arch/riscv/kernel/vdso/Makefile

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 # Copied from arch/tile/kernel/vdso/Makefile
   3
   4 # Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
   5 # the inclusion of generic Makefile.
   6 ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
   7 include $(srctree)/lib/vdso/Makefile
   8 # Symbols present in the vdso
   9 vdso-syms  = rt_sigreturn
  10 ifdef CONFIG_64BIT
  11 vdso-syms += vgettimeofday
  12 endif
  13 vdso-syms += getcpu
  14 vdso-syms += flush_icache
  15
  16 # Files to link into the vdso
  17 obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
  18
  19 ccflags-y := -fno-stack-protector
  20
  21 ifneq ($(c-gettimeofday-y),)
  22   CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
  23 endif
  24
  25 # Build rules
  26 targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
  27 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
  28
  29 obj-y += vdso.o vdso-syms.o
  30 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
  31
  32 # Disable -pg to prevent insert call site
  33 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
  34
  35 # Disable profiling and instrumentation for VDSO code
  36 GCOV_PROFILE := n
  37 KCOV_INSTRUMENT := n
  38 KASAN_SANITIZE := n
  39
  40 # Force dependency
  41 $(obj)/vdso.o: $(obj)/vdso.so
  42
  43 # link rule for the .so file, .lds has to be first
  44 SYSCFLAGS_vdso.so.dbg = $(c_flags)
  45 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
  46         $(call if_changed,vdsold)
  47 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
  48         -Wl,--build-id=sha1 -Wl,--hash-style=both
  49
  50 # We also create a special relocatable object that should mirror the symbol
  51 # table and layout of the linked DSO. With ld --just-symbols we can then
  52 # refer to these symbols in the kernel code rather than hand-coded addresses.
  53 $(obj)/vdso-syms.S: $(obj)/vdso.so FORCE
  54         $(call if_changed,so2s)
  55
  56 # strip rule for the .so file
  57 $(obj)/%.so: OBJCOPYFLAGS := -S
  58 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  59         $(call if_changed,objcopy)
  60
  61 # actual build commands
  62 # The DSO images are built using a special linker script
  63 # Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
  64 # Make sure only to export the intended __vdso_xxx symbol offsets.
  65 quiet_cmd_vdsold = VDSOLD  $@
  66       cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
  67                            -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
  68                    $(CROSS_COMPILE)objcopy \
  69                            $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
  70                    rm $@.tmp
  71
  72 # Extracts symbol offsets from the VDSO, converting them into an assembly file
  73 # that contains the same symbols at the same offsets.
  74 quiet_cmd_so2s = SO2S    $@
  75       cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@
  76
  77 # install commands for the unstripped file
  78 quiet_cmd_vdso_install = INSTALL $@
  79       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
  80
  81 vdso.so: $(obj)/vdso.so.dbg
  82         @mkdir -p $(MODLIB)/vdso
  83         $(call cmd,vdso_install)
  84
  85 vdso_install: vdso.so