On Mon, Apr 24, 2023 at 9:05 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> Adding support to specify cookies array for uprobe_multi link.
>
> The cookies array share indexes and length with other uprobe_multi
> arrays (paths/offsets/ref_ctr_offsets).
>
> The cookies[i] value defines cookie for i-the uprobe and will be
> returned by bpf_get_attach_cookie helper when called from ebpf
> program hooked to that specific uprobe.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> include/uapi/linux/bpf.h | 1 +
> kernel/bpf/syscall.c | 2 +-
> kernel/trace/bpf_trace.c | 46 +++++++++++++++++++++++++++++++++++++---
> 3 files changed, 45 insertions(+), 4 deletions(-)
>
LGTM, one nit below
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
[...]
> static void bpf_uprobe_unregister(struct bpf_uprobe *uprobes, u32 cnt)
> @@ -2964,6 +2982,7 @@ static int uprobe_prog_run(struct bpf_uprobe *uprobe,
> struct bpf_uprobe_multi_link *link = uprobe->link;
> struct bpf_uprobe_multi_run_ctx run_ctx = {
> .entry_ip = entry_ip,
> + .uprobe = uprobe,
> };
> struct bpf_run_ctx *old_run_ctx;
> int err;
> @@ -3005,6 +3024,16 @@ 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_cookie(struct bpf_run_ctx *ctx)
> +{
> + struct bpf_uprobe_multi_run_ctx *run_ctx;
> +
> + if (WARN_ON_ONCE(!ctx))
> + return 0;
do we need this check?... seems redundant, tbh
> + run_ctx = container_of(current->bpf_ctx, struct bpf_uprobe_multi_run_ctx, run_ctx);
> + return run_ctx->uprobe->cookie;
> +}
> +
[...]
