FAILED: patch "[PATCH] powerpc: Avoid clang warnings around setjmp and longjmp" failed to apply to 5.4-stable tree - Linux-stable-mirror

15 Dec 2019

The patch below does not apply to the 5.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
...
From c9029ef9c95765e7b63c4d9aa780674447db1ec0 Mon Sep 17 00:00:00 2001
From: Nathan Chancellor natechancellor@gmail.com
Date: Mon, 18 Nov 2019 21:57:11 -0700
Subject: [PATCH] powerpc: Avoid clang warnings around setjmp and longjmp
Commit aea447141c7e ("powerpc: Disable -Wbuiltin-requires-header when
setjmp is used") disabled -Wbuiltin-requires-header because of a
warning about the setjmp and longjmp declarations.
r367387 in clang added another diagnostic around this, complaining
that there is no jmp_buf declaration.
In file included from ../arch/powerpc/xmon/xmon.c:47:
  ../arch/powerpc/include/asm/setjmp.h:10:13: error: declaration of
  built-in function 'setjmp' requires the declaration of the 'jmp_buf'
  type, commonly provided in the header <setjmp.h>.
  [-Werror,-Wincomplete-setjmp-declaration]
  extern long setjmp(long *);
              ^
  ../arch/powerpc/include/asm/setjmp.h:11:13: error: declaration of
  built-in function 'longjmp' requires the declaration of the 'jmp_buf'
  type, commonly provided in the header <setjmp.h>.
  [-Werror,-Wincomplete-setjmp-declaration]
  extern void longjmp(long *, long);
              ^
  2 errors generated.
We are not using the standard library's longjmp/setjmp implementations
for obvious reasons; make this clear to clang by using -ffreestanding
on these files.
Cc: stable@vger.kernel.org # 4.14+
Suggested-by: Segher Boessenkool segher@kernel.crashing.org
Reviewed-by: Nick Desaulniers ndesaulniers@google.com
Signed-off-by: Nathan Chancellor natechancellor@gmail.com
Signed-off-by: Michael Ellerman mpe@ellerman.id.au
Link: https://lore.kernel.org/r/20191119045712.39633-3-natechancellor@gmail.com

diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
index 16c1c5a19519..378f6108a414 100644
--- a/arch/powerpc/kexec/Makefile
+++ b/arch/powerpc/kexec/Makefile
@@ -3,8 +3,8 @@
 # Makefile for the linux kernel.
 #
-# Disable clang warning for using setjmp without setjmp.h header
-CFLAGS_crash.o		+= $(call cc-disable-warning, builtin-requires-header)
+# Avoid clang warnings around longjmp/setjmp declarations
+CFLAGS_crash.o += -ffreestanding
obj-y				+= core.o crash.o core_$(BITS).o
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index f142570ad860..c3842dbeb1b7 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -1,8 +1,8 @@
 # SPDX-License-Identifier: GPL-2.0
 # Makefile for xmon
-# Disable clang warning for using setjmp without setjmp.h header
-subdir-ccflags-y := $(call cc-disable-warning, builtin-requires-header)
+# Avoid clang warnings around longjmp/setjmp declarations
+subdir-ccflags-y := -ffreestanding
GCOV_PROFILE := n
 KCOV_INSTRUMENT := n

    