[PATCH] x86/cpufeature: fix __percpu annotation in this_cpu_has()

[PATCH] x86/cpufeature: fix __percpu annotation in this_cpu_has()

[Jann Horn]

&cpu_info.x86_capability is __percpu, and the second argument of
x86_this_cpu_test_bit() is expected to be __percpu. Don't cast the __percpu
away and then implicitly add it again.
This gets rid of 106 lines of sparse warnings with the kernel config I'm
using.

Signed-off-by: Jann Horn <jannh@google.com>
---
 arch/x86/include/asm/cpufeature.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index ce95b8cbd229..0df88893e767 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -113,7 +113,8 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 
 #define this_cpu_has(bit)						\
 	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : 	\
-	 x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
+	 x86_this_cpu_test_bit(bit,					\
+		(unsigned long __percpu *)&cpu_info.x86_capability))
 
 /*
  * This macro is for detection of features which need kernel
-- 
2.21.0.392.gf8f6787159e-goog

[tip:x86/urgent] x86/cpufeature: Fix __percpu annotation in this_cpu_has()

[tip-bot for Jann Horn]

Commit-ID:  f6027c81099e87516d27d123867f10abd04b2d38
Gitweb:     https://git.kernel.org/tip/f6027c81099e87516d27d123867f10abd04b2d38
Author:     Jann Horn <jannh@google.com>
AuthorDate: Thu, 28 Mar 2019 16:49:48 +0100
Committer:  Borislav Petkov <bp@suse.de>
CommitDate: Thu, 28 Mar 2019 17:03:11 +0100

x86/cpufeature: Fix __percpu annotation in this_cpu_has()

&cpu_info.x86_capability is __percpu, and the second argument of
x86_this_cpu_test_bit() is expected to be __percpu. Don't cast the
__percpu away and then implicitly add it again. This gets rid of 106
lines of sparse warnings with the kernel config I'm using.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: Nadav Amit <namit@vmware.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190328154948.152273-1-jannh@google.com
---
 arch/x86/include/asm/cpufeature.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h
index ce95b8cbd229..0e56ff7e4848 100644
--- a/arch/x86/include/asm/cpufeature.h
+++ b/arch/x86/include/asm/cpufeature.h
@@ -112,8 +112,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32];
 	 test_cpu_cap(c, bit))
 
 #define this_cpu_has(bit)						\
-	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : 	\
-	 x86_this_cpu_test_bit(bit, (unsigned long *)&cpu_info.x86_capability))
+	(__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 :	\
+	 x86_this_cpu_test_bit(bit,					\
+		(unsigned long __percpu *)&cpu_info.x86_capability))
 
 /*
  * This macro is for detection of features which need kernel