On Wed, Apr 15, 2020 at 03:15:47PM +0200, gregkh@xxxxxxxxxxxxxxxxxxx wrote:
>
> 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@xxxxxxxxxxxxxxx>.
>
> thanks,
>
> greg k-h
>
> ------------------ original commit in Linus's tree ------------------
>
> From c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 Mon Sep 17 00:00:00 2001
> From: Clement Courbet <courbet@xxxxxxxxxx>
> Date: Mon, 30 Mar 2020 10:03:56 +0200
> Subject: [PATCH] powerpc: Make setjmp/longjmp signature standard
>
> Declaring setjmp()/longjmp() as taking longs makes the signature
> non-standard, and makes clang complain. In the past, this has been
> worked around by adding -ffreestanding to the compile flags.
>
> The implementation looks like it only ever propagates the value
> (in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
> with integer parameters.
>
> This allows removing -ffreestanding from the compilation flags.
>
> Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp")
> Cc: stable@xxxxxxxxxxxxxxx # v4.14+
> Signed-off-by: Clement Courbet <courbet@xxxxxxxxxx>
> Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
> Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@xxxxxxxxxx
>
> diff --git a/arch/powerpc/include/asm/setjmp.h b/arch/powerpc/include/asm/setjmp.h
> index e9f81bb3f83b..f798e80e4106 100644
> --- a/arch/powerpc/include/asm/setjmp.h
> +++ b/arch/powerpc/include/asm/setjmp.h
> @@ -7,7 +7,9 @@
>
> #define JMP_BUF_LEN 23
>
> -extern long setjmp(long *) __attribute__((returns_twice));
> -extern void longjmp(long *, long) __attribute__((noreturn));
> +typedef long jmp_buf[JMP_BUF_LEN];
> +
> +extern int setjmp(jmp_buf env) __attribute__((returns_twice));
> +extern void longjmp(jmp_buf env, int val) __attribute__((noreturn));
>
> #endif /* _ASM_POWERPC_SETJMP_H */
> diff --git a/arch/powerpc/kexec/Makefile b/arch/powerpc/kexec/Makefile
> index 378f6108a414..86380c69f5ce 100644
> --- a/arch/powerpc/kexec/Makefile
> +++ b/arch/powerpc/kexec/Makefile
> @@ -3,9 +3,6 @@
> # Makefile for the linux kernel.
> #
>
> -# Avoid clang warnings around longjmp/setjmp declarations
> -CFLAGS_crash.o += -ffreestanding
> -
> obj-y += core.o crash.o core_$(BITS).o
>
> obj-$(CONFIG_PPC32) += relocate_32.o
> diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
> index c3842dbeb1b7..6f9cccea54f3 100644
> --- a/arch/powerpc/xmon/Makefile
> +++ b/arch/powerpc/xmon/Makefile
> @@ -1,9 +1,6 @@
> # SPDX-License-Identifier: GPL-2.0
> # Makefile for xmon
>
> -# Avoid clang warnings around longjmp/setjmp declarations
> -subdir-ccflags-y := -ffreestanding
> -
> GCOV_PROFILE := n
> KCOV_INSTRUMENT := n
> UBSAN_SANITIZE := n
>
5.4 backport attached.
Cheers,
Nathan
>From 1de31c805515171f5bfb1022e32ff1f491050162 Mon Sep 17 00:00:00 2001
From: Clement Courbet <courbet@xxxxxxxxxx>
Date: Mon, 30 Mar 2020 10:03:56 +0200
Subject: [PATCH 5.4] powerpc: Make setjmp/longjmp signature standard
commit c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 upstream.
Declaring setjmp()/longjmp() as taking longs makes the signature
non-standard, and makes clang complain. In the past, this has been
worked around by adding -ffreestanding to the compile flags.
The implementation looks like it only ever propagates the value
(in longjmp) or sets it to 1 (in setjmp), and we only call longjmp
with integer parameters.
This allows removing -ffreestanding from the compilation flags.
Fixes: c9029ef9c957 ("powerpc: Avoid clang warnings around setjmp and longjmp")
Cc: stable@xxxxxxxxxxxxxxx # v4.14+
Signed-off-by: Clement Courbet <courbet@xxxxxxxxxx>
Reviewed-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Tested-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200330080400.124803-1-courbet@xxxxxxxxxx
Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
---
arch/powerpc/include/asm/setjmp.h | 6 ++++--
arch/powerpc/kernel/Makefile | 3 ---
arch/powerpc/xmon/Makefile | 3 ---
3 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/powerpc/include/asm/setjmp.h b/arch/powerpc/include/asm/setjmp.h
index e9f81bb3f83b0..f798e80e41061 100644
--- a/arch/powerpc/include/asm/setjmp.h
+++ b/arch/powerpc/include/asm/setjmp.h
@@ -7,7 +7,9 @@
#define JMP_BUF_LEN 23
-extern long setjmp(long *) __attribute__((returns_twice));
-extern void longjmp(long *, long) __attribute__((noreturn));
+typedef long jmp_buf[JMP_BUF_LEN];
+
+extern int setjmp(jmp_buf env) __attribute__((returns_twice));
+extern void longjmp(jmp_buf env, int val) __attribute__((noreturn));
#endif /* _ASM_POWERPC_SETJMP_H */
diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile
index 3c02445cf0865..dc0780f930d5b 100644
--- a/arch/powerpc/kernel/Makefile
+++ b/arch/powerpc/kernel/Makefile
@@ -5,9 +5,6 @@
CFLAGS_ptrace.o += -DUTS_MACHINE='"$(UTS_MACHINE)"'
-# Avoid clang warnings around longjmp/setjmp declarations
-CFLAGS_crash.o += -ffreestanding
-
ifdef CONFIG_PPC64
CFLAGS_prom_init.o += $(NO_MINIMAL_TOC)
endif
diff --git a/arch/powerpc/xmon/Makefile b/arch/powerpc/xmon/Makefile
index c3842dbeb1b75..6f9cccea54f3b 100644
--- a/arch/powerpc/xmon/Makefile
+++ b/arch/powerpc/xmon/Makefile
@@ -1,9 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
# Makefile for xmon
-# Avoid clang warnings around longjmp/setjmp declarations
-subdir-ccflags-y := -ffreestanding
-
GCOV_PROFILE := n
KCOV_INSTRUMENT := n
UBSAN_SANITIZE := n
base-commit: bc844d58f697dff3ded4b410094ee89f5cedc04c
--
2.26.1
