On Thu, Nov 9, 2023 at 1:29 AM Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
>
> We will need to return ref_ctr_offsets values through link_info
> interface in following change, so we need to keep them around.
>
> Storing ref_ctr_offsets values directly into bpf_uprobe array.
>
> Acked-by: Song Liu <song@xxxxxxxxxx>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> kernel/trace/bpf_trace.c | 14 +++-----------
> 1 file changed, 3 insertions(+), 11 deletions(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index d525a22b8d56..52c1ec3a0467 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -3035,6 +3035,7 @@ struct bpf_uprobe_multi_link;
> struct bpf_uprobe {
> struct bpf_uprobe_multi_link *link;
> loff_t offset;
> + unsigned long ref_ctr_offset;
> u64 cookie;
> struct uprobe_consumer consumer;
> };
> @@ -3174,7 +3175,6 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> {
> struct bpf_uprobe_multi_link *link = NULL;
> unsigned long __user *uref_ctr_offsets;
> - unsigned long *ref_ctr_offsets = NULL;
> struct bpf_link_primer link_primer;
> struct bpf_uprobe *uprobes = NULL;
> struct task_struct *task = NULL;
> @@ -3247,18 +3247,12 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> if (!uprobes || !link)
> goto error_free;
>
> - if (uref_ctr_offsets) {
> - ref_ctr_offsets = kvcalloc(cnt, sizeof(*ref_ctr_offsets), GFP_KERNEL);
> - if (!ref_ctr_offsets)
> - goto error_free;
> - }
> -
> for (i = 0; i < cnt; i++) {
> if (ucookies && __get_user(uprobes[i].cookie, ucookies + i)) {
> err = -EFAULT;
> goto error_free;
> }
> - if (uref_ctr_offsets && __get_user(ref_ctr_offsets[i], uref_ctr_offsets + i)) {
> + if (uref_ctr_offsets && __get_user(uprobes[i].ref_ctr_offset, uref_ctr_offsets + i)) {
> err = -EFAULT;
> goto error_free;
> }
> @@ -3289,7 +3283,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> for (i = 0; i < cnt; i++) {
> err = uprobe_register_refctr(d_real_inode(link->path.dentry),
> uprobes[i].offset,
> - ref_ctr_offsets ? ref_ctr_offsets[i] : 0,
> + uprobes[i].ref_ctr_offset,
> &uprobes[i].consumer);
> if (err) {
> bpf_uprobe_unregister(&path, uprobes, i);
> @@ -3301,11 +3295,9 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> if (err)
> goto error_free;
>
> - kvfree(ref_ctr_offsets);
> return bpf_link_settle(&link_primer);
>
> error_free:
> - kvfree(ref_ctr_offsets);
> kvfree(uprobes);
> kfree(link);
> if (task)
> --
> 2.41.0
>
