From 4f386914abf8bc5db0eb1b02c15aae68b181a357 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Tue, 1 May 2018 15:31:45 -0700
Subject: [PATCH] proc: Provide details on speculation flaw mitigations

As done with seccomp and no_new_privs, also show speculation flaw
mitigation state in /proc/$pid/status.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

CVE-2018-3639 (x86)

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
---
 fs/proc/array.c | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/fs/proc/array.c b/fs/proc/array.c
index d67a72dcb92c..4944a94a00ef 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -85,6 +85,7 @@
 #include <linux/delayacct.h>
 #include <linux/seq_file.h>
 #include <linux/pid_namespace.h>
+#include <linux/prctl.h>
 #include <linux/ptrace.h>
 #include <linux/tracehook.h>
 #include <linux/string_helpers.h>
@@ -347,6 +348,27 @@ static inline void task_seccomp(struct seq_file *m, struct task_struct *p)
 #ifdef CONFIG_SECCOMP
 	seq_put_decimal_ull(m, "\nSeccomp:\t", p->seccomp.mode);
 #endif
+	seq_printf(m, "\nSpeculation Store Bypass:\t");
+	switch (arch_prctl_spec_ctrl_get(p, PR_SPEC_STORE_BYPASS)) {
+	case -EINVAL:
+		seq_printf(m, "unknown");
+		break;
+	case PR_SPEC_NOT_AFFECTED:
+		seq_printf(m, "not vulnerable");
+		break;
+	case PR_SPEC_PRCTL | PR_SPEC_DISABLE:
+		seq_printf(m, "thread mitigated");
+		break;
+	case PR_SPEC_PRCTL | PR_SPEC_ENABLE:
+		seq_printf(m, "thread vulnerable");
+		break;
+	case PR_SPEC_DISABLE:
+		seq_printf(m, "globally mitigated");
+		break;
+	default:
+		seq_printf(m, "vulnerable");
+		break;
+	}
 	seq_putc(m, '\n');
 }
 
-- 
2.39.2