From b08e84da205023009c456bd7f33feb83c5191c60 Mon Sep 17 00:00:00 2001 From: Aleksandr Nogikh Date: Thu, 29 Oct 2020 17:36:18 +0000 Subject: kernel: make kcov_common_handle consider the current context 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 Reviewed-by: Andrey Konovalov Signed-off-by: Jakub Kicinski --- kernel/kcov.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'kernel/kcov.c') 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); -- cgit v1.2.3