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authorDavid S. Miller <davem@davemloft.net>2021-02-11 00:30:12 +0300
committerDavid S. Miller <davem@davemloft.net>2021-02-11 00:30:12 +0300
commitdc9d87581d464e7b7d38853d6904b70b6c920d99 (patch)
tree15aa27fefb867814899c0a0c194adf327675ba10 /Documentation
parentde1db4a6ed6241e34cab0e5059d4b56f6bae39b9 (diff)
parent291009f656e8eaebbdfd3a8d99f6b190a9ce9deb (diff)
downloadlinux-dc9d87581d464e7b7d38853d6904b70b6c920d99.tar.xz
Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/Makefile2
-rw-r--r--Documentation/admin-guide/syscall-user-dispatch.rst4
-rw-r--r--Documentation/dev-tools/kasan.rst3
-rw-r--r--Documentation/devicetree/bindings/input/adc-keys.txt22
-rw-r--r--Documentation/devicetree/bindings/input/touchscreen/goodix.yaml1
-rw-r--r--Documentation/filesystems/overlayfs.rst8
-rw-r--r--Documentation/kbuild/gcc-plugins.rst47
-rw-r--r--Documentation/kbuild/llvm.rst44
-rw-r--r--Documentation/kbuild/makefiles.rst2
-rw-r--r--Documentation/virt/kvm/nested-vmx.rst6
-rw-r--r--Documentation/virt/kvm/running-nested-guests.rst2
11 files changed, 104 insertions, 37 deletions
diff --git a/Documentation/Makefile b/Documentation/Makefile
index 61a7310b49e0..9c42dde97671 100644
--- a/Documentation/Makefile
+++ b/Documentation/Makefile
@@ -75,7 +75,7 @@ quiet_cmd_sphinx = SPHINX $@ --> file://$(abspath $(BUILDDIR)/$3/$4)
cmd_sphinx = $(MAKE) BUILDDIR=$(abspath $(BUILDDIR)) $(build)=Documentation/userspace-api/media $2 && \
PYTHONDONTWRITEBYTECODE=1 \
BUILDDIR=$(abspath $(BUILDDIR)) SPHINX_CONF=$(abspath $(srctree)/$(src)/$5/$(SPHINX_CONF)) \
- $(PYTHON) $(srctree)/scripts/jobserver-exec \
+ $(PYTHON3) $(srctree)/scripts/jobserver-exec \
$(SHELL) $(srctree)/Documentation/sphinx/parallel-wrapper.sh \
$(SPHINXBUILD) \
-b $2 \
diff --git a/Documentation/admin-guide/syscall-user-dispatch.rst b/Documentation/admin-guide/syscall-user-dispatch.rst
index a380d6515774..60314953c728 100644
--- a/Documentation/admin-guide/syscall-user-dispatch.rst
+++ b/Documentation/admin-guide/syscall-user-dispatch.rst
@@ -70,8 +70,8 @@ trampoline code on the vDSO, that trampoline is never intercepted.
[selector] is a pointer to a char-sized region in the process memory
region, that provides a quick way to enable disable syscall redirection
thread-wide, without the need to invoke the kernel directly. selector
-can be set to PR_SYS_DISPATCH_ON or PR_SYS_DISPATCH_OFF. Any other
-value should terminate the program with a SIGSYS.
+can be set to SYSCALL_DISPATCH_FILTER_ALLOW or SYSCALL_DISPATCH_FILTER_BLOCK.
+Any other value should terminate the program with a SIGSYS.
Security Notes
--------------
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 1651d961f06a..a248ac3941be 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -163,8 +163,7 @@ particular KASAN features.
- ``kasan=off`` or ``=on`` controls whether KASAN is enabled (default: ``on``).
- ``kasan.stacktrace=off`` or ``=on`` disables or enables alloc and free stack
- traces collection (default: ``on`` for ``CONFIG_DEBUG_KERNEL=y``, otherwise
- ``off``).
+ traces collection (default: ``on``).
