[PATCH 28/28] arm64a/ilp32:vdso: Rewrite gettimeofday into C.

[Yury Norov]

Signed-off-by: Yury Norov <ynorov@xxxxxxxxxxxxxxxxxx>
---
 arch/arm64/kernel/vdso-ilp32/Makefile | 20 +++++++++++++++++---
 arch/arm64/kernel/vdso/gettimeofday.c |  9 ++++++++-
 2 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/arch/arm64/kernel/vdso-ilp32/Makefile b/arch/arm64/kernel/vdso-ilp32/Makefile
index 0671e88ce860..ecf62e7d1c8b 100644
--- a/arch/arm64/kernel/vdso-ilp32/Makefile
+++ b/arch/arm64/kernel/vdso-ilp32/Makefile
@@ -11,10 +11,22 @@ obj-ilp32-vdso := gettimeofday-ilp32.o note-ilp32.o sigreturn-ilp32.o
 targets := $(obj-ilp32-vdso) vdso-ilp32.so vdso-ilp32.so.dbg
 obj-ilp32-vdso := $(addprefix $(obj)/, $(obj-ilp32-vdso))
 
-ccflags-y := -shared -fno-common -fno-builtin
+ccflags-y := -shared -fno-common -fno-builtin -fno-stack-protector
+ccflags-y += -DDISABLE_BRANCH_PROFILING
 ccflags-y += -nostdlib -Wl,-soname=linux-ilp32-vdso.so.1 \
 		$(call cc-ldoption, -Wl$(comma)--hash-style=sysv)
 
+# Force -O2 to avoid libgcc dependencies
+CFLAGS_REMOVE_gettimeofday-ilp32.o = -pg -Os
+CFLAGS_gettimeofday-ilp32.o = -O2 -mcmodel=tiny -mabi=ilp32
+
+# Disable gcov profiling for VDSO code
+GCOV_PROFILE := n
+
+# Workaround for bare-metal (ELF) toolchains that neglect to pass -shared
+# down to collect2, resulting in silent corruption of the vDSO image.
+ccflags-y += -Wl,-shared
+
 obj-y += vdso-ilp32.o
 extra-y += vdso-ilp32.lds vdso-ilp32-offsets.h
 CPPFLAGS_vdso-ilp32.lds += -P -C -U$(ARCH) -mabi=ilp32
@@ -46,8 +58,8 @@ $(obj)/vdso-ilp32-offsets.h: $(obj)/vdso-ilp32.so.dbg FORCE
 #$(obj-ilp32-vdso): %.o: $(src)/../vdso/$(subst -ilp32,,%.S)
 #	$(call if_changed_dep,vdso-ilp32as)
 
-$(obj)/gettimeofday-ilp32.o: $(src)/../vdso/gettimeofday.S
-	$(call if_changed_dep,vdso-ilp32as)
+$(obj)/gettimeofday-ilp32.o: $(src)/../vdso/gettimeofday.c
+	$(call if_changed_dep,vdso-ilp32cc)
 
 $(obj)/note-ilp32.o: $(src)/../vdso/note.S
 	$(call if_changed_dep,vdso-ilp32as)
@@ -60,6 +72,8 @@ $(obj)/sigreturn-ilp32.o: $(src)/../vdso/sigreturn.S
 # Actual build commands
 quiet_cmd_vdso-ilp32ld = VDSOILP32L $@
       cmd_vdso-ilp32ld = $(CC) $(c_flags) -mabi=ilp32  -Wl,-n -Wl,-T $^ -o $@
+quiet_cmd_vdso-ilp32as = VDSOILP32C $@
+      cmd_vdso-ilp32cc= $(CC) $(c_flags) -mabi=ilp32 -c -o $@ $<
 quiet_cmd_vdso-ilp32as = VDSOILP32A $@
       cmd_vdso-ilp32as = $(CC) $(a_flags) -mabi=ilp32 -c -o $@ $<
 
diff --git a/arch/arm64/kernel/vdso/gettimeofday.c b/arch/arm64/kernel/vdso/gettimeofday.c
index a0ab8b1bd53e..0c4a00b58963 100644
--- a/arch/arm64/kernel/vdso/gettimeofday.c
+++ b/arch/arm64/kernel/vdso/gettimeofday.c
@@ -26,8 +26,15 @@
 #include <linux/math64.h>
 #include <linux/time.h>
 #include <linux/kernel.h>
+
+#ifdef __ILP32__
+#undef BITS_PER_LONG
+#define BITS_PER_LONG 32
+#endif
+
 #include <linux/hrtimer.h>
 
+
 extern struct vdso_data _vdso_data;
 
 static notrace int gettimeofday_fallback(struct timeval *_tv,
@@ -122,7 +129,7 @@ static notrace u64 get_clock_shifted_nsec(u64 cycle_last, u64 mult)
 
 	res = res - cycle_last;
 	/* We can only guarantee 56 bits of precision. */
-	res &= ~(0xff00ul<<48);
+	res &= ~(0xff00ull<<48);
 	return res * mult;
 }
 
-- 
2.11.0