Messages in this thread Patch in this message | | | From | Arnd Bergmann <> | Subject | [PATCH] nfp: bpf: improve handling for disabled BPF syscall | Date | Fri, 23 Sep 2016 22:23:59 +0200 |
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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> --- drivers/net/ethernet/netronome/nfp/nfp_bpf.h | 10 ---------- drivers/net/ethernet/netronome/nfp/nfp_net_offload.c | 3 +++ 2 files changed, 3 insertions(+), 10 deletions(-)
diff --git a/drivers/net/ethernet/netronome/nfp/nfp_bpf.h b/drivers/net/ethernet/netronome/nfp/nfp_bpf.h index fc220cd04115..87aa8a3e9112 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_bpf.h +++ b/drivers/net/ethernet/netronome/nfp/nfp_bpf.h @@ -192,20 +192,10 @@ struct nfp_bpf_result { bool dense_mode; }; -#ifdef CONFIG_BPF_SYSCALL int nfp_bpf_jit(struct bpf_prog *filter, void *prog, enum nfp_bpf_action_type act, unsigned int prog_start, unsigned int prog_done, unsigned int prog_sz, struct nfp_bpf_result *res); -#else -int -nfp_bpf_jit(struct bpf_prog *filter, void *prog, enum nfp_bpf_action_type act, - unsigned int prog_start, unsigned int prog_done, - unsigned int prog_sz, struct nfp_bpf_result *res) -{ - return -ENOTSUPP; -} -#endif int nfp_prog_verify(struct nfp_prog *nfp_prog, struct bpf_prog *prog); diff --git a/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c b/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c index 43f42f842eda..8acfb631a0ea 100644 --- a/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c +++ b/drivers/net/ethernet/netronome/nfp/nfp_net_offload.c @@ -148,6 +148,9 @@ nfp_net_bpf_offload_prepare(struct nfp_net *nn, unsigned int max_mtu; int ret; + if (!IS_ENABLED(CONFIG_BPF_SYSCALL)) + return -ENOTSUPP; + ret = nfp_net_bpf_get_act(nn, cls_bpf); if (ret < 0) return ret; -- 2.9.0
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