linux-kernel - [PATCH] module: set __jump

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170301220453.4756-1-david.daney@cavium.com>
Date:   Wed,  1 Mar 2017 14:04:53 -0800
From:   David Daney <david.daney@...ium.com>
To:     Jason Baron <jbaron@...mai.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Michael Ellerman <mpe@...erman.id.au>,
        Sachin Sant <sachinp@...ux.vnet.ibm.com>,
        linux-kernel@...r.kernel.org
Cc:     linux-mips@...ux-mips.org, linuxppc-dev@...ts.ozlabs.org,
        linux-arm-kernel@...ts.infradead.org,
        Chris Metcalf <cmetcalf@...lanox.com>,
        Ralf Baechle <ralf@...ux-mips.org>,
        Russell King <linux@...linux.org.uk>,
        Rabin Vincent <rabin@....in>,
        Paul Mackerras <paulus@...ba.org>,
        Anton Blanchard <anton@...ba.org>,
        Ingo Molnar <mingo@...nel.org>, Zhigang Lu <zlu@...hip.com>,
        David Daney <david.daney@...ium.com>
Subject: [PATCH] module: set __jump_table alignment to 8

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.

Signed-off-by: David Daney <david.daney@...ium.com>
Tested-by: Sachin Sant <sachinp@...ux.vnet.ibm.com>
---
 scripts/module-common.lds | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/scripts/module-common.lds b/scripts/module-common.lds
index 73a2c7d..53234e8 100644
--- 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)) }
 }
-- 
2.9.3