linux-kernel - [tip:x86/asm] x86/cpu: Move X86_BUG_ESPFIX initialization to generic

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Message-ID: <tip-0230bb038fa99af0c425fc4cffed307e545a9642@git.kernel.org>
Date:	Wed, 13 Apr 2016 04:30:15 -0700
From:	tip-bot for Andy Lutomirski <tipbot@...or.com>
To:	linux-tip-commits@...r.kernel.org
Cc:	tglx@...utronix.de, torvalds@...ux-foundation.org,
	peterz@...radead.org, mingo@...nel.org, luto@...capital.net,
	linux-kernel@...r.kernel.org, r.marek@...embler.cz,
	luto@...nel.org, brgerst@...il.com, bp@...en8.de,
	dvlasenk@...hat.com, hpa@...or.com, bp@...e.de
Subject: [tip:x86/asm] x86/cpu: Move X86_BUG_ESPFIX initialization to
 generic_identify()

Commit-ID:  0230bb038fa99af0c425fc4cffed307e545a9642
Gitweb:     http://git.kernel.org/tip/0230bb038fa99af0c425fc4cffed307e545a9642
Author:     Andy Lutomirski <luto@...nel.org>
AuthorDate: Thu, 7 Apr 2016 17:31:48 -0700
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 13 Apr 2016 10:20:42 +0200

x86/cpu: Move X86_BUG_ESPFIX initialization to generic_identify()

It was in detect_nopl(), which was either a mistake by me or some kind
of mis-merge.

Signed-off-by: Andy Lutomirski <luto@...nel.org>
Reviewed-by: Borislav Petkov <bp@...e.de>
Cc: Andy Lutomirski <luto@...capital.net>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Denys Vlasenko <dvlasenk@...hat.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rudolf Marek <r.marek@...embler.cz>
Cc: Thomas Gleixner <tglx@...utronix.de>
Fixes: ff236456f072 ("x86/cpu: Move X86_BUG_ESPFIX initialization to generic_identify")
Link: http://lkml.kernel.org/r/0949337f13660461edca08ab67d1a841441289c9.1460075211.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/cpu/common.c | 50 ++++++++++++++++++++++----------------------
 1 file changed, 25 insertions(+), 25 deletions(-)

diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 8e40eee..28d3255 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -862,31 +862,6 @@ static void detect_nopl(struct cpuinfo_x86 *c)
 #else
 	set_cpu_cap(c, X86_FEATURE_NOPL);
 #endif
-
-	/*
-	 * ESPFIX is a strange bug.  All real CPUs have it.  Paravirt
-	 * systems that run Linux at CPL > 0 may or may not have the
-	 * issue, but, even if they have the issue, there's absolutely
-	 * nothing we can do about it because we can't use the real IRET
-	 * instruction.
-	 *
-	 * NB: For the time being, only 32-bit kernels support
-	 * X86_BUG_ESPFIX as such.  64-bit kernels directly choose
-	 * whether to apply espfix using paravirt hooks.  If any
-	 * non-paravirt system ever shows up that does *not* have the
-	 * ESPFIX issue, we can change this.
-	 */
-#ifdef CONFIG_X86_32
-#ifdef CONFIG_PARAVIRT
-	do {
-		extern void native_iret(void);
-		if (pv_cpu_ops.iret == native_iret)
-			set_cpu_bug(c, X86_BUG_ESPFIX);
-	} while (0);
-#else
-	set_cpu_bug(c, X86_BUG_ESPFIX);
-#endif
-#endif
 }
 
 static void detect_null_seg_behavior(struct cpuinfo_x86 *c)
@@ -952,6 +927,31 @@ static void generic_identify(struct cpuinfo_x86 *c)
 	detect_nopl(c);
 
 	detect_null_seg_behavior(c);
+
+	/*
+	 * ESPFIX is a strange bug.  All real CPUs have it.  Paravirt
+	 * systems that run Linux at CPL > 0 may or may not have the
+	 * issue, but, even if they have the issue, there's absolutely
+	 * nothing we can do about it because we can't use the real IRET
+	 * instruction.
+	 *
+	 * NB: For the time being, only 32-bit kernels support
+	 * X86_BUG_ESPFIX as such.  64-bit kernels directly choose
+	 * whether to apply espfix using paravirt hooks.  If any
+	 * non-paravirt system ever shows up that does *not* have the
+	 * ESPFIX issue, we can change this.
+	 */
+#ifdef CONFIG_X86_32
+# ifdef CONFIG_PARAVIRT
+	do {
+		extern void native_iret(void);
+		if (pv_cpu_ops.iret == native_iret)
+			set_cpu_bug(c, X86_BUG_ESPFIX);
+	} while (0);
+# else
+	set_cpu_bug(c, X86_BUG_ESPFIX);
+# endif
+#endif
 }
 
 static void x86_init_cache_qos(struct cpuinfo_x86 *c)