Revision 35bf49e054214a0c7d3b0a0f8606f753f3f6ae96 authored by Lu Baolu on 23 August 2022, 06:15:57 UTC, committed by Joerg Roedel on 07 September 2022, 13:14:57 UTC
With CONFIG_INTEL_IOMMU_DEBUGFS enabled, below lockdep splat are seen
when an I/O fault occurs on a machine with an Intel IOMMU in it.
DMAR: DRHD: handling fault status reg 3
DMAR: [DMA Write NO_PASID] Request device [00:1a.0] fault addr 0x0
[fault reason 0x05] PTE Write access is not set
DMAR: Dump dmar0 table entries for IOVA 0x0
DMAR: root entry: 0x0000000127f42001
DMAR: context entry: hi 0x0000000000001502, low 0x000000012d8ab001
================================
WARNING: inconsistent lock state
5.20.0-0.rc0.20220812git7ebfc85e2cd7.10.fc38.x86_64 #1 Not tainted
--------------------------------
inconsistent {HARDIRQ-ON-W} -> {IN-HARDIRQ-W} usage.
rngd/1006 [HC1[1]:SC0[0]:HE0:SE1] takes:
ff177021416f2d78 (&k->k_lock){?.+.}-{2:2}, at: klist_next+0x1b/0x160
{HARDIRQ-ON-W} state was registered at:
lock_acquire+0xce/0x2d0
_raw_spin_lock+0x33/0x80
klist_add_tail+0x46/0x80
bus_add_device+0xee/0x150
device_add+0x39d/0x9a0
add_memory_block+0x108/0x1d0
memory_dev_init+0xe1/0x117
driver_init+0x43/0x4d
kernel_init_freeable+0x1c2/0x2cc
kernel_init+0x16/0x140
ret_from_fork+0x1f/0x30
irq event stamp: 7812
hardirqs last enabled at (7811): [<ffffffff85000e86>] asm_sysvec_apic_timer_interrupt+0x16/0x20
hardirqs last disabled at (7812): [<ffffffff84f16894>] irqentry_enter+0x54/0x60
softirqs last enabled at (7794): [<ffffffff840ff669>] __irq_exit_rcu+0xf9/0x170
softirqs last disabled at (7787): [<ffffffff840ff669>] __irq_exit_rcu+0xf9/0x170
The klist iterator functions using spin_*lock_irq*() but the klist
insertion functions using spin_*lock(), combined with the Intel DMAR
IOMMU driver iterating over klists from atomic (hardirq) context, where
pci_get_domain_bus_and_slot() calls into bus_find_device() which iterates
over klists.
As currently there's no plan to fix the klist to make it safe to use in
atomic context, this fixes the lockdep splat by avoid calling
pci_get_domain_bus_and_slot() in the hardirq context.
Fixes: 8ac0b64b9735 ("iommu/vt-d: Use pci_get_domain_bus_and_slot() in pgtable_walk()")
Reported-by: Lennert Buytenhek <buytenh@wantstofly.org>
Link: https://lore.kernel.org/linux-iommu/Yvo2dfpEh%2FWC+Wrr@wantstofly.org/
Link: https://lore.kernel.org/linux-iommu/YvyBdPwrTuHHbn5X@wantstofly.org/
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20220819015949.4795-1-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
1 parent a349ffc
page.h
/* SPDX-License-Identifier: GPL-2.0+ */
/*
* Buffer/page management specific to NILFS
*
* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
*
* Written by Ryusuke Konishi and Seiji Kihara.
*/
#ifndef _NILFS_PAGE_H
#define _NILFS_PAGE_H
#include <linux/buffer_head.h>
#include "nilfs.h"
/*
* Extended buffer state bits
*/
enum {
BH_NILFS_Allocated = BH_PrivateStart,
BH_NILFS_Node,
BH_NILFS_Volatile,
BH_NILFS_Checked,
BH_NILFS_Redirected,
};
BUFFER_FNS(NILFS_Node, nilfs_node) /* nilfs node buffers */
BUFFER_FNS(NILFS_Volatile, nilfs_volatile)
BUFFER_FNS(NILFS_Checked, nilfs_checked) /* buffer is verified */
BUFFER_FNS(NILFS_Redirected, nilfs_redirected) /* redirected to a copy */
int __nilfs_clear_page_dirty(struct page *);
struct buffer_head *nilfs_grab_buffer(struct inode *, struct address_space *,
unsigned long, unsigned long);
void nilfs_forget_buffer(struct buffer_head *);
void nilfs_copy_buffer(struct buffer_head *, struct buffer_head *);
int nilfs_page_buffers_clean(struct page *);
void nilfs_page_bug(struct page *);
int nilfs_copy_dirty_pages(struct address_space *, struct address_space *);
void nilfs_copy_back_pages(struct address_space *, struct address_space *);
void nilfs_clear_dirty_page(struct page *, bool);
void nilfs_clear_dirty_pages(struct address_space *, bool);
unsigned int nilfs_page_count_clean_buffers(struct page *, unsigned int,
unsigned int);
unsigned long nilfs_find_uncommitted_extent(struct inode *inode,
sector_t start_blk,
sector_t *blkoff);
#define NILFS_PAGE_BUG(page, m, a...) \
do { nilfs_page_bug(page); BUG(); } while (0)
static inline struct buffer_head *
nilfs_page_get_nth_block(struct page *page, unsigned int count)
{
struct buffer_head *bh = page_buffers(page);
while (count-- > 0)
bh = bh->b_this_page;
get_bh(bh);
return bh;
}
#endif /* _NILFS_PAGE_H */
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