_USER_HELPER,
which means that distros can't really stop loading firmware through
udev without breaking other users (though some have).

Ideally we would remove/disable the udev firmware helper in both the
kernel and in udev, but if we were to disable it in udev and not the
kernel, the result would be (seemingly) hung kernels as no one would
be around to cancel firmware requests.

This patch allows udev firmware loading to be disabled while still
allowing non-udev firmware loading, as done by the dell-rbu driver, to
continue working. This is achieved by only using the fallback
mechanism when the uevent is suppressed.

The patch renames the user-selectable Kconfig from FW_LOADER_USER_HELPER
to FW_LOADER_USER_HELPER_FALLBACK, and the former is reverse-selected
by the latter or the drivers that need userhelper like dell-rbu.

Also, the "default y" is removed together with this change, since it's
been deprecated in udev upstream, thus rather better to disable it
nowadays.

Tested with
    FW_LOADER_USER_HELPER=n
    LATTICE_ECP3_CONFIG=y
    DELL_RBU=y
and udev without the firmware loading support, but I don't have the
hardware to test the lattice/dell drivers, so additional testing would
be appreciated.

Reviewed-by: Tom Gundersen 
Cc: Ming Lei 
Cc: Abhay Salunke 
Cc: Stefan Roese 
Cc: Arnd Bergmann 
Cc: Kay Sievers 
Tested-by: Balaji Singh 
Signed-off-by: Takashi Iwai 
Signed-off-by: Greg Kroah-Hartman