Commit 17dca050 authored by Gustavo A. R. Silva's avatar Gustavo A. R. Silva Committed by Jonathan Corbet
Browse files

docs: deprecated.rst: Update zero-length/one-element arrays section 



Update information in the zero-length and one-element arrays section
and illustrate how to make use of the new flex_array_size() helper,
together with struct_size() and a flexible-array member.

Signed-off-by: default avatarGustavo A. R. Silva <gustavoars@kernel.org>
Acked-by: default avatarKees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20200901010949.GA21398@embeddedor


Signed-off-by: default avatarJonathan Corbet <corbet@lwn.net>
parent 9334e34f

Documentation/process/deprecated.rst

+3 −3
Original line number Diff line number Diff line
@@ -304,7 +304,8 @@ to allocate for a structure containing an array of this kind as a member:: 
In the example above, we had to remember to calculate ``count - 1`` when using

the struct_size() helper, otherwise we would have --unintentionally-- allocated

memory for one too many ``items`` objects. The cleanest and least error-prone way

to implement this is through the use of a `flexible array member`::

to implement this is through the use of a `flexible array member`, together with

struct_size() and flex_array_size() helpers::



        struct something {

                size_t count;
@@ -316,5 +317,4 @@ to implement this is through the use of a `flexible array member`:: 
        instance = kmalloc(struct_size(instance, items, count), GFP_KERNEL);

        instance->count = count;



        size = sizeof(instance->items[0]) * instance->count;

        memcpy(instance->items, source, size);
 
        memcpy(instance->items, source, flex_array_size(instance, items, instance->count));

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