Revision be65e2595b4c1fbeceba336d8ee83406726b1d8d authored by Linus Torvalds on 06 September 2018, 16:06:49 UTC, committed by Linus Torvalds on 06 September 2018, 16:06:49 UTC
Pull tracing fixes from Steven Rostedt:
 "This fixes two annoying bugs:

   - The first one is a side effect caused by using SRCU for rcuidle
     tracepoints. It seems that the perf was depending on the rcuidle
     tracepoints to make RCU watch when it wasn't.

     The real fix will be to have perf use SRCU instead of depending on
     RCU watching, but that can't be done until SRCU is safe to use in
     NMI context (Paul's working on that).

   - The second bug fix is for a bug that's been periodically making my
     tests fail randomly for some time. I haven't had time to track it
     down, but finally have. It has to do with stressing NMIs (via perf)
     while enabling or disabling ftrace function handling with lockdep
     enabled.

     If an interrupt happens and just as it returns, it sets lockdep
     back to "interrupts enabled" but before it returns an NMI is
     triggered, and if this happens while printk_nmi_enter has a
     breakpoint attached to it (because ftrace is converting it to or
     from nop to call fentry), the breakpoint trap also calls into
     lockdep, and since returning from the NMI to a interrupt handler,
     interrupts were disabled when the NMI went off, lockdep keeps its
     state as interrupts disabled when it returns back from the
     interrupt handler where interrupts are enabled.

     This causes lockdep_assert_irqs_enabled() to trigger a false
     positive"

* tag 'trace-v4.19-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  printk/tracing: Do not trace printk_nmi_enter()
  tracing: Add back in rcu_irq_enter/exit_irqson() for rcuidle tracepoints
2 parent s 5404525 + d1c392c
Raw File
x25_proc.c
/*
 *	X.25 Packet Layer release 002
 *
 *	This is ALPHA test software. This code may break your machine,
 *	randomly fail to work with new releases, misbehave and/or generally
 *	screw up. It might even work.
 *
 *	This code REQUIRES 2.4 with seq_file support
 *
 *	This module:
 *		This module is free software; you can redistribute it and/or
 *		modify it under the terms of the GNU General Public License
 *		as published by the Free Software Foundation; either version
 *		2 of the License, or (at your option) any later version.
 *
 *	History
 *	2002/10/06	Arnaldo Carvalho de Melo  seq_file support
 */

#include <linux/init.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include <linux/export.h>
#include <net/net_namespace.h>
#include <net/sock.h>
#include <net/x25.h>

#ifdef CONFIG_PROC_FS

static void *x25_seq_route_start(struct seq_file *seq, loff_t *pos)
	__acquires(x25_route_list_lock)
{
	read_lock_bh(&x25_route_list_lock);
	return seq_list_start_head(&x25_route_list, *pos);
}

static void *x25_seq_route_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return seq_list_next(v, &x25_route_list, pos);
}

static void x25_seq_route_stop(struct seq_file *seq, void *v)
	__releases(x25_route_list_lock)
{
	read_unlock_bh(&x25_route_list_lock);
}

static int x25_seq_route_show(struct seq_file *seq, void *v)
{
	struct x25_route *rt = list_entry(v, struct x25_route, node);

	if (v == &x25_route_list) {
		seq_puts(seq, "Address          Digits  Device\n");
		goto out;
	}

	rt = v;
	seq_printf(seq, "%-15s  %-6d  %-5s\n",
		   rt->address.x25_addr, rt->sigdigits,
		   rt->dev ? rt->dev->name : "???");
out:
	return 0;
}

static void *x25_seq_socket_start(struct seq_file *seq, loff_t *pos)
	__acquires(x25_list_lock)
{
	read_lock_bh(&x25_list_lock);
	return seq_hlist_start_head(&x25_list, *pos);
}

static void *x25_seq_socket_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return seq_hlist_next(v, &x25_list, pos);
}

static void x25_seq_socket_stop(struct seq_file *seq, void *v)
	__releases(x25_list_lock)
{
	read_unlock_bh(&x25_list_lock);
}

static int x25_seq_socket_show(struct seq_file *seq, void *v)
{
	struct sock *s;
	struct x25_sock *x25;
	struct net_device *dev;
	const char *devname;

