crypto: doc - fix documentation for bulk registration functions

Update the documentation for crypto_register_algs() and
crypto_unregister_algs() to match the actual behavior.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Eric Biggers 2016-08-17 15:47:11 -07:00 committed by Herbert Xu
parent d89a67134f
commit f12e4ed8f0
1 changed files with 26 additions and 12 deletions

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@ -797,7 +797,8 @@ kernel crypto API | Caller
include/linux/crypto.h and their definition can be seen below.
The former function registers a single transformation, while
the latter works on an array of transformation descriptions.
The latter is useful when registering transformations in bulk.
The latter is useful when registering transformations in bulk,
for example when a driver implements multiple transformations.
</para>
<programlisting>
@ -822,18 +823,31 @@ kernel crypto API | Caller
</para>
<para>
The bulk registration / unregistration functions require
that struct crypto_alg is an array of count size. These
functions simply loop over that array and register /
unregister each individual algorithm. If an error occurs,
the loop is terminated at the offending algorithm definition.
That means, the algorithms prior to the offending algorithm
are successfully registered. Note, the caller has no way of
knowing which cipher implementations have successfully
registered. If this is important to know, the caller should
loop through the different implementations using the single
instance *_alg functions for each individual implementation.
The bulk registration/unregistration functions
register/unregister each transformation in the given array of
length count. They handle errors as follows:
</para>
<itemizedlist>
<listitem>
<para>
crypto_register_algs() succeeds if and only if it
successfully registers all the given transformations. If an
error occurs partway through, then it rolls back successful
registrations before returning the error code. Note that if
a driver needs to handle registration errors for individual
transformations, then it will need to use the non-bulk
function crypto_register_alg() instead.
</para>
</listitem>
<listitem>
<para>
crypto_unregister_algs() tries to unregister all the given
transformations, continuing on error. It logs errors and
always returns zero.
</para>
</listitem>
</itemizedlist>
</sect1>
<sect1><title>Single-Block Symmetric Ciphers [CIPHER]</title>