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Revision df9576def004d2cd5beedc00cb6e8901427634b9 authored by Yang Shi on 03 August 2019, 04:48:37 UTC, committed by Linus Torvalds on 03 August 2019, 14:02:00 UTC 
Revert "kmemleak: allow to coexist with fault injection"
 
When running ltp's oom test with kmemleak enabled, the below warning was
triggerred since kernel detects __GFP_NOFAIL & ~__GFP_DIRECT_RECLAIM is
passed in:

  WARNING: CPU: 105 PID: 2138 at mm/page_alloc.c:4608 __alloc_pages_nodemask+0x1c31/0x1d50
  Modules linked in: loop dax_pmem dax_pmem_core ip_tables x_tables xfs virtio_net net_failover virtio_blk failover ata_generic virtio_pci virtio_ring virtio libata
  CPU: 105 PID: 2138 Comm: oom01 Not tainted 5.2.0-next-20190710+ #7
  Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.10.2-0-g5f4c7b1-prebuilt.qemu-project.org 04/01/2014
  RIP: 0010:__alloc_pages_nodemask+0x1c31/0x1d50
  ...
   kmemleak_alloc+0x4e/0xb0
   kmem_cache_alloc+0x2a7/0x3e0
   mempool_alloc_slab+0x2d/0x40
   mempool_alloc+0x118/0x2b0
   bio_alloc_bioset+0x19d/0x350
   get_swap_bio+0x80/0x230
   __swap_writepage+0x5ff/0xb20

The mempool_alloc_slab() clears __GFP_DIRECT_RECLAIM, however kmemleak
has __GFP_NOFAIL set all the time due to d9570ee3bd1d4f2 ("kmemleak:
allow to coexist with fault injection").  But, it doesn't make any sense
to have __GFP_NOFAIL and ~__GFP_DIRECT_RECLAIM specified at the same
time.

According to the discussion on the mailing list, the commit should be
reverted for short term solution.  Catalin Marinas would follow up with
a better solution for longer term.

The failure rate of kmemleak metadata allocation may increase in some
circumstances, but this should be expected side effect.

Link: http://lkml.kernel.org/r/1563299431-111710-1-git-send-email-yang.shi@linux.alibaba.com
Fixes: d9570ee3bd1d4f2 ("kmemleak: allow to coexist with fault injection")
Signed-off-by: Yang Shi <yang.shi@linux.alibaba.com>
Suggested-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Qian Cai <cai@lca.pw>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 68d8681
Raw File
proc.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Scatterlist Cryptographic API.
 *
 * Procfs information.
 *
 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
 */

#include <linux/atomic.h>
#include <linux/init.h>
#include <linux/crypto.h>
#include <linux/module.h>	/* for module_name() */
#include <linux/rwsem.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"

static void *c_start(struct seq_file *m, loff_t *pos)
{
	down_read(&crypto_alg_sem);
	return seq_list_start(&crypto_alg_list, *pos);
}

static void *c_next(struct seq_file *m, void *p, loff_t *pos)
{
	return seq_list_next(p, &crypto_alg_list, pos);
}

static void c_stop(struct seq_file *m, void *p)
{
	up_read(&crypto_alg_sem);
}

static int c_show(struct seq_file *m, void *p)
{
	struct crypto_alg *alg = list_entry(p, struct crypto_alg, cra_list);
	
	seq_printf(m, "name         : %s\n", alg->cra_name);
	seq_printf(m, "driver       : %s\n", alg->cra_driver_name);
	seq_printf(m, "module       : %s\n", module_name(alg->cra_module));
	seq_printf(m, "priority     : %d\n", alg->cra_priority);
	seq_printf(m, "refcnt       : %u\n", refcount_read(&alg->cra_refcnt));
	seq_printf(m, "selftest     : %s\n",
		   (alg->cra_flags & CRYPTO_ALG_TESTED) ?
		   "passed" : "unknown");
	seq_printf(m, "internal     : %s\n",
		   (alg->cra_flags & CRYPTO_ALG_INTERNAL) ?
		   "yes" : "no");

	if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
		seq_printf(m, "type         : larval\n");
		seq_printf(m, "flags        : 0x%x\n", alg->cra_flags);
		goto out;
	}

	if (alg->cra_type && alg->cra_type->show) {
		alg->cra_type->show(m, alg);
		goto out;
	}
	
	switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
	case CRYPTO_ALG_TYPE_CIPHER:
		seq_printf(m, "type         : cipher\n");
		seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
		seq_printf(m, "min keysize  : %u\n",
					alg->cra_cipher.cia_min_keysize);
		seq_printf(m, "max keysize  : %u\n",
					alg->cra_cipher.cia_max_keysize);
		break;
	case CRYPTO_ALG_TYPE_COMPRESS:
		seq_printf(m, "type         : compression\n");
		break;
	default:
		seq_printf(m, "type         : unknown\n");
		break;
	}

out:
	seq_putc(m, '\n');
	return 0;
}

static const struct seq_operations crypto_seq_ops = {
	.start		= c_start,
	.next		= c_next,
	.stop		= c_stop,
	.show		= c_show
};

void __init crypto_init_proc(void)
{
	proc_create_seq("crypto", 0, NULL, &crypto_seq_ops);
}

void __exit crypto_exit_proc(void)
{
	remove_proc_entry("crypto", NULL);
}
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