linux/block
Tejun Heo 2a427b49d0 blk-iocost: Fix an UBSAN shift-out-of-bounds warning
When iocg_kick_delay() is called from a CPU different than the one which set
the delay, @now may be in the past of @iocg->delay_at leading to the
following warning:

  UBSAN: shift-out-of-bounds in block/blk-iocost.c:1359:23
  shift exponent 18446744073709 is too large for 64-bit type 'u64' (aka 'unsigned long long')
  ...
  Call Trace:
   <TASK>
   dump_stack_lvl+0x79/0xc0
   __ubsan_handle_shift_out_of_bounds+0x2ab/0x300
   iocg_kick_delay+0x222/0x230
   ioc_rqos_merge+0x1d7/0x2c0
   __rq_qos_merge+0x2c/0x80
   bio_attempt_back_merge+0x83/0x190
   blk_attempt_plug_merge+0x101/0x150
   blk_mq_submit_bio+0x2b1/0x720
   submit_bio_noacct_nocheck+0x320/0x3e0
   __swap_writepage+0x2ab/0x9d0

The underflow itself doesn't really affect the behavior in any meaningful
way; however, the past timestamp may exaggerate the delay amount calculated
later in the code, which shouldn't be a material problem given the nature of
the delay mechanism.

If @now is in the past, this CPU is racing another CPU which recently set up
the delay and there's nothing this CPU can contribute w.r.t. the delay.
Let's bail early from iocg_kick_delay() in such cases.

