On Mon, Jun 5, 2023 at 4:35 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote: > > Hi Ian, > > On Mon, Jun 5, 2023 at 1:28 PM Ian Rogers <irogers@xxxxxxxxxx> wrote: > > > > If generating vmlinux.h, make the code to generate it more tolerant by > > filtering out paths to kernels that lack a .BTF section. > > > > Signed-off-by: Ian Rogers <irogers@xxxxxxxxxx> > > --- > > tools/perf/Makefile.perf | 23 ++++++++++++++++++++--- > > 1 file changed, 20 insertions(+), 3 deletions(-) > > > > diff --git a/tools/perf/Makefile.perf b/tools/perf/Makefile.perf > > index f1840af195c0..c3bb27a912b0 100644 > > --- a/tools/perf/Makefile.perf > > +++ b/tools/perf/Makefile.perf > > @@ -193,6 +193,7 @@ FLEX ?= flex > > BISON ?= bison > > STRIP = strip > > AWK = awk > > +READELF ?= readelf > > > > # include Makefile.config by default and rule out > > # non-config cases > > @@ -1080,12 +1081,28 @@ $(BPFTOOL): | $(SKEL_TMP_OUT) > > $(Q)CFLAGS= $(MAKE) -C ../bpf/bpftool \ > > OUTPUT=$(SKEL_TMP_OUT)/ bootstrap > > > > -VMLINUX_BTF_PATHS ?= $(if $(O),$(O)/vmlinux) \ > > +# Paths to search for a kernel to generate vmlinux.h from. > > +VMLINUX_BTF_ELF_PATHS ?= $(if $(O),$(O)/vmlinux) \ > > $(if $(KBUILD_OUTPUT),$(KBUILD_OUTPUT)/vmlinux) \ > > ../../vmlinux \ > > - /sys/kernel/btf/vmlinux \ > > /boot/vmlinux-$(shell uname -r) > > -VMLINUX_BTF ?= $(abspath $(firstword $(wildcard $(VMLINUX_BTF_PATHS)))) > > + > > +# Paths to BTF information. > > +VMLINUX_BTF_BTF_PATHS ?= /sys/kernel/btf/vmlinux > > + > > +# Filter out kernels that don't exist or without a BTF section. > > +VMLINUX_BTF_ELF_ABSPATHS ?= $(abspath $(wildcard $(VMLINUX_BTF_ELF_PATHS))) > > +VMLINUX_BTF_PATHS ?= $(shell for file in $(VMLINUX_BTF_ELF_ABSPATHS); \ > > + do \ > > + if [ -f $$file ] && ($(READELF) -t "$$file" | grep .BTF); \ > > Wouldn't it be `readelf -S` instead? Also I think grep needs -q to > suppress output. Makes sense, I can change it in v3. > > + then \ > > + echo "$$file"; \ > > + fi; \ > > + done) \ > > + $(wildcard $(VMLINUX_BTF_BTF_PATHS)) > > This changes the order of processing the sysfs file. > But I'm not sure it matters much as both /boot/vmlinux and sysfs > should refer to the running kernel. Agreed. readelf fails for /sys/kernel/btf/vmlinux as it isn't an elf file and I'm not sure it is worth worrying too much about the order here. Thanks, Ian > Thanks, > Namhyung > > > > + > > +# Select the first as the source of vmlinux.h. > > +VMLINUX_BTF ?= $(firstword $(VMLINUX_BTF_PATHS)) > > > > $(SKEL_OUT)/vmlinux.h: $(VMLINUX_BTF) $(BPFTOOL) > > ifeq ($(VMLINUX_H),) > > -- > > 2.41.0.rc0.172.g3f132b7071-goog > >
