[RFC PATCH v2 4/5] kbuild: Add generic hook for architectures to use before the final vmlinux link
From: Naveen N Rao <naveen@kernel.org>
Date: 2024-06-10 08:42:32
Subsystem:
kernel build + files below scripts/ (unless maintained elsewhere), the rest · Maintainers:
Nathan Chancellor, Nicolas Schier, Linus Torvalds
On powerpc, we would like to be able to make a pass on vmlinux.o and generate a new object file to be linked into vmlinux. Add a generic pass in link-vmlinux.sh that architectures can use for this purpose. Architectures need to select CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX and must provide arch/<arch>/tools/vmlinux_o.sh, which will be invoked prior to the final vmlinux link step. Signed-off-by: Naveen N Rao <naveen@kernel.org> --- arch/Kconfig | 3 +++ scripts/link-vmlinux.sh | 18 +++++++++++++++--- 2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/arch/Kconfig b/arch/Kconfig
index 975dd22a2dbd..649f0903e7ef 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig@@ -1643,4 +1643,7 @@ config CC_HAS_SANE_FUNCTION_ALIGNMENT config ARCH_NEED_CMPXCHG_1_EMU bool +config ARCH_WANTS_PRE_LINK_VMLINUX + def_bool n + endmenu
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index 46ce5d04dbeb..07f70e105d82 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh@@ -122,7 +122,7 @@ gen_btf() return 1 fi - vmlinux_link ${1} + vmlinux_link ${1} ${arch_vmlinux_o} info "BTF" ${2} LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
@@ -178,7 +178,7 @@ kallsyms_step() kallsymso=${kallsyms_vmlinux}.o kallsyms_S=${kallsyms_vmlinux}.S - vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o} + vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o} ${arch_vmlinux_o} mksysmap ${kallsyms_vmlinux} ${kallsyms_vmlinux}.syms kallsyms ${kallsyms_vmlinux}.syms ${kallsyms_S}
@@ -203,6 +203,7 @@ sorttable() cleanup() { + rm -f .arch.vmlinux.* rm -f .btf.* rm -f System.map rm -f vmlinux
@@ -223,6 +224,17 @@ fi ${MAKE} -f "${srctree}/scripts/Makefile.build" obj=init init/version-timestamp.o +arch_vmlinux_o="" +if is_enabled CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX; then + arch_vmlinux_o=.arch.vmlinux.o + info "ARCH" ${arch_vmlinux_o} + if ! ${srctree}/arch/${SRCARCH}/tools/vmlinux_o.sh ${arch_vmlinux_o} ; then + echo >&2 "Failed to generate ${arch_vmlinux_o}" + echo >&2 "Try to disable CONFIG_ARCH_WANTS_PRE_LINK_VMLINUX" + exit 1 + fi +fi + btf_vmlinux_bin_o="" if is_enabled CONFIG_DEBUG_INFO_BTF; then btf_vmlinux_bin_o=.btf.vmlinux.bin.o
@@ -273,7 +285,7 @@ if is_enabled CONFIG_KALLSYMS; then fi fi -vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o} +vmlinux_link vmlinux "${kallsymso}" ${btf_vmlinux_bin_o} ${arch_vmlinux_o} # fill in BTF IDs if is_enabled CONFIG_DEBUG_INFO_BTF && is_enabled CONFIG_BPF; then
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2.45.2