This is a note to let you know that I've just added the patch titled vmlinux.lds.h: Avoid orphan section with !SMP to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: vmlinux.lds.h-avoid-orphan-section-with-smp.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From d4c6399900364facd84c9e35ce1540b6046c345f Mon Sep 17 00:00:00 2001 From: Nathan Chancellor <nathan@xxxxxxxxxx> Date: Wed, 5 May 2021 17:14:11 -0700 Subject: vmlinux.lds.h: Avoid orphan section with !SMP From: Nathan Chancellor <nathan@xxxxxxxxxx> commit d4c6399900364facd84c9e35ce1540b6046c345f upstream. With x86_64_defconfig and the following configs, there is an orphan section warning: CONFIG_SMP=n CONFIG_AMD_MEM_ENCRYPT=y CONFIG_HYPERVISOR_GUEST=y CONFIG_KVM=y CONFIG_PARAVIRT=y ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/cpu/vmware.o' being placed in section `.data..decrypted' ld: warning: orphan section `.data..decrypted' from `arch/x86/kernel/kvm.o' being placed in section `.data..decrypted' These sections are created with DEFINE_PER_CPU_DECRYPTED, which ultimately turns into __PCPU_ATTRS, which in turn has a section attribute with a value of PER_CPU_BASE_SECTION + the section name. When CONFIG_SMP is not set, the base section is .data and that is not currently handled in any linker script. Add .data..decrypted to PERCPU_DECRYPTED_SECTION, which is included in PERCPU_INPUT -> PERCPU_SECTION, which is include in the x86 linker script when either CONFIG_X86_64 or CONFIG_SMP is unset, taking care of the warning. Fixes: ac26963a1175 ("percpu: Introduce DEFINE_PER_CPU_DECRYPTED") Link: https://github.com/ClangBuiltLinux/linux/issues/1360 Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Tested-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx> # build Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx> Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@xxxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/asm-generic/vmlinux.lds.h | 1 + 1 file changed, 1 insertion(+) --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -971,6 +971,7 @@ #ifdef CONFIG_AMD_MEM_ENCRYPT #define PERCPU_DECRYPTED_SECTION \ . = ALIGN(PAGE_SIZE); \ + *(.data..decrypted) \ *(.data..percpu..decrypted) \ . = ALIGN(PAGE_SIZE); #else Patches currently in stable-queue which might be from nathan@xxxxxxxxxx are queue-5.10/vmlinux.lds.h-avoid-orphan-section-with-smp.patch