diff mbox series

[bpf-next,1/2] kbuild: Unify options for BTF generation for vmlinux and modules

Message ID 20211023120452.212885-2-jolsa@kernel.org (mailing list archive)
State Changes Requested
Delegated to: BPF
Headers show
Series bpf: Fix BTF data for modules | expand

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netdev/fixes_present success Fixes tag not required for -next series
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf-next
netdev/subject_prefix success Link
netdev/cc_maintainers warning 5 maintainers not CCed: linux-kbuild@vger.kernel.org ndesaulniers@google.com michal.lkml@markovi.net kpsingh@kernel.org masahiroy@kernel.org
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 1 this patch: 1
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success No Fixes tag
netdev/checkpatch warning WARNING: From:/Signed-off-by: email address mismatch: 'From: Jiri Olsa <jolsa@redhat.com>' != 'Signed-off-by: Jiri Olsa <jolsa@kernel.org>' WARNING: added, moved or deleted file(s), does MAINTAINERS need updating?
netdev/build_allmodconfig_warn success Errors and warnings before: 1 this patch: 1
netdev/header_inline success No static functions without inline keyword in header files
bpf/vmtest-bpf-next-PR success PR summary
bpf/vmtest-bpf-next success VM_Test

Commit Message

Jiri Olsa Oct. 23, 2021, 12:04 p.m. UTC 
Using new PAHOLE_FLAGS variable to pass extra arguments to
pahole for both vmlinux and modules BTF data generation.

Adding new scripts/pahole-flags.sh script that detect and
prints pahole options.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
---
 Makefile                  |  3 +++
 scripts/Makefile.modfinal |  2 +-
 scripts/link-vmlinux.sh   | 11 +----------
 scripts/pahole-flags.sh   | 20 ++++++++++++++++++++
 4 files changed, 25 insertions(+), 11 deletions(-)
 create mode 100755 scripts/pahole-flags.sh

Comments

Andrii Nakryiko Oct. 26, 2021, 4:56 a.m. UTC | #1 
On Sat, Oct 23, 2021 at 5:05 AM Jiri Olsa <jolsa@redhat.com> wrote:
>
> Using new PAHOLE_FLAGS variable to pass extra arguments to
> pahole for both vmlinux and modules BTF data generation.
>
> Adding new scripts/pahole-flags.sh script that detect and
> prints pahole options.
>
> Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> ---

LGTM. I suggest posting it separately from the BTF dedup hack.

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  Makefile                  |  3 +++
>  scripts/Makefile.modfinal |  2 +-
>  scripts/link-vmlinux.sh   | 11 +----------
>  scripts/pahole-flags.sh   | 20 ++++++++++++++++++++
>  4 files changed, 25 insertions(+), 11 deletions(-)
>  create mode 100755 scripts/pahole-flags.sh
>

[...]
Jiri Olsa Oct. 26, 2021, 12:03 p.m. UTC | #2 
On Mon, Oct 25, 2021 at 09:56:37PM -0700, Andrii Nakryiko wrote:
> On Sat, Oct 23, 2021 at 5:05 AM Jiri Olsa <jolsa@redhat.com> wrote:
> >
> > Using new PAHOLE_FLAGS variable to pass extra arguments to
> > pahole for both vmlinux and modules BTF data generation.
> >
> > Adding new scripts/pahole-flags.sh script that detect and
> > prints pahole options.
> >
> > Signed-off-by: Jiri Olsa <jolsa@kernel.org>
> > ---
> 
> LGTM. I suggest posting it separately from the BTF dedup hack.

ok, will post today

thanks,
jirka

> 
> Acked-by: Andrii Nakryiko <andrii@kernel.org>
> 
> >  Makefile                  |  3 +++
> >  scripts/Makefile.modfinal |  2 +-
> >  scripts/link-vmlinux.sh   | 11 +----------
> >  scripts/pahole-flags.sh   | 20 ++++++++++++++++++++
> >  4 files changed, 25 insertions(+), 11 deletions(-)
> >  create mode 100755 scripts/pahole-flags.sh
> >
> 
> [...]
>
diff mbox series

