On Sun, Mar 09, 2025 at 09:48:36PM +0100, Nathan Chancellor wrote: > On Sun, Mar 09, 2025 at 09:31:48PM +0100, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > > > > This is a note to let you know that I've just added the patch titled > > > > kbuild: userprogs: use correct lld when linking through clang > > > > to the 6.6-stable tree which can be found at: > > http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary > > > > The filename of the patch is: > > kbuild-userprogs-use-correct-lld-when-linking-through-clang.patch > > and it can be found in the queue-6.6 subdirectory. > > > > If you, or anyone else, feels it should not be added to the stable tree, > > please let <stable@xxxxxxxxxxxxxxx> know about it. > > > > > > From dfc1b168a8c4b376fa222b27b97c2c4ad4b786e1 Mon Sep 17 00:00:00 2001 > > From: =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= <thomas.weissschuh@xxxxxxxxxxxxx> > > Date: Mon, 17 Feb 2025 08:27:54 +0100 > > Subject: kbuild: userprogs: use correct lld when linking through clang > > MIME-Version: 1.0 > > Content-Type: text/plain; charset=UTF-8 > > Content-Transfer-Encoding: 8bit > > > > From: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx> > > > > commit dfc1b168a8c4b376fa222b27b97c2c4ad4b786e1 upstream. > > > > The userprog infrastructure links objects files through $(CC). > > Either explicitly by manually calling $(CC) on multiple object files or > > implicitly by directly compiling a source file to an executable. > > The documentation at Documentation/kbuild/llvm.rst indicates that ld.lld > > would be used for linking if LLVM=1 is specified. > > However clang instead will use either a globally installed cross linker > > from $PATH called ${target}-ld or fall back to the system linker, which > > probably does not support crosslinking. > > For the normal kernel build this is not an issue because the linker is > > always executed directly, without the compiler being involved. > > > > Explicitly pass --ld-path to clang so $(LD) is respected. > > As clang 13.0.1 is required to build the kernel, this option is available. > > > > Fixes: 7f3a59db274c ("kbuild: add infrastructure to build userspace programs") > > Cc: stable@xxxxxxxxxxxxxxx # needs wrapping in $(cc-option) for < 6.9 > > Signed-off-by: Thomas Weißschuh <thomas.weissschuh@xxxxxxxxxxxxx> > > Reviewed-by: Nathan Chancellor <nathan@xxxxxxxxxx> > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > > Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> > > --- > > Makefile | 5 +++++ > > 1 file changed, 5 insertions(+) > > > > --- a/Makefile > > +++ b/Makefile > > @@ -1057,6 +1057,11 @@ endif > > KBUILD_USERCFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) > > KBUILD_USERLDFLAGS += $(filter -m32 -m64 --target=%, $(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS)) > > > > +# userspace programs are linked via the compiler, use the correct linker > > +ifeq ($(CONFIG_CC_IS_CLANG)$(CONFIG_LD_IS_LLD),yy) > > +KBUILD_USERLDFLAGS += --ld-path=$(LD) > > No objections obviously but as the note next to the stable cc mentions > above, can you make this > > $(call cc-option, --ld-path=$(LD)) > > for 6.6 and older? It is only for two clang versions but still :) I'll drop this for 6.6 and older, can you send a backport for this so I know it's correct? :) thanks, greg k-h
