Subject: [PATCH V7 15/16] rv/reactor: Add the printk reactor

A reactor that printks the reaction message.

Cc: Wim Van Sebroeck <[email protected]>
Cc: Guenter Roeck <[email protected]>
Cc: Jonathan Corbet <[email protected]>
Cc: Steven Rostedt <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Will Deacon <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Marco Elver <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: "Paul E. McKenney" <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Gabriele Paoloni <[email protected]>
Cc: Juri Lelli <[email protected]>
Cc: Clark Williams <[email protected]>
Cc: Tao Zhou <[email protected]>
Cc: Randy Dunlap <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Daniel Bristot de Oliveira <[email protected]>
---
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 b259d6e8dc7c..e82d5015e6ab 100644
--- a/kernel/trace/rv/Kconfig
+++ b/kernel/trace/rv/Kconfig
@@ -60,3 +60,11 @@ 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..31899f953af4
--- /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 <[email protected]>
+ *
+ * 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);
+}
+
+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.");
--
2.35.1