Update the documentation for crypto_register_algs() and
crypto_unregister_algs() to match the actual behavior.
Signed-off-by: Eric Biggers <[email protected]>
---
Documentation/DocBook/crypto-API.tmpl | 38 ++++++++++++++++++++++++-----------
1 file changed, 26 insertions(+), 12 deletions(-)
diff --git a/Documentation/DocBook/crypto-API.tmpl b/Documentation/DocBook/crypto-API.tmpl
index fb2a152..088b79c 100644
--- a/Documentation/DocBook/crypto-API.tmpl
+++ b/Documentation/DocBook/crypto-API.tmpl
@@ -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>
--
2.8.0.rc3.226.g39d4020