6.1-stable review patch. If anyone has any objections, please let me know.
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From: Martin Rodriguez Reboredo yakoyoku@gmail.com
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@redhat.com Signed-off-by: Eric Curtin ecurtin@redhat.com Signed-off-by: Martin Rodriguez Reboredo yakoyoku@gmail.com Signed-off-by: Daniel Borkmann daniel@iogearbox.net Tested-by: Eric Curtin ecurtin@redhat.com Reviewed-by: Neal Gompa neal@gompa.dev Acked-by: Miguel Ojeda ojeda@kernel.org Acked-by: Arnaldo Carvalho de Melo acme@redhat.com Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=49358dfe2a... [1] Link: https://git.kernel.org/pub/scm/devel/pahole/pahole.git/commit/?id=8ee363790b... [2] Link: https://github.com/Rust-for-Linux/linux/issues/735 [3] Link: https://lore.kernel.org/bpf/20230111152050.559334-1-yakoyoku@gmail.com Signed-off-by: Jiri Olsa jolsa@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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}