| Message ID | 20210512065201.35268-2-masahiroy@kernel.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | None | expand |
On Tue, May 11, 2021 at 11:52 PM Masahiro Yamada <masahiroy@kernel.org> wrote: > > I do not see a good reason why only the libelf development package must > be so carefully checked. > > Kbuild generally does not check host tools or libraries. > > For example, x86_64 defconfig fails to build with no libssl development > package installed. > > scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory > 21 | #include <openssl/bio.h> > | ^~~~~~~~~~~~~~~ > > To solve the build error, you need to install libssl-dev or openssl-devel > package, depending on your distribution. > > 'apt-file search', 'dnf provides', etc. is your frined to find a proper > package to install. > > This commit removes all the libelf checks from the top Makefile. > > If libelf is missing, objtool will fail to build in a similar pattern: > > .../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory > 10 | #include <gelf.h> > > You need to install libelf-dev, libelf-devel, or elfutils-libelf-devel > to proceed. > > Another remarkable change is, CONFIG_STACK_VALIDATION (without > CONFIG_UNWINDER_ORC) previously continued to build with a warning, > but now it will treat missing libelf as an error. > > This is just a one-time installation, so it should not matter to break > a build and make a user install the package. > > BTW, the traditional way to handle such checks is autotool, but according > to [1], I do not expect the kernel build would have similar scripting > like './configure' does. > > [1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/ > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> > --- > resolve_btfids part looks good to me: Acked-by: Andrii Nakryiko <andrii@kernel.org> > Makefile | 78 +++++++++++---------------------------- > scripts/Makefile.build | 2 - > scripts/Makefile.modfinal | 2 - > 3 files changed, 22 insertions(+), 60 deletions(-) > [...]
(+CC: Josh, Peter) On Thu, May 13, 2021 at 4:36 AM Andrii Nakryiko <andrii.nakryiko@gmail.com> wrote: > > On Tue, May 11, 2021 at 11:52 PM Masahiro Yamada <masahiroy@kernel.org> wrote: > > > > I do not see a good reason why only the libelf development package must > > be so carefully checked. > > > > Kbuild generally does not check host tools or libraries. > > > > For example, x86_64 defconfig fails to build with no libssl development > > package installed. > > > > scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory > > 21 | #include <openssl/bio.h> > > | ^~~~~~~~~~~~~~~ > > > > To solve the build error, you need to install libssl-dev or openssl-devel > > package, depending on your distribution. > > > > 'apt-file search', 'dnf provides', etc. is your frined to find a proper > > package to install. > > > > This commit removes all the libelf checks from the top Makefile. > > > > If libelf is missing, objtool will fail to build in a similar pattern: > > > > .../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory > > 10 | #include <gelf.h> > > > > You need to install libelf-dev, libelf-devel, or elfutils-libelf-devel > > to proceed. > > > > Another remarkable change is, CONFIG_STACK_VALIDATION (without > > CONFIG_UNWINDER_ORC) previously continued to build with a warning, > > but now it will treat missing libelf as an error. > > > > This is just a one-time installation, so it should not matter to break > > a build and make a user install the package. > > > > BTW, the traditional way to handle such checks is autotool, but according > > to [1], I do not expect the kernel build would have similar scripting > > like './configure' does. > > > > [1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/ > > > > Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> > > --- > > > > resolve_btfids part looks good to me: > > Acked-by: Andrii Nakryiko <andrii@kernel.org> > > > Makefile | 78 +++++++++++---------------------------- > > scripts/Makefile.build | 2 - > > scripts/Makefile.modfinal | 2 - > > 3 files changed, 22 insertions(+), 60 deletions(-) > > > > [...]
diff --git a/Makefile b/Makefile index d60dc028f09c..bfbb7c8cbb0f 100644 --- a/Makefile +++ b/Makefile @@ -1081,41 +1081,6 @@ export INSTALL_DTBS_PATH ?= $(INSTALL_PATH)/dtbs/$(KERNELRELEASE) MODLIB = $(INSTALL_MOD_PATH)/lib/modules/$(KERNELRELEASE) export MODLIB -HOST_LIBELF_LIBS = $(shell pkg-config libelf --libs 2>/dev/null || echo -lelf) - -has_libelf = $(call try-run,\ - echo "int main() {}" | $(HOSTCC) $(KBUILD_HOSTLDFLAGS) -xc -o /dev/null $(HOST_LIBELF_LIBS) -,1,0) - -ifdef CONFIG_STACK_VALIDATION - ifeq ($(has_libelf),1) - objtool_target := tools/objtool FORCE - else - SKIP_STACK_VALIDATION := 1 - export SKIP_STACK_VALIDATION - endif -endif - -PHONY += resolve_btfids_clean - -resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids - -# tools/bpf/resolve_btfids directory might not exist -# in output directory, skip its clean in that case -resolve_btfids_clean: -ifneq ($(wildcard $(resolve_btfids_O)),) - $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean -endif - -ifdef CONFIG_BPF -ifdef CONFIG_DEBUG_INFO_BTF - ifeq ($(has_libelf),1) - resolve_btfids_target := tools/bpf/resolve_btfids FORCE - else - ERROR_RESOLVE_BTFIDS := 1 - endif -endif # CONFIG_DEBUG_INFO_BTF -endif # CONFIG_BPF - PHONY += prepare0 export extmod_prefix = $(if $(KBUILD_EXTMOD),$(KBUILD_EXTMOD)/) @@ -1227,7 +1192,7 @@ prepare0: archprepare $(Q)$(MAKE) $(build)=. # All the preparing.. -prepare: prepare0 prepare-objtool prepare-resolve_btfids +prepare: prepare0 PHONY += remove-stale-files remove-stale-files: @@ -1244,26 +1209,6 @@ uapi-asm-generic: $(Q)$(MAKE) $(asm-generic)=arch/$(SRCARCH)/include/generated/uapi/asm \ generic=include/uapi/asm-generic -PHONY += prepare-objtool prepare-resolve_btfids -prepare-objtool: $(objtool_target) -ifeq ($(SKIP_STACK_VALIDATION),1) -ifdef CONFIG_FTRACE_MCOUNT_USE_OBJTOOL - @echo "error: Cannot generate __mcount_loc for CONFIG_DYNAMIC_FTRACE=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -endif -ifdef CONFIG_UNWINDER_ORC - @echo "error: Cannot generate ORC metadata for CONFIG_UNWINDER_ORC=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -else - @echo "warning: Cannot use CONFIG_STACK_VALIDATION=y, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 -endif -endif - -prepare-resolve_btfids: $(resolve_btfids_target) -ifeq ($(ERROR_RESOLVE_BTFIDS),1) - @echo "error: Cannot resolve BTF IDs for CONFIG_DEBUG_INFO_BTF, please install libelf-dev, libelf-devel or elfutils-libelf-devel" >&2 - @false -endif # Generate some files # --------------------------------------------------------------------------- @@ -1354,6 +1299,27 @@ scripts_unifdef: scripts_basic # --------------------------------------------------------------------------- # Tools +ifdef CONFIG_STACK_VALIDATION +prepare: tools/objtool +endif + +ifdef CONFIG_BPF +ifdef CONFIG_DEBUG_INFO_BTF +prepare: tools/bpf/resolve_btfids +endif +endif + +PHONY += resolve_btfids_clean + +resolve_btfids_O = $(abspath $(objtree))/tools/bpf/resolve_btfids + +# tools/bpf/resolve_btfids directory might not exist +# in output directory, skip its clean in that case +resolve_btfids_clean: +ifneq ($(wildcard $(resolve_btfids_O)),) + $(Q)$(MAKE) -sC $(srctree)/tools/bpf/resolve_btfids O=$(resolve_btfids_O) clean +endif + # Clear a bunch of variables before executing the submake ifeq ($(quiet),silent_) tools_silent=s diff --git a/scripts/Makefile.build b/scripts/Makefile.build index 949f723efe53..7adc3a2c3c31 100644 --- a/scripts/Makefile.build +++ b/scripts/Makefile.build @@ -219,7 +219,6 @@ endif # CONFIG_FTRACE_MCOUNT_USE_RECORDMCOUNT ifdef CONFIG_STACK_VALIDATION ifndef CONFIG_LTO_CLANG -ifneq ($(SKIP_STACK_VALIDATION),1) __objtool_obj := $(objtree)/tools/objtool/objtool @@ -233,7 +232,6 @@ objtool_obj = $(if $(patsubst y%,, \ $(OBJECT_FILES_NON_STANDARD_$(basetarget).o)$(OBJECT_FILES_NON_STANDARD)n), \ $(__objtool_obj)) -endif # SKIP_STACK_VALIDATION endif # CONFIG_LTO_CLANG endif # CONFIG_STACK_VALIDATION diff --git a/scripts/Makefile.modfinal b/scripts/Makefile.modfinal index dd87cea9fba7..bdee3babc5cf 100644 --- a/scripts/Makefile.modfinal +++ b/scripts/Makefile.modfinal @@ -39,12 +39,10 @@ prelink-ext := .lto # so let's now process the prelinked binary before we link the module. ifdef CONFIG_STACK_VALIDATION -ifneq ($(SKIP_STACK_VALIDATION),1) cmd_ld_ko_o += \ $(objtree)/tools/objtool/objtool $(objtool_args) \ $(@:.ko=$(prelink-ext).o); -endif # SKIP_STACK_VALIDATION endif # CONFIG_STACK_VALIDATION endif # CONFIG_LTO_CLANG
I do not see a good reason why only the libelf development package must be so carefully checked. Kbuild generally does not check host tools or libraries. For example, x86_64 defconfig fails to build with no libssl development package installed. scripts/extract-cert.c:21:10: fatal error: openssl/bio.h: No such file or directory 21 | #include <openssl/bio.h> | ^~~~~~~~~~~~~~~ To solve the build error, you need to install libssl-dev or openssl-devel package, depending on your distribution. 'apt-file search', 'dnf provides', etc. is your frined to find a proper package to install. This commit removes all the libelf checks from the top Makefile. If libelf is missing, objtool will fail to build in a similar pattern: .../linux/tools/objtool/include/objtool/elf.h:10:10: fatal error: gelf.h: No such file or directory 10 | #include <gelf.h> You need to install libelf-dev, libelf-devel, or elfutils-libelf-devel to proceed. Another remarkable change is, CONFIG_STACK_VALIDATION (without CONFIG_UNWINDER_ORC) previously continued to build with a warning, but now it will treat missing libelf as an error. This is just a one-time installation, so it should not matter to break a build and make a user install the package. BTW, the traditional way to handle such checks is autotool, but according to [1], I do not expect the kernel build would have similar scripting like './configure' does. [1]: https://lore.kernel.org/lkml/CA+55aFzr2HTZVOuzpHYDwmtRJLsVzE-yqg2DHpHi_9ePsYp5ug@mail.gmail.com/ Signed-off-by: Masahiro Yamada <masahiroy@kernel.org> --- Makefile | 78 +++++++++++---------------------------- scripts/Makefile.build | 2 - scripts/Makefile.modfinal | 2 - 3 files changed, 22 insertions(+), 60 deletions(-)