uprobe_perf_open()->uprobe_apply() can fail, but this error is wrongly
ignored. Change uprobe_perf_open() to do uprobe_perf_close() and return
the error code in this case.
Change uprobe_perf_close() to propogate the error from uprobe_apply()
as well, although it should not fail.
The patch looks more complicated because it moves uprobe_perf_close()
up to make it visible to uprobe_perf_open().
Signed-off-by: Oleg Nesterov <o...@redhat.com>
---
kernel/trace/trace_uprobe.c | 46 +++++++++++++++++++++++-------------------
1 files changed, 25 insertions(+), 21 deletions(-)
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 930e514..9aad3e2 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1003,56 +1003,60 @@ uprobe_filter_event(struct trace_uprobe *tu, struct
perf_event *event)
return __uprobe_perf_filter(&tu->filter, event->hw.tp_target->mm);
}
-static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
+static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
{
bool done;
write_lock(&tu->filter.rwlock);
if (event->hw.tp_target) {
- /*
- * event->parent != NULL means copy_process(), we can avoid
- * uprobe_apply(). current->mm must be probed and we can rely
- * on dup_mmap() which preserves the already installed bp's.
- *
- * attr.enable_on_exec means that exec/mmap will install the
- * breakpoints we need.
- */
+ list_del(&event->hw.tp_list);
done = tu->filter.nr_systemwide ||
- event->parent || event->attr.enable_on_exec ||
+ (event->hw.tp_target->flags & PF_EXITING) ||
uprobe_filter_event(tu, event);
- list_add(&event->hw.tp_list, &tu->filter.perf_events);
} else {
+ tu->filter.nr_systemwide--;
done = tu->filter.nr_systemwide;
- tu->filter.nr_systemwide++;
}
write_unlock(&tu->filter.rwlock);
if (!done)
- uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
+ return uprobe_apply(tu->inode, tu->offset, &tu->consumer,
false);
return 0;
}
-static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
+static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
{
bool done;
+ int err;
write_lock(&tu->filter.rwlock);
if (event->hw.tp_target) {
- list_del(&event->hw.tp_list);
+ /*
+ * event->parent != NULL means copy_process(), we can avoid
+ * uprobe_apply(). current->mm must be probed and we can rely
+ * on dup_mmap() which preserves the already installed bp's.
+ *
+ * attr.enable_on_exec means that exec/mmap will install the
+ * breakpoints we need.
+ */
done = tu->filter.nr_systemwide ||
- (event->hw.tp_target->flags & PF_EXITING) ||
+ event->parent || event->attr.enable_on_exec ||
uprobe_filter_event(tu, event);
+ list_add(&event->hw.tp_list, &tu->filter.perf_events);
} else {
- tu->filter.nr_systemwide--;
done = tu->filter.nr_systemwide;
+ tu->filter.nr_systemwide++;
}
write_unlock(&tu->filter.rwlock);
- if (!done)
- uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
-
- return 0;
+ err = 0;
+ if (!done) {
+ err = uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
+ if (err)
+ uprobe_perf_close(tu, event);
+ }
+ return err;
}
static bool uprobe_perf_filter(struct uprobe_consumer *uc,
--
1.5.5.1
--
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