Merge tag 'trace-v4.20' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt...

[sfrench/cifs-2.6.git] / kernel / events / core.c

diff --git a/kernel/events/core.c b/kernel/events/core.c
index 5a97f34bc14c8e2e31a452cb6fdcd38774a3b9a1..8c490130c4fb0072838801534948d9ec6b9a285f 100644 (file)
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -8376,30 +8376,39 @@ static struct pmu perf_tracepoint = {
  *
  * PERF_PROBE_CONFIG_IS_RETPROBE if set, create kretprobe/uretprobe
  *                               if not set, create kprobe/uprobe
+ *
+ * The following values specify a reference counter (or semaphore in the
+ * terminology of tools like dtrace, systemtap, etc.) Userspace Statically
+ * Defined Tracepoints (USDT). Currently, we use 40 bit for the offset.
+ *
+ * PERF_UPROBE_REF_CTR_OFFSET_BITS     # of bits in config as th offset
+ * PERF_UPROBE_REF_CTR_OFFSET_SHIFT    # of bits to shift left
  */
 enum perf_probe_config {
        PERF_PROBE_CONFIG_IS_RETPROBE = 1U << 0,  /* [k,u]retprobe */
+       PERF_UPROBE_REF_CTR_OFFSET_BITS = 32,
+       PERF_UPROBE_REF_CTR_OFFSET_SHIFT = 64 - PERF_UPROBE_REF_CTR_OFFSET_BITS,
 };
 
 PMU_FORMAT_ATTR(retprobe, "config:0");
+#endif
 
-static struct attribute *probe_attrs[] = {
+#ifdef CONFIG_KPROBE_EVENTS
+static struct attribute *kprobe_attrs[] = {
        &format_attr_retprobe.attr,
        NULL,
 };
 
-static struct attribute_group probe_format_group = {
+static struct attribute_group kprobe_format_group = {
        .name = "format",
-       .attrs = probe_attrs,
+       .attrs = kprobe_attrs,
 };
 
-static const struct attribute_group *probe_attr_groups[] = {
-       &probe_format_group,
+static const struct attribute_group *kprobe_attr_groups[] = {
+       &kprobe_format_group,
        NULL,
 };
-#endif
 
-#ifdef CONFIG_KPROBE_EVENTS
 static int perf_kprobe_event_init(struct perf_event *event);
 static struct pmu perf_kprobe = {
        .task_ctx_nr    = perf_sw_context,
@@ -8409,7 +8418,7 @@ static struct pmu perf_kprobe = {
        .start          = perf_swevent_start,
        .stop           = perf_swevent_stop,
        .read           = perf_swevent_read,
-       .attr_groups    = probe_attr_groups,
+       .attr_groups    = kprobe_attr_groups,
 };
 
 static int perf_kprobe_event_init(struct perf_event *event)
@@ -8441,6 +8450,24 @@ static int perf_kprobe_event_init(struct perf_event *event)
 #endif /* CONFIG_KPROBE_EVENTS */
 
 #ifdef CONFIG_UPROBE_EVENTS
+PMU_FORMAT_ATTR(ref_ctr_offset, "config:32-63");
+
+static struct attribute *uprobe_attrs[] = {
+       &format_attr_retprobe.attr,
+       &format_attr_ref_ctr_offset.attr,
+       NULL,
+};
+
+static struct attribute_group uprobe_format_group = {
+       .name = "format",
+       .attrs = uprobe_attrs,
+};
+
+static const struct attribute_group *uprobe_attr_groups[] = {
+       &uprobe_format_group,
+       NULL,
+};
+
 static int perf_uprobe_event_init(struct perf_event *event);
 static struct pmu perf_uprobe = {
        .task_ctx_nr    = perf_sw_context,
@@ -8450,12 +8477,13 @@ static struct pmu perf_uprobe = {
        .start          = perf_swevent_start,
        .stop           = perf_swevent_stop,
        .read           = perf_swevent_read,
-       .attr_groups    = probe_attr_groups,
+       .attr_groups    = uprobe_attr_groups,
 };
 
 static int perf_uprobe_event_init(struct perf_event *event)
 {
        int err;
+       unsigned long ref_ctr_offset;
        bool is_retprobe;
 
        if (event->attr.type != perf_uprobe.type)
@@ -8471,7 +8499,8 @@ static int perf_uprobe_event_init(struct perf_event *event)
                return -EOPNOTSUPP;
 
        is_retprobe = event->attr.config & PERF_PROBE_CONFIG_IS_RETPROBE;
-       err = perf_uprobe_init(event, is_retprobe);
+       ref_ctr_offset = event->attr.config >> PERF_UPROBE_REF_CTR_OFFSET_SHIFT;
+       err = perf_uprobe_init(event, ref_ctr_offset, is_retprobe);
        if (err)
                return err;