[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>

1 files changed, 17 insertions, 0 deletions

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index cb66b5745fa0..006f09218ae7 100644
--- 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)