1 files changed, 34 insertions, 0 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 1a796e0799ec..b1a3545d0ec8 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -672,6 +672,40 @@ void __weak bpf_jit_free(struct bpf_prog *fp)
         bpf_prog_unlock_free(fp);
 }
 
+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)
+{
+        s16 off = insn->off;
+        s32 imm = insn->imm;
+        u8 *addr;
+
+        *func_addr_fixed = insn->src_reg != BPF_PSEUDO_CALL;
+        if (!*func_addr_fixed) {
+                /* Place-holder address till the last pass has collected
+                 * all addresses for JITed subprograms in which case we
+                 * can pick them up from prog->aux.
+                 */
+                if (!extra_pass)
+                        addr = NULL;
+                else if (prog->aux->func &&
+                         off >= 0 && off < prog->aux->func_cnt)
+                        addr = (u8 *)prog->aux->func[off]->bpf_func;
+                else
+                        return -EINVAL;
+        } else {
+                /* Address of a BPF helper call. Since part of the core
+                 * kernel, it's always at a fixed location. __bpf_call_base
+                 * and the helper with imm relative to it are both in core
+                 * kernel.
+                 */
+                addr = (u8 *)__bpf_call_base + imm;
+        }
+
+        *func_addr = (unsigned long)addr;
+        return 0;
+}
+
 static int bpf_jit_blind_insn(const struct bpf_insn *from,
                               const struct bpf_insn *aux,
                               struct bpf_insn *to_buff)