This is a note to let you know that I've just added the patch titled
btf, scripts: Exclude Rust CUs with pahole
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
btf-scripts-exclude-rust-cus-with-pahole.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From c1177979af9c616661a126a80dd486ad0543b836 Mon Sep 17 00:00:00 2001
From: Martin Rodriguez Reboredo <yakoyoku@xxxxxxxxx>
Date: Wed, 11 Jan 2023 12:20:50 -0300
Subject: btf, scripts: Exclude Rust CUs with pahole
From: Martin Rodriguez Reboredo <yakoyoku@xxxxxxxxx>
commit c1177979af9c616661a126a80dd486ad0543b836 upstream.
Version 1.24 of pahole has the capability to exclude compilation units (CUs)
of specific languages [1] [2]. Rust, as of writing, is not currently supported
by pahole and if it's used with a build that has BTF debugging enabled it
results in malformed kernel and module binaries [3]. So it's better for pahole
to exclude Rust CUs until support for it arrives.
Co-developed-by: Eric Curtin <ecurtin@xxxxxxxxxx>
Signed-off-by: Eric Curtin <ecurtin@xxxxxxxxxx>
Signed-off-by: Martin Rodriguez Reboredo <yakoyoku@xxxxxxxxx>
Signed-off-by: Daniel Borkmann <daniel@xxxxxxxxxxxxx>
Tested-by: Eric Curtin <ecurtin@xxxxxxxxxx>
Reviewed-by: Neal Gompa <neal@xxxxxxxxx>
Acked-by: Miguel Ojeda <ojeda@xxxxxxxxxx>
Acked-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=49358dfe2aaae4e90b072332c3e324019826783f [1]
Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b7437283c53090a85a9fec2f0b0fbc4 [2]
Link: https://github.com/Rust-for-Linux/linux/issues/735 [3]
Link: https://lore.kernel.org/bpf/20230111152050.559334-1-yakoyoku@xxxxxxxxx
Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
init/Kconfig | 2 +-
lib/Kconfig.debug | 9 +++++++++
scripts/pahole-flags.sh | 4 ++++
3 files changed, 14 insertions(+), 1 deletion(-)
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1914,7 +1914,7 @@ config RUST
depends on !MODVERSIONS
depends on !GCC_PLUGINS
depends on !RANDSTRUCT
- depends on !DEBUG_INFO_BTF
+ depends on !DEBUG_INFO_BTF || PAHOLE_HAS_LANG_EXCLUDE
select CONSTRUCTORS
help
Enables Rust support in the kernel.
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -364,6 +364,15 @@ config PAHOLE_HAS_BTF_TAG
btf_decl_tag) or not. Currently only clang compiler implements
these attributes, so make the config depend on CC_IS_CLANG.
+config PAHOLE_HAS_LANG_EXCLUDE
+ def_bool PAHOLE_VERSION >= 124
+ help
+ Support for the --lang_exclude flag which makes pahole exclude
+ compilation units from the supplied language. Used in Kbuild to
+ omit Rust CUs which are not supported in version 1.24 of pahole,
+ otherwise it would emit malformed kernel and module binaries when
+ using DEBUG_INFO_BTF_MODULES.
+
config DEBUG_INFO_BTF_MODULES
def_bool y
depends on DEBUG_INFO_BTF && MODULES && PAHOLE_HAS_SPLIT_BTF
--- a/scripts/pahole-flags.sh
+++ b/scripts/pahole-flags.sh
@@ -19,5 +19,9 @@ fi
if [ "${pahole_ver}" -ge "122" ]; then
extra_paholeopt="${extra_paholeopt} -j"
fi
+if [ "${pahole_ver}" -ge "124" ]; then
+ # see PAHOLE_HAS_LANG_EXCLUDE
+ extra_paholeopt="${extra_paholeopt} --lang_exclude=rust"
+fi
echo ${extra_paholeopt}
Patches currently in stable-queue which might be from yakoyoku@xxxxxxxxx are
queue-6.1/btf-scripts-exclude-rust-cus-with-pahole.patch
