Merge branch 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 FPU updates from Ingo Molnar:
 "Three changes: fix a race that can result in FPU corruption, plus two
  cleanups"

* 'x86-fpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/fpu: Deactivate FPU state after failure during state load
  x86/fpu/xstate: Make xfeature_is_supervisor()/xfeature_is_user() return bool
  x86/fpu/xstate: Fix small issues

2 files changed, 11 insertions, 10 deletions

diff --git a/arch/x86/kernel/fpu/signal.c b/arch/x86/kernel/fpu/signal.c
index 0071b794ed19..400a05e1c1c5 100644
--- a/arch/x86/kernel/fpu/signal.c
+++ b/arch/x86/kernel/fpu/signal.c
@@ -352,6 +352,7 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
 			fpregs_unlock();
 			return 0;
 		}
+		fpregs_deactivate(fpu);
 		fpregs_unlock();
 	}
 
@@ -403,6 +404,8 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size)
 	}
 	if (!ret)
 		fpregs_mark_activate();
+	else
+		fpregs_deactivate(fpu);
 	fpregs_unlock();
 
 err_out:
diff --git a/arch/x86/kernel/fpu/xstate.c b/arch/x86/kernel/fpu/xstate.c
index fa31470bbf24..a1806598aaa4 100644
--- a/arch/x86/kernel/fpu/xstate.c
+++ b/arch/x86/kernel/fpu/xstate.c
@@ -107,23 +107,20 @@ int cpu_has_xfeatures(u64 xfeatures_needed, const char **feature_name)
 }
 EXPORT_SYMBOL_GPL(cpu_has_xfeatures);
 
-static int xfeature_is_supervisor(int xfeature_nr)
+static bool xfeature_is_supervisor(int xfeature_nr)
 {
 	/*
-	 * We currently do not support supervisor states, but if
-	 * we did, we could find out like this.
-	 *
-	 * SDM says: If state component 'i' is a user state component,
-	 * ECX[0] return 0; if state component i is a supervisor
-	 * state component, ECX[0] returns 1.
+	 * Extended State Enumeration Sub-leaves (EAX = 0DH, ECX = n, n > 1)
+	 * returns ECX[0] set to (1) for a supervisor state, and cleared (0)
+	 * for a user state.
 	 */
 	u32 eax, ebx, ecx, edx;
 
 	cpuid_count(XSTATE_CPUID, xfeature_nr, &eax, &ebx, &ecx, &edx);
-	return !!(ecx & 1);
+	return ecx & 1;
 }
 
-static int xfeature_is_user(int xfeature_nr)
+static bool xfeature_is_user(int xfeature_nr)
 {
 	return !xfeature_is_supervisor(xfeature_nr);
 }
@@ -419,7 +416,8 @@ static void __init setup_init_fpu_buf(void)
 	print_xstate_features();
 
 	if (boot_cpu_has(X86_FEATURE_XSAVES))
-		init_fpstate.xsave.header.xcomp_bv = (u64)1 << 63 | xfeatures_mask;
+		init_fpstate.xsave.header.xcomp_bv = XCOMP_BV_COMPACTED_FORMAT |
+						     xfeatures_mask;
 
 	/*
 	 * Init all the features state with header.xfeatures being 0x0