[tip:x86/pti] x86/retpoline/checksum32: Convert assembler indirect jumps - tip-bot for David Woodhouse

From: tip-bot for David Woodhouse <tipbot@zytor.com>
To: linux-tip-commits@vger.kernel.org
Cc: jikos@kernel.org, hpa@zytor.com, mingo@kernel.org,
	linux-kernel@vger.kernel.org, tim.c.chen@linux.intel.com,
	riel@redhat.com, torvalds@linux-foundation.org,
	ak@linux.intel.com, peterz@infradead.org, arjan@linux.intel.com,
	tglx@linutronix.de, luto@amacapital.net,
	gregkh@linux-foundation.org, jpoimboe@redhat.com,
	dave.hansen@intel.com, keescook@google.com, dwmw@amazon.co.uk,
	pjt@google.com
Subject: [tip:x86/pti] x86/retpoline/checksum32: Convert assembler indirect jumps
Date: Thu, 11 Jan 2018 15:26:19 -0800	[thread overview]
Message-ID: <tip-5096732f6f695001fa2d6f1335a2680b37912c69@git.kernel.org> (raw)
In-Reply-To: <1515707194-20531-11-git-send-email-dwmw@amazon.co.uk>

Commit-ID:  5096732f6f695001fa2d6f1335a2680b37912c69
Gitweb:     https://git.kernel.org/tip/5096732f6f695001fa2d6f1335a2680b37912c69
Author:     David Woodhouse <dwmw@amazon.co.uk>
AuthorDate: Thu, 11 Jan 2018 21:46:32 +0000
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Fri, 12 Jan 2018 00:14:31 +0100

x86/retpoline/checksum32: Convert assembler indirect jumps

Convert all indirect jumps in 32bit checksum assembler code to use
non-speculative sequences when CONFIG_RETPOLINE is enabled.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: Rik van Riel <riel@redhat.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: thomas.lendacky@amd.com
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Jiri Kosina <jikos@kernel.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Kees Cook <keescook@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Greg Kroah-Hartman <gregkh@linux-foundation.org>
Cc: Paul Turner <pjt@google.com>
Link: https://lkml.kernel.org/r/1515707194-20531-11-git-send-email-dwmw@amazon.co.uk

---
 arch/x86/lib/checksum_32.S | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/arch/x86/lib/checksum_32.S b/arch/x86/lib/checksum_32.S
index 4d34bb5..46e71a7 100644
--- a/arch/x86/lib/checksum_32.S
+++ b/arch/x86/lib/checksum_32.S
@@ -29,7 +29,8 @@
 #include <asm/errno.h>
 #include <asm/asm.h>
 #include <asm/export.h>
-				
+#include <asm/nospec-branch.h>
+
 /*
  * computes a partial checksum, e.g. for TCP/UDP fragments
  */
@@ -156,7 +157,7 @@ ENTRY(csum_partial)
 	negl %ebx
 	lea 45f(%ebx,%ebx,2), %ebx
 	testl %esi, %esi
-	jmp *%ebx
+	JMP_NOSPEC %ebx
 
 	# Handle 2-byte-aligned regions
 20:	addw (%esi), %ax
@@ -439,7 +440,7 @@ ENTRY(csum_partial_copy_generic)
 	andl $-32,%edx
 	lea 3f(%ebx,%ebx), %ebx
 	testl %esi, %esi 
-	jmp *%ebx
+	JMP_NOSPEC %ebx
 1:	addl $64,%esi
 	addl $64,%edi 
 	SRC(movb -32(%edx),%bl)	; SRC(movb (%edx),%bl)
