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Revision 4f2112351b4ac964b0249bdd883f7b79601f39d8 authored by Linus Torvalds on 22 April 2015, 18:27:36 UTC, committed by Linus Torvalds on 22 April 2015, 18:27:36 UTC 
Merge tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
 
Pull tracing fixes from Steven Rostedt:
 "This adds three fixes for the tracing code.

  The first is a bug when ftrace_dump_on_oops is triggered in atomic
  context and function graph tracer is the tracer that is being
  reported.

  The second fix is bad parsing of the trace_events from the kernel
  command line, where it would ignore specific events if the system name
  is used with defining the event(it enables all events within the
  system).

  The last one is a fix to the TRACE_DEFINE_ENUM(), where a check was
  missing to see if the ptr was incremented to the end of the string,
  but the loop increments it again and can miss the nul delimiter to
  stop processing"

* tag 'trace-v4.1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Fix possible out of bounds memory access when parsing enums
  tracing: Fix incorrect enabling of trace events by boot cmdline
  tracing: Handle ftrace_dump() atomic context in graph_trace_open()
2 parent s 9b60afe + 3193899
Raw File
ratelimit.c 
/*
 * ratelimit.c - Do something with rate limit.
 *
 * Isolated from kernel/printk.c by Dave Young <hidave.darkstar@gmail.com>
 *
 * 2008-05-01 rewrite the function and use a ratelimit_state data struct as
 * parameter. Now every user can use their own standalone ratelimit_state.
 *
 * This file is released under the GPLv2.
 */

#include <linux/ratelimit.h>
#include <linux/jiffies.h>
#include <linux/export.h>

/*
 * __ratelimit - rate limiting
 * @rs: ratelimit_state data
 * @func: name of calling function
 *
 * This enforces a rate limit: not more than @rs->burst callbacks
 * in every @rs->interval
 *
 * RETURNS:
 * 0 means callbacks will be suppressed.
 * 1 means go ahead and do it.
 */
int ___ratelimit(struct ratelimit_state *rs, const char *func)
{
	unsigned long flags;
	int ret;

	if (!rs->interval)
		return 1;

	/*
	 * If we contend on this state's lock then almost
	 * by definition we are too busy to print a message,
	 * in addition to the one that will be printed by
	 * the entity that is holding the lock already:
	 */
	if (!raw_spin_trylock_irqsave(&rs->lock, flags))
		return 0;

	if (!rs->begin)
		rs->begin = jiffies;

	if (time_is_before_jiffies(rs->begin + rs->interval)) {
		if (rs->missed)
			printk(KERN_WARNING "%s: %d callbacks suppressed\n",
				func, rs->missed);
		rs->begin   = 0;
		rs->printed = 0;
		rs->missed  = 0;
	}
	if (rs->burst && rs->burst > rs->printed) {
		rs->printed++;
		ret = 1;
	} else {
		rs->missed++;
		ret = 0;
	}
	raw_spin_unlock_irqrestore(&rs->lock, flags);

	return ret;
}
EXPORT_SYMBOL(___ratelimit);
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