The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 467a3bf219cee12259182c5cb4821f88fd518a51 Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Date: Mon, 23 Apr 2018 14:31:36 +0200
Subject: [PATCH] s390/crc32-vx: use expoline for indirect branches
The return from the crc32_le_vgfm_16/crc32c_le_vgfm_16 and the
crc32_be_vgfm_16 functions are done with "br %r14". These are indirect
branches as well and need to use execute trampolines for CONFIG_EXPOLINE=y.
Cc: stable@xxxxxxxxxxxxxxx # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Reviewed-by: Hendrik Brueckner <brueckner@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
diff --git a/arch/s390/crypto/crc32be-vx.S b/arch/s390/crypto/crc32be-vx.S
index e8077f0971f8..2bf01ba44107 100644
--- a/arch/s390/crypto/crc32be-vx.S
+++ b/arch/s390/crypto/crc32be-vx.S
@@ -13,6 +13,7 @@
*/
#include <linux/linkage.h>
+#include <asm/nospec-insn.h>
#include <asm/vx-insn.h>
/* Vector register range containing CRC-32 constants */
@@ -67,6 +68,8 @@
.previous
+ GEN_BR_THUNK %r14
+
.text
/*
* The CRC-32 function(s) use these calling conventions:
@@ -203,6 +206,6 @@ ENTRY(crc32_be_vgfm_16)
.Ldone:
VLGVF %r2,%v2,3
- br %r14
+ BR_EX %r14
.previous
diff --git a/arch/s390/crypto/crc32le-vx.S b/arch/s390/crypto/crc32le-vx.S
index d8c67a58c0c5..7d6f568bd3ad 100644
--- a/arch/s390/crypto/crc32le-vx.S
+++ b/arch/s390/crypto/crc32le-vx.S
@@ -14,6 +14,7 @@
*/
#include <linux/linkage.h>
+#include <asm/nospec-insn.h>
#include <asm/vx-insn.h>
/* Vector register range containing CRC-32 constants */
@@ -76,6 +77,7 @@
.previous
+ GEN_BR_THUNK %r14
.text
@@ -264,6 +266,6 @@ crc32_le_vgfm_generic:
.Ldone:
VLGVF %r2,%v2,2
- br %r14
+ BR_EX %r14
.previous
