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>
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Kconfig
# SPDX-License-Identifier: GPL-2.0-only
config NTFS_FS
tristate "NTFS file system support"
select NLS
help
NTFS is the file system of Microsoft Windows NT, 2000, XP and 2003.
Saying Y or M here enables read support. There is partial, but
safe, write support available. For write support you must also
say Y to "NTFS write support" below.
There are also a number of user-space tools available, called
ntfsprogs. These include ntfsundelete and ntfsresize, that work
without NTFS support enabled in the kernel.
This is a rewrite from scratch of Linux NTFS support and replaced
the old NTFS code starting with Linux 2.5.11. A backport to
the Linux 2.4 kernel series is separately available as a patch
from the project web site.
For more information see <file:Documentation/filesystems/ntfs.rst>
and <http://www.linux-ntfs.org/>.
To compile this file system support as a module, choose M here: the
module will be called ntfs.
If you are not using Windows NT, 2000, XP or 2003 in addition to
Linux on your computer it is safe to say N.
config NTFS_DEBUG
bool "NTFS debugging support"
depends on NTFS_FS
help
If you are experiencing any problems with the NTFS file system, say
Y here. This will result in additional consistency checks to be
performed by the driver as well as additional debugging messages to
be written to the system log. Note that debugging messages are
disabled by default. To enable them, supply the option debug_msgs=1
at the kernel command line when booting the kernel or as an option
to insmod when loading the ntfs module. Once the driver is active,
you can enable debugging messages by doing (as root):
echo 1 > /proc/sys/fs/ntfs-debug
Replacing the "1" with "0" would disable debug messages.
If you leave debugging messages disabled, this results in little
overhead, but enabling debug messages results in very significant
slowdown of the system.
When reporting bugs, please try to have available a full dump of
debugging messages while the misbehaviour was occurring.
config NTFS_RW
bool "NTFS write support"
depends on NTFS_FS
depends on PAGE_SIZE_LESS_THAN_64KB
help
This enables the partial, but safe, write support in the NTFS driver.
The only supported operation is overwriting existing files, without
changing the file length. No file or directory creation, deletion or
renaming is possible. Note only non-resident files can be written to
so you may find that some very small files (<500 bytes or so) cannot
be written to.
While we cannot guarantee that it will not damage any data, we have
so far not received a single report where the driver would have
damaged someones data so we assume it is perfectly safe to use.
Note: While write support is safe in this version (a rewrite from
scratch of the NTFS support), it should be noted that the old NTFS
write support, included in Linux 2.5.10 and before (since 1997),
is not safe.
This is currently useful with TopologiLinux. TopologiLinux is run
on top of any DOS/Microsoft Windows system without partitioning your
hard disk. Unlike other Linux distributions TopologiLinux does not
need its own partition. For more information see
<http://topologi-linux.sourceforge.net/>
It is perfectly safe to say N here.
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