Re: [PATCH v2 5/6] bna: Avoid clashing function prototypes

From: Kees Cook
Date: Sat Oct 29 2022 - 03:12:33 EST


On Thu, Oct 27, 2022 at 03:20:47PM -0500, Gustavo A. R. Silva 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 227 warnings like these:
>
> drivers/net/ethernet/brocade/bna/bna_enet.c:519:3: warning: cast from 'void (*)(struct bna_ethport *, enum bna_ethport_event)' to 'bfa_fsm_t' (aka 'void (*)(void *, int)') converts to incompatible function type [-Wcast-function-type-strict]
> bfa_fsm_set_state(ethport, bna_ethport_sm_down);
> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
> The bna state machine code heavily overloads its state machine functions,
> so these have been separated into their own sets of structs, enums,
> typedefs, and helper functions. There are almost zero binary code changes,
> all seem to be related to header file line numbers changing, or the
> addition of the new stats helper.

This looks like it borrowed from
https://lore.kernel.org/linux-hardening/20220929230334.2109344-1-keescook@xxxxxxxxxxxx/
Nice to get a couple hundred more fixed. :)

> [1] https://reviews.llvm.org/D134831
> Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
> ---
> Changes in v2:
> - None. This patch is new in the series.

This is relatively stand-alone (not an iw_handler patch), so it could
also go separately too.

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

--
Kees Cook