Mingzheng Xing ca09f772cc
riscv: Handle zicsr/zifencei issue between gcc and binutils
Binutils-2.38 and GCC-12.1.0 bumped[0][1] the default ISA spec to the newer
20191213 version which moves some instructions from the I extension to the
Zicsr and Zifencei extensions. So if one of the binutils and GCC exceeds
that version, we should explicitly specifying Zicsr and Zifencei via -march
to cope with the new changes. but this only occurs when binutils >= 2.36
and GCC >= 11.1.0. It's a different story when binutils < 2.36.

binutils-2.36 supports the Zifencei extension[2] and splits Zifencei and
Zicsr from I[3]. GCC-11.1.0 is particular[4] because it add support Zicsr
and Zifencei extension for -march. binutils-2.35 does not support the
Zifencei extension, and does not need to specify Zicsr and Zifencei when
working with GCC >= 12.1.0.

To make our lives easier, let's relax the check to binutils >= 2.36 in
CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI. For the other two cases,
where clang < 17 or GCC < 11.1.0, we will deal with them in
CONFIG_TOOLCHAIN_NEEDS_OLD_ISA_SPEC.

For more information, please refer to:
commit 6df2a016c0c8 ("riscv: fix build with binutils 2.38")
commit e89c2e815e76 ("riscv: Handle zicsr/zifencei issues between clang and binutils")

Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=aed44286efa8ae8717a77d94b51ac3614e2ca6dc [0]
Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=98416dbb0a62579d4a7a4a76bab51b5b52fec2cd [1]
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=5a1b31e1e1cee6e9f1c92abff59cdcfff0dddf30 [2]
Link: https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=729a53530e86972d1143553a415db34e6e01d5d2 [3]
Link: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=b03be74bad08c382da47e048007a78fa3fb4ef49 [4]
Link: https://lore.kernel.org/all/20230308220842.1231003-1-conor@kernel.org
Link: https://lore.kernel.org/all/20230223220546.52879-1-conor@kernel.org
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Acked-by: Guo Ren <guoren@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Mingzheng Xing <xingmingzheng@iscas.ac.cn>
Link: https://lore.kernel.org/r/20230809165648.21071-1-xingmingzheng@iscas.ac.cn
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-08-16 07:39:38 -07:00

89 lines
2.9 KiB
Makefile

# SPDX-License-Identifier: GPL-2.0-only
#
# Makefile for compat_vdso
#
# Symbols present in the compat_vdso
compat_vdso-syms = rt_sigreturn
compat_vdso-syms += getcpu
compat_vdso-syms += flush_icache
COMPAT_CC := $(CC)
COMPAT_LD := $(LD)
# binutils 2.35 does not support the zifencei extension, but in the ISA
# spec 20191213, G stands for IMAFD_ZICSR_ZIFENCEI.
ifdef CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
COMPAT_CC_FLAGS := -march=rv32g -mabi=ilp32
else
COMPAT_CC_FLAGS := -march=rv32imafd -mabi=ilp32
endif
COMPAT_LD_FLAGS := -melf32lriscv
# Disable attributes, as they're useless and break the build.
COMPAT_CC_FLAGS += $(call cc-option,-mno-riscv-attribute)
COMPAT_CC_FLAGS += $(call as-option,-Wa$(comma)-mno-arch-attr)
# Files to link into the compat_vdso
obj-compat_vdso = $(patsubst %, %.o, $(compat_vdso-syms)) note.o
# Build rules
targets := $(obj-compat_vdso) compat_vdso.so compat_vdso.so.dbg compat_vdso.lds
obj-compat_vdso := $(addprefix $(obj)/, $(obj-compat_vdso))
obj-y += compat_vdso.o
CPPFLAGS_compat_vdso.lds += -P -C -DCOMPAT_VDSO -U$(ARCH)
# Disable profiling and instrumentation for VDSO code
GCOV_PROFILE := n
KCOV_INSTRUMENT := n
KASAN_SANITIZE := n
UBSAN_SANITIZE := n
# Force dependency
$(obj)/compat_vdso.o: $(obj)/compat_vdso.so
# link rule for the .so file, .lds has to be first
$(obj)/compat_vdso.so.dbg: $(obj)/compat_vdso.lds $(obj-compat_vdso) FORCE
$(call if_changed,compat_vdsold)
LDFLAGS_compat_vdso.so.dbg = -shared -S -soname=linux-compat_vdso.so.1 \
--build-id=sha1 --hash-style=both --eh-frame-hdr
$(obj-compat_vdso): %.o: %.S FORCE
$(call if_changed_dep,compat_vdsoas)
# strip rule for the .so file
$(obj)/%.so: OBJCOPYFLAGS := -S
$(obj)/%.so: $(obj)/%.so.dbg FORCE
$(call if_changed,objcopy)
# Generate VDSO offsets using helper script
gen-compat_vdsosym := $(srctree)/$(src)/gen_compat_vdso_offsets.sh
quiet_cmd_compat_vdsosym = VDSOSYM $@
cmd_compat_vdsosym = $(NM) $< | $(gen-compat_vdsosym) | LC_ALL=C sort > $@
include/generated/compat_vdso-offsets.h: $(obj)/compat_vdso.so.dbg FORCE
$(call if_changed,compat_vdsosym)
# actual build commands
# The DSO images are built using a special linker script
# Make sure only to export the intended __compat_vdso_xxx symbol offsets.
quiet_cmd_compat_vdsold = VDSOLD $@
cmd_compat_vdsold = $(COMPAT_LD) $(ld_flags) $(COMPAT_LD_FLAGS) -T $(filter-out FORCE,$^) -o $@.tmp && \
$(OBJCOPY) $(patsubst %, -G __compat_vdso_%, $(compat_vdso-syms)) $@.tmp $@ && \
rm $@.tmp
# actual build commands
quiet_cmd_compat_vdsoas = VDSOAS $@
cmd_compat_vdsoas = $(COMPAT_CC) $(a_flags) $(COMPAT_CC_FLAGS) -c -o $@ $<
# install commands for the unstripped file
quiet_cmd_compat_vdso_install = INSTALL $@
cmd_compat_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/compat_vdso/$@
compat_vdso.so: $(obj)/compat_vdso.so.dbg
@mkdir -p $(MODLIB)/compat_vdso
$(call cmd,compat_vdso_install)
compat_vdso_install: compat_vdso.so