On Mon, Jul 1, 2024 at 9:42 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Placing bpf_session_run_ctx layer in between bpf_run_ctx and
> bpf_uprobe_multi_run_ctx, so the session data can be retrieved
> from uprobe_multi link.
>
> Plus granting session kfuncs access to uprobe session programs.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> kernel/trace/bpf_trace.c | 23 +++++++++++++++--------
> 1 file changed, 15 insertions(+), 8 deletions(-)
>
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 1b19c1cdb5e1..d431b880ca11 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -3184,7 +3184,7 @@ struct bpf_uprobe_multi_link {
> };
>
> struct bpf_uprobe_multi_run_ctx {
> - struct bpf_run_ctx run_ctx;
> + struct bpf_session_run_ctx session_ctx;
> unsigned long entry_ip;
> struct bpf_uprobe *uprobe;
> };
> @@ -3297,10 +3297,15 @@ static const struct bpf_link_ops bpf_uprobe_multi_link_lops = {
>
> static int uprobe_prog_run(struct bpf_uprobe *uprobe,
> unsigned long entry_ip,
> - struct pt_regs *regs)
> + struct pt_regs *regs,
> + bool is_return, void *data)
> {
> struct bpf_uprobe_multi_link *link = uprobe->link;
> struct bpf_uprobe_multi_run_ctx run_ctx = {
> + .session_ctx = {
> + .is_return = is_return,
> + .data = data,
> + },
> .entry_ip = entry_ip,
> .uprobe = uprobe,
> };
> @@ -3319,7 +3324,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
>
> migrate_disable();
>
> - old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx);
> + old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx);
> err = bpf_prog_run(link->link.prog, regs);
> bpf_reset_run_ctx(old_run_ctx);
>
> @@ -3349,7 +3354,7 @@ uprobe_multi_link_handler(struct uprobe_consumer *con, struct pt_regs *regs,
> struct bpf_uprobe *uprobe;
>
> uprobe = container_of(con, struct bpf_uprobe, consumer);
> - return uprobe_prog_run(uprobe, instruction_pointer(regs), regs);
> + return uprobe_prog_run(uprobe, instruction_pointer(regs), regs, false, data);
> }
>
> static int
> @@ -3359,14 +3364,15 @@ uprobe_multi_link_ret_handler(struct uprobe_consumer *con, unsigned long func, s
> struct bpf_uprobe *uprobe;
>
> uprobe = container_of(con, struct bpf_uprobe, consumer);
> - return uprobe_prog_run(uprobe, func, regs);
> + return uprobe_prog_run(uprobe, func, regs, true, data);
> }
>
> 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);
> + run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
> + session_ctx.run_ctx);
> return run_ctx->entry_ip;
> }
>
> @@ -3374,7 +3380,8 @@ static u64 bpf_uprobe_multi_cookie(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);
> + run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx,
> + session_ctx.run_ctx);
> return run_ctx->uprobe->cookie;
> }
>
> @@ -3565,7 +3572,7 @@ static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id)
> if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id))
> return 0;
>
> - if (!is_kprobe_session(prog))
> + if (!is_kprobe_session(prog) && !is_uprobe_session(prog))
> return -EACCES;
>
> return 0;
> --
> 2.45.2
>
>
