From: Arnd Bergmann <arnd@kernel.org>
To: Marco Elver <elver@google.com>
Cc: Arnd Bergmann <arnd@arndb.de>, Kees Cook <keescook@chromium.org>,
Dmitry Vyukov <dvyukov@google.com>,
Josh Poimboeuf <jpoimboe@kernel.org>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Miroslav Benes <mbenes@suse.cz>,
kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [PATCH] kcsan: select CONFIG_CONSTRUCTORS
Date: Wed, 15 Feb 2023 10:14:48 +0100 [thread overview]
Message-ID: <20230215091503.1490152-1-arnd@kernel.org> (raw)
From: Arnd Bergmann <arnd@arndb.de>
Building a kcsan enabled kernel for x86_64 with gcc-11 results in a lot
of build warnings or errors without CONFIG_CONSTRUCTORS:
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/copy_mc.o'
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/cpu.o'
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/csum-partial_64.o'
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/csum-wrappers_64.o'
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/insn-eval.o'
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/insn.o'
x86_64-linux-ld: error: unplaced orphan section `.ctors.65436' from `arch/x86/lib/misc.o'
The same thing has been reported for mips64. I can't reproduce it for
any other compiler version, so I don't know if constructors are always
required here or if this is a gcc-11 specific implementation detail.
I see no harm in always enabling constructors here, and this reliably
fixes the build warnings for me.
Link: https://lore.kernel.org/lkml/202204181801.r3MMkwJv-lkp@intel.com/T/
Cc: Kees Cook <keescook@chromium.org>
See-also: 3e6631485fae ("vmlinux.lds.h: Keep .ctors.* with .ctors")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
lib/Kconfig.kcsan | 1 +
1 file changed, 1 insertion(+)
diff --git a/lib/Kconfig.kcsan b/lib/Kconfig.kcsan
index 4dedd61e5192..609ddfc73de5 100644
--- a/lib/Kconfig.kcsan
+++ b/lib/Kconfig.kcsan
@@ -14,6 +14,7 @@ menuconfig KCSAN
bool "KCSAN: dynamic data race detector"
depends on HAVE_ARCH_KCSAN && HAVE_KCSAN_COMPILER
depends on DEBUG_KERNEL && !KASAN
+ select CONSTRUCTORS
select STACKTRACE
help
The Kernel Concurrency Sanitizer (KCSAN) is a dynamic
--
2.39.1
next reply other threads:[~2023-02-15 9:15 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-15 9:14 Arnd Bergmann [this message]
2023-02-15 9:25 ` [PATCH] kcsan: select CONFIG_CONSTRUCTORS Marco Elver
2023-02-15 9:48 ` Arnd Bergmann
2023-02-15 22:42 ` Paul E. McKenney
2023-02-16 7:00 ` Marco Elver
2023-02-16 18:36 ` Paul E. McKenney
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