bpf: Add bpf_get_func_ip helper support for uprobe link

Adding support for bpf_get_func_ip helper being called from
ebpf program attached by uprobe_multi link.

It returns the ip of the uprobe.

Acked-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230809083440.3209381-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index e45aebe..a7264b2 100644 (file)
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -88,6 +88,7 @@ static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx);
 static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
 
 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx);
+static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx);
 
 /**
  * trace_call_bpf - invoke BPF program
@@ -1106,6 +1107,18 @@ static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
        .arg1_type      = ARG_PTR_TO_CTX,
 };
 
+BPF_CALL_1(bpf_get_func_ip_uprobe_multi, struct pt_regs *, regs)
+{
+       return bpf_uprobe_multi_entry_ip(current->bpf_ctx);
+}
+
+static const struct bpf_func_proto bpf_get_func_ip_proto_uprobe_multi = {
+       .func           = bpf_get_func_ip_uprobe_multi,
+       .gpl_only       = false,
+       .ret_type       = RET_INTEGER,
+       .arg1_type      = ARG_PTR_TO_CTX,
+};
+
 BPF_CALL_1(bpf_get_attach_cookie_uprobe_multi, struct pt_regs *, regs)
 {
        return bpf_uprobe_multi_cookie(current->bpf_ctx);
@@ -1560,9 +1573,11 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
                return &bpf_override_return_proto;
 #endif
        case BPF_FUNC_get_func_ip:
-               return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
-                       &bpf_get_func_ip_proto_kprobe_multi :
-                       &bpf_get_func_ip_proto_kprobe;
+               if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
+                       return &bpf_get_func_ip_proto_kprobe_multi;
+               if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
+                       return &bpf_get_func_ip_proto_uprobe_multi;
+               return &bpf_get_func_ip_proto_kprobe;
        case BPF_FUNC_get_attach_cookie:
                if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
                        return &bpf_get_attach_cookie_proto_kmulti;
@@ -3113,6 +3128,14 @@ uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, s
        return uprobe_prog_run(uprobe, func, regs);
 }
 
+static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
+{
+       struct bpf_uprobe_multi_run_ctx *run_ctx;
+
+       run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
+       return run_ctx->entry_ip;
+}
+
 static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
 {
        struct bpf_uprobe_multi_run_ctx *run_ctx;
@@ -3272,4 +3295,8 @@ static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
 {
        return 0;
 }
+static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx)
+{
+       return 0;
+}
 #endif /* CONFIG_UPROBES */