Messages in this thread | | | From | Marco Elver <> | Date | Wed, 15 Feb 2023 10:25:44 +0100 | Subject | Re: [PATCH] kcsan: select CONFIG_CONSTRUCTORS |
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On Wed, 15 Feb 2023 at 10:15, Arnd Bergmann <arnd@kernel.org> wrote: > > 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>
Reviewed-by: Marco Elver <elver@google.com>
Looks like KASAN does select CONSTRUCTORS already, so KCSAN should as well.
Do you have a tree to take this through, or should it go through -rcu as usual for KCSAN patches?
Thanks, -- Marco
> --- > 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 >
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