arch/riscv/kernel/vdso/Makefile

   1 # SPDX-License-Identifier: GPL-2.0-only
   2 # Copied from arch/tile/kernel/vdso/Makefile
   3
   4 # Symbols present in the vdso
   5 vdso-syms  = rt_sigreturn
   6 ifdef CONFIG_64BIT
   7 vdso-syms += gettimeofday
   8 vdso-syms += clock_gettime
   9 vdso-syms += clock_getres
  10 endif
  11 vdso-syms += getcpu
  12 vdso-syms += flush_icache
  13
  14 # Files to link into the vdso
  15 obj-vdso = $(patsubst %, %.o, $(vdso-syms))
  16
  17 # Build rules
  18 targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-dummy.o
  19 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
  20
  21 obj-y += vdso.o vdso-syms.o
  22 CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
  23
  24 # Disable gcov profiling for VDSO code
  25 GCOV_PROFILE := n
  26
  27 # Force dependency
  28 $(obj)/vdso.o: $(obj)/vdso.so
  29
  30 # link rule for the .so file, .lds has to be first
  31 SYSCFLAGS_vdso.so.dbg = $(c_flags)
  32 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(obj-vdso) FORCE
  33         $(call if_changed,vdsold)
  34
  35 # We also create a special relocatable object that should mirror the symbol
  36 # table and layout of the linked DSO.  With ld -R we can then refer to
  37 # these symbols in the kernel code rather than hand-coded addresses.
  38
  39 SYSCFLAGS_vdso.so.dbg = -shared -s -Wl,-soname=linux-vdso.so.1 \
  40         -Wl,--build-id -Wl,--hash-style=both
  41 $(obj)/vdso-dummy.o: $(src)/vdso.lds $(obj)/rt_sigreturn.o FORCE
  42         $(call if_changed,vdsold)
  43
  44 LDFLAGS_vdso-syms.o := -r -R
  45 $(obj)/vdso-syms.o: $(obj)/vdso-dummy.o FORCE
  46         $(call if_changed,ld)
  47
  48 # strip rule for the .so file
  49 $(obj)/%.so: OBJCOPYFLAGS := -S
  50 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  51         $(call if_changed,objcopy)
  52
  53 # actual build commands
  54 # The DSO images are built using a special linker script
  55 # Add -lgcc so rv32 gets static muldi3 and lshrdi3 definitions.
  56 # Make sure only to export the intended __vdso_xxx symbol offsets.
  57 quiet_cmd_vdsold = VDSOLD  $@
  58       cmd_vdsold = $(CC) $(KBUILD_CFLAGS) $(call cc-option, -no-pie) -nostdlib -nostartfiles $(SYSCFLAGS_$(@F)) \
  59                            -Wl,-T,$(filter-out FORCE,$^) -o $@.tmp && \
  60                    $(CROSS_COMPILE)objcopy \
  61                            $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
  62                    rm $@.tmp
  63
  64 # install commands for the unstripped file
  65 quiet_cmd_vdso_install = INSTALL $@
  66       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
  67
  68 vdso.so: $(obj)/vdso.so.dbg
  69         @mkdir -p $(MODLIB)/vdso
  70         $(call cmd,vdso_install)
  71
  72 vdso_install: vdso.so