@@ -768,15 +768,18 @@ config KUSER_HELPERS
the CPU type fitted to the system. This permits binaries to be
run on ARMv4 through to ARMv7 without modification.
+ See Documentation/arm/kernel_user_helpers.txt for details.
+
However, the fixed address nature of these helpers can be used
by ROP (return orientated programming) authors when creating
exploits.
If all of the binaries and libraries which run on your platform
are built specifically for your platform, and make no use of
- these helpers, then you can turn this option off. However,
- when such an binary or library is run, it will receive a SIGILL
- signal, which will terminate the program.
+ these helpers, then you can turn this option off to hinder
+ such exploits. However, in that case, if a binary or library
+ relying on those helpers is run, it will receive a SIGILL signal,
+ which will terminate the program.
Say N here only if you are absolutely certain that you do not
need these helpers; otherwise, the safe option is to say Y.
This is a note to let you know that I have just added a patch titled ARM: 7816/1: CONFIG_KUSER_HELPERS: fix help text to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.5.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From 408c1c5e3bd4e58ade6734870ba6fbf49601ac6a Mon Sep 17 00:00:00 2001 From: Nicolas Pitre <nicolas.pitre@linaro.org> Date: Wed, 14 Aug 2013 22:36:32 +0100 Subject: [PATCH] ARM: 7816/1: CONFIG_KUSER_HELPERS: fix help text commit ac124504ecf6b20a2457d873d0728a8b991a5b0c upstream. Commit f6f91b0d9fd9 ("ARM: allow kuser helpers to be removed from the vector page") introduced some help text for the CONFIG_KUSER_HELPERS option which is rather contradictory. Let's fix that, and improve it a little. Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- arch/arm/mm/Kconfig | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) -- 1.8.3.2