For md_check_recovery():
1) if 'MD_RECOVERY_RUNING' is not set, register new sync_thread.
2) if 'MD_RECOVERY_RUNING' is set:
a) if 'MD_RECOVERY_DONE' is not set, don't do anything, wait for
md_do_sync() to be done.
b) if 'MD_RECOVERY_DONE' is set, unregister sync_thread. Current code
expects that sync_thread is not NULL, otherwise new sync_thread will
be registered, which will corrupt the array.
Make sure md_check_recovery() won't register new sync_thread if
'MD_RECOVERY_RUNING' is still set, and a new WARN_ON_ONCE() is added for
the above corruption,
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Xiao Ni <xni@redhat.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529132037.2124527-7-yukuai1@huaweicloud.com
Our test found a following deadlock in raid10:
1) Issue a normal write, and such write failed:
raid10_end_write_request
set_bit(R10BIO_WriteError, &r10_bio->state)
one_write_done
reschedule_retry
// later from md thread
raid10d
handle_write_completed
list_add(&r10_bio->retry_list, &conf->bio_end_io_list)
// later from md thread
raid10d
if (!test_bit(MD_SB_CHANGE_PENDING, &mddev->sb_flags))
list_move(conf->bio_end_io_list.prev, &tmp)
r10_bio = list_first_entry(&tmp, struct r10bio, retry_list)
raid_end_bio_io(r10_bio)
Dependency chain 1: normal io is waiting for updating superblock
2) Trigger a recovery:
raid10_sync_request
raise_barrier
Dependency chain 2: sync thread is waiting for normal io
3) echo idle/frozen to sync_action:
action_store
mddev_lock
md_unregister_thread
kthread_stop
Dependency chain 3: drop 'reconfig_mutex' is waiting for sync thread
4) md thread can't update superblock:
raid10d
md_check_recovery
if (mddev_trylock(mddev))
md_update_sb
Dependency chain 4: update superblock is waiting for 'reconfig_mutex'
Hence cyclic dependency exist, in order to fix the problem, we must
break one of them. Dependency 1 and 2 can't be broken because they are
foundation design. Dependency 4 may be possible if it can be guaranteed
that no io can be inflight, however, this requires a new mechanism which
seems complex. Dependency 3 is a good choice, because idle/frozen only
requires sync thread to finish, which can be done asynchronously that is
already implemented, and 'reconfig_mutex' is not needed anymore.
This patch switch 'idle' and 'frozen' to wait sync thread to be done
asynchronously, and this patch also add a sequence counter to record how
many times sync thread is done, so that 'idle' won't keep waiting on new
started sync thread.
Noted that raid456 has similiar deadlock([1]), and it's verified[2] this
deadlock can be fixed by this patch as well.
[1] https://lore.kernel.org/linux-raid/5ed54ffc-ce82-bf66-4eff-390cb23bc1ac@molgen.mpg.de/T/#t
[2] https://lore.kernel.org/linux-raid/e9067438-d713-f5f3-0d3d-9e6b0e9efa0e@huaweicloud.com/
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529132037.2124527-5-yukuai1@huaweicloud.com
Currently, for idle and frozen, action_store will hold 'reconfig_mutex'
and call md_reap_sync_thread() to stop sync thread, however, this will
cause deadlock (explained in the next patch). In order to fix the
problem, following patch will release 'reconfig_mutex' and wait on
'resync_wait', like md_set_readonly() and do_md_stop() does.
Consider that action_store() will set/clear 'MD_RECOVERY_FROZEN'
unconditionally, which might cause unexpected problems, for example,
frozen just set 'MD_RECOVERY_FROZEN' and is still in progress, while
'idle' clear 'MD_RECOVERY_FROZEN' and new sync thread is started, which
might starve in progress frozen. A mutex is added to synchronize idle
and frozen from action_store().
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529132037.2124527-4-yukuai1@huaweicloud.com
This reverts commit 9dfbdafda3.
Because it will introduce a defect that sync_thread can be running while
MD_RECOVERY_RUNNING is cleared, which will cause some unexpected problems,
for example:
list_add corruption. prev->next should be next (ffff0001ac1daba0), but was ffff0000ce1a02a0. (prev=ffff0000ce1a02a0).
Call trace:
__list_add_valid+0xfc/0x140
insert_work+0x78/0x1a0
__queue_work+0x500/0xcf4
queue_work_on+0xe8/0x12c
md_check_recovery+0xa34/0xf30
raid10d+0xb8/0x900 [raid10]
md_thread+0x16c/0x2cc
kthread+0x1a4/0x1ec
ret_from_fork+0x10/0x18
This is because work is requeued while it's still inside workqueue:
t1: t2:
action_store
mddev_lock
if (mddev->sync_thread)
mddev_unlock
md_unregister_thread
// first sync_thread is done
md_check_recovery
mddev_try_lock
/*
* once MD_RECOVERY_DONE is set, new sync_thread
* can start.
