lkml.org 
[lkml]   [2015]   [Jan]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v10 16/17] module: fix types of device tables aliases
On Thu, 29 Jan 2015 18:12:00 +0300 Andrey Ryabinin <a.ryabinin@samsung.com> wrote:

> MODULE_DEVICE_TABLE() macro used to create aliases to device tables.
> Normally alias should have the same type as aliased symbol.
>
> Device tables are arrays, so they have 'struct type##_device_id[x]'
> types. Alias created by MODULE_DEVICE_TABLE() will have non-array type -
> 'struct type##_device_id'.
>
> This inconsistency confuses compiler, it could make a wrong
> assumption about variable's size which leads KASan to
> produce a false positive report about out of bounds access.

The changelog describes the problem but doesn't describe how the patch
addresses the problem. Some more details would be useful.

> --- a/include/linux/module.h
> +++ b/include/linux/module.h
> @@ -135,7 +135,7 @@ void trim_init_extable(struct module *m);
> #ifdef MODULE
> /* Creates an alias so file2alias.c can find device table. */
> #define MODULE_DEVICE_TABLE(type, name) \
> - extern const struct type##_device_id __mod_##type##__##name##_device_table \
> +extern typeof(name) __mod_##type##__##name##_device_table \
> __attribute__ ((unused, alias(__stringify(name))))

We lost the const? If that's deliberate then why? What are the
implications? Do the device tables now go into rw memory?


\
 
 \ /
  Last update: 2015-01-30 00:21    [W:0.286 / U:0.480 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site