On Sun, Feb 16, 2014 at 07:41:23AM +0800, Herbert Xu wrote: > On Fri, Feb 14, 2014 at 06:01:06PM -0800, Tim Chen wrote: > > > > Module A selects CRYPTO_ALG_B in config, which causes the generic > > ALG_B to get built and a module dependency to the generic > > ALG_B to be established. Then when module A loads, > > No, if you select ALG_B then yes it'll get built but it certainly > won't establish a module dependency on ALG_B. Only a softdep could > create such a dependency. > My understanding was that the soft dependencies were there to work exactly at the softdep directive was in modprobe.conf. That it to say, "Module B would like to have Module A installed, but it won't be fatal if it can't be done". The more correct example I've seen thus far has been the crct10dif crc algorithm for x86. In lib/crc-t10dif we have a crc-t10dif function which makes use of the generic crc_t10dif_generic function defined in crct10dif_common.c. However, x86 has an accelerated version of the function defined in the crct10dif-pcmul module (thats aliased to crct10dif). So the library funcion in the kernel lists crct10dif as a soft dependency and modprobe tries to load it, but just carries on if it fails. Although as I write that, several things confuse me. When are module dependencies meant to be satisfied on behalf of the monolithic kernel, where that dependecy is defined? I'm guessing right before the init routine is called for that code, but I'm not sure. Also, I'm a bit confused by Marco and Lukas' statement about how they see soft dependencies working. I'm not sure where the requirement to recognize soft dependencies comes from in depmod. Regards Neil > Cheers, > -- > Email: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt > -- > To unsubscribe from this list: send the line "unsubscribe linux-crypto" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-crypto" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
