From 497649b03d28e429690b1b3c0eb6f1cde620ef7d Mon Sep 17 00:00:00 2001

From: Song Liu <song@kernel.org>

Date: Tue, 28 Jan 2025 17:13:31 -0800

Subject: [PATCH 118/118] kpatch-build: lto: sed logic for --lto-obj-path in

 newer kernel

In newer kernel, the thinlto-cache-dir line is removed from Makefile.

Therefore, we cannot use it to add theh --lto-obj-path option. Use

a different sed logic for newer kernel.

Signed-off-by: Song Liu <song@kernel.org>

---

 kpatch-build/kpatch-build | 8 +++++++-

 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/kpatch-build/kpatch-build b/kpatch-build/kpatch-build

index c284d77..a14fd48 100755

--- a/kpatch-build/kpatch-build

+++ b/kpatch-build/kpatch-build

@@ -1244,7 +1244,13 @@ if [[ -n "$CONFIG_LTO_CLANG" ]]; then

 	# update Makefile so that ld.lld generate vmlinux.o.thinlto.o* files for vmlinux.o

 	backup_kernel_file "Makefile"

-	sed -i "s/--thinlto-cache-dir=\$(extmod_prefix).thinlto-cache/--lto-obj-path=vmlinux.o.thinlto.o/g" "$KERNEL_SRCDIR"/Makefile

+	# For older kernel (<=v6.9.4), replace the --thinlto-cache-dir line with --lto-obj-path=...

+	# For newer kernel (>=v6.9.5), add the --lto-obj-path=... line after CONFIG_LTO_CLANG_THIN

+	if grep -q thinlto-cache-dir "$KERNEL_SRCDIR"/Makefile ; then

+		sed -i "s/--thinlto-cache-dir=\$(extmod_prefix).thinlto-cache/--lto-obj-path=vmlinux.o.thinlto.o/g" "$KERNEL_SRCDIR"/Makefile

+	else

+		sed -i "/CONFIG_LTO_CLANG_THIN/a KBUILD_LDFLAGS += --lto-obj-path=vmlinux.o.thinlto.o" "$KERNEL_SRCDIR"/Makefile

+	fi

 	# update scripts/Makefile.build so that ld.lld generate XX.o.thinlto.o* files for modules

 	backup_kernel_file "scripts/Makefile.build"

-- 

2.48.1