From: Thorsten Leemhuis <linux@leemhuis.info>
To: Jonathan Corbet <corbet@lwn.net>
Cc: workflows@vger.kernel.org, linux-doc@vger.kernel.org,
regressions@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: [PATCH v1 10/30] docs: reporting-issues: move 'check tainted flag' upwards
Date: Sun, 26 Oct 2025 13:42:01 +0100 [thread overview]
Message-ID: <93cac5463d1e51b57b7cf74181397039137bcdb5.1761481839.git.linux@leemhuis.info> (raw)
In-Reply-To: <cover.1761481839.git.linux@leemhuis.info>
Move text around to improve diffability in the follow-up patch.
Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info>
---
.../admin-guide/reporting-issues.rst | 142 +++++++++---------
1 file changed, 71 insertions(+), 71 deletions(-)
diff --git a/Documentation/admin-guide/reporting-issues.rst b/Documentation/admin-guide/reporting-issues.rst
index 63ce6ae51df266..19f1ffabf5ae30 100644
--- a/Documentation/admin-guide/reporting-issues.rst
+++ b/Documentation/admin-guide/reporting-issues.rst
@@ -85,6 +85,9 @@ following the others is usually in your own interest.
[:ref:`details <checklog_repiref>`]
+ * Check if your kernel was 'tainted' when the issue occurred, as the event
+ that made the kernel set this flag might be causing the issue you face.
+
* Perform a rough search for existing reports with your favorite internet
search engine; additionally, check the archives of the `Linux Kernel Mailing
List (LKML) <https://lore.kernel.org/lkml/>`_. If you find matching reports,
@@ -103,9 +106,6 @@ following the others is usually in your own interest.
kernel modules on-the-fly, which solutions like DKMS might be doing locally
without your knowledge.
- * Check if your kernel was 'tainted' when the issue occurred, as the event
- that made the kernel set this flag might be causing the issue you face.
-
* Write down coarsely how to reproduce the issue.
* If you are facing a regression within a stable or longterm version line
@@ -397,6 +397,74 @@ to set warnings and errors apart.
[:ref:`back to step-by-step guide <checklog_repisbs>`]
+Check 'taint' flag
+------------------
+
+ *Check if your kernel was 'tainted' when the issue occurred, as the event
+ that made the kernel set this flag might be causing the issue you face.*
+
+The kernel marks itself with a 'taint' flag when something happens that might
+lead to follow-up errors that look totally unrelated. The issue you face might
+be such an error if your kernel is tainted. That's why it's in your interest to
+rule this out early before investing more time into this process. This is the
+only reason why this step is here, as this process later will tell you to
+install the latest mainline kernel; you will need to check the taint flag again
+then, as that's when it matters because it's the kernel the report will focus
+on.
+
+On a running system is easy to check if the kernel tainted itself: if ``cat
+/proc/sys/kernel/tainted`` returns '0' then the kernel is not tainted and
+everything is fine. Checking that file is impossible in some situations; that's
+why the kernel also mentions the taint status when it reports an internal
+problem (a 'kernel bug'), a recoverable error (a 'kernel Oops') or a
+non-recoverable error before halting operation (a 'kernel panic'). Look near
+the top of the error messages printed when one of these occurs and search for a
+line starting with 'CPU:'. It should end with 'Not tainted' if the kernel was
+not tainted when it noticed the problem; it was tainted if you see 'Tainted:'
+followed by a few spaces and some letters.
+
+If your kernel is tainted, study Documentation/admin-guide/tainted-kernels.rst
+to find out why. Try to eliminate the reason. Often it's caused by one these
+three things:
+
+ 1. A recoverable error (a 'kernel Oops') occurred and the kernel tainted
+ itself, as the kernel knows it might misbehave in strange ways after that
+ point. In that case check your kernel or system log and look for a section
+ that starts with this::
+
+ Oops: 0000 [#1] SMP
+
+ That's the first Oops since boot-up, as the '#1' between the brackets shows.
+ Every Oops and any other problem that happens after that point might be a
+ follow-up problem to that first Oops, even if both look totally unrelated.
+ Rule this out by getting rid of the cause for the first Oops and reproducing
+ the issue afterwards. Sometimes simply restarting will be enough, sometimes
+ a change to the configuration followed by a reboot can eliminate the Oops.
