From: Nathan Chancellor <nathan@kernel.org>
To: Linus Torvalds <torvalds@linux-foundation.org>, x86@kernel.org
Cc: Nick Desaulniers <ndesaulniers@google.com>,
Peter Zijlstra <peterz@infradead.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
Nathan Chancellor <nathan@kernel.org>,
stable@vger.kernel.org, kernel test robot <lkp@intel.com>
Subject: [PATCH] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current
Date: Wed, 13 Jul 2022 08:22:22 -0700 [thread overview]
Message-ID: <20220713152222.1697913-1-nathan@kernel.org> (raw)
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@vger.kernel.org
Fixes: fc02735b14ff ("KVM: VMX: Prevent guest RSB poisoning attacks with eIBRS")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
---
arch/x86/include/asm/nospec-branch.h | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/include/asm/nospec-branch.h b/arch/x86/include/asm/nospec-branch.h
index bb05ed4f46bd..99a29c83adf8 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -6,6 +6,7 @@
#include <linux/static_key.h>
#include <linux/objtool.h>
#include <linux/linkage.h>
+#include <linux/percpu.h>
#include <asm/alternative.h>
#include <asm/cpufeatures.h>
@@ -280,7 +281,7 @@ static inline void indirect_branch_prediction_barrier(void)
/* 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);
base-commit: 72a8e05d4f66b5af7854df4490e3135168694b6b
--
2.37.1
next reply other threads:[~2022-07-13 15:22 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-13 15:22 Nathan Chancellor [this message]
2022-07-13 15:24 ` [PATCH] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current Nathan Chancellor
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