[dpdk-stable] [PATCH] lib/bpf: fix clang build warnings for aarch64

[dpdk-stable] [PATCH] lib/bpf: fix clang build warnings for aarch64

[Ruifeng Wang]

Couple of warnings will block build when warnings been treated as errors.
Clang version 8.0 was used.

Warning messages during build:
../lib/librte_bpf/bpf_jit_arm64.c:1438:26: warning: incompatible pointer
types passing 'uint32_t *' (aka 'unsigned int *') to parameter of type
'char *' [-Wincompatible-pointer-types]
        __builtin___clear_cache(ctx.ins, ctx.ins + ctx.idx);
                                ^~~~~~~
../lib/librte_bpf/bpf_jit_arm64.c:1438:35: warning: incompatible pointer
types passing 'uint32_t *' (aka 'unsigned int *') to parameter of type
'char *' [-Wincompatible-pointer-types]
        __builtin___clear_cache(ctx.ins, ctx.ins + ctx.idx);
                                         ^~~~~~~~~~~~~~~~~

Fixes: f3e516772464 ("bpf/arm: add prologue and epilogue")
Cc: stable@dpdk.org

Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
Reviewed-by: Phil Yang <phil.yang@arm.com>
Reviewed-by: Gavin Hu <gavin.hu@arm.com>
---
 lib/librte_bpf/bpf_jit_arm64.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/librte_bpf/bpf_jit_arm64.c b/lib/librte_bpf/bpf_jit_arm64.c
index 8882fee67..a5a5d46f0 100644
--- a/lib/librte_bpf/bpf_jit_arm64.c
+++ b/lib/librte_bpf/bpf_jit_arm64.c
@@ -1435,7 +1435,7 @@ bpf_jit_arm64(struct rte_bpf *bpf)
 	}
 
 	/* Flush the icache */
-	__builtin___clear_cache(ctx.ins, ctx.ins + ctx.idx);
+	__builtin___clear_cache((char *)ctx.ins, (char *)(ctx.ins + ctx.idx));
 
 	bpf->jit.func = (void *)ctx.ins;
 	bpf->jit.sz = size;
-- 
2.17.1

Re: [dpdk-stable] [dpdk-dev] [PATCH] lib/bpf: fix clang build warnings for aarch64

[Jerin Jacob]

On Fri, Nov 15, 2019 at 8:48 AM Ruifeng Wang <ruifeng.wang@arm.com> wrote:
>
> Couple of warnings will block build when warnings been treated as errors.
> Clang version 8.0 was used.
>
> Warning messages during build:
> ../lib/librte_bpf/bpf_jit_arm64.c:1438:26: warning: incompatible pointer
> types passing 'uint32_t *' (aka 'unsigned int *') to parameter of type
> 'char *' [-Wincompatible-pointer-types]
>         __builtin___clear_cache(ctx.ins, ctx.ins + ctx.idx);
>                                 ^~~~~~~
> ../lib/librte_bpf/bpf_jit_arm64.c:1438:35: warning: incompatible pointer
> types passing 'uint32_t *' (aka 'unsigned int *') to parameter of type
> 'char *' [-Wincompatible-pointer-types]
>         __builtin___clear_cache(ctx.ins, ctx.ins + ctx.idx);
>                                          ^~~~~~~~~~~~~~~~~
>
> Fixes: f3e516772464 ("bpf/arm: add prologue and epilogue")
> Cc: stable@dpdk.org

No need to CC stable as this has been added in this release.

Is clang prototype for __builtin___clear_cache() different? If so,
update the git commit for the reason for the failure.

in gcc[1], it is void *.
[1]
void __builtin___clear_cache (void *begin, void *end)

>
> Signed-off-by: Ruifeng Wang <ruifeng.wang@arm.com>
> Reviewed-by: Phil Yang <phil.yang@arm.com>
> Reviewed-by: Gavin Hu <gavin.hu@arm.com>