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Revision a16a1647fa6b6783c2e91623e72e86f0c2adac5e authored by Pablo Neira Ayuso on 16 March 2012, 02:00:34 UTC, committed by David S. Miller on 17 March 2012, 08:47:08 UTC 
netfilter: ctnetlink: fix race between delete and timeout expiration
 
Kerin Millar reported hardlockups while running `conntrackd -c'
in a busy firewall. That system (with several processors) was
acting as backup in a primary-backup setup.

After several tries, I found a race condition between the deletion
operation of ctnetlink and timeout expiration. This patch fixes
this problem.

Tested-by: Kerin Millar <kerframil@gmail.com>
Reported-by: Kerin Millar <kerframil@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent c577923
Raw File
show_mem.c 
/*
 * Generic show_mem() implementation
 *
 * Copyright (C) 2008 Johannes Weiner <hannes@saeurebad.de>
 * All code subject to the GPL version 2.
 */

#include <linux/mm.h>
#include <linux/nmi.h>
#include <linux/quicklist.h>

void show_mem(unsigned int filter)
{
	pg_data_t *pgdat;
	unsigned long total = 0, reserved = 0, shared = 0,
		nonshared = 0, highmem = 0;

	printk("Mem-Info:\n");
	show_free_areas(filter);

	for_each_online_pgdat(pgdat) {
		unsigned long i, flags;

		pgdat_resize_lock(pgdat, &flags);
		for (i = 0; i < pgdat->node_spanned_pages; i++) {
			struct page *page;
			unsigned long pfn = pgdat->node_start_pfn + i;

			if (unlikely(!(i % MAX_ORDER_NR_PAGES)))
				touch_nmi_watchdog();

			if (!pfn_valid(pfn))
				continue;

			page = pfn_to_page(pfn);

			if (PageHighMem(page))
				highmem++;

			if (PageReserved(page))
				reserved++;
			else if (page_count(page) == 1)
				nonshared++;
			else if (page_count(page) > 1)
				shared += page_count(page) - 1;

			total++;
		}
		pgdat_resize_unlock(pgdat, &flags);
	}

	printk("%lu pages RAM\n", total);
#ifdef CONFIG_HIGHMEM
	printk("%lu pages HighMem\n", highmem);
#endif
	printk("%lu pages reserved\n", reserved);
	printk("%lu pages shared\n", shared);
	printk("%lu pages non-shared\n", nonshared);
#ifdef CONFIG_QUICKLIST
	printk("%lu pages in pagetable cache\n",
		quicklist_total_size());
#endif
}
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