perf_event_open.2: Add type kprobe and uprobe

Two new types kprobe and uprobe are being added to
perf_event_open(), which allow creating kprobe or
uprobe with perf_event_open. This patch adds
information about these types.

Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man2/perf_event_open.2

@@ -256,11 +256,15 @@ struct perf_event_attr {
 
     union {
         __u64 bp_addr;          /* breakpoint address */
+        __u64 kprobe_func;      /* for perf_kprobe */
+        __u64 uprobe_path;      /* for perf_uprobe */
         __u64 config1;          /* extension of config */
     };
 
     union {
         __u64 bp_len;           /* breakpoint length */
+        __u64 kprobe_addr;      /* with kprobe_func == NULL */
+        __u64 probe_offset;     /* for perf_[k,u]probe */
         __u64 config2;          /* extension of config1 */
     };
     __u64 branch_sample_type;   /* enum perf_branch_sample_type */
@@ -336,6 +340,14 @@ field.
 For instance,
 .I /sys/bus/event_source/devices/cpu/type
 contains the value for the core CPU PMU, which is usually 4.
+.TP
+.BR kprobe " and " uprobe " (since Linux 4.16)"
+These two dynamic PMUs create a kprobe/uprobe and attach it to the
+file descriptor generated by perf_event_open. The kprobe/uprobe
+will be destroyed on the destruction of the file descriptor.
+See fields
+.IR kprobe_func ", " uprobe_path ", " kprobe_addr ", and " probe_offset
+for more details.
 .RE
 .TP
 .I "size"
@@ -627,6 +639,45 @@ then leave
 .I config
 set to zero.
 Its parameters are set in other places.
+.PP
+If
+.I type
+is
+.BR kprobe
+or
+.BR uprobe ,
+set
+.IR retprobe
+(bit 0 of
+.IR config ,
+see /sys/bus/event_source/devices/[k,u]probe/format/retprobe)
+for kretprobe/uretprobe. See fields
+.IR kprobe_func ", " uprobe_path ", " kprobe_addr ", and " probe_offset
+for more details.
+.RE
+.TP
+.IR kprobe_func ", " uprobe_path ", " kprobe_addr ", and " probe_offset
+.EE
+These fields describes the kprobe/uprobe for dynamic PMU
+.BR kprobe
+and
+.BR uprobe .
+For
+.BR kprobe ": "
+use
+.I kprobe_func
+and
+.IR probe_offset ,
+or use
+.I kprobe_addr
+and leave
+.I kprobe_func
+as NULL. For
+.BR uprobe ": "
+use
+.I uprobe_path
+and
+.IR probe_offset .
 .RE
 .TP
 .IR sample_period ", " sample_freq