Skip to contentSkip to conversation

FAILED: patch "[PATCH] powerpc: Make setjmp/longjmp signature standard" failed to apply to 4.19-stable tree

PATCH [email protected] 2 participants 2 messages Apr 15, 2020

Subsystems (2)
Stable branch PowerPC
lore
Share & tools
lore

[email protected]

author maintainer
#0 lore raw

The patch below does not apply to the 4.19-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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 Mon Sep 17 00:00:00 2001
From: Clement Courbet <[email protected]>
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 [email protected] # v4.14+
Signed-off-by Clement Courbet <[email protected]>
Reviewed-by Nathan Chancellor <[email protected]>
Tested-by Nathan Chancellor <[email protected]>
Signed-off-by Michael Ellerman <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
arch/powerpc/include/asm/setjmp.h +4 -2
index e9f81bb3f83b..f798e80e4106 100644
@@ -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 */
arch/powerpc/kexec/Makefile +0 -3
index 378f6108a414..86380c69f5ce 100644
@@ -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
arch/powerpc/xmon/Makefile +0 -3
index c3842dbeb1b7..6f9cccea54f3 100644
@@ -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
#1 lore raw
Quoted 71 lines · On Wed, Apr 15, 2020 at 03:15:46PM +0200, [email protected] wrote:

The patch below does not apply to the 4.19-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 <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From c17eb4dca5a353a9dbbb8ad6934fe57af7165e91 Mon Sep 17 00:00:00 2001
From: Clement Courbet <[email protected]>
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 [email protected] # v4.14+
Signed-off-by Clement Courbet <[email protected]>
Reviewed-by Nathan Chancellor <[email protected]>
Tested-by Nathan Chancellor <[email protected]>
Signed-off-by Michael Ellerman <[email protected]>
Link https://lore.kernel.org/r/[email protected] open here
arch/powerpc/include/asm/setjmp.h +4 -2
index e9f81bb3f83b..f798e80e4106 100644
@@ -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 */
arch/powerpc/kexec/Makefile +0 -3
index 378f6108a414..86380c69f5ce 100644
@@ -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
arch/powerpc/xmon/Makefile +0 -0
index c3842dbeb1b7..6f9cccea54f3 100644

arch/powerpc/xmon/Makefile line 6

Quoted 9 lines
arch/powerpc/xmon/Makefile +0 -3
@@ -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

Attached is a backport for 4.19 (that patch plus a prerequisite one).

Cheers,
Nathan