*/
set_bit(MD_RECOVERY_RUNNING, &mddev->recovery)
INIT_WORK(&mddev->del_work, md_start_sync)
queue_work(md_misc_wq, &mddev->del_work)
test_and_set_bit(WORK_STRUCT_PENDING_BIT, ...)
// set pending bit
insert_work
list_add_tail
mddev_unlock
mddev_lock_nointr
md_reap_sync_thread
// MD_RECOVERY_RUNNING is cleared
mddev_unlock
t3:
// before queued work started from t2
md_check_recovery
// MD_RECOVERY_RUNNING is not set, a new sync_thread can be started
INIT_WORK(&mddev->del_work, md_start_sync)
work->data = 0
// work pending bit is cleared
queue_work(md_misc_wq, &mddev->del_work)
insert_work
list_add_tail
// list is corrupted
The above commit is reverted to fix the problem, the deadlock this
commit tries to fix will be fixed in following patches.
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230529132037.2124527-2-yukuai1@huaweicloud.com
blk_mq_run_queue() runs the queue asynchronously if BLK_MQ_F_BLOCKING
has been set. This is suboptimal since running the queue asynchronously
is slower than running the queue synchronously. This patch modifies
blk_mq_run_queue() as follows if BLK_MQ_F_BLOCKING has been set:
- Run the queue synchronously if it is allowed to sleep.
- Run the queue asynchronously if it is not allowed to sleep.
Additionally, blk_mq_run_hw_queue(hctx, false) calls are modified into
blk_mq_run_hw_queue(hctx, hctx->flags & BLK_MQ_F_BLOCKING) if the caller
may be invoked from atomic context.
The following caller chains have been reviewed:
blk_mq_run_hw_queue(hctx, false)
blk_mq_get_tag() /* may sleep, hence the functions it calls may also sleep */
blk_execute_rq() /* may sleep */
blk_mq_run_hw_queues(q, async=false)
blk_freeze_queue_start() /* may sleep */
blk_mq_requeue_work() /* may sleep */
scsi_kick_queue()
scsi_requeue_run_queue() /* may sleep */
scsi_run_host_queues()
scsi_ioctl_reset() /* may sleep */
blk_mq_insert_requests(hctx, ctx, list, run_queue_async=false)
blk_mq_dispatch_plug_list(plug, from_sched=false)
blk_mq_flush_plug_list(plug, from_schedule=false)
__blk_flush_plug(plug, from_schedule=false)
blk_add_rq_to_plug()
blk_mq_submit_bio() /* may sleep if REQ_NOWAIT has not been set */
blk_mq_plug_issue_direct()
blk_mq_flush_plug_list() /* see above */
blk_mq_dispatch_plug_list(plug, from_sched=false)
blk_mq_flush_plug_list() /* see above */
blk_mq_try_issue_directly()
blk_mq_submit_bio() /* may sleep if REQ_NOWAIT has not been set */
blk_mq_try_issue_list_directly(hctx, list)
blk_mq_insert_requests() /* see above */
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20230721172731.955724-4-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
blk_mq_kick_requeue_list() calls blk_mq_run_hw_queues() asynchronously.
Leave out the direct blk_mq_run_hw_queues() call. This patch causes
scsi_run_queue() to call blk_mq_run_hw_queues() asynchronously instead
of synchronously. Since scsi_run_queue() is not called from the hot I/O
submission path, this patch does not affect the hot path.
This patch prepares for allowing blk_mq_run_hw_queue() to sleep if
BLK_MQ_F_BLOCKING has been set. scsi_run_queue() may be called from
atomic context and must not sleep. Hence the removal of the
blk_mq_run_hw_queues(q, false) call. See also scsi_unblock_requests().
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20230721172731.955724-3-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
There is no good reason to pass the bio to bio_try_merge_hw_seg. Just
pass the current bvec and rename the function to bvec_try_merge_hw_page.
This will allow reusing this function for supporting multi-page integrity
payload bvecs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinyoung Choi <j-young.choi@samsung.com>
Link: https://lore.kernel.org/r/20230724165433.117645-9-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The update of bi_size is the only thing in __bio_try_merge_page that
needs a bio. Move it to the callers, and merge __bio_try_merge_page
and page_is_mergeable into a single bvec_try_merge_page that only takes
the current bvec instead of a full bio. This will allow reusing this
function for supporting multi-page integrity payload bvecs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinyoung Choi <j-young.choi@samsung.com>
Link: https://lore.kernel.org/r/20230724165433.117645-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Checking for availability in bi_size in a function that attempts to
merge into an existing segment is a bit odd, as the limit also applies
when adding a new segment. This code works fine as we always call
__bio_try_merge_page, but contributes to sub-optimal calling conventions
and doesn't lead to clear code.
