| From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| Date: Thu, 15 Mar 2018 08:44:24 -0400 |
| Subject: tracepoint: Do not warn on ENOMEM |
| |
| commit d66a270be3310d7aa132fec0cea77d3d32a0ff75 upstream. |
| |
| Tracepoint should only warn when a kernel API user does not respect the |
| required preconditions (e.g. same tracepoint enabled twice, or called |
| to remove a tracepoint that does not exist). |
| |
| Silence warning in out-of-memory conditions, given that the error is |
| returned to the caller. |
| |
| This ensures that out-of-memory error-injection testing does not trigger |
| warnings in tracepoint.c, which were seen by syzbot. |
| |
| Link: https://lkml.kernel.org/r/001a114465e241a8720567419a72@google.com |
| Link: https://lkml.kernel.org/r/001a1140e0de15fc910567464190@google.com |
| Link: http://lkml.kernel.org/r/20180315124424.32319-1-mathieu.desnoyers@efficios.com |
| |
| CC: Peter Zijlstra <peterz@infradead.org> |
| CC: Jiri Olsa <jolsa@redhat.com> |
| CC: Arnaldo Carvalho de Melo <acme@kernel.org> |
| CC: Alexander Shishkin <alexander.shishkin@linux.intel.com> |
| CC: Namhyung Kim <namhyung@kernel.org> |
| Fixes: de7b2973903c6 ("tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints") |
| Reported-by: syzbot+9c0d616860575a73166a@syzkaller.appspotmail.com |
| Reported-by: syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com |
| Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> |
| Signed-off-by: Ben Hutchings <ben@decadent.org.uk> |
| --- |
| kernel/tracepoint.c | 4 ++-- |
| 1 file changed, 2 insertions(+), 2 deletions(-) |
| |
| --- a/kernel/tracepoint.c |
| +++ b/kernel/tracepoint.c |
| @@ -185,7 +185,7 @@ static int tracepoint_add_func(struct tr |
| lockdep_is_held(&tracepoints_mutex)); |
| old = func_add(&tp_funcs, func); |
| if (IS_ERR(old)) { |
| - WARN_ON_ONCE(1); |
| + WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); |
| return PTR_ERR(old); |
| } |
| |
| @@ -218,7 +218,7 @@ static int tracepoint_remove_func(struct |
| lockdep_is_held(&tracepoints_mutex)); |
| old = func_remove(&tp_funcs, func); |
| if (IS_ERR(old)) { |
| - WARN_ON_ONCE(1); |
| + WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); |
| return PTR_ERR(old); |
| } |
| |
