uprobes/tracing: Fix uprobe_perf_open() on uprobe_apply() failure

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.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Steven Rostedt <rostedt@goodmis.org>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>

1 files changed, 9 insertions, 5 deletions

diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c
index 51bd071eaca0..5a7f1a6b3b8b 100644
--- a/kernel/trace/trace_uprobe.c
+++ b/kernel/trace/trace_uprobe.c
@@ -1026,7 +1026,7 @@ static int uprobe_perf_close(struct trace_uprobe *tu, struct perf_event *event)
         write_unlock(&tu->filter.rwlock);
 
         if (!done)
-                uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
+                return uprobe_apply(tu->inode, tu->offset, &tu->consumer, false);
 
         return 0;
 }
@@ -1034,6 +1034,7 @@ 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) {
@@ -1055,10 +1056,13 @@ static int uprobe_perf_open(struct trace_uprobe *tu, struct perf_event *event)
         }
         write_unlock(&tu->filter.rwlock);
 
-        if (!done)
-                uprobe_apply(tu->inode, tu->offset, &tu->consumer, true);
-
-        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,