bpf: Move bpf_jit_get_prog_name() to core.c

bpf_jit_get_prog_name() will be used by all JITs when enabling support
for private stack. This function is currently implemented in the x86
JIT.

Move the function to core.c so that other JITs can easily use it in
their implementation of private stack.

Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/bpf/20250724120257.7299-2-puranjay@kernel.org

Author: puranjaymohan

arch/x86/net/bpf_jit_comp.c

@@ -3501,13 +3501,6 @@ int arch_prepare_bpf_dispatcher(void *image, void *buf, s64 *funcs, int num_func
 	return emit_bpf_dispatcher(&prog, 0, num_funcs - 1, funcs, image, buf);
 }
 
-static const char *bpf_get_prog_name(struct bpf_prog *prog)
-{
-	if (prog->aux->ksym.prog)
-		return prog->aux->ksym.name;
-	return prog->aux->name;
-}
-
 static void priv_stack_init_guard(void __percpu *priv_stack_ptr, int alloc_size)
 {
 	int cpu, underflow_idx = (alloc_size - PRIV_STACK_GUARD_SZ) >> 3;
@@ -3531,7 +3524,7 @@ static void priv_stack_check_guard(void __percpu *priv_stack_ptr, int alloc_size
 		if (stack_ptr[0] != PRIV_STACK_GUARD_VAL ||
 		    stack_ptr[underflow_idx] != PRIV_STACK_GUARD_VAL) {
 			pr_err("BPF private stack overflow/underflow detected for prog %sx\n",
-			       bpf_get_prog_name(prog));
+			       bpf_jit_get_prog_name(prog));
 			break;
 		}
 	}

include/linux/filter.h

@@ -1278,6 +1278,8 @@ int bpf_jit_get_func_addr(const struct bpf_prog *prog,
 			  const struct bpf_insn *insn, bool extra_pass,
 			  u64 *func_addr, bool *func_addr_fixed);
 
+const char *bpf_jit_get_prog_name(struct bpf_prog *prog);
+
 struct bpf_prog *bpf_jit_blind_constants(struct bpf_prog *fp);
 void bpf_jit_prog_release_other(struct bpf_prog *fp, struct bpf_prog *fp_other);
 

kernel/bpf/core.c

@@ -1297,6 +1297,13 @@ int bpf_jit_get_func_addr(const struct bpf_prog *prog,
 	return 0;
 }
 
+const char *bpf_jit_get_prog_name(struct bpf_prog *prog)
+{
+	if (prog->aux->ksym.prog)
+		return prog->aux->ksym.name;
+	return prog->aux->name;
+}
+
 static int bpf_jit_blind_insn(const struct bpf_insn *from,
 			      const struct bpf_insn *aux,
 			      struct bpf_insn *to_buff,