- ``kasan.fault=report`` or ``=panic`` controls whether to only print a KASAN
report or also panic the kernel (default: ``report``).
diff --git a/Documentation/devicetree/bindings/input/adc-keys.txt b/Documentation/devicetree/bindings/input/adc-keys.txt
index e551814629b4..6c8be6a9ace2 100644
--- a/Documentation/devicetree/bindings/input/adc-keys.txt
+++ b/Documentation/devicetree/bindings/input/adc-keys.txt
@@ -5,7 +5,8 @@ Required properties:
- compatible: "adc-keys"
- io-channels: Phandle to an ADC channel
- io-channel-names = "buttons";
- - keyup-threshold-microvolt: Voltage at which all the keys are considered up.
+ - keyup-threshold-microvolt: Voltage above or equal to which all the keys are
+ considered up.
Optional properties:
- poll-interval: Poll interval time in milliseconds
@@ -17,7 +18,12 @@ Each button (key) is represented as a sub-node of "adc-keys":
Required subnode-properties:
- label: Descriptive name of the key.
- linux,code: Keycode to emit.
- - press-threshold-microvolt: Voltage ADC input when this key is pressed.
+ - press-threshold-microvolt: voltage above or equal to which this key is
+ considered pressed.
+
+No two values of press-threshold-microvolt may be the same.
+All values of press-threshold-microvolt must be less than
+keyup-threshold-microvolt.
Example:
@@ -47,3 +53,15 @@ Example:
press-threshold-microvolt = <500000>;
};
};
+
++--------------------------------+------------------------+
+| 2.000.000 <= value | no key pressed |
++--------------------------------+------------------------+
+| 1.500.000 <= value < 2.000.000 | KEY_VOLUMEUP pressed |
++--------------------------------+------------------------+
+| 1.000.000 <= value < 1.500.000 | KEY_VOLUMEDOWN pressed |
++--------------------------------+------------------------+
+| 500.000 <= value < 1.000.000 | KEY_ENTER pressed |
++--------------------------------+------------------------+
+| value < 500.000 | no key pressed |
++--------------------------------+------------------------+
diff --git a/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml b/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
index da5b0d87e16d..93f2ce3130ae 100644
--- a/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
+++ b/Documentation/devicetree/bindings/input/touchscreen/goodix.yaml
@@ -26,6 +26,7 @@ properties:
- goodix,gt927
- goodix,gt9271
- goodix,gt928
+ - goodix,gt9286
- goodix,gt967
reg:
diff --git a/Documentation/filesystems/overlayfs.rst b/Documentation/filesystems/overlayfs.rst
index 587a93973929..78240e29b0bb 100644
--- a/Documentation/filesystems/overlayfs.rst
+++ b/Documentation/filesystems/overlayfs.rst
@@ -586,6 +586,14 @@ without significant effort.
The advantage of mounting with the "volatile" option is that all forms of
sync calls to the upper filesystem are omitted.
+In order to avoid a giving a false sense of safety, the syncfs (and fsync)
+semantics of volatile mounts are slightly different than that of the rest of
+VFS. If any writeback error occurs on the upperdir's filesystem after a
+volatile mount takes place, all sync functions will return an error. Once this
+condition is reached, the filesystem will not recover, and every subsequent sync
+call will return an error, even if the upperdir has not experience a new error
+since the last sync call.
+
When overlay is mounted with "volatile" option, the directory
"$workdir/work/incompat/volatile" is created. During next mount, overlay
checks for this directory and refuses to mount if present. This is a strong
diff --git a/Documentation/kbuild/gcc-plugins.rst b/Documentation/kbuild/gcc-plugins.rst
index 4b1c10f88e30..3349966f213d 100644
--- a/Documentation/kbuild/gcc-plugins.rst
+++ b/Documentation/kbuild/gcc-plugins.rst
@@ -11,16 +11,13 @@ compiler [1]_. They are useful for runtime instrumentation and static analysis.
