On Mon, Jul 27, 2020 at 09:05:59AM -0700, Nathan Chancellor wrote: > On Mon, Jul 27, 2020 at 03:07:57PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote: > > > > The patch below does not apply to the 4.4-stable tree. > > If someone wants it applied there, or to any other stable or longterm > > tree, then please email the backport, including the original git commit > > id to <stable@xxxxxxxxxxxxxxx>. > > > > thanks, > > > > greg k-h > > > > ------------------ original commit in Linus's tree ------------------ > > > > From ca9b31f6bb9c6aa9b4e5f0792f39a97bbffb8c51 Mon Sep 17 00:00:00 2001 > > From: Fangrui Song <maskray@xxxxxxxxxx> > > Date: Tue, 21 Jul 2020 10:31:23 -0700 > > Subject: [PATCH] Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross > > compilation > > > > When CROSS_COMPILE is set (e.g. aarch64-linux-gnu-), if > > $(CROSS_COMPILE)elfedit is found at /usr/bin/aarch64-linux-gnu-elfedit, > > GCC_TOOLCHAIN_DIR will be set to /usr/bin/. --prefix= will be set to > > /usr/bin/ and Clang as of 11 will search for both > > $(prefix)aarch64-linux-gnu-$needle and $(prefix)$needle. > > > > GCC searchs for $(prefix)aarch64-linux-gnu/$version/$needle, > > $(prefix)aarch64-linux-gnu/$needle and $(prefix)$needle. In practice, > > $(prefix)aarch64-linux-gnu/$needle rarely contains executables. > > > > To better model how GCC's -B/--prefix takes in effect in practice, newer > > Clang (since > > https://github.com/llvm/llvm-project/commit/3452a0d8c17f7166f479706b293caf6ac76ffd90) > > only searches for $(prefix)$needle. Currently it will find /usr/bin/as > > instead of /usr/bin/aarch64-linux-gnu-as. > > > > Set --prefix= to $(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE)) > > (/usr/bin/aarch64-linux-gnu-) so that newer Clang can find the > > appropriate cross compiling GNU as (when -no-integrated-as is in > > effect). > > > > Cc: stable@xxxxxxxxxxxxxxx > > Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > > Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx> > > Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > > Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> > > Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Link: https://github.com/ClangBuiltLinux/linux/issues/1099 > > Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> > > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> > > > > diff --git a/Makefile b/Makefile > > index 676f1cfb1d56..9d9d4166c0be 100644 > > --- a/Makefile > > +++ b/Makefile > > @@ -567,7 +567,7 @@ ifneq ($(shell $(CC) --version 2>&1 | head -n 1 | grep clang),) > > ifneq ($(CROSS_COMPILE),) > > CLANG_FLAGS += --target=$(notdir $(CROSS_COMPILE:%-=%)) > > GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit)) > > -CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR) > > +CLANG_FLAGS += --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE)) > > GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) > > endif > > ifneq ($(GCC_TOOLCHAIN),) > > > > Patch attached. Now queued up, thanks! greg k-h
