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 v5 1/3] kernel: make kcov_common_handle consider the current context
Date: Thu, 29 Oct 2020 17:36:18 +0000 [thread overview]
Message-ID: <20201029173620.2121359-2-aleksandrnogikh@gmail.com> (raw)
In-Reply-To: <20201029173620.2121359-1-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);
--
2.29.1.341.ge80a0c044ae-goog
next prev parent reply other threads:[~2020-10-29 17:37 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-29 17:36 [PATCH v5 0/3] net, mac80211, kernel: enable KCOV remote coverage collection for 802.11 frame handling Aleksandr Nogikh
2020-10-29 17:36 ` Aleksandr Nogikh [this message]
2020-10-29 17:36 ` [PATCH v5 2/3] net: add kcov handle to skb extensions Aleksandr Nogikh
2020-11-21 16:09 ` Ido Schimmel
2020-11-21 16:52 ` Florian Westphal
2020-11-21 17:39 ` Johannes Berg
2020-11-21 18:06 ` Jakub Kicinski
2020-11-21 18:12 ` Johannes Berg
2020-11-21 18:35 ` Jakub Kicinski
2020-11-21 19:30 ` Johannes Berg
2020-11-21 20:55 ` Jakub Kicinski
2020-11-21 20:58 ` Johannes Berg
2020-11-21 21:02 ` Jakub Kicinski
2020-11-25 16:30 ` Marco Elver
2020-12-01 1:52 ` Jakub Kicinski
2020-12-01 7:35 ` Ido Schimmel
2020-12-01 16:43 ` Jakub Kicinski
2020-10-29 17:36 ` [PATCH v5 3/3] mac80211: add KCOV remote annotations to incoming frame processing Aleksandr Nogikh
2020-10-29 17:44 ` Johannes Berg
2020-10-29 18:00 ` Marco Elver
2020-10-29 19:08 ` Andrey Konovalov
2020-11-03 3:00 ` [PATCH v5 0/3] net, mac80211, kernel: enable KCOV remote coverage collection for 802.11 frame handling Jakub Kicinski
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