arch/riscv/kernel/vdso/Makefile

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