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>
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page_actor.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2013
* Phillip Lougher <phillip@squashfs.org.uk>
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/pagemap.h>
#include "page_actor.h"
/*
* This file contains implementations of page_actor for decompressing into
* an intermediate buffer, and for decompressing directly into the
* page cache.
*
* Calling code should avoid sleeping between calls to squashfs_first_page()
* and squashfs_finish_page().
*/
/* Implementation of page_actor for decompressing into intermediate buffer */
static void *cache_first_page(struct squashfs_page_actor *actor)
{
actor->next_page = 1;
return actor->buffer[0];
}
static void *cache_next_page(struct squashfs_page_actor *actor)
{
if (actor->next_page == actor->pages)
return NULL;
return actor->buffer[actor->next_page++];
}
static void cache_finish_page(struct squashfs_page_actor *actor)
{
/* empty */
}
struct squashfs_page_actor *squashfs_page_actor_init(void **buffer,
int pages, int length)
{
struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
if (actor == NULL)
return NULL;
actor->length = length ? : pages * PAGE_SIZE;
actor->buffer = buffer;
actor->pages = pages;
actor->next_page = 0;
actor->squashfs_first_page = cache_first_page;
actor->squashfs_next_page = cache_next_page;
actor->squashfs_finish_page = cache_finish_page;
return actor;
}
/* Implementation of page_actor for decompressing directly into page cache. */
static void *direct_first_page(struct squashfs_page_actor *actor)
{
actor->next_page = 1;
return actor->pageaddr = kmap_atomic(actor->page[0]);
}
static void *direct_next_page(struct squashfs_page_actor *actor)
{
if (actor->pageaddr)
kunmap_atomic(actor->pageaddr);
return actor->pageaddr = actor->next_page == actor->pages ? NULL :
kmap_atomic(actor->page[actor->next_page++]);
}
static void direct_finish_page(struct squashfs_page_actor *actor)
{
if (actor->pageaddr)
kunmap_atomic(actor->pageaddr);
}
struct squashfs_page_actor *squashfs_page_actor_init_special(struct page **page,
int pages, int length)
{
struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
if (actor == NULL)
return NULL;
actor->length = length ? : pages * PAGE_SIZE;
actor->page = page;
actor->pages = pages;
actor->next_page = 0;
actor->pageaddr = NULL;
actor->squashfs_first_page = direct_first_page;
actor->squashfs_next_page = direct_next_page;
actor->squashfs_finish_page = direct_finish_page;
return actor;
}
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