Re: [PATCH v2 2/6] hostap: Avoid clashing function prototypes

From: Kalle Valo
Date: Tue Nov 01 2022 - 05:38:57 EST


"Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx> wrote:

> When built with Control Flow Integrity, function prototypes between
> caller and function declaration must match. These mismatches are visible
> at compile time with the new -Wcast-function-type-strict in Clang[1].
>
> Fix a total of 42 warnings like these:
>
> ../drivers/net/wireless/intersil/hostap/hostap_ioctl.c:3868:2: warning: cast from 'int (*)(struct net_device *, struct iw_request_info *, char *, char *)' to 'iw_handler' (aka 'int (*)(struct net_device *, struct iw_request_info *, union iwreq_data *, char *)') converts to incompatible function type [-Wcast-function-type-strict]
> (iw_handler) prism2_get_name, /* SIOCGIWNAME */
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The hostap Wireless Extension handler callbacks (iw_handler) use a
> union for the data argument. Actually use the union and perform explicit
> member selection in the function body instead of having a function
> prototype mismatch. There are no resulting binary differences
> before/after changes.
>
> Link: https://github.com/KSPP/linux/issues/235
> Link: https://reviews.llvm.org/D134831 [1]
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>

Please add "wifi: " to all wireless patches, for example this one should be:

wifi: hostap: Avoid clashing function prototypes

--
https://patchwork.kernel.org/project/linux-wireless/patch/8388b5ed9e729eb9dadec875a7576219e6d61223.1666894751.git.gustavoars@xxxxxxxxxx/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches