LoongArch: BPF: Fix uninitialized symbol 'retval_off'

commit 7b6c2d172d023d344527d3cb4516d0d6b29f4919 upstream.

In __arch_prepare_bpf_trampoline(), retval_off is meaningful only when
save_ret is not 0, so the current logic is correct. But it may cause a
build warning:

arch/loongarch/net/bpf_jit.c:1547 __arch_prepare_bpf_trampoline() error: uninitialized symbol 'retval_off'.

So initialize retval_off unconditionally to fix it.

Cc: stable@vger.kernel.org
Fixes: f9b6b41f0cf3 ("LoongArch: BPF: Add basic bpf trampoline support")
Closes: https://lore.kernel.org/r/202508191020.PBBh07cK-lkp@intel.com/
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/loongarch/net/bpf_jit.c b/arch/loongarch/net/bpf_jit.c
index 2ed710dbd78c707a53cf8986dda6a58ac01279d9..99f55c0bb5e000c40f5e3168a71fcc5015eb30d3 100644 (file)
--- a/arch/loongarch/net/bpf_jit.c
+++ b/arch/loongarch/net/bpf_jit.c
@@ -1538,11 +1538,10 @@ static int __arch_prepare_bpf_trampoline(struct jit_ctx *ctx, struct bpf_tramp_i
        stack_size = 16;
 
        save_ret = flags & (BPF_TRAMP_F_CALL_ORIG | BPF_TRAMP_F_RET_FENTRY_RET);
-       if (save_ret) {
-               /* Save BPF R0 and A0 */
-               stack_size += 16;
-               retval_off = stack_size;
-       }
+       if (save_ret)
+               stack_size += 16; /* Save BPF R0 and A0 */
+
+       retval_off = stack_size;
 
        /* Room of trampoline frame to store args */
        nargs = m->nr_args;