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

From: tip-bot for Jann Horn
Date: Thu Mar 28 2019 - 12:14:02 EST


Commit-ID: f6027c81099e87516d27d123867f10abd04b2d38
Gitweb: https://git.kernel.org/tip/f6027c81099e87516d27d123867f10abd04b2d38
Author: Jann Horn <jannh@xxxxxxxxxx>
AuthorDate: Thu, 28 Mar 2019 16:49:48 +0100
Committer: Borislav Petkov <bp@xxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Ingo Molnar <mingo@xxxxxxxxxx>
Cc: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: x86-ml <x86@xxxxxxxxxx>
Link: https://lkml.kernel.org/r/20190328154948.152273-1-jannh@xxxxxxxxxx
---
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