module: Add retpoline tag to VERMAGIC

Add a marker for retpoline to the module VERMAGIC. This catches the case
when a non RETPOLINE compiled module gets loaded into a retpoline kernel,
making it insecure.

It doesn't handle the case when retpoline has been runtime disabled.  Even
in this case the match of the retcompile status will be enforced.  This
implies that even with retpoline run time disabled all modules loaded need
to be recompiled.

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: David Woodhouse <dwmw@amazon.co.uk>
Cc: rusty@rustcorp.com.au
Cc: arjan.van.de.ven@intel.com
Cc: jeyu@kernel.org
Cc: torvalds@linux-foundation.org
Link: https://lkml.kernel.org/r/20180116205228.4890-1-andi@firstfloor.org
This commit is contained in:
Andi Kleen 2018-01-16 12:52:28 -08:00 committed by Thomas Gleixner
parent 4fdec2034b
commit 6cfb521ac0

View File

@ -31,11 +31,17 @@
#else
#define MODULE_RANDSTRUCT_PLUGIN
#endif
#ifdef RETPOLINE
#define MODULE_VERMAGIC_RETPOLINE "retpoline "
#else
#define MODULE_VERMAGIC_RETPOLINE ""
#endif
#define VERMAGIC_STRING \
UTS_RELEASE " " \
MODULE_VERMAGIC_SMP MODULE_VERMAGIC_PREEMPT \
MODULE_VERMAGIC_MODULE_UNLOAD MODULE_VERMAGIC_MODVERSIONS \
MODULE_ARCH_VERMAGIC \
MODULE_RANDSTRUCT_PLUGIN
MODULE_RANDSTRUCT_PLUGIN \
MODULE_VERMAGIC_RETPOLINE