We can analyse, change and add further code during compilation via
callbacks [2]_, GIMPLE [3]_, IPA [4]_ and RTL passes [5]_.
-The GCC plugin infrastructure of the kernel supports all gcc versions from
-4.5 to 6.0, building out-of-tree modules, cross-compilation and building in a
-separate directory.
-Plugin source files have to be compilable by both a C and a C++ compiler as well
-because gcc versions 4.5 and 4.6 are compiled by a C compiler,
-gcc-4.7 can be compiled by a C or a C++ compiler,
-and versions 4.8+ can only be compiled by a C++ compiler.
+The GCC plugin infrastructure of the kernel supports building out-of-tree
+modules, cross-compilation and building in a separate directory.
+Plugin source files have to be compilable by a C++ compiler.
-Currently the GCC plugin infrastructure supports only the x86, arm, arm64 and
-powerpc architectures.
+Currently the GCC plugin infrastructure supports only some architectures.
+Grep "select HAVE_GCC_PLUGINS" to find out which architectures support
+GCC plugins.
This infrastructure was ported from grsecurity [6]_ and PaX [7]_.
@@ -47,20 +44,13 @@ Files
This is a compatibility header for GCC plugins.
It should be always included instead of individual gcc headers.
-**$(src)/scripts/gcc-plugin.sh**
-
- This script checks the availability of the included headers in
- gcc-common.h and chooses the proper host compiler to build the plugins
- (gcc-4.7 can be built by either gcc or g++).
-
**$(src)/scripts/gcc-plugins/gcc-generate-gimple-pass.h,
$(src)/scripts/gcc-plugins/gcc-generate-ipa-pass.h,
$(src)/scripts/gcc-plugins/gcc-generate-simple_ipa-pass.h,
$(src)/scripts/gcc-plugins/gcc-generate-rtl-pass.h**
These headers automatically generate the registration structures for
- GIMPLE, SIMPLE_IPA, IPA and RTL passes. They support all gcc versions
- from 4.5 to 6.0.
+ GIMPLE, SIMPLE_IPA, IPA and RTL passes.
They should be preferred to creating the structures by hand.
@@ -68,21 +58,25 @@ Usage
=====
You must install the gcc plugin headers for your gcc version,
-e.g., on Ubuntu for gcc-4.9::
+e.g., on Ubuntu for gcc-10::
- apt-get install gcc-4.9-plugin-dev
+ apt-get install gcc-10-plugin-dev
Or on Fedora::
dnf install gcc-plugin-devel
-Enable a GCC plugin based feature in the kernel config::
+Enable the GCC plugin infrastructure and some plugin(s) you want to use
+in the kernel config::
- CONFIG_GCC_PLUGIN_CYC_COMPLEXITY = y
+ CONFIG_GCC_PLUGINS=y
+ CONFIG_GCC_PLUGIN_CYC_COMPLEXITY=y
+ CONFIG_GCC_PLUGIN_LATENT_ENTROPY=y
+ ...
-To compile only the plugin(s)::
+To compile the minimum tool set including the plugin(s)::
- make gcc-plugins
+ make scripts
or just run the kernel make and compile the whole kernel with
the cyclomatic complexity GCC plugin.
@@ -91,7 +85,8 @@ the cyclomatic complexity GCC plugin.
4. How to add a new GCC plugin
==============================
-The GCC plugins are in $(src)/scripts/gcc-plugins/. You can use a file or a directory
-here. It must be added to $(src)/scripts/gcc-plugins/Makefile,
-$(src)/scripts/Makefile.gcc-plugins and $(src)/arch/Kconfig.
+The GCC plugins are in scripts/gcc-plugins/. You need to put plugin source files
+right under scripts/gcc-plugins/. Creating subdirectories is not supported.
+It must be added to scripts/gcc-plugins/Makefile, scripts/Makefile.gcc-plugins
+and a relevant Kconfig file.
