Commit 9fd112b1 authored by Jiri Olsa's avatar Jiri Olsa Committed by Alexei Starovoitov
Browse files

bpf: Store cookies in kprobe_multi bpf_link_info data 



Storing cookies in kprobe_multi bpf_link_info data. The cookies
field is optional and if provided it needs to be an array of
__u64 with kprobe_multi.count length.

Acked-by: default avatarYafang Shao <laoar.shao@gmail.com>
Signed-off-by: default avatarJiri Olsa <jolsa@kernel.org>
Acked-by: default avatarSong Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20240119110505.400573-3-jolsa@kernel.org


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent d5c16492

include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -6563,6 +6563,7 @@ struct bpf_link_info { 
			__u32 count; /* in/out: kprobe_multi function count */

			__u32 flags;

			__u64 missed;

			__aligned_u64 cookies;

		} kprobe_multi;

		struct {

			__aligned_u64 path;

kernel/trace/bpf_trace.c

+15 −0
Original line number Diff line number Diff line
@@ -2679,6 +2679,7 @@ static void bpf_kprobe_multi_link_dealloc(struct bpf_link *link) 
static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link,

						struct bpf_link_info *info)

{

	u64 __user *ucookies = u64_to_user_ptr(info->kprobe_multi.cookies);

	u64 __user *uaddrs = u64_to_user_ptr(info->kprobe_multi.addrs);

	struct bpf_kprobe_multi_link *kmulti_link;

	u32 ucount = info->kprobe_multi.count;
@@ -2686,6 +2687,8 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 


	if (!uaddrs ^ !ucount)

		return -EINVAL;

	if (ucookies && !ucount)

		return -EINVAL;



	kmulti_link = container_of(link, struct bpf_kprobe_multi_link, link);

	info->kprobe_multi.count = kmulti_link->cnt;
@@ -2699,6 +2702,18 @@ static int bpf_kprobe_multi_link_fill_link_info(const struct bpf_link *link, 
	else

		ucount = kmulti_link->cnt;



	if (ucookies) {

		if (kmulti_link->cookies) {

			if (copy_to_user(ucookies, kmulti_link->cookies, ucount * sizeof(u64)))

				return -EFAULT;

		} else {

			for (i = 0; i < ucount; i++) {

				if (put_user(0, ucookies + i))

					return -EFAULT;

			}

		}

	}



	if (kallsyms_show_value(current_cred())) {

		if (copy_to_user(uaddrs, kmulti_link->addrs, ucount * sizeof(u64)))

			return -EFAULT;

tools/include/uapi/linux/bpf.h

+1 −0
Original line number Diff line number Diff line
@@ -6563,6 +6563,7 @@ struct bpf_link_info { 
			__u32 count; /* in/out: kprobe_multi function count */

			__u32 flags;

			__u64 missed;

			__aligned_u64 cookies;

		} kprobe_multi;

		struct {

			__aligned_u64 path;