linux-kernel - [RFC PATCH 6/6] x86/fpu: Fix the "Giving up, no FPU found" test

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Message-Id: <9bb4f6c812ae632ae26676ed6862cc1b51d44657.1480985979.git.luto@kernel.org>
Date:   Mon,  5 Dec 2016 17:01:15 -0800
From:   Andy Lutomirski <luto@...nel.org>
To:     x86@...nel.org
Cc:     One Thousand Gnomes <gnomes@...rguk.ukuu.org.uk>,
        Borislav Petkov <bp@...en8.de>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Brian Gerst <brgerst@...il.com>,
        Matthew Whitehead <tedheadster@...il.com>,
        Andy Lutomirski <luto@...nel.org>
Subject: [RFC PATCH 6/6] 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>
---
 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 75e1bf3b0319..d41924a72576 100644
--- a/arch/x86/kernel/fpu/init.c
+++ b/arch/x86/kernel/fpu/init.c
@@ -80,7 +80,7 @@ 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");
-- 
2.9.3