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From: Jann Horn <jannh@google.com>
To: Alexander Potapenko <glider@google.com>,
	 Dmitry Vyukov <dvyukov@google.com>,
	Andrey Konovalov <andreyknvl@gmail.com>,
	 kasan-dev@googlegroups.com,
	Andrew Morton <akpm@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org, Jann Horn <jannh@google.com>
Subject: [PATCH] kcov: update documentation on remote coverage collection
Date: Tue, 19 May 2026 18:06:06 +0200	[thread overview]
Message-ID: <20260519-kcov-docs-v1-1-5bb22f4cb20c@google.com> (raw)

Adjust the docs on remote coverage collection to reflect the changes made
in "kcov: refactor common handle ID into kcov_common_handle_id" and
"kcov: allow simultaneous KCOV_ENABLE/KCOV_REMOTE_ENABLE".

Suggested-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Jann Horn <jannh@google.com>
---
 Documentation/dev-tools/kcov.rst | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Documentation/dev-tools/kcov.rst b/Documentation/dev-tools/kcov.rst
index 8127849d40f5..54a0baeb917a 100644
--- a/Documentation/dev-tools/kcov.rst
+++ b/Documentation/dev-tools/kcov.rst
@@ -246,6 +246,8 @@ KCOV supports collecting remote coverage from the following contexts:
 2. Local kernel background tasks. These are spawned when a userspace process
    interacts with some kernel interface and are usually killed when the process
    exits (e.g. vhost workers).
+   This can be combined with another KCOV instance that is configured for normal
+   coverage collection.
 
 3. Soft interrupts.
 
@@ -262,6 +264,9 @@ gets saved to the ``kcov_handle`` field in the current ``task_struct`` and
 needs to be passed to the newly spawned local tasks via custom kernel code
 modifications. Those tasks should in turn use the passed handle in their
 ``kcov_remote_start`` and ``kcov_remote_stop`` annotations.
+In the kernel, common handles are wrapped in a ``kcov_common_handle_id``, which
+consumes no space in builds without ``CONFIG_KCOV``; subsystems that integrate
+with this mechanism should not need to use any ``#ifdef CONFIG_KCOV`` or such.
 
 KCOV follows a predefined format for both global and common handles. Each
 handle is a ``u64`` integer. Currently, only the one top and the lower 4 bytes

---
base-commit: ab5fce87a778cb780a05984a2ca448f2b41aafbf
change-id: 20260519-kcov-docs-15feabfb10aa

--  
Jann Horn <jannh@google.com>


             reply	other threads:[~2026-05-19 16:06 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-19 16:06 Jann Horn [this message]
2026-05-20  8:27 ` Alexander Potapenko
2026-05-20 17:51 ` Andrey Konovalov
2026-05-20 18:15   ` Jann Horn

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