From: Mathieu Desnoyers <[email protected]> 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/[email protected] Link: https://lkml.kernel.org/r/[email protected] Link: http://lkml.kernel.org/r/[email protected] CC: Peter Zijlstra <[email protected]> CC: Jiri Olsa <[email protected]> CC: Arnaldo Carvalho de Melo <[email protected]> CC: Alexander Shishkin <[email protected]> CC: Namhyung Kim <[email protected]> CC: [email protected] Fixes: de7b2973903c6 ("tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints") Reported-by: [email protected] Reported-by: [email protected] Signed-off-by: Mathieu Desnoyers <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]> --- kernel/tracepoint.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c index 671b13457387..1e37da2e0c25 100644 --- a/kernel/tracepoint.c +++ b/kernel/tracepoint.c @@ -207,7 +207,7 @@ static int tracepoint_add_func(struct tracepoint *tp, lockdep_is_held(&tracepoints_mutex)); old = func_add(&tp_funcs, func, prio); if (IS_ERR(old)) { - WARN_ON_ONCE(1); + WARN_ON_ONCE(PTR_ERR(old) != -ENOMEM); return PTR_ERR(old); } @@ -239,7 +239,7 @@ static int tracepoint_remove_func(struct tracepoint *tp, 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); } -- 2.17.0
