From bc4f2f5469ac2a52affadc4c00c1276d76151a39 Mon Sep 17 00:00:00 2001
From: Kees Cook <keescook@chromium.org>
Date: Tue, 10 Apr 2018 16:32:33 -0700
Subject: [PATCH] taint: add taint for randstruct
Since the randstruct plugin can intentionally produce extremely unusual
kernel structure layouts (even performance pathological ones), some
maintainers want to be able to trivially determine if an Oops is coming
from a randstruct-built kernel, so as to keep their sanity when
debugging. This adds the new flag and initializes taint_mask
immediately when built with randstruct.
Link: http://lkml.kernel.org/r/1519084390-43867-4-git-send-email-keescook@chromium.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
Documentation/sysctl/kernel.txt | 1 +
include/linux/kernel.h | 3 ++-
kernel/panic.c | 4 +++-
3 files changed, 6 insertions(+), 2 deletions(-)
diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt
index 4a890c7fb6c33..eded671d55eb2 100644
--- a/Documentation/sysctl/kernel.txt
+++ b/Documentation/sysctl/kernel.txt
@@ -991,6 +991,7 @@ ORed together. The letters are seen in "Tainted" line of Oops reports.
16384 (L): A soft lockup has previously occurred on the system.
32768 (K): The kernel has been live patched.
65536 (X): Auxiliary taint, defined and used by for distros.
+131072 (T): The kernel was built with the struct randomization plugin.
==============================================================
diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 086e8e80f7658..6a1eb0b0aad96 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -562,7 +562,8 @@ extern enum system_states {
#define TAINT_SOFTLOCKUP 14
#define TAINT_LIVEPATCH 15
#define TAINT_AUX 16
-#define TAINT_FLAGS_COUNT 17
+#define TAINT_RANDSTRUCT 17
+#define TAINT_FLAGS_COUNT 18
struct taint_flag {
char c_true; /* character printed when tainted */
diff --git a/kernel/panic.c b/kernel/panic.c
index 5ceb9cbec4a26..42e4874885542 100644
--- a/kernel/panic.c
+++ b/kernel/panic.c
@@ -34,7 +34,8 @@
#define PANIC_BLINK_SPD 18
int panic_on_oops = CONFIG_PANIC_ON_OOPS_VALUE;
-static unsigned long tainted_mask;
+static unsigned long tainted_mask =
+ IS_ENABLED(CONFIG_GCC_PLUGIN_RANDSTRUCT) ? (1 << TAINT_RANDSTRUCT) : 0;
static int pause_on_oops;
static int pause_on_oops_flag;
static DEFINE_SPINLOCK(pause_on_oops_lock);
@@ -325,6 +326,7 @@ const struct taint_flag taint_flags[TAINT_FLAGS_COUNT] = {
[ TAINT_SOFTLOCKUP ] = { 'L', ' ', false },
[ TAINT_LIVEPATCH ] = { 'K', ' ', true },
[ TAINT_AUX ] = { 'X', ' ', true },
+ [ TAINT_RANDSTRUCT ] = { 'T', ' ', true },
};
/**
--
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