arch/x86/um/vdso/Makefile

   1 # SPDX-License-Identifier: GPL-2.0
   2 #
   3 # Building vDSO images for x86.
   4 #
   5
   6 # Prevents link failures: __sanitizer_cov_trace_pc() is not linked in.
   7 KCOV_INSTRUMENT                := n
   8
   9 VDSO64-y                := y
  10
  11 vdso-install-$(VDSO64-y)        += vdso.so
  12
  13
  14 # files to link into the vdso
  15 vobjs-y := vdso-note.o um_vdso.o
  16
  17 # files to link into kernel
  18 obj-$(VDSO64-y)                 += vdso.o vma.o
  19
  20 vobjs := $(foreach F,$(vobjs-y),$(obj)/$F)
  21
  22 $(obj)/vdso.o: $(obj)/vdso.so
  23
  24 targets += vdso.so vdso.so.dbg vdso.lds $(vobjs-y)
  25
  26 export CPPFLAGS_vdso.lds += -P -C
  27
  28 VDSO_LDFLAGS_vdso.lds = -m64 -Wl,-soname=linux-vdso.so.1 \
  29        -Wl,-z,max-page-size=4096 -Wl,-z,common-page-size=4096
  30
  31 $(obj)/vdso.o: $(src)/vdso.S $(obj)/vdso.so
  32
  33 $(obj)/vdso.so.dbg: $(src)/vdso.lds $(vobjs) FORCE
  34         $(call if_changed,vdso)
  35
  36 $(obj)/%.so: OBJCOPYFLAGS := -S
  37 $(obj)/%.so: $(obj)/%.so.dbg FORCE
  38         $(call if_changed,objcopy)
  39
  40 #
  41 # Don't omit frame pointers for ease of userspace debugging, but do
  42 # optimize sibling calls.
  43 #
  44 CFL := $(PROFILING) -mcmodel=small -fPIC -O2 -fasynchronous-unwind-tables -m64 \
  45        $(filter -g%,$(KBUILD_CFLAGS)) $(call cc-option, -fno-stack-protector) \
  46        -fno-omit-frame-pointer -foptimize-sibling-calls
  47
  48 $(vobjs): KBUILD_CFLAGS += $(CFL)
  49
  50 #
  51 # vDSO code runs in userspace and -pg doesn't help with profiling anyway.
  52 #
  53 CFLAGS_REMOVE_vdso-note.o = -pg -fprofile-arcs -ftest-coverage
  54 CFLAGS_REMOVE_um_vdso.o = -pg -fprofile-arcs -ftest-coverage
  55
  56 targets += vdso-syms.lds
  57 extra-$(VDSO64-y)                       += vdso-syms.lds
  58
  59 #
  60 # Match symbols in the DSO that look like VDSO*; produce a file of constants.
  61 #
  62 sed-vdsosym := -e 's/^00*/0/' \
  63         -e 's/^\([0-9a-fA-F]*\) . \(VDSO[a-zA-Z0-9_]*\)$$/\2 = 0x\1;/p'
  64 quiet_cmd_vdsosym = VDSOSYM $@
  65 define cmd_vdsosym
  66         $(NM) $< | LC_ALL=C sed -n $(sed-vdsosym) | LC_ALL=C sort > $@
  67 endef
  68
  69 $(obj)/%-syms.lds: $(obj)/%.so.dbg FORCE
  70         $(call if_changed,vdsosym)
  71
  72 #
  73 # The DSO images are built using a special linker script.
  74 #
  75 quiet_cmd_vdso = VDSO    $@
  76       cmd_vdso = $(CC) -nostdlib -o $@ \
  77                        $(VDSO_LDFLAGS) $(VDSO_LDFLAGS_$(filter %.lds,$(^F))) \
  78                        -Wl,-T,$(filter %.lds,$^) $(filter %.o,$^) && \
  79                  sh $(srctree)/$(src)/checkundef.sh '$(NM)' '$@'
  80
  81 VDSO_LDFLAGS = -fPIC -shared $(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
  82 GCOV_PROFILE := n
  83
  84 #
  85 # Install the unstripped copy of vdso*.so listed in $(vdso-install-y).
  86 #
  87 quiet_cmd_vdso_install = INSTALL $@
  88       cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
  89 $(vdso-install-y): %.so: $(obj)/%.so.dbg FORCE
  90         @mkdir -p $(MODLIB)/vdso
  91         $(call cmd,vdso_install)
  92
  93 PHONY += vdso_install $(vdso-install-y)
  94 vdso_install: $(vdso-install-y)