On 5/28/2025 8:27 AM, Alexei Starovoitov wrote:
From: Alexei Starovoitov <ast@xxxxxxxxxx>
Remove unused-but-set function and variable to fix the build warning:
arch/arm64/net/bpf_jit_comp.c: In function 'arch_bpf_trampoline_size':
arch/arm64/net/bpf_jit_comp.c:2547:6: warning: variable 'nregs' set but not used [-Wunused-but-set-variable]
2547 | int nregs, ret;
| ^~~~~
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Closes: https://lore.kernel.org/oe-kbuild-all/202505280643.h0qYcSCM-lkp@xxxxxxxxx/
Fixes: 9014cf56f13d ("bpf, arm64: Support up to 12 function arguments")
Signed-off-by: Alexei Starovoitov <ast@xxxxxxxxxx>
---
arch/arm64/net/bpf_jit_comp.c | 21 ++-------------------
1 file changed, 2 insertions(+), 19 deletions(-)
diff --git a/arch/arm64/net/bpf_jit_comp.c b/arch/arm64/net/bpf_jit_comp.c
index b5c3ab623536..14d4c6ac4ca0 100644
--- a/arch/arm64/net/bpf_jit_comp.c
+++ b/arch/arm64/net/bpf_jit_comp.c
@@ -2520,21 +2520,6 @@ static int prepare_trampoline(struct jit_ctx *ctx, struct bpf_tramp_image *im,
return ctx->idx;
}
-static int btf_func_model_nregs(const struct btf_func_model *m)
-{
- int nregs = m->nr_args;
- int i;
-
- /* extra registers needed for struct argument */
- for (i = 0; i < MAX_BPF_FUNC_ARGS; i++) {
- /* The arg_size is at most 16 bytes, enforced by the verifier. */
- if (m->arg_flags[i] & BTF_FMODEL_STRUCT_ARG)
- nregs += (m->arg_size[i] + 7) / 8 - 1;
- }
-
- return nregs;
-}
-
int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
struct bpf_tramp_links *tlinks, void *func_addr)
{
@@ -2543,10 +2528,8 @@ int arch_bpf_trampoline_size(const struct btf_func_model *m, u32 flags,
.idx = 0,
};
struct bpf_tramp_image im;
- struct arg_aux aaux;
- int nregs, ret;
-
- nregs = btf_func_model_nregs(m);
+ struct arg_aux aaux;
+ int ret;
ret = calc_arg_aux(m, &aaux);
if (ret < 0)
Oops, sorry for not noticing that nregs is set but not used.
Now that the number of regs for both struct and non-struct
args is calculated in calc_arg_aux(), we can safely drop
btf_func_model_nregs().
Acked-by: Xu Kuohai <xukuohai@xxxxxxxxxx>