See the cyc_complexity_plugin.c (CONFIG_GCC_PLUGIN_CYC_COMPLEXITY) GCC plugin.
diff --git a/Documentation/kbuild/llvm.rst b/Documentation/kbuild/llvm.rst
index 21c847890d03..b18401d2ba82 100644
--- a/Documentation/kbuild/llvm.rst
+++ b/Documentation/kbuild/llvm.rst
@@ -63,6 +63,50 @@ They can be enabled individually. The full list of the parameters: ::
Currently, the integrated assembler is disabled by default. You can pass
``LLVM_IAS=1`` to enable it.
+Supported Architectures
+-----------------------
+
+LLVM does not target all of the architectures that Linux supports and
+just because a target is supported in LLVM does not mean that the kernel
+will build or work without any issues. Below is a general summary of
+architectures that currently work with ``CC=clang`` or ``LLVM=1``. Level
+of support corresponds to "S" values in the MAINTAINERS files. If an
+architecture is not present, it either means that LLVM does not target
+it or there are known issues. Using the latest stable version of LLVM or
+even the development tree will generally yield the best results.
+An architecture's ``defconfig`` is generally expected to work well,
+certain configurations may have problems that have not been uncovered
+yet. Bug reports are always welcome at the issue tracker below!
+
+.. list-table::
+ :widths: 10 10 10
+ :header-rows: 1
+
+ * - Architecture
+ - Level of support
+ - ``make`` command
+ * - arm
+ - Supported
+ - ``LLVM=1``
+ * - arm64
+ - Supported
+ - ``LLVM=1``
+ * - mips
+ - Maintained
+ - ``CC=clang``
+ * - powerpc
+ - Maintained
+ - ``CC=clang``
+ * - riscv
+ - Maintained
+ - ``CC=clang``
+ * - s390
+ - Maintained
+ - ``CC=clang``
+ * - x86
+ - Supported
+ - ``LLVM=1``
+
Getting Help
------------
diff --git a/Documentation/kbuild/makefiles.rst b/Documentation/kbuild/makefiles.rst
index 9f6a11881951..300d8edcb994 100644
--- a/Documentation/kbuild/makefiles.rst
+++ b/Documentation/kbuild/makefiles.rst
@@ -755,7 +755,7 @@ more details, with real examples.
bits on the scripts nonetheless.
Kbuild provides variables $(CONFIG_SHELL), $(AWK), $(PERL),
- $(PYTHON) and $(PYTHON3) to refer to interpreters for the respective
+ and $(PYTHON3) to refer to interpreters for the respective
scripts.
Example::
diff --git a/Documentation/virt/kvm/nested-vmx.rst b/Documentation/virt/kvm/nested-vmx.rst
index 6ab4e35cee23..ac2095d41f02 100644
--- a/Documentation/virt/kvm/nested-vmx.rst
+++ b/Documentation/virt/kvm/nested-vmx.rst
@@ -37,8 +37,10 @@ call L2.
Running nested VMX
------------------
-The nested VMX feature is disabled by default. It can be enabled by giving
-the "nested=1" option to the kvm-intel module.
+The nested VMX feature is enabled by default since Linux kernel v4.20. For
+older Linux kernel, it can be enabled by giving the "nested=1" option to the
+kvm-intel module.
+
No modifications are required to user space (qemu). However, qemu's default
emulated CPU type (qemu64) does not list the "VMX" CPU feature, so it must be
diff --git a/Documentation/virt/kvm/running-nested-guests.rst b/Documentation/virt/kvm/running-nested-guests.rst
index d0a1fc754c84..bd70c69468ae 100644
--- a/Documentation/virt/kvm/running-nested-guests.rst
+++ b/Documentation/virt/kvm/running-nested-guests.rst
@@ -74,7 +74,7 @@ few:
Enabling "nested" (x86)
-----------------------
-From Linux kernel v4.19 onwards, the ``nested`` KVM parameter is enabled
+From Linux kernel v4.20 onwards, the ``nested`` KVM parameter is enabled
by default for Intel and AMD. (Though your Linux distribution might
override this default.)