Documentation: Better document the softlockup_panic sysctl

Commit 9c44bc03fff4 ("softlockup: allow panic on lockup") added the
softlockup_panic sysctl, but didn't add information about it to the file
Documentation/admin-guide/sysctl/kernel.rst (which in that time certainly
wasn't rst and had other name!).

This patch just adds the respective documentation and references it from
the corresponding entry in Documentation/admin-guide/kernel-parameters.txt.

This patch was strongly based on Scott Wood's commit d22881dc13b6
("Documentation: Better document the hardlockup_panic sysctl").

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com>
Link: https://lore.kernel.org/r/20200310183649.23163-1-gpiccoli@canonical.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>

diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 4220477079bd1ffdb9a6326b30ab5b147eb37697..b3b5aa7408df97fee77e40ee3629c0f3d39cb936 100644 (file)
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -4516,10 +4516,10 @@
                        Format: <integer>
 
                        A nonzero value instructs the soft-lockup detector
-                       to panic the machine when a soft-lockup occurs. This
-                       is also controlled by CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC
-                       which is the respective build-time switch to that
-                       functionality.
+                       to panic the machine when a soft-lockup occurs. It is
+                       also controlled by the kernel.softlockup_panic sysctl
+                       and CONFIG_BOOTPARAM_SOFTLOCKUP_PANIC, which is the
+                       respective build-time switch to that functionality.
 
        softlockup_all_cpu_backtrace=
                        [KNL] Should the soft-lockup detector generate

diff --git a/Documentation/admin-guide/sysctl/kernel.rst b/Documentation/admin-guide/sysctl/kernel.rst
index 1c48ab4bfe3024d3347e1f7362e767ddc35db37c..335696d3360da617121420825144edfe59becb03 100644 (file)
--- a/Documentation/admin-guide/sysctl/kernel.rst
+++ b/Documentation/admin-guide/sysctl/kernel.rst
@@ -1036,6 +1036,20 @@ NMI.
 = ============================================
 
 
+softlockup_panic
+=================
+
+This parameter can be used to control whether the kernel panics
+when a soft lockup is detected.
+
+= ============================================
+0 Don't panic on soft lockup.
+1 Panic on soft lockup.
+= ============================================
+
+This can also be set using the softlockup_panic kernel parameter.
+
+
 soft_watchdog
 =============