4.14-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
commit 06dd688ddda5819025e014b79aea9af6ab475fa2 upstream.
Peter pointed out that the set/clear_bit32() variants are broken in various aspects.
Replace them with open coded set/clear_bit() and type cast cpu_info::x86_capability as it's done in all other places throughout x86.
Fixes: 0b00de857a64 ("x86/cpuid: Add generic table for CPUID dependencies") Reported-by: Peter Ziljstra peterz@infradead.org Signed-off-by: Thomas Gleixner tglx@linutronix.de Cc: Andi Kleen ak@linux.intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/x86/kernel/cpu/cpuid-deps.c | 26 +++++++++++--------------- 1 file changed, 11 insertions(+), 15 deletions(-)
--- a/arch/x86/kernel/cpu/cpuid-deps.c +++ b/arch/x86/kernel/cpu/cpuid-deps.c @@ -62,23 +62,19 @@ const static struct cpuid_dep cpuid_deps {} };
-static inline void __clear_cpu_cap(struct cpuinfo_x86 *c, unsigned int bit) -{ - clear_bit32(bit, c->x86_capability); -} - -static inline void __setup_clear_cpu_cap(unsigned int bit) -{ - clear_cpu_cap(&boot_cpu_data, bit); - set_bit32(bit, cpu_caps_cleared); -} - static inline void clear_feature(struct cpuinfo_x86 *c, unsigned int feature) { - if (!c) - __setup_clear_cpu_cap(feature); - else - __clear_cpu_cap(c, feature); + /* + * Note: This could use the non atomic __*_bit() variants, but the + * rest of the cpufeature code uses atomics as well, so keep it for + * consistency. Cleanup all of it separately. + */ + if (!c) { + clear_cpu_cap(&boot_cpu_data, feature); + set_bit(feature, (unsigned long *)cpu_caps_cleared); + } else { + clear_bit(feature, (unsigned long *)c->x86_capability); + } }
/* Take the capabilities and the BUG bits into account */