[ARM] 3112/1: old ABI compat: config option to turn it on

Patch from Nicolas Pitre

Enjoy !

Signed-off-by: Nicolas Pitre <nico@cam.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index cb66b5745fa0eb1ceb462ca8b9db95b713750c25..006f09218ae7418a870aa1370f78bc15678f218b 100644 (file)
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -416,6 +416,23 @@ config AEABI
 
          To use this you need GCC version 4.0.0 or later.
 
+config OABI_COMPAT
+       bool "Allow old ABI binaries to run with this kernel"
+       depends on AEABI
+       default y
+       help
+         This option preserves the old syscall interface along with the
+         new (ARM EABI) one. It also provides a compatibility layer to
+         intercept syscalls that have structure arguments which layout
+         in memory differs between the legacy ABI and the new ARM EABI
+         (only for non "thumb" binaries). This option adds a tiny
+         overhead to all syscalls and produces a slightly larger kernel.
+         If you know you'll be using only pure EABI user space then you
+         can say N here. If this option is not selected and you attempt
+         to execute a legacy ABI binary then the result will be
+         UNPREDICTABLE (in fact it can be predicted that it won't work
+         at all). If in doubt say Y.
+
 config ARCH_DISCONTIGMEM_ENABLE
        bool
        default (ARCH_LH7A40X && !LH7A40X_CONTIGMEM)