[PATCH 3/5] kcsan: unset panic_on_warn before calling panic()

From: Tiezhu Yang
Date: Fri Jan 28 2022 - 06:42:58 EST


As done in the full WARN() handler, panic_on_warn needs to be cleared
before calling panic() to avoid recursive panics.

Signed-off-by: Tiezhu Yang <yangtiezhu@xxxxxxxxxxx>
---
kernel/kcsan/report.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/kernel/kcsan/report.c b/kernel/kcsan/report.c
index 6779440..752ab33 100644
--- a/kernel/kcsan/report.c
+++ b/kernel/kcsan/report.c
@@ -492,8 +492,16 @@ static void print_report(enum kcsan_value_change value_change,
dump_stack_print_info(KERN_DEFAULT);
pr_err("==================================================================\n");

- if (panic_on_warn)
+ if (panic_on_warn) {
+ /*
+ * This thread may hit another WARN() in the panic path.
+ * Resetting this prevents additional WARN() from panicking the
+ * system on this thread. Other threads are blocked by the
+ * panic_mutex in panic().
+ */
+ panic_on_warn = 0;
panic("panic_on_warn set ...\n");
+ }
}

static void release_report(unsigned long *flags, struct other_info *other_info)
--
2.1.0