From: Ankur Arora <ankur.a.arora@oracle.com>
Date: Wed, 25 Apr 2018 21:38:58 +0000 (-0400)
Subject: x86/cpufeatures: use cpu_data in init_scattered_cpuid_flags()
X-Git-Tag: v4.1.12-124.31.3~815
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=0fa448d49af55bf1215b2afa5548b8f95c34be67;p=users%2Fjedix%2Flinux-maple.git

x86/cpufeatures: use cpu_data in init_scattered_cpuid_flags()

Post SMP init, cpu_data() contains the current cpuinfo state with
the boot_cpu_data potentially going stale.

Switch all boot_cpu_data references to cpu_data() in
init_scattered_cpuid_flags().

Orabug: 27878230

Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Reviewed-by: Krish Sadhukhan <krish.sadhukhan@oracle.com>
Reviewed-by: John Haxby <john.haxby@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

(cherry-picked from commit 6258d6d6ce2b9cf41830e8616ffc7841b3fddca9)

Conflict:
  arch/x86/kernel/cpu/common.c

[Backport: Modify init_scattered_cpuid_flags() instead of
 init_speculation_control().]

Signed-off-by: Brian Maly <brian.maly@oracle.com>
---

diff --git a/arch/x86/kernel/cpu/scattered.c b/arch/x86/kernel/cpu/scattered.c
index aceb904642fa..4cbbf2520bdd 100644
--- a/arch/x86/kernel/cpu/scattered.c
+++ b/arch/x86/kernel/cpu/scattered.c
@@ -160,13 +160,13 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c,
 		if (xen_pv_domain())
 			ignore = true;
 
-		if (boot_cpu_has(X86_FEATURE_IBRS)) {
+		if (cpu_has(c, X86_FEATURE_IBRS)) {
 			printk_once(KERN_INFO "FEATURE SPEC_CTRL Present%s\n",
 				    ignore ? " but ignored (Xen)": "");
 		} else {
 			printk(KERN_INFO "FEATURE SPEC_CTRL Not Present\n");
 		}
-		if (boot_cpu_has(X86_FEATURE_IBPB)) {
+		if (cpu_has(c, X86_FEATURE_IBPB)) {
 			printk_once(KERN_INFO "FEATURE IBPB Present%s\n",
 					    ignore ? " but ignored (Xen)": "");
 		} else {
@@ -178,14 +178,14 @@ void init_scattered_cpuid_features(struct cpuinfo_x86 *c,
 
 	if ((cpu_has(c, X86_FEATURE_IBRS) ||
 	     cpu_has(c, X86_FEATURE_STIBP)) && bad_spectre_microcode(c)) {
-		if (&boot_cpu_data == c)
+		if (c->cpu_index == 0)
 			pr_warn("Intel Spectre v2 broken microcode detected; disabling SPEC_CTRL/IBRS\n");
 		clear_cpu_cap(c, X86_FEATURE_IBRS);
 		clear_cpu_cap(c, X86_FEATURE_IBPB);
 		clear_cpu_cap(c, X86_FEATURE_STIBP);
 	}
 
-	if (&boot_cpu_data == c) {
+	if (c->cpu_index == 0) {
 		mutex_lock(&spec_ctrl_mutex);
 		if (cpu_has(c, X86_FEATURE_IBRS)) {
 			set_ibrs_supported();