FAILED: patch "[PATCH] s390: correct module section names for expoline code revert" failed to apply to 4.16-stable tree

FAILED: patch "[PATCH] s390: correct module section names for expoline code revert" failed to apply to 4.16-stable tree

[gregkh]

The patch below does not apply to the 4.16-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@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 6cf09958f32b9667bb3ebadf74367c791112771b Mon Sep 17 00:00:00 2001
From: Martin Schwidefsky <schwidefsky@de.ibm.com>
Date: Fri, 20 Apr 2018 12:48:52 +0200
Subject: [PATCH] s390: correct module section names for expoline code revert

The main linker script vmlinux.lds.S for the kernel image merges
the expoline code patch tables into two section ".nospec_call_table"
and ".nospec_return_table". This is *not* done for the modules,
there the sections retain their original names as generated by gcc:
".s390_indirect_call", ".s390_return_mem" and ".s390_return_reg".

The module_finalize code has to check for the compiler generated
section names, otherwise no code patching is done. This slows down
the module code in case of "spectre_v2=off".

Cc: stable@vger.kernel.org # 4.16
Fixes: f19fbd5ed6 ("s390: introduce execute-trampolines for branches")
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index 5a83be955c70..0dc8ac8548ee 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -465,11 +465,11 @@ int module_finalize(const Elf_Ehdr *hdr,
 			apply_alternatives(aseg, aseg + s->sh_size);
 
 		if (IS_ENABLED(CONFIG_EXPOLINE) &&
-		    (!strcmp(".nospec_call_table", secname)))
+		    (!strncmp(".s390_indirect", secname, 14)))
 			nospec_revert(aseg, aseg + s->sh_size);
 
 		if (IS_ENABLED(CONFIG_EXPOLINE) &&
-		    (!strcmp(".nospec_return_table", secname)))
+		    (!strncmp(".s390_return", secname, 12)))
 			nospec_revert(aseg, aseg + s->sh_size);
 	}