From ebcc5928c5d925b1c8d968d9c89cdb0d0186db17 Mon Sep 17 00:00:00 2001
From: Dave Martin <Dave.Martin@arm.com>
Date: Thu, 6 Jun 2019 11:33:43 +0100
Subject: [PATCH] arm64: Silence gcc warnings about arch ABI drift

Since GCC 9, the compiler warns about evolution of the
platform-specific ABI, in particular relating for the marshaling of
certain structures involving bitfields.

The kernel is a standalone binary, and of course nobody would be
so stupid as to expose structs containing bitfields as function
arguments in ABI.  (Passing a pointer to such a struct, however
inadvisable, should be unaffected by this change.  perf and various
drivers rely on that.)

So these warnings do more harm than good: turn them off.

We may miss warnings about future ABI drift, but that's too bad.
Future ABI breaks of this class will have to be debugged and fixed
the traditional way unless the compiler evolves finer-grained
diagnostics.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
 arch/arm64/Makefile | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm64/Makefile b/arch/arm64/Makefile
index b025304bde462..8fbd583b18e1f 100644
--- a/arch/arm64/Makefile
+++ b/arch/arm64/Makefile
@@ -51,6 +51,7 @@ endif
 
 KBUILD_CFLAGS	+= -mgeneral-regs-only $(lseinstr) $(brokengasinst)
 KBUILD_CFLAGS	+= -fno-asynchronous-unwind-tables
+KBUILD_CFLAGS	+= -Wno-psabi
 KBUILD_AFLAGS	+= $(lseinstr) $(brokengasinst)
 
 KBUILD_CFLAGS	+= $(call cc-option,-mabi=lp64)
-- 
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