On Tue, Mar 10, 2020 at 12:15:03PM -0300, Guilherme G. Piccoli wrote:
> 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").
>
> Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
-Kees
> ---
> Documentation/admin-guide/kernel-parameters.txt | 6 +++---
> Documentation/admin-guide/sysctl/kernel.rst | 13 +++++++++++++
> 2 files changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index c07815d230bc..adf77ead02c3 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4515,9 +4515,9 @@
>
> 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.
> + is also controlled by 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 def074807cee..95b2f3256323 100644
> --- a/Documentation/admin-guide/sysctl/kernel.rst
> +++ b/Documentation/admin-guide/sysctl/kernel.rst
> @@ -95,6 +95,7 @@ show up in /proc/sys/kernel:
> - shmmax [ sysv ipc ]
> - shmmni
> - softlockup_all_cpu_backtrace
> +- softlockup_panic
> - soft_watchdog
> - stack_erasing
> - stop-a [ SPARC only ]
> @@ -1029,6 +1030,18 @@ NMI.
> 1: on detection capture more debug information.
>
>
> +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:
> ==============
>
> --
> 2.24.1
>
--
Kees Cook
