From: Aleksandr Nogikh <nogikh@xxxxxxxxxx>
kcov_common_handle is a method that is used to obtain a "default" KCOV
remote handle of the current process. The handle can later be passed
to kcov_remote_start in order to collect coverage for the processing
that is initiated by one process, but done in another. For details see
Documentation/dev-tools/kcov.rst and comments in kernel/kcov.c.
Presently, if kcov_common_handle is called in an IRQ context, it will
return a handle for the interrupted process. This may lead to
unreliable and incorrect coverage collection.
Adjust the behavior of kcov_common_handle in the following way. If it
is called in a task context, return the common handle for the
currently running task. Otherwise, return 0.
Signed-off-by: Aleksandr Nogikh <nogikh@xxxxxxxxxx>
Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Reviewed-by: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
---
kernel/kcov.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/kcov.c b/kernel/kcov.c
index 6b8368be89c8..80bfe71bbe13 100644
--- a/kernel/kcov.c
+++ b/kernel/kcov.c
@@ -1023,6 +1023,8 @@ EXPORT_SYMBOL(kcov_remote_stop);
/* See the comment before kcov_remote_start() for usage details. */
u64 kcov_common_handle(void)
{
+ if (!in_task())
+ return 0;
return current->kcov_handle;
}
EXPORT_SYMBOL(kcov_common_handle);
--
2.29.2.454.gaff20da3a2-goog