Move it to two of the callers instead, the third one already has a more
strict check that includes max_hw_segments anyway.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinyoung Choi <j-young.choi@samsung.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230724165433.117645-6-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
__bio_try_merge_page is a way too low-level helper to assert that the
bio is not cloned. Move the check into bio_add_page and
bio_iov_iter_get_pages instead, which are the high level entry points
that should enforce this variant. bio_add_hw_page already this
check, coverig the third (indirect) caller of __bio_try_merge_page.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinyoung Choi <j-young.choi@samsung.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20230724165433.117645-4-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
bio_add_hw_page already checks if the number of bytes trying to be added
even fit into max_hw_sectors limit of the queue. Remove the call to
bio_full and just do a check for the smaller of the number of segments
in the bio and the queue max segments limit, and do this cheap check
before the more expensive gap to previous check.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jinyoung Choi <j-young.choi@samsung.com>
Link: https://lore.kernel.org/r/20230724165433.117645-2-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Since we don't need to maintain inflight flush_data requests list
anymore, we can reuse rq->queuelist for flush pending list.
Note in mq_flush_data_end_io(), we need to re-initialize rq->queuelist
before reusing it in the state machine when end, since the rq->rq_next
also reuse it, may have corrupted rq->queuelist by the driver.
This patch decrease the size of struct request by 16 bytes.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Link: https://lore.kernel.org/r/20230717040058.3993930-5-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
The flush state machine use a double list to link all inflight
flush_data requests, to avoid issuing separate post-flushes for
these flush_data requests which shared PREFLUSH.
So we can't reuse rq->queuelist, this is why we need rq->flush.list
In preparation of the next patch that reuse rq->queuelist for flush
state machine, we change the double linked list to unsigned long
counter, which count all inflight flush_data requests.
This is ok since we only need to know if there is any inflight
flush_data request, so unsigned long counter is good.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230717040058.3993930-4-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If the policy == (REQ_FSEQ_DATA | REQ_FSEQ_POSTFLUSH), it means that the
data sequence and post-flush sequence need to be done for this request.
The rq->flush.seq should record what sequences have been done (or don't
need to be done). So in this case, pre-flush doesn't need to be done,
we should init rq->flush.seq to REQ_FSEQ_PREFLUSH not REQ_FSEQ_POSTFLUSH.
Fixes: 615939a2ae ("blk-mq: defer to the normal submission path for post-flush requests")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230717040058.3993930-3-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
If request need to be completed remotely, we insert it into percpu llist,
and smp_call_function_single_async() if llist is empty previously.
We don't need to use per-rq csd, percpu csd is enough. And the size of
struct request is decreased by 24 bytes.
This way is cleaner, and looks correct, given block softirq is guaranteed
to be scheduled to consume the list if one new request is added to this
percpu list, either smp_call_function_single_async() returns -EBUSY or 0.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230717040058.3993930-2-chengming.zhou@linux.dev
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Currently the write_cache attribute allows enabling the QUEUE_FLAG_WC
flag on devices that never claimed the capability.
Fix that by adding a QUEUE_FLAG_HW_WC flag that is set by
blk_queue_write_cache and guards re-enabling the cache through sysfs.
Note that any rescan that calls blk_queue_write_cache will still
re-enable the write cache as in the current code.
Fixes: 93e9d8e836 ("block: add ability to flag write back caching on a device")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20230707094239.107968-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Add a module alias to nbd.ko that allows the generic netlink core to
automatically load the module when netlink messages for nbd are
received.
This frees the user from manually having to load the module before using
nbd functionality via netlink.
If the system policy allows it this can even be used to load the nbd
module from containers which would otherwise not have access to the
necessary module files to do a normal "modprobe nbd".
For example this avoids the following error when using nbd-client:
$ nbd-client localhost 10809 /dev/nbd0
...
