Re: [PATCH] RDMA/irdma: avoid fortify-string warning in irdma_clr_wqes

[Jason Gunthorpe]

On Tue, May 23, 2023 at 01:18:45PM +0200, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@xxxxxxxx>
> 
> Commit df8fc4e934c1 ("kbuild: Enable -fstrict-flex-arrays=3") triggers
> a warning for fortified memset():
> 
> In function 'fortify_memset_chk',
>     inlined from 'irdma_clr_wqes' at drivers/infiniband/hw/irdma/uk.c:103:4:
> include/linux/fortify-string.h:493:25: error: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Werror=attribute-warning]
>   493 |                         __write_overflow_field(p_size_field, size);
>       |                         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 
> The problem here isthat the inner array only has four 8-byte elements,
> so clearing 4096 bytes overflows that. As this structure is part of an
> outer array, change the code to pass a pointer to the irdma_qp_quanta
> instead, and change the size argument for readability, matching the
> comment above it.
> 
> Fixes: 551c46edc769 ("RDMA/irdma: Add user/kernel shared libraries")
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> Acked-by: Shiraz Saleem <shiraz.saleem@xxxxxxxxx>
> ---
>  drivers/infiniband/hw/irdma/uk.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)

Applied to for-next, thanks

Jason