+ But don't invest too much time into this at this point of the process, as
+ the cause for the Oops might already be fixed in the newer Linux kernel
+ version you are going to install later in this process.
+
+ 2. Your system uses a software that installs its own kernel modules, for
+ example Nvidia's proprietary graphics driver or VirtualBox. The kernel
+ taints itself when it loads such module from external sources (even if
+ they are Open Source): they sometimes cause errors in unrelated kernel
+ areas and thus might be causing the issue you face. You therefore have to
+ prevent those modules from loading when you want to report an issue to the
+ Linux kernel developers. Most of the time the easiest way to do that is:
+ temporarily uninstall such software including any modules they might have
+ installed. Afterwards reboot.
+
+ 3. The kernel also taints itself when it's loading a module that resides in
+ the staging tree of the Linux kernel source. That's a special area for
+ code (mostly drivers) that does not yet fulfill the normal Linux kernel
+ quality standards. When you report an issue with such a module it's
+ obviously okay if the kernel is tainted; just make sure the module in
+ question is the only reason for the taint. If the issue happens in an
+ unrelated area reboot and temporarily block the module from being loaded
+ by specifying ``foo.blacklist=1`` as kernel parameter (replace 'foo' with
+ the name of the module in question).
+
+
Search for existing reports, first run
--------------------------------------
@@ -548,74 +616,6 @@ module not part of the Linux kernel. That why your might need to uninstall the
packages with such software to get rid of any 3rd party kernel module.
-Check 'taint' flag
-------------------
-
- *Check if your kernel was 'tainted' when the issue occurred, as the event
- that made the kernel set this flag might be causing the issue you face.*
-
-The kernel marks itself with a 'taint' flag when something happens that might
-lead to follow-up errors that look totally unrelated. The issue you face might
-be such an error if your kernel is tainted. That's why it's in your interest to
-rule this out early before investing more time into this process. This is the
-only reason why this step is here, as this process later will tell you to
-install the latest mainline kernel; you will need to check the taint flag again
-then, as that's when it matters because it's the kernel the report will focus
-on.
-
-On a running system is easy to check if the kernel tainted itself: if ``cat
-/proc/sys/kernel/tainted`` returns '0' then the kernel is not tainted and
-everything is fine. Checking that file is impossible in some situations; that's
-why the kernel also mentions the taint status when it reports an internal
-problem (a 'kernel bug'), a recoverable error (a 'kernel Oops') or a
-non-recoverable error before halting operation (a 'kernel panic'). Look near
-the top of the error messages printed when one of these occurs and search for a
-line starting with 'CPU:'. It should end with 'Not tainted' if the kernel was
-not tainted when it noticed the problem; it was tainted if you see 'Tainted:'
-followed by a few spaces and some letters.
-
-If your kernel is tainted, study Documentation/admin-guide/tainted-kernels.rst
-to find out why. Try to eliminate the reason. Often it's caused by one these
-three things:
-
- 1. A recoverable error (a 'kernel Oops') occurred and the kernel tainted
- itself, as the kernel knows it might misbehave in strange ways after that
- point. In that case check your kernel or system log and look for a section
- that starts with this::
-
- Oops: 0000 [#1] SMP
-
- That's the first Oops since boot-up, as the '#1' between the brackets shows.
- Every Oops and any other problem that happens after that point might be a
- follow-up problem to that first Oops, even if both look totally unrelated.
- Rule this out by getting rid of the cause for the first Oops and reproducing
- the issue afterwards. Sometimes simply restarting will be enough, sometimes
- a change to the configuration followed by a reboot can eliminate the Oops.
- But don't invest too much time into this at this point of the process, as
- the cause for the Oops might already be fixed in the newer Linux kernel
- version you are going to install later in this process.
-
- 2. Your system uses a software that installs its own kernel modules, for
- example Nvidia's proprietary graphics driver or VirtualBox. The kernel
- taints itself when it loads such module from external sources (even if
- they are Open Source): they sometimes cause errors in unrelated kernel
- areas and thus might be causing the issue you face. You therefore have to
- prevent those modules from loading when you want to report an issue to the
- Linux kernel developers. Most of the time the easiest way to do that is:
- temporarily uninstall such software including any modules they might have
- installed. Afterwards reboot.
