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>
This commit is contained in:
Dave Martin 2019-06-06 11:33:43 +01:00 committed by Will Deacon
parent 2b55d83e9a
commit ebcc5928c5

View File

@ -51,6 +51,7 @@ endif
KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst) KBUILD_CFLAGS += -mgeneral-regs-only $(lseinstr) $(brokengasinst)
KBUILD_CFLAGS += -fno-asynchronous-unwind-tables KBUILD_CFLAGS += -fno-asynchronous-unwind-tables
KBUILD_CFLAGS += -Wno-psabi
KBUILD_AFLAGS += $(lseinstr) $(brokengasinst) KBUILD_AFLAGS += $(lseinstr) $(brokengasinst)
KBUILD_CFLAGS += $(call cc-option,-mabi=lp64) KBUILD_CFLAGS += $(call cc-option,-mabi=lp64)