From: Vincenzo Frascino <vincenzo.frascino@arm.com>
Date: Tue, 28 Apr 2020 16:08:54 +0100
Subject: arm64: vdso: Add '-Bsymbolic' to ldflags
Git-commit: 86b8783701246a22a734824674cc3f87a5ed9f13
Patch-mainline: v5.8-rc1
References: git-fixes

Commit 28b1a824a4f44 ("arm64: vdso: Substitute gettimeofday() with C
implementation") introduced an unused 'VDSO_LDFLAGS' variable to the
vdso Makefile, suggesting that we should be passing '-Bsymbolic' to the
linker, as we do when linking the compat vDSO.

Although it's not strictly necessary to pass this flag, it would be
required if we were to add any internal references to the exported
symbols. It's also consistent with how we link the compat vdso so, since
there's no real downside from passing it, add '-Bsymbolic' to the ldflags
for the native vDSO.

Fixes: 28b1a824a4f44 ("arm64: vdso: Substitute gettimeofday() with C implementation")
Reported-by: Geoff Levand <geoff@infradead.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200428150854.33130-1-vincenzo.frascino@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
Signed-off-by: Matthias Brugger <mbrugger@suse.com>
---
 arch/arm64/kernel/vdso/Makefile | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kernel/vdso/Makefile b/arch/arm64/kernel/vdso/Makefile
index dd2514bb1511..abf61c96edbc 100644
--- a/arch/arm64/kernel/vdso/Makefile
+++ b/arch/arm64/kernel/vdso/Makefile
@@ -17,14 +17,16 @@ obj-vdso := vgettimeofday.o note.o sigreturn.o
 targets := $(obj-vdso) vdso.so vdso.so.dbg
 obj-vdso := $(addprefix $(obj)/, $(obj-vdso))
 
+# -Bsymbolic has been added for consistency with arm, the compat vDSO and
+# potential future proofing if we end up with internal calls to the exported
+# routines, as x86 does (see 6f121e548f83 ("x86, vdso: Reimplement vdso.so
+# preparation in build-time C")).
 ldflags-y := -shared -nostdlib -soname=linux-vdso.so.1 --hash-style=sysv \
-		--build-id -n -T
+		-Bsymbolic --build-id -n -T
 
 ccflags-y := -fno-common -fno-builtin -fno-stack-protector -ffixed-x18
 ccflags-y += -DDISABLE_BRANCH_PROFILING
 
-VDSO_LDFLAGS := -Bsymbolic
-
 CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os
 KBUILD_CFLAGS			+= $(DISABLE_LTO)
 KASAN_SANITIZE			:= n
-- 
2.29.2