From: Aleksandr Nogikh <aleksandrnogikh@gmail.com>
To: davem@davemloft.net, kuba@kernel.org, johannes@sipsolutions.net
Cc: edumazet@google.com, andreyknvl@google.com, dvyukov@google.com,
elver@google.com, linux-kernel@vger.kernel.org,
netdev@vger.kernel.org, linux-wireless@vger.kernel.org,
willemdebruijn.kernel@gmail.com,
Aleksandr Nogikh <nogikh@google.com>
Subject: [PATCH v3 1/3] kernel: make kcov_common_handle consider the current context
Date: Mon, 26 Oct 2020 15:08:49 +0000 [thread overview]
Message-ID: <20201026150851.528148-2-aleksandrnogikh@gmail.com> (raw)
In-Reply-To: <20201026150851.528148-1-aleksandrnogikh@gmail.com>
From: Aleksandr Nogikh <nogikh@google.com>
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>
---
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);
--
2.29.0.rc1.297.gfa9743e501-goog
next prev parent reply other threads:[~2020-10-26 15:10 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-26 15:08 [PATCH v3 0/3] net, mac80211, kernel: enable KCOV remote coverage collection for 802.11 frame handling Aleksandr Nogikh
2020-10-26 15:08 ` Aleksandr Nogikh [this message]
2020-10-26 15:08 ` [PATCH v3 2/3] net: add kcov handle to skb extensions Aleksandr Nogikh
2020-10-26 16:56 ` Willem de Bruijn
2020-10-27 12:31 ` Aleksandr Nogikh
2020-10-27 13:13 ` Willem de Bruijn
2020-10-26 17:34 ` kernel test robot
2020-10-26 18:55 ` kernel test robot
2020-10-26 15:08 ` [PATCH v3 3/3] mac80211: add KCOV remote annotations to incoming frame processing Aleksandr Nogikh
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