On Thu, Jun 15, 2023 at 6:21 PM Jiri Olsa [off-list ref] wrote:

On Mon, Jun 12, 2023 at 03:16:06PM +0000, Yafang Shao wrote:

SNIP

quoted

 /* User bpf_sock_addr struct to access socket fields and sockaddr struct passed

diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index 80c9ec0..fe354d5 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c

@@ -3303,9 +3303,133 @@ static void bpf_perf_link_dealloc(struct bpf_link *link)
      kfree(perf_link);
 }

+static int bpf_perf_link_fill_name(const struct perf_event *event,
+                                char __user *uname, u32 ulen,
+                                u64 *probe_offset, u64 *probe_addr,
+                                u32 *fd_type)
+{

this function name sounds misleading, it does query all the link data
plus copying the name.. seems like this should be renamed and separated

Will do it.

quoted

+     const char *buf;
+     u32 prog_id;
+     size_t len;
+     int err;
+
+     if (!ulen ^ !uname)
+             return -EINVAL;
+     if (!uname)
+             return 0;
+
+     err = bpf_get_perf_event_info(event, &prog_id, fd_type, &buf,
+                                   probe_offset, probe_addr);
+     if (err)
+             return err;
+
+     len = strlen(buf);
+     if (buf) {
+             err = bpf_copy_to_user(uname, buf, ulen, len);
+             if (err)
+                     return err;
+     } else {
+             char zero = '\0';
+
+             if (put_user(zero, uname))
+                     return -EFAULT;
+     }
+     return 0;
+}
+
+static int bpf_perf_link_fill_probe(const struct perf_event *event,
+                                 struct bpf_link_info *info)
+{
+     char __user *uname;
+     u64 addr, offset;
+     u32 ulen, type;
+     int err;
+
+#ifdef CONFIG_KPROBE_EVENTS

this will break compilation when CONFIG_KPROBE_EVENTS or CONFIG_UPROBE_EVENTS
options are not defined

Indeed. Will improve it.

-- 
Regards
Yafang