linux-kernel - [tip:x86/fpu] x86/fpu: Fix the "Giving up, no FPU found" test

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Date:   Wed, 25 Jan 2017 03:43:07 -0800
From:   tip-bot for Andy Lutomirski <tipbot@...or.com>
To:     linux-tip-commits@...r.kernel.org
Cc:     hpa@...or.com, yu-cheng.yu@...el.com, gnomes@...rguk.ukuu.org.uk,
        dave.hansen@...ux.intel.com, linux-kernel@...r.kernel.org,
        bp@...e.de, bp@...en8.de, mingo@...nel.org,
        torvalds@...ux-foundation.org, tglx@...utronix.de, oleg@...hat.com,
        riel@...hat.com, peterz@...radead.org, tedheadster@...il.com,
        luto@...nel.org, fenghua.yu@...el.com, brgerst@...il.com
Subject: [tip:x86/fpu] x86/fpu: Fix the "Giving up, no FPU found" test

Commit-ID:  9729017f844431ab2800519297d8d1b0ecbc420d
Gitweb:     http://git.kernel.org/tip/9729017f844431ab2800519297d8d1b0ecbc420d
Author:     Andy Lutomirski <luto@...nel.org>
AuthorDate: Wed, 18 Jan 2017 11:15:42 -0800
Committer:  Ingo Molnar <mingo@...nel.org>
CommitDate: Wed, 25 Jan 2017 10:12:44 +0100

x86/fpu: Fix the "Giving up, no FPU found" test

We would never print "Giving up, no FPU found" because
X86_FEATURE_FPU was in REQUIRED_MASK on non-FPU-emulating builds, so
the boot_cpu_has() test didn't do anything.

Signed-off-by: Andy Lutomirski <luto@...nel.org>
Reviewed-by: Borislav Petkov <bp@...e.de>
Cc: Borislav Petkov <bp@...en8.de>
Cc: Brian Gerst <brgerst@...il.com>
Cc: Dave Hansen <dave.hansen@...ux.intel.com>
Cc: Fenghua Yu <fenghua.yu@...el.com>
Cc: H. Peter Anvin <hpa@...or.com>
Cc: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: Matthew Whitehead <tedheadster@...il.com>
Cc: Oleg Nesterov <oleg@...hat.com>
Cc: One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>
Cc: Peter Zijlstra <peterz@...radead.org>
Cc: Rik van Riel <riel@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>
Cc: Yu-cheng Yu <yu-cheng.yu@...el.com>
Link: http://lkml.kernel.org/r/1499077fa76f0f84b8ea28e37d3fa70beca4e310.1484705016.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@...nel.org>
---
 arch/x86/kernel/fpu/init.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kernel/fpu/init.c b/arch/x86/kernel/fpu/init.c
index 8b526c5..19bdd1b 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -77,7 +77,7 @@ static void fpu__init_system_early_generic(struct cpuinfo_x86 *c)
 	}
 
 #ifndef CONFIG_MATH_EMULATION
-	if (!boot_cpu_has(X86_FEATURE_FPU)) {
+	if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_FPU)) {
 		pr_emerg("x86/fpu: Giving up, no FPU found and no math emulation present\n");
 		for (;;)
 			asm volatile("hlt");