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
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
aegis.h
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * AEGIS common definitions
 *
 * Copyright (c) 2018 Ondrej Mosnacek <omosnacek@gmail.com>
 * Copyright (c) 2018 Red Hat, Inc. All rights reserved.
 */

#ifndef _CRYPTO_AEGIS_H
#define _CRYPTO_AEGIS_H

#include <crypto/aes.h>
#include <linux/types.h>

#define AEGIS_BLOCK_SIZE 16

union aegis_block {
	__le64 words64[AEGIS_BLOCK_SIZE / sizeof(__le64)];
	__le32 words32[AEGIS_BLOCK_SIZE / sizeof(__le32)];
	u8 bytes[AEGIS_BLOCK_SIZE];
};

#define AEGIS_BLOCK_ALIGN (__alignof__(union aegis_block))
#define AEGIS_ALIGNED(p) IS_ALIGNED((uintptr_t)p, AEGIS_BLOCK_ALIGN)

static const union aegis_block crypto_aegis_const[2] = {
	{ .words64 = {
		cpu_to_le64(U64_C(0x0d08050302010100)),
		cpu_to_le64(U64_C(0x6279e99059372215)),
	} },
	{ .words64 = {
		cpu_to_le64(U64_C(0xf12fc26d55183ddb)),
		cpu_to_le64(U64_C(0xdd28b57342311120)),
	} },
};

static void crypto_aegis_block_xor(union aegis_block *dst,
				   const union aegis_block *src)
{
	dst->words64[0] ^= src->words64[0];
	dst->words64[1] ^= src->words64[1];
}

static void crypto_aegis_block_and(union aegis_block *dst,
				   const union aegis_block *src)
{
	dst->words64[0] &= src->words64[0];
	dst->words64[1] &= src->words64[1];
}

static void crypto_aegis_aesenc(union aegis_block *dst,
				const union aegis_block *src,
				const union aegis_block *key)
{
	const u8  *s  = src->bytes;
	const u32 *t0 = crypto_ft_tab[0];
	const u32 *t1 = crypto_ft_tab[1];
	const u32 *t2 = crypto_ft_tab[2];
	const u32 *t3 = crypto_ft_tab[3];
	u32 d0, d1, d2, d3;

	d0 = t0[s[ 0]] ^ t1[s[ 5]] ^ t2[s[10]] ^ t3[s[15]];
	d1 = t0[s[ 4]] ^ t1[s[ 9]] ^ t2[s[14]] ^ t3[s[ 3]];
	d2 = t0[s[ 8]] ^ t1[s[13]] ^ t2[s[ 2]] ^ t3[s[ 7]];
	d3 = t0[s[12]] ^ t1[s[ 1]] ^ t2[s[ 6]] ^ t3[s[11]];

	dst->words32[0] = cpu_to_le32(d0) ^ key->words32[0];
	dst->words32[1] = cpu_to_le32(d1) ^ key->words32[1];
	dst->words32[2] = cpu_to_le32(d2) ^ key->words32[2];
	dst->words32[3] = cpu_to_le32(d3) ^ key->words32[3];
}

#endif /* _CRYPTO_AEGIS_H */
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