From d2ccde1c8e90d38cee87a1b0309ad2827f3fd30d Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 11 Dec 2023 02:45:28 +0000
Subject: [PATCH] add boot partition size
---
kernel/Documentation/bpf/bpf_devel_QA.rst | 68 +++++++++++++++++++++-------------
1 files changed, 42 insertions(+), 26 deletions(-)
diff --git a/kernel/Documentation/bpf/bpf_devel_QA.rst b/kernel/Documentation/bpf/bpf_devel_QA.rst
index c9856b9..5b613d2 100644
--- a/kernel/Documentation/bpf/bpf_devel_QA.rst
+++ b/kernel/Documentation/bpf/bpf_devel_QA.rst
@@ -20,11 +20,11 @@
Q: How do I report bugs for BPF kernel code?
--------------------------------------------
A: Since all BPF kernel development as well as bpftool and iproute2 BPF
-loader development happens through the netdev kernel mailing list,
+loader development happens through the bpf kernel mailing list,
please report any found issues around BPF to the following mailing
list:
- netdev@vger.kernel.org
+ bpf@vger.kernel.org
This may also include issues related to XDP, BPF tracing, etc.
@@ -46,17 +46,12 @@
Q: To which mailing list do I need to submit my BPF patches?
------------------------------------------------------------
-A: Please submit your BPF patches to the netdev kernel mailing list:
+A: Please submit your BPF patches to the bpf kernel mailing list:
- netdev@vger.kernel.org
-
-Historically, BPF came out of networking and has always been maintained
-by the kernel networking community. Although these days BPF touches
-many other subsystems as well, the patches are still routed mainly
-through the networking community.
+ bpf@vger.kernel.org
In case your patch has changes in various different subsystems (e.g.
-tracing, security, etc), make sure to Cc the related kernel mailing
+networking, tracing, security, etc), make sure to Cc the related kernel mailing
lists and maintainers from there as well, so they are able to review
the changes and provide their Acked-by's to the patches.
@@ -65,13 +60,13 @@
A: All patches that are Cc'ed to netdev are queued for review under netdev
patchwork project:
- http://patchwork.ozlabs.org/project/netdev/list/
+ https://patchwork.kernel.org/project/netdevbpf/list/
Those patches which target BPF, are assigned to a 'bpf' delegate for
further processing from BPF maintainers. The current queue with
patches under review can be found at:
- https://patchwork.ozlabs.org/project/netdev/list/?delegate=77147
+ https://patchwork.kernel.org/project/netdevbpf/list/?delegate=121173
Once the patches have been reviewed by the BPF community as a whole
and approved by the BPF maintainers, their status in patchwork will be
@@ -154,7 +149,7 @@
again in a second or later revision, it is also required to add a
version number (``v2``, ``v3``, ...) into the subject prefix::
- git format-patch --subject-prefix='PATCH net-next v2' start..finish
+ git format-patch --subject-prefix='PATCH bpf-next v2' start..finish
When changes have been requested to the patch series, always send the
whole patch series again with the feedback incorporated (never send
@@ -168,7 +163,7 @@
Be aware that this is not a final verdict that the patch will
automatically get accepted into net or net-next trees eventually:
-On the netdev kernel mailing list reviews can come in at any point
+On the bpf kernel mailing list reviews can come in at any point
in time. If discussions around a patch conclude that they cannot
get included as-is, we will either apply a follow-up fix or drop
them from the trees entirely. Therefore, we also reserve to rebase
@@ -442,6 +437,21 @@
See the kernels selftest `Documentation/dev-tools/kselftest.rst`_
document for further documentation.
+To maximize the number of tests passing, the .config of the kernel
+under test should match the config file fragment in
+tools/testing/selftests/bpf as closely as possible.
+
+Finally to ensure support for latest BPF Type Format features -
+discussed in `Documentation/bpf/btf.rst`_ - pahole version 1.16
+is required for kernels built with CONFIG_DEBUG_INFO_BTF=y.
+pahole is delivered in the dwarves package or can be built
+from source at
+
+https://github.com/acmel/dwarves
+
+Some distros have pahole version 1.16 packaged already, e.g.
+Fedora, Gentoo.
+
Q: Which BPF kernel selftests version should I run my kernel against?
---------------------------------------------------------------------
A: If you run a kernel ``xyz``, then always run the BPF kernel selftests
@@ -469,17 +479,18 @@
$ llc --version
LLVM (http://llvm.org/):
- LLVM version 6.0.0svn
+ LLVM version 10.0.0
Optimized build.
Default target: x86_64-unknown-linux-gnu
Host CPU: skylake
Registered Targets:
- bpf - BPF (host endian)
- bpfeb - BPF (big endian)
- bpfel - BPF (little endian)
- x86 - 32-bit X86: Pentium-Pro and above
- x86-64 - 64-bit X86: EM64T and AMD64
+ aarch64 - AArch64 (little endian)
+ bpf - BPF (host endian)
+ bpfeb - BPF (big endian)
+ bpfel - BPF (little endian)
+ x86 - 32-bit X86: Pentium-Pro and above
+ x86-64 - 64-bit X86: EM64T and AMD64
For developers in order to utilize the latest features added to LLVM's
BPF back end, it is advisable to run the latest LLVM releases. Support
@@ -494,18 +505,22 @@
that set up, proceed with building the latest LLVM and clang version
from the git repositories::
- $ git clone http://llvm.org/git/llvm.git
- $ cd llvm/tools
- $ git clone --depth 1 http://llvm.org/git/clang.git
- $ cd ..; mkdir build; cd build
- $ cmake .. -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
+ $ git clone https://github.com/llvm/llvm-project.git
+ $ mkdir -p llvm-project/llvm/build/install
+ $ cd llvm-project/llvm/build
+ $ cmake .. -G "Ninja" -DLLVM_TARGETS_TO_BUILD="BPF;X86" \
+ -DLLVM_ENABLE_PROJECTS="clang" \
-DBUILD_SHARED_LIBS=OFF \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_BUILD_RUNTIME=OFF
- $ make -j $(getconf _NPROCESSORS_ONLN)
+ $ ninja
The built binaries can then be found in the build/bin/ directory, where
you can point the PATH variable to.
+
+Set ``-DLLVM_TARGETS_TO_BUILD`` equal to the target you wish to build, you
+will find a full list of targets within the llvm-project/llvm/lib/Target
+directory.
Q: Reporting LLVM BPF issues
----------------------------
@@ -633,5 +648,6 @@
.. _selftests: ../../tools/testing/selftests/bpf/
.. _Documentation/dev-tools/kselftest.rst:
https://www.kernel.org/doc/html/latest/dev-tools/kselftest.html
+.. _Documentation/bpf/btf.rst: btf.rst
Happy BPF hacking!
--
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