lkml.org 
[lkml]   [2023]   [Feb]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
SubjectRe: [PATCH -next] mux: convert mux_chip->mux to flexible array
From
On 2/22/2023 5:42 PM, Jacob Keller wrote:
> The mux_chip structure size is over allocated to additionally include both
> the array of mux controllers as well as a device specific private area.
> The controllers array is then pointed to by assigning mux_chip->mux to the
> first block of extra memory, while the private area is extracted via
> mux_chip_priv() and points to the area just after the controllers.
>
> The size of the mux_chip allocation uses direct multiplication and addition
> rather than the <linux/overflow.h> helpers. In addition, the mux_chip->mux
> struct member wastes space by having to store the pointer as part of the
> structures.
>
> Convert struct mux_chip to use a flexible array member for the mux
> controller array. Use struct_size() and size_add() to compute the size of
> the structure while protecting against overflow.
>
> After converting the mux pointer, notice that two 4-byte holes remain in
> the structure layout due to the alignment requirements for the dev
> sub-structure and the ops pointer.
>
> These can be easily fixed through re-ordering the id field to the 4-byte
> hole just after the controllers member.

Looks good to me (just a driver dev, not a mux dev!). Also added
linux-i2c mailing list and a couple others for more review.

Reviewed-by: Jesse Brandeburg <jesse.brandeburg@intel.com>

related thread (cocci script) at [1]

[1]
https://lore.kernel.org/all/20230227202428.3657443-1-jacob.e.keller@intel.com/



\
 
 \ /
  Last update: 2023-03-27 00:37    [W:1.281 / U:0.204 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site