[ Including the printk folks ]
On Tue, 19 Jul 2022 19:27:20 +0200
Daniel Bristot de Oliveira <bristot@xxxxxxxxxx> wrote:
> A reactor that printks the reaction message.
>
> Cc: Wim Van Sebroeck <wim@xxxxxxxxxxxxxxxxxx>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: Jonathan Corbet <corbet@xxxxxxx>
> Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
> Cc: Ingo Molnar <mingo@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> Cc: Will Deacon <will@xxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Marco Elver <elver@xxxxxxxxxx>
> Cc: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> Cc: "Paul E. McKenney" <paulmck@xxxxxxxxxx>
> Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
> Cc: Gabriele Paoloni <gpaoloni@xxxxxxxxxx>
> Cc: Juri Lelli <juri.lelli@xxxxxxxxxx>
> Cc: Clark Williams <williams@xxxxxxxxxx>
> Cc: Tao Zhou <tao.zhou@xxxxxxxxx>
> Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
> Cc: linux-doc@xxxxxxxxxxxxxxx
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: linux-trace-devel@xxxxxxxxxxxxxxx
> Signed-off-by: Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
> ---
> kernel/trace/rv/Kconfig | 8 ++++++
> kernel/trace/rv/Makefile | 3 ++-
> kernel/trace/rv/reactor_printk.c | 42 ++++++++++++++++++++++++++++++++
> 3 files changed, 52 insertions(+), 1 deletion(-)
> create mode 100644 kernel/trace/rv/reactor_printk.c
>
> diff --git a/kernel/trace/rv/Kconfig b/kernel/trace/rv/Kconfig
> index d8c40fd67e88..f1d92d431130 100644
> --- a/kernel/trace/rv/Kconfig
> +++ b/kernel/trace/rv/Kconfig
> @@ -63,3 +63,11 @@ config RV_REACTORS
> on the model's execution. By default, the monitors have
> tracing reactions, printing the monitor output via tracepoints,
> but other reactions can be added (on-demand) via this interface.
> +
> +config RV_REACT_PRINTK
> + bool "Printk reactor"
> + depends on RV_REACTORS
> + default y
> + help
> + Enables the printk reactor. The printk reactor emits a printk()
> + message if an exception is found.
> diff --git a/kernel/trace/rv/Makefile b/kernel/trace/rv/Makefile
> index af0ff9a46418..a13c750a35c1 100644
> --- a/kernel/trace/rv/Makefile
> +++ b/kernel/trace/rv/Makefile
> @@ -1,6 +1,7 @@
> # SPDX-License-Identifier: GPL-2.0
>
> obj-$(CONFIG_RV) += rv.o
> -obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
> obj-$(CONFIG_RV_MON_WIP) += monitors/wip/wip.o
> obj-$(CONFIG_RV_MON_WWNR) += monitors/wwnr/wwnr.o
> +obj-$(CONFIG_RV_REACTORS) += rv_reactors.o
> +obj-$(CONFIG_RV_REACT_PRINTK) += reactor_printk.o
> diff --git a/kernel/trace/rv/reactor_printk.c b/kernel/trace/rv/reactor_printk.c
> new file mode 100644
> index 000000000000..8b5c70b05634
> --- /dev/null
> +++ b/kernel/trace/rv/reactor_printk.c
> @@ -0,0 +1,42 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (C) 2019-2022 Red Hat, Inc. Daniel Bristot de Oliveira <bristot@xxxxxxxxxx>
> + *
> + * Printk RV reactor:
> + * Prints the exception msg to the kernel message log.
> + */
> +#include <linux/ftrace.h>
> +#include <linux/tracepoint.h>
> +#include <linux/kernel.h>
> +#include <linux/module.h>
> +#include <linux/init.h>
> +#include <linux/rv.h>
> +
> +static void rv_printk_reaction(char *msg)
> +{
> + printk_deferred(msg);
I added the printk folks just so that they are aware of another
printk_deferred() being added to the kernel.
-- Steve
> +}
> +
> +static struct rv_reactor rv_printk = {
> + .name = "printk",
> + .description = "prints the exception msg to the kernel message log",
> + .react = rv_printk_reaction
> +};
> +
> +static int register_react_printk(void)
> +{
> + rv_register_reactor(&rv_printk);
> + return 0;
> +}
> +
> +static void unregister_react_printk(void)
> +{
> + rv_unregister_reactor(&rv_printk);
> +}
> +
> +module_init(register_react_printk);
> +module_exit(unregister_react_printk);
> +
> +MODULE_LICENSE("GPL");
> +MODULE_AUTHOR("Daniel Bristot de Oliveira");
> +MODULE_DESCRIPTION("printk rv reactor: printk if an exception is hit");
