ELF: document some de-facto PT_* ABI quirks

Turns out rules about PT_INTERP, PT_GNU_STACK and PT_GNU_PROPERTY
program headers are slightly different.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail

ELF: document some de-facto PT_* ABI quirks

Turns out rules about PT_INTERP, PT_GNU_STACK and PT_GNU_PROPERTY
program headers are slightly different.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Link: https://lore.kernel.org/r/88d3f1bb-f4e0-4c40-9304-3843513a1262@p183
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

iommufd: Document overview of iommufd

Add iommufd into the documentation tree, and supply initial documentation.
Much of this is linked from code comments by kdoc.

Link: https://lore.kernel.org/r/5

iommufd: Document overview of iommufd

Add iommufd into the documentation tree, and supply initial documentation.
Much of this is linked from code comments by kdoc.

Link: https://lore.kernel.org/r/5-v6-a196d26f289e+11787-iommufd_jgg@nvidia.com
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

show more ...

docs: netlink: basic introduction to Netlink

Provide a bit of a brain dump of netlink related information
as documentation. Hopefully this will be useful to people
trying to navigate implementing YA

docs: netlink: basic introduction to Netlink

Provide a bit of a brain dump of netlink related information
as documentation. Hopefully this will be useful to people
trying to navigate implementing YAML based parsing in languages
we won't be able to help with.

I started writing this doc while trying to figure out what
it'd take to widen the applicability of YAML to good old rtnl,
but the doc grew beyond that as it usually happens.

In all honesty a lot of this information is new to me as I usually
follow the "copy an existing example, drink to forget" process
of writing netlink user space, so reviews will be much appreciated.

Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Acked-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20220819200221.422801-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

futex2: Documentation: Document sys_futex_waitv() uAPI

Create userspace documentation for futex_waitv() syscall, detailing how
the arguments are used.

Signed-off-by: André Almeida <andrealmeid@coll

futex2: Documentation: Document sys_futex_waitv() uAPI

Create userspace documentation for futex_waitv() syscall, detailing how
the arguments are used.

Signed-off-by: André Almeida <andrealmeid@collabora.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210923171111.300673-23-andrealmeid@collabora.com

show more ...

Documentation: Add documentation for VDUSE

VDUSE (vDPA Device in Userspace) is a framework to support
implementing software-emulated vDPA devices in userspace. This
document is intended to clarify t

Documentation: Add documentation for VDUSE

VDUSE (vDPA Device in Userspace) is a framework to support
implementing software-emulated vDPA devices in userspace. This
document is intended to clarify the VDUSE design and usage.

Signed-off-by: Xie Yongji <xieyongji@bytedance.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210831103634.33-14-xieyongji@bytedance.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

show more ...

landlock: Add user and kernel documentation

Add a first document describing userspace API: how to define and enforce
a Landlock security policy. This is explained with a simple example.
The Landloc

landlock: Add user and kernel documentation

Add a first document describing userspace API: how to define and enforce
a Landlock security policy. This is explained with a simple example.
The Landlock system calls are described with their expected behavior and
current limitations.

Another document is dedicated to kernel developers, describing guiding
principles and some important kernel structures.

This documentation can be built with the Sphinx framework.

Cc: James Morris <jmorris@namei.org>
Cc: Jann Horn <jannh@google.com>
Cc: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: Mickaël Salaün <mic@linux.microsoft.com>
Reviewed-by: Vincent Dagonneau <vincent.dagonneau@ssi.gouv.fr>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20210422154123.13086-13-mic@digikod.net
Signed-off-by: James Morris <jamorris@linux.microsoft.com>

show more ...

docs/bpf: Add bpf() syscall command reference

Generate the syscall command reference from the UAPI header file and
include it in the main bpf docs page.

Signed-off-by: Joe Stringer <joe@cilium.io>

docs/bpf: Add bpf() syscall command reference

Generate the syscall command reference from the UAPI header file and
include it in the main bpf docs page.

Signed-off-by: Joe Stringer <joe@cilium.io>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Quentin Monnet <quentin@isovalent.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/bpf/20210302171947.2268128-15-joe@cilium.io

show more ...

