arm64: remove no-op -p linker flag

Linking the ARM64 defconfig kernel with LLVM lld fails with the error:

  ld.lld: error: unknown argument: -p
  Makefile:1015: recipe for target 'vmlinux' failed

Without this flag, the ARM64 defconfig kernel successfully links with
lld and boots on Dragonboard 410c.

After digging through binutils source and changelogs, it turns out that
-p is only relevant to ancient binutils installations targeting 32-bit
ARM.  binutils accepts -p for AArch64 too, but it's always been
undocumented and silently ignored.  A comment in
ld/emultempl/aarch64elf.em explains that it's "Only here for backwards
compatibility".

Since this flag is a no-op on ARM64, we can safely drop it.

Acked-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Hackmann <ghackmann@google.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index 48158c550110dc307b08f32018b829943b5b5539..7976d2d242fa194b853a3c011b554fa6c979ef8e 100644 (file)
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -10,7 +10,7 @@
 #
 # Copyright (C) 1995-2001 by Russell King
 
-LDFLAGS_vmlinux        :=-p --no-undefined -X
+LDFLAGS_vmlinux        :=--no-undefined -X
 CPPFLAGS_vmlinux.lds = -DTEXT_OFFSET=$(TEXT_OFFSET)
 GZFLAGS                :=-9