From d94b93a9101573eb75b819dee94b1417acff631b Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 30 Dec 2020 16:54:56 +0100 Subject: [PATCH 1/2] ARM: cpuidle: Avoid orphan section warning Since commit 83109d5d5fba ("x86/build: Warn on orphan section placement"), we get a warning for objects in orphan sections. The cpuidle implementation for OMAP causes this when CONFIG_CPU_IDLE is disabled: arm-linux-gnueabi-ld: warning: orphan section `__cpuidle_method_of_table' from `arch/arm/mach-omap2/pm33xx-core.o' being placed in section `__cpuidle_method_of_table' arm-linux-gnueabi-ld: warning: orphan section `__cpuidle_method_of_table' from `arch/arm/mach-omap2/pm33xx-core.o' being placed in section `__cpuidle_method_of_table' arm-linux-gnueabi-ld: warning: orphan section `__cpuidle_method_of_table' from `arch/arm/mach-omap2/pm33xx-core.o' being placed in section `__cpuidle_method_of_table' Change the definition of CPUIDLE_METHOD_OF_DECLARE() to silently drop the table and all code referenced from it when CONFIG_CPU_IDLE is disabled. Fixes: 06ee7a950b6a ("ARM: OMAP2+: pm33xx-core: Add cpuidle_ops for am335x/am437x") Signed-off-by: Arnd Bergmann Reviewed-by: Miguel Ojeda Reviewed-by: Nick Desaulniers Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20201230155506.1085689-1-arnd@kernel.org --- arch/arm/include/asm/cpuidle.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/cpuidle.h b/arch/arm/include/asm/cpuidle.h index 0d67ed682e07..bc4ffa7ca04c 100644 --- a/arch/arm/include/asm/cpuidle.h +++ b/arch/arm/include/asm/cpuidle.h @@ -7,9 +7,11 @@ #ifdef CONFIG_CPU_IDLE extern int arm_cpuidle_simple_enter(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index); +#define __cpuidle_method_section __used __section("__cpuidle_method_of_table") #else static inline int arm_cpuidle_simple_enter(struct cpuidle_device *dev, struct cpuidle_driver *drv, int index) { return -ENODEV; } +#define __cpuidle_method_section __maybe_unused /* drop silently */ #endif /* Common ARM WFI state */ @@ -42,8 +44,7 @@ struct of_cpuidle_method { #define CPUIDLE_METHOD_OF_DECLARE(name, _method, _ops) \ static const struct of_cpuidle_method __cpuidle_method_of_table_##name \ - __used __section("__cpuidle_method_of_table") \ - = { .method = _method, .ops = _ops } + __cpuidle_method_section = { .method = _method, .ops = _ops } extern int arm_cpuidle_suspend(int index); From d4c6399900364facd84c9e35ce1540b6046c345f Mon Sep 17 00:00:00 2001 From: Nathan Chancellor Date: Wed, 5 May 2021 17:14:11 -0700 Subject: [PATCH 2/2] vmlinux.lds.h: Avoid orphan section with !SMP 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 Signed-off-by: Nathan Chancellor Tested-by: Nick Desaulniers # build Signed-off-by: Kees Cook Link: https://lore.kernel.org/r/20210506001410.1026691-1-nathan@kernel.org --- include/asm-generic/vmlinux.lds.h | 1 + 1 file changed, 1 insertion(+) diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h index 40a9c101565e..17325416e2de 100644 --- a/include/asm-generic/vmlinux.lds.h +++ b/include/asm-generic/vmlinux.lds.h @@ -960,6 +960,7 @@ #ifdef CONFIG_AMD_MEM_ENCRYPT #define PERCPU_DECRYPTED_SECTION \ . = ALIGN(PAGE_SIZE); \ + *(.data..decrypted) \ *(.data..percpu..decrypted) \ . = ALIGN(PAGE_SIZE); #else