Documentation: Add documentation for new platform_profile sysfs attribute

On modern systems the platform performance, temperature, fan and other
hardware related characteristics are often dynamicall

Documentation: Add documentation for new platform_profile sysfs attribute

On modern systems the platform performance, temperature, fan and other
hardware related characteristics are often dynamically configurable. The
profile is often automatically adjusted to the load by some
automatic-mechanism (which may very well live outside the kernel).

These auto platform-adjustment mechanisms often can be configured with
one of several 'platform-profiles', with either a bias towards low-power
consumption or towards performance (and higher power consumption and
thermals).

Introduce a new platform_profile sysfs API which offers a generic API for
selecting the performance-profile of these automatic-mechanisms.

Co-developed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Mark Pearson <markpearson@lenovo.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

show more ...

docs: userspace-api: add iommu.rst to the index file

There's a new uAPI doc for IOMMU. Add it to the index file.
Should address this warning:

.../Documentation/userspace-api/iommu.rst: WARNING: do

docs: userspace-api: add iommu.rst to the index file

There's a new uAPI doc for IOMMU. Add it to the index file.
Should address this warning:

.../Documentation/userspace-api/iommu.rst: WARNING: document isn't included in any toctree

Fixes: d0023e3ee28d ("docs: IOMMU user API")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/cc55219a551e29848e2282cd8939a4115067234c.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

media: docs: get rid of Documentation/media/

Now that everything got moved, we can get rid of the
old media directory.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

docs: Move the user-space ioctl() docs to userspace-api

This is strictly user-space material at this point, so put it with the
other user-space API documentation.

Signed-off-by: Jonathan Corbet <co

docs: Move the user-space ioctl() docs to userspace-api

This is strictly user-space material at this point, so put it with the
other user-space API documentation.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

docs: ocxl.rst: add it to the uAPI book

The content of this file is user-faced.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>

prctl: Add speculation control prctls

Add two new prctls to control aspects of speculation related vulnerabilites
and their mitigations to provide finer grained control over performance
impacting mi

prctl: Add speculation control prctls

Add two new prctls to control aspects of speculation related vulnerabilites
and their mitigations to provide finer grained control over performance
impacting mitigations.

PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature
which is selected with arg2 of prctl(2). The return value uses bit 0-2 with
the following meaning:

Bit Define Description
0 PR_SPEC_PRCTL Mitigation can be controlled per task by
PR_SET_SPECULATION_CTRL
1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is
disabled
2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is
enabled

If all bits are 0 the CPU is not affected by the speculation misfeature.

If PR_SPEC_PRCTL is set, then the per task control of the mitigation is
available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation
misfeature will fail.

PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which
is selected by arg2 of prctl(2) per task. arg3 is used to hand in the
control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE.

The common return values are:

EINVAL prctl is not implemented by the architecture or the unused prctl()
arguments are not 0
ENODEV arg2 is selecting a not supported speculation misfeature

PR_SET_SPECULATION_CTRL has these additional return values:

ERANGE arg3 is incorrect, i.e. it's not either PR_SPEC_ENABLE or PR_SPEC_DISABLE
ENXIO prctl control of the selected speculation misfeature is disabled

The first supported controlable speculation misfeature is
PR_SPEC_STORE_BYPASS. Add the define so this can be shared between
architectures.

Based on an initial patch from Tim Chen and mostly rewritten.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

doc: ReSTify no_new_privs.txt

This updates no_new_privs documentation to ReST markup and adds it to
the user-space API documentation.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by:

doc: ReSTify no_new_privs.txt

This updates no_new_privs documentation to ReST markup and adds it to
the user-space API documentation.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

doc: ReSTify seccomp_filter.txt

This updates seccomp_filter.txt for ReST markup, and moves it under the
user-space API index, since it describes how application author can use
seccomp.

Signed-off-b

doc: ReSTify seccomp_filter.txt

This updates seccomp_filter.txt for ReST markup, and moves it under the
user-space API index, since it describes how application author can use
seccomp.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

docs: Convert unshare.txt to RST and add to the user-space API manual

This is a straightforward conversion, without any real textual changes.
Since this document has seen no substantive changes sinc

docs: Convert unshare.txt to RST and add to the user-space API manual

This is a straightforward conversion, without any real textual changes.
Since this document has seen no substantive changes since its addition in
2006, some such changes are probably warranted.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

docs: Create a user-space API guide

This is meant to be the place for documentation relevant to application
developers. It's empty for the moment, but at least we have a place now!

