Revision 8cf66504210d308a35cca35fe9c310b1241f9fa7 authored by Qian Cai on 11 July 2019, 16:17:45 UTC, committed by Linus Torvalds on 21 July 2019, 16:57:13 UTC
The commit b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops
method") incorrectly changed the checking from dma_ops_alloc_iova() in
map_sg() causes a crash under memory pressure as dma_ops_alloc_iova()
never return DMA_MAPPING_ERROR on failure but 0, so the error handling
is all wrong.
kernel BUG at drivers/iommu/iova.c:801!
Workqueue: kblockd blk_mq_run_work_fn
RIP: 0010:iova_magazine_free_pfns+0x7d/0xc0
Call Trace:
free_cpu_cached_iovas+0xbd/0x150
alloc_iova_fast+0x8c/0xba
dma_ops_alloc_iova.isra.6+0x65/0xa0
map_sg+0x8c/0x2a0
scsi_dma_map+0xc6/0x160
pqi_aio_submit_io+0x1f6/0x440 [smartpqi]
pqi_scsi_queue_command+0x90c/0xdd0 [smartpqi]
scsi_queue_rq+0x79c/0x1200
blk_mq_dispatch_rq_list+0x4dc/0xb70
blk_mq_sched_dispatch_requests+0x249/0x310
__blk_mq_run_hw_queue+0x128/0x200
blk_mq_run_work_fn+0x27/0x30
process_one_work+0x522/0xa10
worker_thread+0x63/0x5b0
kthread+0x1d2/0x1f0
ret_from_fork+0x22/0x40
Fixes: b3aa14f02254 ("iommu: remove the mapping_error dma_map_ops method")
Signed-off-by: Qian Cai <cai@lca.pw>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent 618381f
Kconfig
# SPDX-License-Identifier: GPL-2.0-only
config SYSFS
bool "sysfs file system support" if EXPERT
default y
select KERNFS
help
The sysfs filesystem is a virtual filesystem that the kernel uses to
export internal kernel objects, their attributes, and their
relationships to one another.
Users can use sysfs to ascertain useful information about the running
kernel, such as the devices the kernel has discovered on each bus and
which driver each is bound to. sysfs can also be used to tune devices
and other kernel subsystems.
Some system agents rely on the information in sysfs to operate.
/sbin/hotplug uses device and object attributes in sysfs to assist in
delegating policy decisions, like persistently naming devices.
sysfs is currently used by the block subsystem to mount the root
partition. If sysfs is disabled you must specify the boot device on
the kernel boot command line via its major and minor numbers. For
example, "root=03:01" for /dev/hda1.
Designers of embedded systems may wish to say N here to conserve space.
Computing file changes ...