Patch

diff --git a/Makefile b/Makefile
index 437ccc66a1c2..ee514b80c62e 100644
--- a/Makefile
+++ b/Makefile
@@ -480,6 +480,8 @@  LZ4		= lz4c
 XZ		= xz
 ZSTD		= zstd
 
+PAHOLE_FLAGS	= $(shell PAHOLE=$(PAHOLE) scripts/pahole-flags.sh)
+
 CHECKFLAGS     := -D__linux__ -Dlinux -D__STDC__ -Dunix -D__unix__ \
 		  -Wbitwise -Wno-return-void -Wno-unknown-attribute $(CF)
 NOSTDINC_FLAGS :=
@@ -534,6 +536,7 @@  export KBUILD_CFLAGS CFLAGS_KERNEL CFLAGS_MODULE
 export KBUILD_AFLAGS AFLAGS_KERNEL AFLAGS_MODULE
 export KBUILD_AFLAGS_MODULE KBUILD_CFLAGS_MODULE KBUILD_LDFLAGS_MODULE
 export KBUILD_AFLAGS_KERNEL KBUILD_CFLAGS_KERNEL
+export PAHOLE_FLAGS
 
 # Files to ignore in find ... statements
 
diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal
index 1fb45b011e4b..7f39599e9fae 100644
--- a/scripts/Makefile.modfinal
+++ b/scripts/Makefile.modfinal
@@ -40,7 +40,7 @@  quiet_cmd_ld_ko_o = LD [M]  $@
 quiet_cmd_btf_ko = BTF [M] $@
       cmd_btf_ko = 							\
 	if [ -f vmlinux ]; then						\
-		LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J --btf_base vmlinux $@; \
+		LLVM_OBJCOPY="$(OBJCOPY)" $(PAHOLE) -J $(PAHOLE_FLAGS) --btf_base vmlinux $@; \
 		$(RESOLVE_BTFIDS) -b vmlinux $@; 			\
 	else								\
 		printf "Skipping BTF generation for %s due to unavailability of vmlinux\n" $@ 1>&2; \
diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
index d74cee5c4326..3ea7cece7c97 100755
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -205,7 +205,6 @@  vmlinux_link()
 gen_btf()
 {
 	local pahole_ver
-	local extra_paholeopt=
 
 	if ! [ -x "$(command -v ${PAHOLE})" ]; then
 		echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
@@ -220,16 +219,8 @@  gen_btf()
 
 	vmlinux_link ${1}
 
-	if [ "${pahole_ver}" -ge "118" ] && [ "${pahole_ver}" -le "121" ]; then
-		# pahole 1.18 through 1.21 can't handle zero-sized per-CPU vars
-		extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_vars"
-	fi
-	if [ "${pahole_ver}" -ge "121" ]; then
-		extra_paholeopt="${extra_paholeopt} --btf_gen_floats"
-	fi
-
 	info "BTF" ${2}
-	LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${extra_paholeopt} ${1}
+	LLVM_OBJCOPY="${OBJCOPY}" ${PAHOLE} -J ${PAHOLE_FLAGS} ${1}
 
 	# Create ${2} which contains just .BTF section but no symbols. Add
 	# SHF_ALLOC because .BTF will be part of the vmlinux image. --strip-all
diff --git a/scripts/pahole-flags.sh b/scripts/pahole-flags.sh
new file mode 100755
index 000000000000..2b99fc77019c
--- /dev/null
+++ b/scripts/pahole-flags.sh
@@ -0,0 +1,20 @@ 
+#!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
+
+extra_paholeopt=
+
+if ! [ -x "$(command -v ${PAHOLE})" ]; then
+	return
+fi
+
+pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
+
+if [ "${pahole_ver}" -ge "118" ] && [ "${pahole_ver}" -le "121" ]; then
+	# pahole 1.18 through 1.21 can't handle zero-sized per-CPU vars
+	extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_vars"
+fi
+if [ "${pahole_ver}" -ge "121" ]; then
+	extra_paholeopt="${extra_paholeopt} --btf_gen_floats"
+fi
+
+echo ${extra_paholeopt}