Signed-off-by:

docs: Create a user-space API guide

This is meant to be the place for documentation relevant to application
developers. It's empty for the moment, but at least we have a place now!

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

docs: userspace-api: add iommu.rst to the index file

There's a new uAPI doc for IOMMU. Add it to the index file.
Should address this warning:

.../Documentation/userspace

docs: userspace-api: add iommu.rst to the index file

There's a new uAPI doc for IOMMU. Add it to the index file.
Should address this warning:

.../Documentation/userspace-api/iommu.rst: WARNING: document isn't included in any toctree

Fixes: d0023e3ee28d ("docs: IOMMU user API")
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/cc55219a551e29848e2282cd8939a4115067234c.1603791716.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

media: docs: get rid of Documentation/media/

Now that everything got moved, we can get rid of the
old media directory.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kerne

media: docs: get rid of Documentation/media/

Now that everything got moved, we can get rid of the
old media directory.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

show more ...

docs: Move the user-space ioctl() docs to userspace-api

This is strictly user-space material at this point, so put it with the
other user-space API documentation.

Signed-off-by:

docs: Move the user-space ioctl() docs to userspace-api

This is strictly user-space material at this point, so put it with the
other user-space API documentation.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

docs: ocxl.rst: add it to the uAPI book

The content of this file is user-faced.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Donnellan <ajd

docs: ocxl.rst: add it to the uAPI book

The content of this file is user-faced.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Acked-by: Andrew Donnellan <ajd@linux.ibm.com>

show more ...

prctl: Add speculation control prctls

Add two new prctls to control aspects of speculation related vulnerabilites
and their mitigations to provide finer grained control over performance

prctl: Add speculation control prctls

Add two new prctls to control aspects of speculation related vulnerabilites
and their mitigations to provide finer grained control over performance
impacting mitigations.

PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature
which is selected with arg2 of prctl(2). The return value uses bit 0-2 with
the following meaning:

Bit Define Description
0 PR_SPEC_PRCTL Mitigation can be controlled per task by
PR_SET_SPECULATION_CTRL
1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is
disabled
2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is
enabled

If all bits are 0 the CPU is not affected by the speculation misfeature.

If PR_SPEC_PRCTL is set, then the per task control of the mitigation is
available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation
misfeature will fail.

PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which
is selected by arg2 of prctl(2) per task. arg3 is used to hand in the
control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE.

The common return values are:

EINVAL prctl is not implemented by the architecture or the unused prctl()
arguments are not 0
ENODEV arg2 is selecting a not supported speculation misfeature

PR_SET_SPECULATION_CTRL has these additional return values:

ERANGE arg3 is incorrect, i.e. it's not either PR_SPEC_ENABLE or PR_SPEC_DISABLE
ENXIO prctl control of the selected speculation misfeature is disabled

The first supported controlable speculation misfeature is
PR_SPEC_STORE_BYPASS. Add the define so this can be shared between
architectures.

Based on an initial patch from Tim Chen and mostly rewritten.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

show more ...

doc: ReSTify no_new_privs.txt

This updates no_new_privs documentation to ReST markup and adds it to
the user-space API documentation.

Signed-off-by: Kees Cook <keescook@chromium

doc: ReSTify no_new_privs.txt

This updates no_new_privs documentation to ReST markup and adds it to
the user-space API documentation.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

doc: ReSTify seccomp_filter.txt

This updates seccomp_filter.txt for ReST markup, and moves it under the
user-space API index, since it describes how application author can use
seccom

doc: ReSTify seccomp_filter.txt

This updates seccomp_filter.txt for ReST markup, and moves it under the
user-space API index, since it describes how application author can use
seccomp.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...

docs: Convert unshare.txt to RST and add to the user-space API manual

This is a straightforward conversion, without any real textual changes.
Since this document has seen no substantive

docs: Convert unshare.txt to RST and add to the user-space API manual

This is a straightforward conversion, without any real textual changes.
Since this document has seen no substantive changes since its addition in
2006, some such changes are probably warranted.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

show more ...