[PATCH 4.1 049/123] x86, perf: Fix static_key bug in load_mm_cr4()

From: Greg Kroah-Hartman
Date: Sat Aug 08 2015 - 18:23:43 EST

4.1-stable review patch. If anyone has any objections, please let me know.


From: Peter Zijlstra <peterz@xxxxxxxxxxxxx>

commit a833581e372a4adae2319d8dc379493edbc444e9 upstream.

Mikulas reported his K6-3 not booting. This is because the
static_key API confusion struck and bit Andy, this wants to be

Reported-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Tested-by: Mikulas Patocka <mpatocka@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Cc: Andrea Arcangeli <aarcange@xxxxxxxxxx>
Cc: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Brian Gerst <brgerst@xxxxxxxxx>
Cc: Denys Vlasenko <dvlasenk@xxxxxxxxxx>
Cc: H. Peter Anvin <hpa@xxxxxxxxx>
Cc: Kees Cook <keescook@xxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Paul Mackerras <paulus@xxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Valdis Kletnieks <Valdis.Kletnieks@xxxxxx>
Cc: Vince Weaver <vince@xxxxxxxxxx>
Cc: hillf.zj <hillf.zj@xxxxxxxxxxxxxxx>
Fixes: a66734297f78 ("perf/x86: Add /sys/devices/cpu/rdpmc=2 to allow rdpmc for all tasks")
Link: http://lkml.kernel.org/r/20150709172338.GC19282@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

arch/x86/include/asm/mmu_context.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/include/asm/mmu_context.h
+++ b/arch/x86/include/asm/mmu_context.h
@@ -23,7 +23,7 @@ extern struct static_key rdpmc_always_av

static inline void load_mm_cr4(struct mm_struct *mm)
- if (static_key_true(&rdpmc_always_available) ||
+ if (static_key_false(&rdpmc_always_available) ||

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