See also Documentation/trace/ftrace.txt "trace options"
section.
+ traceoff_on_warning
+ [FTRACE] enable this option to disable tracing when a
+ warning is hit. This turns off "tracing_on". Tracing can
+ be enabled again by echoing '1' into the "tracing_on"
+ file located in /sys/kernel/debug/tracing/
+
+ This option is useful, as it disables the trace before
+ the WARNING dump is called, which prevents the trace to
+ be filled with content caused by the warning output.
+
+ This option can also be set at run time via the sysctl
+ option: kernel/traceoff_on_warning
+
transparent_hugepage=
[KNL]
Format: [always|madvise|never]
extern enum ftrace_dump_mode ftrace_dump_on_oops;
+extern void disable_trace_on_warning(void);
+extern int __disable_trace_on_warning;
+
#ifdef CONFIG_PREEMPT
#define INIT_TRACE_RECURSION .trace_recursion = 0,
#endif
+#else /* CONFIG_TRACING */
+static inline void disable_trace_on_warning(void) { }
#endif /* CONFIG_TRACING */
#ifndef INIT_TRACE_RECURSION
#include <linux/notifier.h>
#include <linux/module.h>
#include <linux/random.h>
+#include <linux/ftrace.h>
#include <linux/reboot.h>
#include <linux/delay.h>
#include <linux/kexec.h>
static void warn_slowpath_common(const char *file, int line, void *caller,
unsigned taint, struct slowpath_args *args)
{
+ disable_trace_on_warning();
+
printk(KERN_WARNING "------------[ cut here ]------------\n");
printk(KERN_WARNING "WARNING: at %s:%d %pS()\n", file, line, caller);
.mode = 0644,
.proc_handler = proc_dointvec,
},
+ {
+ .procname = "traceoff_on_warning",
+ .data = &__disable_trace_on_warning,
+ .maxlen = sizeof(__disable_trace_on_warning),
+ .mode = 0644,
+ .proc_handler = proc_dointvec,
+ },
#endif
#ifdef CONFIG_MODULES
{
enum ftrace_dump_mode ftrace_dump_on_oops;
+/* When set, tracing will stop when a WARN*() is hit */
+int __disable_trace_on_warning;
+
static int tracing_set_tracer(const char *buf);
#define MAX_TRACER_SIZE 100
}
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
+static int __init stop_trace_on_warning(char *str)
+{
+ __disable_trace_on_warning = 1;
+ return 1;
+}
+__setup("traceoff_on_warning=", stop_trace_on_warning);
+
static int __init boot_alloc_snapshot(char *str)
{
allocate_snapshot = true;
}
__setup("trace_options=", set_trace_boot_options);
+
unsigned long long ns2usecs(cycle_t nsec)
{
nsec += 500;
}
EXPORT_SYMBOL_GPL(tracing_off);
+void disable_trace_on_warning(void)
+{
+ if (__disable_trace_on_warning)
+ tracing_off();
+}
+
/**
* tracing_is_on - show state of ring buffers enabled
*/