CONFIG_ASYNC_XOR not visible through menuconfig/gconfig

Question

Hello everyone,

I am using linux kernel version 2.6.26.8 and I need to use async_XXX (async_xor, async_memcpy etc) API. So I need to build the ASYNC_XXX modules with my kernel. But I can't see the config options related to ASYNC_XOR or ASYNC_MEMCPY etc through menuconfig or gconfig under Security Options.

In gconfig if I select show all options I can see these config options under "Security Options" but I can't select them.

I am not sure if this is because of some missing prerequisite CONFIG options in my config file or something else. I could directly add these options in the config file manually but I wanted to be sure it won't have any side effects.

I am posting the Security Options portion of my working .config file here...

#

Security options

#

CONFIG_KEYS is not set

CONFIG_SECURITY is not set

CONFIG_SECURITY_FILE_CAPABILITIES is not set

CONFIG_CRYPTO=y

Thanking you in advance.

Regards, Vikash Kumar

Answer 1

The quick answer is there isn't a menu option to select these items; instead, they need to be selected indirectly via a second option.

Looking at crypto/async_tx/Kconfig you can see the various options in question (ASYNC_XOR, ASYNC_MEMCPY, etc), but none of the tristate options have a prompt string. Without a prompt string, you will not see the option when running something like gconfig or menuconfig.

Take a look at the RAID4/5/6 driver (drivers/md/Kconfig) configuration. Selecting this driver indirectly selects ASYNC_MEMCPY and ASYNC_XOR. If you are developing a driver that needs these options, you should consider selecting these options in the driver's config block. Alternatively, if this is a platform wide feature, you might consider selecting these options in the config block of whichever arch/*/mach-*/Kconfig you are building.