lkml.org 
[lkml]   [2016]   [Sep]   [25]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] nfp: bpf: improve handling for disabled BPF syscall
On Fri, 23 Sep 2016 22:23:59 +0200, Arnd Bergmann wrote:
> I stumbled over a new warning during randconfig testing,
> with CONFIG_BPF_SYSCALL disabled:
>
> drivers/net/ethernet/netronome/nfp/nfp_net_offload.c: In function 'nfp_net_bpf_offload':
> drivers/net/ethernet/netronome/nfp/nfp_net_offload.c:263:3: error: '*((void *)&res+4)' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/net/ethernet/netronome/nfp/nfp_net_offload.c:263:3: error: 'res.n_instr' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>
> As far as I can tell, this is a false positive caused by the compiler
> getting confused about a function that is partially inlined, but it's
> easy to avoid while improving the code:
>
> The nfp_bpf_jit() stub helper for that configuration is unusual as it
> is defined in a header file but not marked 'static inline'. By moving
> the compile-time check into the caller using the IS_ENABLED() macro,
> we can remove that stub and simplify the nfp_net_bpf_offload_prepare()
> function enough to unconfuse the compiler.
>
> Fixes: 7533fdc0f77f ("nfp: bpf: add hardware bpf offload")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Thanks Arnd! static inline definitely missing there but if we can
depend on dead code elimination to remove the symbol that's even cooler!

Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>

\
 
 \ /
  Last update: 2016-09-25 17:53    [W:2.108 / U:0.100 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site