Patch "module: set __jump_table alignment to 8" has been added to the 4.9-stable tree

Patch "module: set __jump_table alignment to 8" has been added to the 4.9-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    module: set __jump_table alignment to 8

to the 4.9-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     module-set-__jump_table-alignment-to-8.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Tue Dec 12 13:26:17 CET 2017
From: David Daney <david.daney@cavium.com>
Date: Wed, 1 Mar 2017 14:04:53 -0800
Subject: module: set __jump_table alignment to 8

From: David Daney <david.daney@cavium.com>


[ Upstream commit ab42632156becd35d3884ee5c14da2bedbf3149a ]

For powerpc the __jump_table section in modules is not aligned, this
causes a WARN_ON() splat when loading a module containing a __jump_table.

Strict alignment became necessary with commit 3821fd35b58d
("jump_label: Reduce the size of struct static_key"), currently in
linux-next, which uses the two least significant bits of pointers to
__jump_table elements.

Fix by forcing __jump_table to 8, which is the same alignment used for
this section in the kernel proper.

Link: http://lkml.kernel.org/r/20170301220453.4756-1-david.daney@cavium.com

Reviewed-by: Jason Baron <jbaron@akamai.com>
Acked-by: Jessica Yu <jeyu@redhat.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Tested-by: Sachin Sant <sachinp@linux.vnet.ibm.com>
Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 scripts/module-common.lds |    2 ++
 1 file changed, 2 insertions(+)

--- a/scripts/module-common.lds
+++ b/scripts/module-common.lds
@@ -19,4 +19,6 @@ SECTIONS {
 
 	. = ALIGN(8);
 	.init_array		0 : { *(SORT(.init_array.*)) *(.init_array) }
+
+	__jump_table		0 : ALIGN(8) { KEEP(*(__jump_table)) }
 }


Patches currently in stable-queue which might be from david.daney@cavium.com are

queue-4.9/module-set-__jump_table-alignment-to-8.patch