From: Nathan Chancellor nathan@kernel.org
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@intel.com Signed-off-by: Nathan Chancellor nathan@kernel.org Tested-by: Nick Desaulniers ndesaulniers@google.com # build Signed-off-by: Kees Cook keescook@chromium.org Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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 @@ -882,6 +882,7 @@ #ifdef CONFIG_AMD_MEM_ENCRYPT #define PERCPU_DECRYPTED_SECTION \ . = ALIGN(PAGE_SIZE); \ + *(.data..decrypted) \ *(.data..percpu..decrypted) \ . = ALIGN(PAGE_SIZE); #else