This is a note to let you know that I've just added the patch titled x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current 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: x86-speculation-use-declare_per_cpu-for-x86_spec_ctrl_current.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 db886979683a8360ced9b24ab1125ad0c4d2cf76 Mon Sep 17 00:00:00 2001 From: Nathan Chancellor <nathan@xxxxxxxxxx> Date: Wed, 13 Jul 2022 08:24:37 -0700 Subject: x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current From: Nathan Chancellor <nathan@xxxxxxxxxx> commit db886979683a8360ced9b24ab1125ad0c4d2cf76 upstream. Clang warns: arch/x86/kernel/cpu/bugs.c:58:21: error: section attribute is specified on redeclared variable [-Werror,-Wsection] DEFINE_PER_CPU(u64, x86_spec_ctrl_current); ^ arch/x86/include/asm/nospec-branch.h:283:12: note: previous declaration is here extern u64 x86_spec_ctrl_current; ^ 1 error generated. The declaration should be using DECLARE_PER_CPU instead so all attributes stay in sync. Cc: stable@xxxxxxxxxxxxxxx Fixes: fc02735b14ff ("KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS") Reported-by: kernel test robot <lkp@xxxxxxxxx> Signed-off-by: Nathan Chancellor <nathan@xxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- arch/x86/include/asm/nospec-branch.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/arch/x86/include/asm/nospec-branch.h +++ b/arch/x86/include/asm/nospec-branch.h @@ -11,6 +11,7 @@ #include <asm/cpufeatures.h> #include <asm/msr-index.h> #include <asm/unwind_hints.h> +#include <asm/percpu.h> #define RETPOLINE_THUNK_SIZE 32 @@ -281,7 +282,7 @@ static inline void indirect_branch_predi /* The Intel SPEC CTRL MSR base value cache */ extern u64 x86_spec_ctrl_base; -extern u64 x86_spec_ctrl_current; +DECLARE_PER_CPU(u64, x86_spec_ctrl_current); extern void write_spec_ctrl_current(u64 val, bool force); extern u64 spec_ctrl_current(void); Patches currently in stable-queue which might be from nathan@xxxxxxxxxx are queue-5.10/objtool-fix-symbol-creation.patch queue-5.10/objtool-only-rewrite-unconditional-retpoline-thunk-calls.patch queue-5.10/x86-speculation-use-declare_per_cpu-for-x86_spec_ctrl_current.patch queue-5.10/objtool-teach-get_alt_entry-about-more-relocation-types.patch