On Fri, Jul 21, 2023 at 10:18:27AM +0800, Yafang Shao wrote:
> On Thu, Jul 20, 2023 at 7:36 PM 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 (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.
> >
> > Acked-by: Andrii Nakryiko <andrii@xxxxxxxxxx>
> > Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> > ---
> > include/uapi/linux/bpf.h | 1 +
> > kernel/bpf/syscall.c | 2 +-
> > kernel/trace/bpf_trace.c | 45 +++++++++++++++++++++++++++++++---
> > tools/include/uapi/linux/bpf.h | 1 +
> > 4 files changed, 44 insertions(+), 5 deletions(-)
> >
> > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h
> > index e764af513425..c6fbb0f948f4 100644
> > --- a/include/uapi/linux/bpf.h
> > +++ b/include/uapi/linux/bpf.h
> > @@ -1604,6 +1604,7 @@ union bpf_attr {
> > __aligned_u64 path;
> > __aligned_u64 offsets;
> > __aligned_u64 ref_ctr_offsets;
> > + __aligned_u64 cookies;
> > __u32 cnt;
> > __u32 flags;
> > } uprobe_multi;
> > diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
> > index f4c6a265731e..840b622b7db1 100644
> > --- a/kernel/bpf/syscall.c
> > +++ b/kernel/bpf/syscall.c
> > @@ -4832,7 +4832,7 @@ static int bpf_map_do_batch(const union bpf_attr *attr,
> > return err;
> > }
> >
> > -#define BPF_LINK_CREATE_LAST_FIELD link_create.kprobe_multi.cookies
> > +#define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.cookies
>
> Shouldn't it be :
>
> #define BPF_LINK_CREATE_LAST_FIELD link_create.uprobe_multi.flags ?
>
> other than that, this patch looks good.
ugh, I changed order of fields and forgot to update last fields,
will fix that in next version
thanks,
jirka
>
>
> > static int link_create(union bpf_attr *attr, bpfptr_t uattr)
> > {
> > struct bpf_prog *prog;
> > diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> > index 10284fd46f98..d73a47bd2bbd 100644
> > --- a/kernel/trace/bpf_trace.c
> > +++ b/kernel/trace/bpf_trace.c
> > @@ -87,6 +87,8 @@ static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size,
> > 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);
> > +
> > /**
> > * trace_call_bpf - invoke BPF program
> > * @call: tracepoint event
> > @@ -1099,6 +1101,18 @@ static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = {
> > .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);
> > +}
> > +
> > +static const struct bpf_func_proto bpf_get_attach_cookie_proto_umulti = {
> > + .func = bpf_get_attach_cookie_uprobe_multi,
> > + .gpl_only = false,
> > + .ret_type = RET_INTEGER,
> > + .arg1_type = ARG_PTR_TO_CTX,
> > +};
> > +
> > BPF_CALL_1(bpf_get_attach_cookie_trace, void *, ctx)
> > {
> > struct bpf_trace_run_ctx *run_ctx;
> > @@ -1545,9 +1559,11 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
> > &bpf_get_func_ip_proto_kprobe_multi :
> > &bpf_get_func_ip_proto_kprobe;
> > case BPF_FUNC_get_attach_cookie:
> > - return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI ?
> > - &bpf_get_attach_cookie_proto_kmulti :
> > - &bpf_get_attach_cookie_proto_trace;
> > + if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI)
> > + return &bpf_get_attach_cookie_proto_kmulti;
> > + if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI)
> > + return &bpf_get_attach_cookie_proto_umulti;
> > + return &bpf_get_attach_cookie_proto_trace;
> > default:
> > return bpf_tracing_func_proto(func_id, prog);
> > }
> > @@ -2973,6 +2989,7 @@ struct bpf_uprobe_multi_link;
> > struct bpf_uprobe {
> > struct bpf_uprobe_multi_link *link;
> > loff_t offset;
> > + u64 cookie;
> > struct uprobe_consumer consumer;
> > };
> >
> > @@ -2986,6 +3003,7 @@ struct bpf_uprobe_multi_link {
> > struct bpf_uprobe_multi_run_ctx {
> > struct bpf_run_ctx run_ctx;
> > unsigned long entry_ip;
> > + struct bpf_uprobe *uprobe;
> > };
> >
> > static void bpf_uprobe_unregister(struct path *path, struct bpf_uprobe *uprobes,
> > @@ -3029,6 +3047,7 @@ 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_prog *prog = link->link.prog;
> > bool sleepable = prog->aux->sleepable;
> > @@ -3075,6 +3094,14 @@ 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_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);
> > + return run_ctx->uprobe->cookie;
> > +}
> > +
> > int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *prog)
> > {
> > struct bpf_uprobe_multi_link *link = NULL;
> > @@ -3083,6 +3110,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> > struct bpf_link_primer link_primer;
> > struct bpf_uprobe *uprobes = NULL;
> > unsigned long __user *uoffsets;
> > + u64 __user *ucookies;
> > void __user *upath;
> > u32 flags, cnt, i;
> > struct path path;
> > @@ -3102,7 +3130,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> >
> > /*
> > * path, offsets and cnt are mandatory,
> > - * ref_ctr_offsets is optional
> > + * ref_ctr_offsets and cookies are optional
> > */
> > upath = u64_to_user_ptr(attr->link_create.uprobe_multi.path);
> > uoffsets = u64_to_user_ptr(attr->link_create.uprobe_multi.offsets);
> > @@ -3112,6 +3140,7 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> > return -EINVAL;
> >
> > uref_ctr_offsets = u64_to_user_ptr(attr->link_create.uprobe_multi.ref_ctr_offsets);
> > + ucookies = u64_to_user_ptr(attr->link_create.uprobe_multi.cookies);
> >
> > name = strndup_user(upath, PATH_MAX);
> > if (IS_ERR(name)) {
> > @@ -3144,6 +3173,10 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> > }
> >
> > 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)) {
> > err = -EFAULT;
> > goto error_free;
> > @@ -3201,4 +3234,8 @@ int bpf_uprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr
> > {
> > return -EOPNOTSUPP;
> > }
> > +static u64 bpf_uprobe_multi_cookie(struct bpf_run_ctx *ctx)
> > +{
> > + return 0;
> > +}
> > #endif /* CONFIG_UPROBES */
> > diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
> > index 659afbf9bb8b..492072ef5029 100644
> > --- a/tools/include/uapi/linux/bpf.h
> > +++ b/tools/include/uapi/linux/bpf.h
> > @@ -1604,6 +1604,7 @@ union bpf_attr {
> > __aligned_u64 path;
> > __aligned_u64 offsets;
> > __aligned_u64 ref_ctr_offsets;
> > + __aligned_u64 cookies;
> > __u32 cnt;
> > __u32 flags;
> > } uprobe_multi;
> > --
> > 2.41.0
> >
> >
>
>
> --
> Regards
> Yafang
