linux-kernel - [PATCH 3.16 109/131] x86/bugs: Move the l1tf function and define pr

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Message-ID: <lsq.1538257387.17469208@decadent.org.uk>
Date:   Sat, 29 Sep 2018 22:43:07 +0100
From:   Ben Hutchings <ben@...adent.org.uk>
To:     linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:     akpm@...ux-foundation.org, "David Woodhouse" <dwmw@...zon.co.uk>,
        "Greg Kroah-Hartman" <gregkh@...uxfoundation.org>,
        "Thomas Gleixner" <tglx@...utronix.de>,
        "Konrad Rzeszutek Wilk" <konrad.wilk@...cle.com>,
        "Guenter Roeck" <linux@...ck-us.net>
Subject: [PATCH 3.16 109/131] x86/bugs: Move the l1tf function and define
 pr_fmt properly

3.16.59-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>

commit 56563f53d3066afa9e63d6c997bf67e76a8b05c0 upstream.

The pr_warn in l1tf_select_mitigation would have used the prior pr_fmt
which was defined as "Spectre V2 : ".

Move the function to be past SSBD and also define the pr_fmt.

Fixes: 17dbca119312 ("x86/speculation/l1tf: Add sysfs reporting for l1tf")
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>
Signed-off-by: Thomas Gleixner <tglx@...utronix.de>
Signed-off-by: David Woodhouse <dwmw@...zon.co.uk>
Signed-off-by: Guenter Roeck <linux@...ck-us.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 arch/x86/kernel/cpu/bugs.c | 55 ++++++++++++++++++++------------------
 1 file changed, 29 insertions(+), 26 deletions(-)

--- a/arch/x86/kernel/cpu/bugs.c
+++ b/arch/x86/kernel/cpu/bugs.c
@@ -270,32 +270,6 @@ static void x86_amd_ssb_disable(void)
 		wrmsrl(MSR_AMD64_LS_CFG, msrval);
 }
 
-static void __init l1tf_select_mitigation(void)
-{
-	u64 half_pa;
-
-	if (!boot_cpu_has_bug(X86_BUG_L1TF))
-		return;
-
-#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
-	pr_warn("Kernel not compiled for PAE. No mitigation for L1TF\n");
-	return;
-#endif
-
-	/*
-	 * This is extremely unlikely to happen because almost all
-	 * systems have far more MAX_PA/2 than RAM can be fit into
-	 * DIMM slots.
-	 */
-	half_pa = (u64)l1tf_pfn_limit() << PAGE_SHIFT;
-	if (e820_any_mapped(half_pa, ULLONG_MAX - half_pa, E820_RAM)) {
-		pr_warn("System has more than MAX_PA/2 memory. L1TF mitigation not effective.\n");
-		return;
-	}
-
-	setup_force_cpu_cap(X86_FEATURE_L1TF_PTEINV);
-}
-
 #ifdef RETPOLINE
 static bool spectre_v2_bad_module;
 
@@ -721,6 +695,35 @@ void x86_spec_ctrl_setup_ap(void)
 		x86_amd_ssb_disable();
 }
 
+#undef pr_fmt
+#define pr_fmt(fmt)	"L1TF: " fmt
+static void __init l1tf_select_mitigation(void)
+{
+	u64 half_pa;
+
+	if (!boot_cpu_has_bug(X86_BUG_L1TF))
+		return;
+
+#if defined(CONFIG_X86_32) && !defined(CONFIG_X86_PAE)
+	pr_warn("Kernel not compiled for PAE. No mitigation for L1TF\n");
+	return;
+#endif
+
+	/*
+	 * This is extremely unlikely to happen because almost all
+	 * systems have far more MAX_PA/2 than RAM can be fit into
+	 * DIMM slots.
+	 */
+	half_pa = (u64)l1tf_pfn_limit() << PAGE_SHIFT;
+	if (e820_any_mapped(half_pa, ULLONG_MAX - half_pa, E820_RAM)) {
+		pr_warn("System has more than MAX_PA/2 memory. L1TF mitigation not effective.\n");
+		return;
+	}
+
+	setup_force_cpu_cap(X86_FEATURE_L1TF_PTEINV);
+}
+#undef pr_fmt
+
 #ifdef CONFIG_SYSFS
 
 static ssize_t cpu_show_common(struct device *dev, struct device_attribute *attr,