Reported-by: Breno Leitão <leitao@debian.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 5160a5a53c ("blk-iocost: implement delay adjustment hysteresis")
Link: https://lore.kernel.org/r/ZVvc9L_CYk5LO1fT@slm.duckdns.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2024-02-08 10:11:39 -07:00
..
partitions block: Move checking GENHD_FL_NO_PART to bdev_add_partition() 2024-01-22 09:51:29 -07:00
badblocks.c badblocks: avoid checking invalid range in badblocks_check() 2023-12-23 18:38:08 -07:00
bdev.c vfs-6.8.super 2024-01-08 10:43:51 -08:00
bfq-cgroup.c blkcg: Restructure blkg_conf_prep() and friends 2023-04-13 06:46:49 -06:00
bfq-iosched.c SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
bfq-iosched.h block, bfq: remove BFQ_WEIGHT_LEGACY_DFL 2023-04-06 16:17:32 -06:00
bfq-wf2q.c
bio-integrity.c block: bio-integrity: fix kcalloc() arguments order 2024-01-16 09:51:22 -07:00
bio.c block: support adding less than len in bio_add_hw_page 2023-12-15 07:34:27 -07:00
blk-cgroup-fc-appid.c block: Replace all non-returning strlcpy with strscpy 2023-06-01 09:13:31 -06:00
blk-cgroup-rwstat.c Revert "blk-cgroup: pin the gendisk in struct blkcg_gq" 2023-02-14 14:24:09 -07:00
blk-cgroup-rwstat.h
blk-cgroup.c block: Correct a documentation comment in blk-cgroup.c 2024-01-15 07:23:38 -07:00
blk-cgroup.h blk-cgroup: fix rcu lockdep warning in blkg_lookup() 2024-01-04 16:08:54 -07:00
blk-core.c block: Fix where bio IO priority gets set 2024-02-01 11:00:06 -07:00
blk-crypto-fallback.c blk-crypto: dynamically allocate fallback profile 2023-08-18 15:00:39 -06:00
blk-crypto-internal.h blk-crypto: remove blk_crypto_insert_cloned_request() 2023-03-16 09:35:09 -06:00
blk-crypto-profile.c blk-crypto: use dynamic lock class for blk_crypto_profile::lock 2023-07-05 16:36:12 -06:00
blk-crypto-sysfs.c block: make kobj_type structures constant 2023-02-09 09:38:16 -07:00
blk-crypto.c blk-crypto: make blk_crypto_evict_key() more robust 2023-03-16 09:35:09 -06:00
blk-flush.c blk-mq: remove RQF_MQ_INFLIGHT 2023-09-22 08:52:13 -06:00
blk-ia-ranges.c block: make kobj_type structures constant 2023-02-09 09:38:16 -07:00
blk-integrity.c blk-integrity: register sysfs attributes on struct device 2023-04-26 18:22:50 -06:00
blk-ioc.c blk-ioc: fix recursive spin_lock/unlock_irq() in ioc_clear_queue() 2023-06-07 07:51:00 -06:00
blk-iocost.c blk-iocost: Fix an UBSAN shift-out-of-bounds warning 2024-02-08 10:11:39 -07:00
blk-iolatency.c block: fix bad lockdep annotation in blk-iolatency 2023-08-10 17:24:53 -06:00
blk-ioprio.c blk-ioprio: Introduce promote-to-rt policy 2023-06-06 22:26:26 -06:00
blk-ioprio.h
blk-lib.c
blk-map.c block: Fix WARNING in _copy_from_iter 2024-01-23 08:56:55 -07:00
blk-merge.c block: remove two comments in bio_split_discard 2023-12-29 08:44:12 -07:00
blk-mq-cpumap.c blk-mq: include <linux/blk-mq.h> in block/blk-mq.h 2023-04-13 06:52:29 -06:00
blk-mq-debugfs-zoned.c
blk-mq-debugfs.c blk-mq: Remove the hctx 'run' debugfs attribute 2024-01-17 14:16:34 -07:00
blk-mq-debugfs.h
blk-mq-pci.c blk-mq: include <linux/blk-mq.h> in block/blk-mq.h 2023-04-13 06:52:29 -06:00
blk-mq-sched.c blk-mq: Remove the hctx 'run' debugfs attribute 2024-01-17 14:16:34 -07:00
blk-mq-sched.h blk-mq: make sure elevator callbacks aren't called for passthrough request 2023-05-18 19:42:54 -06:00
blk-mq-sysfs.c blk-mq: include <linux/blk-mq.h> in block/blk-mq.h 2023-04-13 06:52:29 -06:00
blk-mq-tag.c for-6.5/block-2023-06-23 2023-06-26 12:47:20 -07:00
blk-mq-virtio.c blk-mq: include <linux/blk-mq.h> in block/blk-mq.h 2023-04-13 06:52:29 -06:00
blk-mq.c block: Fix where bio IO priority gets set 2024-02-01 11:00:06 -07:00
blk-mq.h blk-mq: update driver tags request table when start request 2023-09-22 08:52:13 -06:00
blk-pm.c block: Remove blk_set_runtime_active() 2023-11-20 10:22:40 -07:00
blk-pm.h
blk-rq-qos.c block: correct stale comment in rq_qos_wait 2023-09-18 14:15:28 -06:00
blk-rq-qos.h block: skip QUEUE_FLAG_STATS and rq-qos for passthrough io 2023-12-01 18:29:18 -07:00
blk-settings.c block: floor the discard granularity to the physical block size 2024-01-04 16:05:49 -07:00
blk-stat.c blk-mq: include <linux/blk-mq.h> in block/blk-mq.h 2023-04-13 06:52:29 -06:00
blk-stat.h
blk-sysfs.c for-6.8/block-2024-01-08 2024-01-11 13:58:04 -08:00
blk-throttle.c blk-throttle: fix lockdep warning of "cgroup_mutex or RCU read lock required!" 2023-11-17 10:48:58 -07:00
blk-throttle.h blk-throttle: print signed value 'carryover_bytes/ios' for user 2023-08-30 10:15:01 -06:00
blk-timeout.c
blk-wbt.c blk-wbt: Fix detection of dirty-throttled tasks 2024-02-06 09:44:03 -07:00
blk-wbt.h blk-wbt: remove the separate write cache tracking 2023-12-26 09:28:10 -07:00
blk-zoned.c block: Treat sequential write preferred zone type as invalid 2024-01-08 08:34:24 -07:00
blk.h block: simplify disk_set_zoned 2023-12-19 20:17:43 -07:00
bounce.c
bsg-lib.c scsi: replace the fmode_t argument to ->sg_io_fn with a simple bool 2023-06-12 08:04:04 -06:00
bsg.c SCSI misc on 20230629 2023-06-30 11:57:07 -07:00
disk-events.c block: move bdev_mark_dead out of disk_check_media_change 2023-10-28 13:29:23 +02:00
early-lookup.c block: don't return -EINVAL for not found names in devt_from_devname 2023-06-22 09:09:33 -06:00
elevator.c blk-mq: release scheduler resource when request completes 2023-08-19 07:47:17 -06:00
elevator.h blk-mq: pass a flags argument to elevator_type->insert_requests 2023-04-13 06:52:30 -06:00
fops.c fs: convert block_write_full_page to block_write_full_folio 2023-12-29 11:58:35 -08:00
genhd.c block: add check of 'minors' and 'first_minor' in device_add_disk() 2023-12-19 08:23:12 -07:00
holder.c
ioctl.c block: Move checking GENHD_FL_NO_PART to bdev_add_partition() 2024-01-22 09:51:29 -07:00
ioprio.c block: move __get_task_ioprio() into header file 2024-01-08 12:27:39 -07:00
Kconfig block: Add config option to not allow writing to mounted devices 2023-11-18 14:59:25 +01:00
Kconfig.iosched block: Default to use cgroup support for BFQ 2023-01-30 09:42:42 -07:00
kyber-iosched.c blk-mq: pass a flags argument to elevator_type->insert_requests 2023-04-13 06:52:30 -06:00
Makefile block: move the code to do early boot lookup of block devices to block/ 2023-06-05 10:57:40 -06:00
mq-deadline.c block/mq-deadline: use correct way to throttling write requests 2023-08-08 15:46:41 -06:00
opal_proto.h block: sed-opal: Implement IOC_OPAL_REVERT_LSP 2023-08-22 11:10:26 -06:00
sed-opal.c for-6.7/block-2023-10-30 2023-11-01 12:30:07 -10:00
t10-pi.c