From a0fe2c6479aab5723239b315ef1b552673f434a3 Mon Sep 17 00:00:00 2001
From: Jann Horn <jannh@google.com>
Date: Fri, 29 Mar 2019 22:46:49 +0100
Subject: [PATCH 1/2] linux/kernel.h: Use parentheses around argument in
 u64_to_user_ptr()

Use parentheses around uses of the argument in u64_to_user_ptr() to
ensure that the cast doesn't apply to part of the argument.

There are existing uses of the macro of the form

  u64_to_user_ptr(A + B)

which expands to

  (void __user *)(uintptr_t)A + B

(the cast applies to the first operand of the addition, the addition
is a pointer addition). This happens to still work as intended, the
semantic difference doesn't cause a difference in behavior.

But I want to use u64_to_user_ptr() with a ternary operator in the
argument, like so:

  u64_to_user_ptr(A ? B : C)

This currently doesn't work as intended.

Signed-off-by: Jann Horn <jannh@google.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Mukesh Ojha <mojha@codeaurora.org>
Cc: Andrei Vagin <avagin@openvz.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jani Nikula <jani.nikula@intel.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Cc: NeilBrown <neilb@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Qiaowei Ren <qiaowei.ren@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190329214652.258477-1-jannh@google.com
---
 include/linux/kernel.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/include/linux/kernel.h b/include/linux/kernel.h
index 34a5036debd3..2d14e21c16c0 100644
--- a/include/linux/kernel.h
+++ b/include/linux/kernel.h
@@ -47,8 +47,8 @@
 
 #define u64_to_user_ptr(x) (		\
 {					\
-	typecheck(u64, x);		\
-	(void __user *)(uintptr_t)x;	\
+	typecheck(u64, (x));		\
+	(void __user *)(uintptr_t)(x);	\
 }					\
 )
 

From 4fa5ecda2bf96be7464eb406df8aba9d89260227 Mon Sep 17 00:00:00 2001
From: Josh Poimboeuf <jpoimboe@redhat.com>
Date: Thu, 4 Apr 2019 12:17:35 -0500
Subject: [PATCH 2/2] objtool: Add rewind_stack_do_exit() to the noreturn list

This fixes the following warning seen on GCC 7.3:

  arch/x86/kernel/dumpstack.o: warning: objtool: oops_end() falls through to next function show_regs()

Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lkml.kernel.org/r/3418ebf5a5a9f6ed7e80954c741c0b904b67b5dc.1554398240.git.jpoimboe@redhat.com
---
 tools/objtool/check.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/tools/objtool/check.c b/tools/objtool/check.c
index 5dde107083c6..479196aeb409 100644
--- a/tools/objtool/check.c
+++ b/tools/objtool/check.c
@@ -165,6 +165,7 @@ static int __dead_end_function(struct objtool_file *file, struct symbol *func,
 		"fortify_panic",
 		"usercopy_abort",
 		"machine_real_restart",
+		"rewind_stack_do_exit",
 	};
 
 	if (func->bind == STB_WEAK)