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authorNicolas Pitre <nicolas.pitre@linaro.org>2013-08-14 22:36:32 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2013-08-20 00:25:31 +0100
commitac124504ecf6b20a2457d873d0728a8b991a5b0c (patch)
tree6fe1664e434c849b49199674a92a779e4eadad34 /arch/arm/mm
parent7cb3be0a27805c625ff7cce20c53c926d9483243 (diff)
ARM: 7816/1: CONFIG_KUSER_HELPERS: fix help text
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. Cc: <stable@vger.kernel.org> Signed-off-by: Nicolas Pitre <nico@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/Kconfig9
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index db5c2cab8fd..cd2c88e7a8f 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -809,15 +809,18 @@ 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.