[PATCH] tracepoint: Allow trace events in modules with TAINT_TEST

From: alison . schofield
Date: Fri Aug 26 2022 - 18:35:47 EST


From: Alison Schofield <alison.schofield@xxxxxxxxx>

Commit 2852ca7fba9f ("panic: Taint kernel if tests are run")
introduced a new taint type, TAINT_TEST, to signal that an
in-kernel test has been run.

TAINT_TEST taint type defaults into a 'bad_taint' list for
kernel tracing and blocks the creation of trace events. This
causes a problem for CXL testing where loading the cxl_test
module makes all CXL modules out-of-tree, blocking any trace
events.

Trace events are in development for CXL at the moment and this
issue was found in test with v6.0-rc1.

Reported-by: Ira Weiny <ira.weiny@xxxxxxxxx>
Suggested-by: Dan Williams <dan.j.williams@xxxxxxxxx>
Signed-off-by: Alison Schofield <alison.schofield@xxxxxxxxx>
---
kernel/tracepoint.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/kernel/tracepoint.c b/kernel/tracepoint.c
index 64ea283f2f86..5f17378c9dc2 100644
--- a/kernel/tracepoint.c
+++ b/kernel/tracepoint.c
@@ -571,7 +571,8 @@ static void for_each_tracepoint_range(
bool trace_module_has_bad_taint(struct module *mod)
{
return mod->taints & ~((1 << TAINT_OOT_MODULE) | (1 << TAINT_CRAP) |
- (1 << TAINT_UNSIGNED_MODULE));
+ (1 << TAINT_UNSIGNED_MODULE) |
+ (1 << TAINT_TEST));
}

static BLOCKING_NOTIFIER_HEAD(tracepoint_notify_list);

base-commit: 4c612826bec1441214816827979b62f84a097e91
--
2.31.1