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 v2] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current
Date: Wed, 13 Jul 2022 08:24:37 -0700 [thread overview]
Message-ID: <20220713152436.2294819-1-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>
---
v1 -> v2: https://lore.kernel.org/20220713152222.1697913-1-nathan@kernel.org/
* Use asm/percpu.h instead of linux/percpu.h to avoid static call
include errors.
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..10a3bfc1eb23 100644
--- 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
@@ -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 15:25 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-07-13 15:24 Nathan Chancellor [this message]
2022-07-13 15:36 ` [PATCH v2] x86/speculation: Use DECLARE_PER_CPU for x86_spec_ctrl_current Nick Desaulniers
2022-07-13 16:22 ` Peter Zijlstra
2022-07-13 16:27 ` Nathan Chancellor
2022-07-14 21:30 ` Jakub Kicinski
2022-07-14 21:51 ` Linus Torvalds
2022-07-14 21:56 ` Linus Torvalds
2022-07-14 22:11 ` Peter Zijlstra
2022-07-14 21:56 ` Jakub Kicinski
2022-07-14 22:14 ` Linus Torvalds
2022-07-14 22:18 ` Jakub Kicinski
2022-07-15 16:00 ` Borislav Petkov
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