summaryrefslogtreecommitdiffstats
path: root/arch/riscv/kernel/vdso/Makefile
diff options
context:
space:
mode:
Diffstat (limited to 'arch/riscv/kernel/vdso/Makefile')
-rw-r--r--arch/riscv/kernel/vdso/Makefile85
1 files changed, 85 insertions, 0 deletions
diff --git a/arch/riscv/kernel/vdso/Makefile b/arch/riscv/kernel/vdso/Makefile
new file mode 100644
index 000000000..f4ac7ff56
--- /dev/null
+++ b/arch/riscv/kernel/vdso/Makefile
@@ -0,0 +1,85 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copied from arch/tile/kernel/vdso/Makefile
+
+# Absolute relocation type $(ARCH_REL_TYPE_ABS) needs to be defined before
+# the inclusion of generic Makefile.
+ARCH_REL_TYPE_ABS := R_RISCV_32|R_RISCV_64|R_RISCV_JUMP_SLOT
+include $(srctree)/lib/vdso/Makefile
+# Symbols present in the vdso
+vdso-syms = rt_sigreturn
+ifdef CONFIG_64BIT
+vdso-syms += vgettimeofday
+endif
+vdso-syms += getcpu
+vdso-syms += flush_icache
+
+# Files to link into the vdso
+obj-vdso = $(patsubst %, %.o, $(vdso-syms)) note.o
+
+ccflags-y := -fno-stack-protector
+ccflags-y += -DDISABLE_BRANCH_PROFILING
+
+ifneq ($(c-gettimeofday-y),)
+ CFLAGS_vgettimeofday.o += -fPIC -include $(c-gettimeofday-y)
+endif
+
+# Build rules
+targets := $(obj-vdso) vdso.so vdso.so.dbg vdso.lds vdso-syms.S
+obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
+
+obj-y += vdso.o vdso-syms.o
+CPPFLAGS_vdso.lds += -P -C -U$(ARCH)
+ifneq ($(filter vgettimeofday, $(vdso-syms)),)
+CPPFLAGS_vdso.lds += -DHAS_VGETTIMEOFDAY
+endif
+
+# Disable -pg to prevent insert call site
+CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE)
+
+# Disable profiling and instrumentation for VDSO code
+GCOV_PROFILE := n
+KCOV_INSTRUMENT := n
+KASAN_SANITIZE := n
+
+# Force dependency
+$(obj)/vdso.o: $(obj)/vdso.so
+
+# link rule for the .so file, .lds has to be first
+$(obj)/vdso.so.dbg: $(obj)/vdso.lds $(obj-vdso) FORCE
+ $(call if_changed,vdsold)
+LDFLAGS_vdso.so.dbg = -shared -s -soname=linux-vdso.so.1 \
+ --build-id=sha1 --hash-style=both --eh-frame-hdr
+
+# We also create a special relocatable object that should mirror the symbol
+# table and layout of the linked DSO. With ld --just-symbols we can then
+# refer to these symbols in the kernel code rather than hand-coded addresses.
+$(obj)/vdso-syms.S: $(obj)/vdso.so FORCE
+ $(call if_changed,so2s)
+
+# strip rule for the .so file
+$(obj)/%.so: OBJCOPYFLAGS := -S
+$(obj)/%.so: $(obj)/%.so.dbg FORCE
+ $(call if_changed,objcopy)
+
+# actual build commands
+# The DSO images are built using a special linker script
+# Make sure only to export the intended __vdso_xxx symbol offsets.
+quiet_cmd_vdsold = VDSOLD $@
+ cmd_vdsold = $(LD) $(ld_flags) -T $(filter-out FORCE,$^) -o $@.tmp && \
+ $(OBJCOPY) $(patsubst %, -G __vdso_%, $(vdso-syms)) $@.tmp $@ && \
+ rm $@.tmp
+
+# Extracts symbol offsets from the VDSO, converting them into an assembly file
+# that contains the same symbols at the same offsets.
+quiet_cmd_so2s = SO2S $@
+ cmd_so2s = $(NM) -D $< | $(srctree)/$(src)/so2s.sh > $@
+
+# install commands for the unstripped file
+quiet_cmd_vdso_install = INSTALL $@
+ cmd_vdso_install = cp $(obj)/$@.dbg $(MODLIB)/vdso/$@
+
+vdso.so: $(obj)/vdso.so.dbg
+ @mkdir -p $(MODLIB)/vdso
+ $(call cmd,vdso_install)
+
+vdso_install: vdso.so