From e8df1a95b685af84a81698199ee206e0e66a8b44 Mon Sep 17 00:00:00 2001 From: Dave Hansen Date: Fri, 13 May 2016 15:13:28 -0700 Subject: [PATCH] x86/cpufeature, x86/mm/pkeys: Fix broken compile-time disabling of pkeys When I added support for the Memory Protection Keys processor feature, I had to reindent the REQUIRED/DISABLED_MASK macros, and also consult the later cpufeature words. I'm not quite sure how I bungled it, but I consulted the wrong word at the end. This only affected required or disabled cpu features in cpufeature words 14, 15 and 16. So, only Protection Keys itself was screwed over here. The result was that if you disabled pkeys in your .config, you might still see some code show up that should have been compiled out. There should be no functional problems, though. In verifying this patch I also realized that the DISABLE_PKU/OSPKE macros were defined backwards and that the cpu_has() check in setup_pku() was not doing the compile-time disabled checks. So also fix the macro for DISABLE_PKU/OSPKE and add a compile-time check for pkeys being enabled in setup_pku(). Signed-off-by: Dave Hansen Cc: Cc: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Dave Hansen Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Fixes: dfb4a70f20c5 ("x86/cpufeature, x86/mm/pkeys: Add protection keys related CPUID definitions") Link: http://lkml.kernel.org/r/20160513221328.C200930B@viggo.jf.intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/cpufeature.h | 12 ++++++------ arch/x86/include/asm/disabled-features.h | 6 +++--- arch/x86/kernel/cpu/common.c | 4 ++++ 3 files changed, 13 insertions(+), 9 deletions(-) diff --git a/arch/x86/include/asm/cpufeature.h b/arch/x86/include/asm/cpufeature.h index 3636ec06c887..aeab47932933 100644 --- a/arch/x86/include/asm/cpufeature.h +++ b/arch/x86/include/asm/cpufeature.h @@ -63,9 +63,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; (((bit)>>5)==11 && (1UL<<((bit)&31) & REQUIRED_MASK11)) || \ (((bit)>>5)==12 && (1UL<<((bit)&31) & REQUIRED_MASK12)) || \ (((bit)>>5)==13 && (1UL<<((bit)&31) & REQUIRED_MASK13)) || \ - (((bit)>>5)==13 && (1UL<<((bit)&31) & REQUIRED_MASK14)) || \ - (((bit)>>5)==13 && (1UL<<((bit)&31) & REQUIRED_MASK15)) || \ - (((bit)>>5)==14 && (1UL<<((bit)&31) & REQUIRED_MASK16)) ) + (((bit)>>5)==14 && (1UL<<((bit)&31) & REQUIRED_MASK14)) || \ + (((bit)>>5)==15 && (1UL<<((bit)&31) & REQUIRED_MASK15)) || \ + (((bit)>>5)==16 && (1UL<<((bit)&31) & REQUIRED_MASK16)) ) #define DISABLED_MASK_BIT_SET(bit) \ ( (((bit)>>5)==0 && (1UL<<((bit)&31) & DISABLED_MASK0 )) || \ @@ -82,9 +82,9 @@ extern const char * const x86_bug_flags[NBUGINTS*32]; (((bit)>>5)==11 && (1UL<<((bit)&31) & DISABLED_MASK11)) || \ (((bit)>>5)==12 && (1UL<<((bit)&31) & DISABLED_MASK12)) || \ (((bit)>>5)==13 && (1UL<<((bit)&31) & DISABLED_MASK13)) || \ - (((bit)>>5)==13 && (1UL<<((bit)&31) & DISABLED_MASK14)) || \ - (((bit)>>5)==13 && (1UL<<((bit)&31) & DISABLED_MASK15)) || \ - (((bit)>>5)==14 && (1UL<<((bit)&31) & DISABLED_MASK16)) ) + (((bit)>>5)==14 && (1UL<<((bit)&31) & DISABLED_MASK14)) || \ + (((bit)>>5)==15 && (1UL<<((bit)&31) & DISABLED_MASK15)) || \ + (((bit)>>5)==16 && (1UL<<((bit)&31) & DISABLED_MASK16)) ) #define cpu_has(c, bit) \ (__builtin_constant_p(bit) && REQUIRED_MASK_BIT_SET(bit) ? 1 : \ diff --git a/arch/x86/include/asm/disabled-features.h b/arch/x86/include/asm/disabled-features.h index 39343be7d4f4..911e9358ceb1 100644 --- a/arch/x86/include/asm/disabled-features.h +++ b/arch/x86/include/asm/disabled-features.h @@ -29,11 +29,11 @@ #endif /* CONFIG_X86_64 */ #ifdef CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS -# define DISABLE_PKU (1<<(X86_FEATURE_PKU)) -# define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE)) -#else # define DISABLE_PKU 0 # define DISABLE_OSPKE 0 +#else +# define DISABLE_PKU (1<<(X86_FEATURE_PKU & 31)) +# define DISABLE_OSPKE (1<<(X86_FEATURE_OSPKE & 31)) #endif /* CONFIG_X86_INTEL_MEMORY_PROTECTION_KEYS */ /* diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index 8394b3d1f94f..f45a4b9d28c8 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -310,6 +310,10 @@ static bool pku_disabled; static __always_inline void setup_pku(struct cpuinfo_x86 *c) { + /* check the boot processor, plus compile options for PKU: */ + if (!cpu_feature_enabled(X86_FEATURE_PKU)) + return; + /* checks the actual processor's cpuid bits: */ if (!cpu_has(c, X86_FEATURE_PKU)) return; if (pku_disabled) -- 2.20.1