scripts/gen-btf.sh: Use CONFIG_SHELL for execution

According to the docs [1], kernel build scripts should be executed via
CONFIG_SHELL, which is sh by default.

Fixup gen-btf.sh to be runnable with sh, and use CONFIG_SHELL at every
invocation site.

See relevant discussion for context [2].

[1] https://docs.kernel.org/kbuild/makefiles.html#script-invocation
[2] https://lore.kernel.org/bpf/CAADnVQ+dxmSNoJAGb6xV89ffUCKXe5CJXovXZt22nv5iYFV5mw@mail.gmail.com/

Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Tested-by: Gary Guo <gary@garyguo.net>
Reported-by: Gary Guo <gary@garyguo.net>
Suggested-by: Thomas Weißschuh <linux@weissschuh.net>
Fixes: 522397d05e7d ("resolve_btfids: Change in-place update with raw binary output")
Link: https://lore.kernel.org/r/20260121181617.820300-1-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 422c56dc878e93e2899895dfbd97ee324070cb3f..adcbcde16a07180b1492d5865c8c727de1d1bd0d 100644 (file)
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -43,7 +43,7 @@ quiet_cmd_btf_ko = BTF [M] $@
        if [ ! -f $(objtree)/vmlinux ]; then                            \
                printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
        else    \
-               $(srctree)/scripts/gen-btf.sh --btf_base $(objtree)/vmlinux $@; \
+               $(CONFIG_SHELL) $(srctree)/scripts/gen-btf.sh --btf_base $(objtree)/vmlinux $@; \
        fi;
 
 # Same as newer-prereqs, but allows to exclude specified extra dependencies

diff --git a/scripts/gen-btf.sh b/scripts/gen-btf.sh
index be21ccee3487cfb4184312f6259eda3d1ec443cd..8ca96eb10a69e025119c1db8f42cd97f7c16b929 100755 (executable)
--- a/scripts/gen-btf.sh
+++ b/scripts/gen-btf.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/bin/sh
 # SPDX-License-Identifier: GPL-2.0
 # Copyright (c) 2025 Meta Platforms, Inc. and affiliates.
 #
@@ -81,7 +81,7 @@ gen_btf_data()
 
 gen_btf_o()
 {
-       local btf_data=${ELF_FILE}.btf.o
+       btf_data=${ELF_FILE}.btf.o
 
        # Create ${btf_data} which contains just .BTF section but no symbols. Add
        # SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
@@ -107,11 +107,11 @@ embed_btf_data()
        ${OBJCOPY} --add-section .BTF=${ELF_FILE}.BTF ${ELF_FILE}
 
        # a module might not have a .BTF_ids or .BTF.base section
-       local btf_base="${ELF_FILE}.BTF.base"
+       btf_base="${ELF_FILE}.BTF.base"
        if [ -f "${btf_base}" ]; then
                ${OBJCOPY} --add-section .BTF.base=${btf_base} ${ELF_FILE}
        fi
-       local btf_ids="${ELF_FILE}.BTF_ids"
+       btf_ids="${ELF_FILE}.BTF_ids"
        if [ -f "${btf_ids}" ]; then
                ${RESOLVE_BTFIDS} --patch_btfids ${btf_ids} ${ELF_FILE}
        fi

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 08cd8e25c65ce73c963e7c5ff882e03efccc9d9e..16d6a048e07c68b130a602a8eff4f1c03226d95d 100755 (executable)
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -206,7 +206,7 @@ fi
 
 if is_enabled CONFIG_DEBUG_INFO_BTF; then
        info BTF .tmp_vmlinux1
-       if ! ${srctree}/scripts/gen-btf.sh .tmp_vmlinux1; then
+       if ! ${CONFIG_SHELL} ${srctree}/scripts/gen-btf.sh .tmp_vmlinux1; then
                echo >&2 "Failed to generate BTF for vmlinux"
                echo >&2 "Try to disable CONFIG_DEBUG_INFO_BTF"
                exit 1