[PATCH 4.4.y 046/101] x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
From: Ingo Molnar
commit d72f4e29e6d84b7ec02ae93088aa459ac70e733b upstream.
firmware_restrict_branch_speculation_*() recently started using
preempt_enable()/disable(), but those are relatively high level
primitives and cause build failures on some 32-bit builds.
Since we want to keep low level, convert
them to macros to avoid header hell...
Cc: David Woodhouse
Cc: Thomas Gleixner
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: arjan.van.de@intel.com
Cc: b...@alien8.de
Cc: dave.han...@intel.com
Cc: jmatt...@google.com
Cc: karah...@amazon.de
Cc: k...@vger.kernel.org
Cc: pbonz...@redhat.com
Cc: rkrc...@redhat.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Srivatsa S. Bhat
Reviewed-by: Matt Helsley (VMware)
Reviewed-by: Alexey Makhalov
Reviewed-by: Bo Gan
---
arch/x86/include/asm/nospec-branch.h | 26 ++
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/nospec-branch.h
b/arch/x86/include/asm/nospec-branch.h
index 36ded24..b9dd1d9 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -214,20 +214,22 @@ static inline void
indirect_branch_prediction_barrier(void)
/*
* With retpoline, we must use IBRS to restrict branch prediction
* before calling into firmware.
+ *
+ * (Implemented as CPP macros due to header hell.)
*/
-static inline void firmware_restrict_branch_speculation_start(void)
-{
- preempt_disable();
- alternative_msr_write(MSR_IA32_SPEC_CTRL, SPEC_CTRL_IBRS,
- X86_FEATURE_USE_IBRS_FW);
-}
+#define firmware_restrict_branch_speculation_start() \
+do { \
+ preempt_disable(); \
+ alternative_msr_write(MSR_IA32_SPEC_CTRL, SPEC_CTRL_IBRS, \
+ X86_FEATURE_USE_IBRS_FW); \
+} while (0)
-static inline void firmware_restrict_branch_speculation_end(void)
-{
- alternative_msr_write(MSR_IA32_SPEC_CTRL, 0,
- X86_FEATURE_USE_IBRS_FW);
- preempt_enable();
-}
+#define firmware_restrict_branch_speculation_end() \
+do { \
+ alternative_msr_write(MSR_IA32_SPEC_CTRL, 0,\
+ X86_FEATURE_USE_IBRS_FW); \
+ preempt_enable(); \
+} while (0)
#endif /* __ASSEMBLY__ */
[PATCH 4.4.y 046/101] x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
From: Ingo Molnar
commit d72f4e29e6d84b7ec02ae93088aa459ac70e733b upstream.
firmware_restrict_branch_speculation_*() recently started using
preempt_enable()/disable(), but those are relatively high level
primitives and cause build failures on some 32-bit builds.
Since we want to keep low level, convert
them to macros to avoid header hell...
Cc: David Woodhouse
Cc: Thomas Gleixner
Cc: Linus Torvalds
Cc: Peter Zijlstra
Cc: arjan.van.de@intel.com
Cc: b...@alien8.de
Cc: dave.han...@intel.com
Cc: jmatt...@google.com
Cc: karah...@amazon.de
Cc: k...@vger.kernel.org
Cc: pbonz...@redhat.com
Cc: rkrc...@redhat.com
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar
Signed-off-by: Greg Kroah-Hartman
Signed-off-by: Srivatsa S. Bhat
Reviewed-by: Matt Helsley (VMware)
Reviewed-by: Alexey Makhalov
Reviewed-by: Bo Gan
---
arch/x86/include/asm/nospec-branch.h | 26 ++
1 file changed, 14 insertions(+), 12 deletions(-)
diff --git a/arch/x86/include/asm/nospec-branch.h
b/arch/x86/include/asm/nospec-branch.h
index 36ded24..b9dd1d9 100644
--- a/arch/x86/include/asm/nospec-branch.h
+++ b/arch/x86/include/asm/nospec-branch.h
@@ -214,20 +214,22 @@ static inline void
indirect_branch_prediction_barrier(void)
/*
* With retpoline, we must use IBRS to restrict branch prediction
* before calling into firmware.
+ *
+ * (Implemented as CPP macros due to header hell.)
*/
-static inline void firmware_restrict_branch_speculation_start(void)
-{
- preempt_disable();
- alternative_msr_write(MSR_IA32_SPEC_CTRL, SPEC_CTRL_IBRS,
- X86_FEATURE_USE_IBRS_FW);
-}
+#define firmware_restrict_branch_speculation_start() \
+do { \
+ preempt_disable(); \
+ alternative_msr_write(MSR_IA32_SPEC_CTRL, SPEC_CTRL_IBRS, \
+ X86_FEATURE_USE_IBRS_FW); \
+} while (0)
-static inline void firmware_restrict_branch_speculation_end(void)
-{
- alternative_msr_write(MSR_IA32_SPEC_CTRL, 0,
- X86_FEATURE_USE_IBRS_FW);
- preempt_enable();
-}
+#define firmware_restrict_branch_speculation_end() \
+do { \
+ alternative_msr_write(MSR_IA32_SPEC_CTRL, 0,\
+ X86_FEATURE_USE_IBRS_FW); \
+ preempt_enable(); \
+} while (0)
#endif /* __ASSEMBLY__ */
