[PATCH 4.18 13/79] x86/bugs: Move the l1tf function and define pr_fmt properly

From: Greg Kroah-Hartman
Date: Tue Aug 14 2018 - 13:24:22 EST


4.18-stable review patch. If anyone has any objections, please let me know.

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

From: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>

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@xxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -211,32 +211,6 @@ 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 CONFIG_PGTABLE_LEVELS == 2
- 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__mapped_any(half_pa, ULLONG_MAX - half_pa, E820_TYPE_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;

@@ -660,6 +634,35 @@ 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 CONFIG_PGTABLE_LEVELS == 2
+ 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__mapped_any(half_pa, ULLONG_MAX - half_pa, E820_TYPE_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,