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. Cheers, Nathan
>From daab2c7d8578f450e6f96b72f01c85abcb46e525 Mon Sep 17 00:00:00 2001 From: Fangrui Song <maskray@xxxxxxxxxx> Date: Tue, 21 Jul 2020 10:31:23 -0700 Subject: [PATCH 4.4] Makefile: Fix GCC_TOOLCHAIN_DIR prefix for Clang cross compilation commit ca9b31f6bb9c6aa9b4e5f0792f39a97bbffb8c51 upstream. 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 $(CROSS_COMPILE)) (/usr/bin/aarch64-linux-gnu-) so that newer Clang can find the appropriate cross compiling GNU as (when -no-integrated-as is in effect). Cc: stable@xxxxxxxxxxxxxxx Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Signed-off-by: Fangrui Song <maskray@xxxxxxxxxx> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Link: https://github.com/ClangBuiltLinux/linux/issues/1099 Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx> [nc: Adjust context, CLANG_FLAGS does not exist in 4.4] Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 46178c83906c..de97963888fc 100644 --- a/Makefile +++ b/Makefile @@ -607,7 +607,7 @@ ifeq ($(cc-name),clang) ifneq ($(CROSS_COMPILE),) CLANG_TARGET := --target=$(notdir $(CROSS_COMPILE:%-=%)) GCC_TOOLCHAIN_DIR := $(dir $(shell which $(CROSS_COMPILE)elfedit)) -CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR) +CLANG_PREFIX := --prefix=$(GCC_TOOLCHAIN_DIR)$(notdir $(CROSS_COMPILE)) GCC_TOOLCHAIN := $(realpath $(GCC_TOOLCHAIN_DIR)/..) endif ifneq ($(GCC_TOOLCHAIN),) base-commit: 554bbfc0d87fcbc842a18997c2a11a772dc3f003 -- 2.28.0.rc1