	if (v == SEQ_START_TOKEN) {
		seq_printf(seq, "dest_addr  src_addr   dev   lci st vs vr "
				"va   t  t2 t21 t22 t23 Snd-Q Rcv-Q inode\n");
		goto out;
	}

	s = sk_entry(v);
	x25 = x25_sk(s);

	if (!x25->neighbour || (dev = x25->neighbour->dev) == NULL)
		devname = "???";
	else
		devname = x25->neighbour->dev->name;

	seq_printf(seq, "%-10s %-10s %-5s %3.3X  %d  %d  %d  %d %3lu %3lu "
			"%3lu %3lu %3lu %5d %5d %ld\n",
		   !x25->dest_addr.x25_addr[0] ? "*" : x25->dest_addr.x25_addr,
		   !x25->source_addr.x25_addr[0] ? "*" : x25->source_addr.x25_addr,
		   devname, x25->lci & 0x0FFF, x25->state, x25->vs, x25->vr,
		   x25->va, x25_display_timer(s) / HZ, x25->t2  / HZ,
		   x25->t21 / HZ, x25->t22 / HZ, x25->t23 / HZ,
		   sk_wmem_alloc_get(s),
		   sk_rmem_alloc_get(s),
		   s->sk_socket ? SOCK_INODE(s->sk_socket)->i_ino : 0L);
out:
	return 0;
}

static void *x25_seq_forward_start(struct seq_file *seq, loff_t *pos)
	__acquires(x25_forward_list_lock)
{
	read_lock_bh(&x25_forward_list_lock);
	return seq_list_start_head(&x25_forward_list, *pos);
}

static void *x25_seq_forward_next(struct seq_file *seq, void *v, loff_t *pos)
{
	return seq_list_next(v, &x25_forward_list, pos);
}

static void x25_seq_forward_stop(struct seq_file *seq, void *v)
	__releases(x25_forward_list_lock)
{
	read_unlock_bh(&x25_forward_list_lock);
}

static int x25_seq_forward_show(struct seq_file *seq, void *v)
{
	struct x25_forward *f = list_entry(v, struct x25_forward, node);

	if (v == &x25_forward_list) {
		seq_printf(seq, "lci dev1       dev2\n");
		goto out;
	}

	f = v;

	seq_printf(seq, "%d %-10s %-10s\n",
			f->lci, f->dev1->name, f->dev2->name);
out:
	return 0;
}

static const struct seq_operations x25_seq_route_ops = {
	.start  = x25_seq_route_start,
	.next   = x25_seq_route_next,
	.stop   = x25_seq_route_stop,
	.show   = x25_seq_route_show,
};

static const struct seq_operations x25_seq_socket_ops = {
	.start  = x25_seq_socket_start,
	.next   = x25_seq_socket_next,
	.stop   = x25_seq_socket_stop,
	.show   = x25_seq_socket_show,
};

static const struct seq_operations x25_seq_forward_ops = {
	.start  = x25_seq_forward_start,
	.next   = x25_seq_forward_next,
	.stop   = x25_seq_forward_stop,
	.show   = x25_seq_forward_show,
};

int __init x25_proc_init(void)
{
	if (!proc_mkdir("x25", init_net.proc_net))
		return -ENOMEM;

	if (!proc_create_seq("x25/route", 0444, init_net.proc_net,
			 &x25_seq_route_ops))
		goto out;

	if (!proc_create_seq("x25/socket", 0444, init_net.proc_net,
			 &x25_seq_socket_ops))
		goto out;

	if (!proc_create_seq("x25/forward", 0444, init_net.proc_net,
			 &x25_seq_forward_ops))
		goto out;
	return 0;

out:
	remove_proc_subtree("x25", init_net.proc_net);
	return -ENOMEM;
}

void __exit x25_proc_exit(void)
{
	remove_proc_subtree("x25", init_net.proc_net);
}

#else /* CONFIG_PROC_FS */

int __init x25_proc_init(void)
{
	return 0;
}

void __exit x25_proc_exit(void)
{
}
#endif /* CONFIG_PROC_FS */
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