arch/riscv/kernel/compat_vdso/Makefile

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 #
   3 # Makefile for compat_vdso
   4 #
   5
   6 # Symbols present in the compat_vdso
   7 compat_vdso-syms  = rt_sigreturn
   8 compat_vdso-syms += getcpu
   9 compat_vdso-syms += flush_icache
  10
  11 COMPAT_CC := $(CC)
  12 COMPAT_LD := $(LD)
  13
  14 # binutils 2.35 does not support the zifencei extension, but in the ISA
  15 # spec 20191213, G stands for IMAFD_ZICSR_ZIFENCEI.
  16 ifdef CONFIG_TOOLCHAIN_NEEDS_EXPLICIT_ZICSR_ZIFENCEI
  17         COMPAT_CC_FLAGS := -march=rv32g -mabi=ilp32
  18 else
  19         COMPAT_CC_FLAGS := -march=rv32imafd -mabi=ilp32
  20 endif
  21 COMPAT_LD_FLAGS := -melf32lriscv
  22
  23 # Disable attributes, as they're useless and break the build.
  24 COMPAT_CC_FLAGS += $(call cc-option,-mno-riscv-attribute)
  25 COMPAT_CC_FLAGS += $(call as-option,-Wa$(comma)-mno-arch-attr)
  26
  27 # Files to link into the compat_vdso
  28 obj-compat_vdso = $(patsubst %, %.o, $(compat_vdso-syms)) note.o
  29
  30 # Build rules
  31 targets := $(obj-compat_vdso) compat_vdso.so compat_vdso.so.dbg compat_vdso.lds
  32 obj-compat_vdso := $(addprefix $(obj)/, $(obj-compat_vdso))
  33
  34 obj-y += compat_vdso.o
  35 CPPFLAGS_compat_vdso.lds += -P -C -DCOMPAT_VDSO -U$(ARCH)
  36
  37 # Force dependency
  38 $(obj)/compat_vdso.o: $(obj)/compat_vdso.so
  39
  40 # link rule for the .so file, .lds has to be first
  41 $(obj)/compat_vdso.so.dbg: $(obj)/compat_vdso.lds $(obj-compat_vdso) FORCE
  42         $(call if_changed,compat_vdsold)
  43 LDFLAGS_compat_vdso.so.dbg = -shared -S -soname=linux-compat_vdso.so.1 \
  44         --build-id=sha1 --hash-style=both --eh-frame-hdr
  45
  46 $(obj-compat_vdso): %.o: %.S FORCE
  47         $(call if_changed_dep,compat_vdsoas)
  48
  49 # strip rule for the .so file
  50 $(obj)/%.so: OBJCOPYFLAGS := -S
  51 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  52         $(call if_changed,objcopy)
  53
  54 # Generate VDSO offsets using helper script
  55 gen-compat_vdsosym := $(src)/gen_compat_vdso_offsets.sh
  56 quiet_cmd_compat_vdsosym = VDSOSYM $@
  57         cmd_compat_vdsosym = $(NM) $< | $(gen-compat_vdsosym) | LC_ALL=C sort > $@
  58
  59 include/generated/compat_vdso-offsets.h: $(obj)/compat_vdso.so.dbg FORCE
  60         $(call if_changed,compat_vdsosym)
  61
  62 # actual build commands
  63 # The DSO images are built using a special linker script
  64 # Make sure only to export the intended __compat_vdso_xxx symbol offsets.
  65 quiet_cmd_compat_vdsold = VDSOLD  $@
  66       cmd_compat_vdsold = $(COMPAT_LD) $(ld_flags) $(COMPAT_LD_FLAGS) -T $(filter-out FORCE,$^) -o $@.tmp && \
  67                    $(OBJCOPY) $(patsubst %, -G __compat_vdso_%, $(compat_vdso-syms)) $@.tmp $@ && \
  68                    rm $@.tmp
  69
  70 # actual build commands
  71 quiet_cmd_compat_vdsoas = VDSOAS  $@
  72       cmd_compat_vdsoas = $(COMPAT_CC) $(a_flags) $(COMPAT_CC_FLAGS) -c -o $@ $<