[PATCH] kbuild: split the build log of kallsyms

From: Masahiro Yamada
Date: Thu Sep 24 2020 - 11:46:13 EST


Currently, the build log shows KSYM + object name.

Precisely speaking, kallsyms generates a .S file and then the compiler
compiles it into a .o file. Split the build log into two.

[Before]

GEN modules.builtin
LD .tmp_vmlinux.kallsyms1
KSYM .tmp_vmlinux.kallsyms1.o
LD .tmp_vmlinux.kallsyms2
KSYM .tmp_vmlinux.kallsyms2.o
LD vmlinux

[After]

GEN modules.builtin
LD .tmp_vmlinux.kallsyms1
KSYMS .tmp_vmlinux.kallsyms1.S
AS .tmp_vmlinux.kallsyms1.o
LD .tmp_vmlinux.kallsyms2
KSYMS .tmp_vmlinux.kallsyms2.S
AS .tmp_vmlinux.kallsyms2.o
LD vmlinux

Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---

scripts/link-vmlinux.sh | 20 ++++++++++----------
1 file changed, 10 insertions(+), 10 deletions(-)

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index e6e2d9e5ff48..d9bcf36a1583 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -169,10 +169,9 @@ gen_btf()
printf '\1' | dd of=${2} conv=notrunc bs=1 seek=16 status=none
}

-# Create ${2} .o file with all symbols from the ${1} object file
+# Create ${2} .S file with all symbols from the ${1} object file
kallsyms()
{
- info KSYM ${2}
local kallsymopt;

if [ -n "${CONFIG_KALLSYMS_ALL}" ]; then
@@ -187,13 +186,8 @@ kallsyms()
kallsymopt="${kallsymopt} --base-relative"
fi

- local aflags="${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
- ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS}"
-
- local afile="`basename ${2} .o`.S"
-
- ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${afile}
- ${CC} ${aflags} -c -o ${2} ${afile}
+ info KSYMS ${2}
+ ${NM} -n ${1} | scripts/kallsyms ${kallsymopt} > ${2}
}

# Perform one step in kallsyms generation, including temporary linking of
@@ -203,9 +197,15 @@ kallsyms_step()
kallsymso_prev=${kallsymso}
kallsyms_vmlinux=.tmp_vmlinux.kallsyms${1}
kallsymso=${kallsyms_vmlinux}.o
+ kallsyms_S=${kallsyms_vmlinux}.S

vmlinux_link ${kallsyms_vmlinux} "${kallsymso_prev}" ${btf_vmlinux_bin_o}
- kallsyms ${kallsyms_vmlinux} ${kallsymso}
+ kallsyms ${kallsyms_vmlinux} ${kallsyms_S}
+
+ info AS ${kallsyms_S}
+ ${CC} ${NOSTDINC_FLAGS} ${LINUXINCLUDE} ${KBUILD_CPPFLAGS} \
+ ${KBUILD_AFLAGS} ${KBUILD_AFLAGS_KERNEL} \
+ -c -o ${kallsymso} ${kallsyms_S}
}

# Create map file with all symbols from ${1}
--
2.25.1