arch/x86/um/vdso/Makefile

   1 #
   2 # Building vDSO images for x86.
   3 #
   4
   5 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
   6 KCOV_INSTRUMENT                := n
   7
   8 VDSO64-y                := y
   9
  10 vdso-install-$(VDSO64-y)        += vdso.so
  11
  12
  13 # files to link into the vdso
  14 vobjs-y := vdso-note.o um_vdso.o
  15
  16 # files to link into kernel
  17 obj-$(VDSO64-y)                 += vdso.o vma.o
  18
  19 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  20
  21 $(obj)/vdso.o: $(obj)/vdso.so
  22
  23 targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
  24
  25 export CPPFLAGS_vdso.lds += -P -C
  26
  27 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  28        -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
  29
  30 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  31
  32 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  33         $(call if_changed,vdso)
  34
  35 $(obj)/%.so: OBJCOPYFLAGS := -S
  36 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  37         $(call if_changed,objcopy)
  38
  39 #
  40 # Don't omit frame pointers for ease of userspace debugging, but do
  41 # optimize sibling calls.
  42 #
  43 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  44        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  45        -fno-omit-frame-pointer -foptimize-sibling-calls
  46
  47 $(vobjs): KBUILD_CFLAGS += $(CFL)
  48
  49 #
  50 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  51 #
  52 CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage
  53 CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage
  54
  55 targets += vdso-syms.lds
  56 obj-$(VDSO64-y)                 += vdso-syms.lds
  57
  58 #
  59 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  60 #
  61 sed-vdsosym := -e 's/^00*/0/' \
  62         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  63 quiet_cmd_vdsosym = VDSOSYM $@
  64 define cmd_vdsosym
  65         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  66 endef
  67
  68 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  69         $(call if_changed,vdsosym)
  70
  71 #
  72 # The DSO images are built using a special linker script.
  73 #
  74 quiet_cmd_vdso = VDSO    $@
  75       cmd_vdso = $(CC) -nostdlib -o $@ \
  76                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
  77                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
  78                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
  79
  80 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
  81 GCOV_PROFILE := n
  82
  83 #
  84 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
  85 #
  86 quiet_cmd_vdso_install = INSTALL $@
  87       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
  88 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
  89         @mkdir -p $(MODLIB)/vdso
  90         $(call cmd,vdso_install)
  91
  92 PHONY += vdso_install $(vdso-install-y)
  93 vdso_install: $(vdso-install-y)