-
- 3. The kernel also taints itself when it's loading a module that resides in
- the staging tree of the Linux kernel source. That's a special area for
- code (mostly drivers) that does not yet fulfill the normal Linux kernel
- quality standards. When you report an issue with such a module it's
- obviously okay if the kernel is tainted; just make sure the module in
- question is the only reason for the taint. If the issue happens in an
- unrelated area reboot and temporarily block the module from being loaded
- by specifying ``foo.blacklist=1`` as kernel parameter (replace 'foo' with
- the name of the module in question).
-
-
Document how to reproduce issue
-------------------------------
--
2.51.0
next prev parent reply other threads:[~2025-10-26 12:42 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-26 12:41 [PATCH v1 00/30] docs: reporting-issues: rework Thorsten Leemhuis
2025-10-26 12:41 ` [PATCH v1 01/30] docs: reporting-issues: mention text is best viewed rendered Thorsten Leemhuis
2025-10-27 17:18 ` Jonathan Corbet
2025-10-27 21:19 ` Randy Dunlap
2025-10-26 12:41 ` [PATCH v1 02/30] docs: reporting-issues: tweak the reference section intro Thorsten Leemhuis
2025-10-27 17:27 ` Jonathan Corbet
2025-10-26 12:41 ` [PATCH v1 03/30] docs: reporting-issues: add conclusion to the step-by-step guide Thorsten Leemhuis
2025-10-27 17:29 ` Jonathan Corbet
2025-10-26 12:41 ` [PATCH v1 04/30] docs: reporting-issues: add proper appendix Thorsten Leemhuis
2025-10-27 17:38 ` Jonathan Corbet
2025-10-26 12:41 ` [PATCH v1 05/30] docs: reporting-issues: outline why reporting is complicated Thorsten Leemhuis
2025-10-27 17:44 ` Jonathan Corbet
2025-10-26 12:41 ` [PATCH v1 06/30] docs: reporting-issues: replace TLDR guide with more of an into Thorsten Leemhuis
2025-10-28 21:32 ` Jonathan Corbet
2025-10-26 12:41 ` [PATCH v1 07/30] docs: reporting-issues: explain need for fresh vanilla kernel Thorsten Leemhuis
2025-10-28 21:40 ` Jonathan Corbet
2025-10-26 12:41 ` [PATCH v1 08/30] docs: reporting-issues: add step about processing issues separately Thorsten Leemhuis
2025-10-28 21:42 ` Jonathan Corbet
2025-10-26 12:42 ` [PATCH v1 09/30] docs: reporting-issues: tell users to check the kernel log Thorsten Leemhuis
2025-10-28 21:43 ` Jonathan Corbet
2025-10-26 12:42 ` Thorsten Leemhuis [this message]
2025-10-28 21:47 ` [PATCH v1 10/30] docs: reporting-issues: move 'check tainted flag' upwards Jonathan Corbet
2025-10-26 12:42 ` [PATCH v1 11/30] docs: reporting-issues: improve first tainted check Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 12/30] docs: reporting-issues: move 'check environment' upwards Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 13/30] docs: reporting-issues: improve environment check Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 14/30] docs: reporting-issues: improve text about checking for existing issues Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 15/30] docs: reporting-issues: improve text on classifying the bug Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 16/30] docs: reporting-issues: add fast-track for regressions Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 17/30] docs: reporting-issues: move text on 'check MAINTAINERS file' upwards Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 18/30] docs: reporting-issues: improve text on looking up place to report Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 19/30] docs: reporting-issues: move text on 'check other places' upwards Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 20/30] docs: reporting-issues: improve text on check other places Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 21/30] docs: reporting-issues: improve text on backup et. al Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 22/30] docs: reporting-issues: move text on 'initial write-up' upwards Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 23/30] docs: reporting-issues: improve text on initial write-up Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 24/30] docs: reporting-issues: improve text on bug verification Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 25/30] docs: reporting-issues: improve text on non-regressions in stable Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 26/30] docs: reporting-issues: improve text on second search Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 27/30] docs: reporting-issues: make collecting files a separate step Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 28/30] docs: reporting-issues: separate steps for optimizing and submitting reports Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 29/30] docs: reporting-issues: separate steps for follow-up tasks Thorsten Leemhuis
2025-10-26 12:42 ` [PATCH v1 30/30] docs: reporting-issues: fix a few line breaks Thorsten Leemhuis
2025-10-27 17:16 ` [PATCH v1 00/30] docs: reporting-issues: rework Jonathan Corbet
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