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authorAleksandr Nogikh <nogikh@google.com>2020-10-29 17:36:18 +0000
committerJakub Kicinski <kuba@kernel.org>2020-11-02 18:00:20 -0800
commitb08e84da205023009c456bd7f33feb83c5191c60 (patch)
treeae9485a2eee965fbe97dba350887c00cb71e7c9e
parent0e8c266c59b56acc94d3289d3b3fb142d22fb46c (diff)
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 <nogikh@google.com> Reviewed-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
-rw-r--r--kernel/kcov.c2
1 files changed, 2 insertions, 0 deletions
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);