Error: Couldn't resolve the nbd netlink family, make sure the nbd module is loaded and your nbd driver supports the netlink interface.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Josef Bacik <josef@toxicpadna.com>
Link: https://lore.kernel.org/r/20230713-b4-nbd-genl-v3-1-226cbddba04b@weissschuh.net
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Pull xtensa fixes from Max Filippov:
- fix interaction between unaligned exception handler and load/store
exception handler
- fix parsing ISS network interface specification string
- add comment about etherdev freeing to ISS network driver
* tag 'xtensa-20230716' of https://github.com/jcmvbkbc/linux-xtensa:
xtensa: fix unaligned and load/store configuration interaction
xtensa: ISS: fix call to split_if_spec
xtensa: ISS: add comment about etherdev freeing
Pull perf fix from Borislav Petkov:
- Fix a lockdep warning when the event given is the first one, no event
group exists yet but the code still goes and iterates over event
siblings
* tag 'perf_urgent_for_v6.5_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86: Fix lockdep warning in for_each_sibling_event() on SPR
Pull objtool fixes from Borislav Petkov:
- Mark copy_iovec_from_user() __noclone in order to prevent gcc from
doing an inter-procedural optimization and confuse objtool
- Initialize struct elf fully to avoid build failures
* tag 'objtool_urgent_for_v6.5_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
iov_iter: Mark copy_iovec_from_user() noclone
objtool: initialize all of struct elf
Pull scheduler fixes from Borislav Petkov:
- Remove a cgroup from under a polling process properly
- Fix the idle sibling selection
* tag 'sched_urgent_for_v6.5_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/psi: use kernfs polling functions for PSI trigger polling
sched/fair: Use recent_used_cpu to test p->cpus_ptr
Pull pin control fixes from Linus Walleij:
"I'm mostly on vacation but what would vacation be without a few
critical fixes so people can use their gaming laptops when hiding away
from the sun (or rain)?
- Fix a really annoying interrupt storm in the AMD driver affecting
Asus TUF gaming notebooks
- Fix device tree parsing in the Renesas driver"
* tag 'pinctrl-v6.5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl:
pinctrl: amd: Unify debounce handling into amd_pinconf_set()
pinctrl: amd: Drop pull up select configuration
pinctrl: amd: Use amd_pinconf_set() for all config options
pinctrl: amd: Only use special debounce behavior for GPIO 0
pinctrl: renesas: rzg2l: Handle non-unique subnode names
pinctrl: renesas: rzv2m: Handle non-unique subnode names
Pull smb client fixes from Steve French:
- Two reconnect fixes: important fix to address inFlight count to leak
(which can leak credits), and fix for better handling a deleted share
- DFS fix
- SMB1 cleanup fix
- deferred close fix
* tag '6.5-rc1-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
cifs: fix mid leak during reconnection after timeout threshold
cifs: is_network_name_deleted should return a bool
smb: client: fix missed ses refcounting
smb: client: Fix -Wstringop-overflow issues
cifs: if deferred close is disabled then close files immediately
Pull powerpc fixes from Michael Ellerman:
- Fix Speculation_Store_Bypass reporting in /proc/self/status on
Power10
- Fix HPT with 4K pages since recent changes by implementing pmd_same()
- Fix 64-bit native_hpte_remove() to be irq-safe
Thanks to Aneesh Kumar K.V, Nageswara R Sastry, and Russell Currey.
* tag 'powerpc-6.5-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
powerpc/mm/book3s64/hash/4k: Add pmd_same callback for 4K page size
powerpc/64e: Fix obtool warnings in exceptions-64e.S
powerpc/security: Fix Speculation_Store_Bypass reporting on Power10
powerpc/64s: Fix native_hpte_remove() to be irq-safe
Pull hardening fixes from Kees Cook:
- Remove LTO-only suffixes from promoted global function symbols
(Yonghong Song)
- Remove unused .text..refcount section from vmlinux.lds.h (Petr Pavlu)
- Add missing __always_inline to sparc __arch_xchg() (Arnd Bergmann)
- Claim maintainership of string routines
* tag 'hardening-v6.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
sparc: mark __arch_xchg() as __always_inline
MAINTAINERS: Foolishly claim maintainership of string routines
kallsyms: strip LTO-only suffixes from promoted global functions
vmlinux.lds.h: Remove a reference to no longer used sections .text..refcount
Pull probe fixes from Masami Hiramatsu:
- fprobe: Add a comment why fprobe will be skipped if another kprobe is
running in fprobe_kprobe_handler().
- probe-events: Fix some issues related to fetch-arguments:
- Fix double counting of the string length for user-string and
symstr. This will require longer buffer in the array case.
- Fix not to count error code (minus value) for the total used
length in array argument. This makes the total used length
shorter.
- Fix to update dynamic used data size counter only if fetcharg uses
the dynamic size data. This may mis-count the used dynamic data
size and corrupt data.
- Revert "tracing: Add "(fault)" name injection to kernel probes"
because that did not work correctly with a bug, and we agreed the
current '(fault)' output (instead of '"(fault)"' like a string)
explains what happened more clearly.
- Fix to record 0-length (means fault access) data_loc data in fetch
function itself, instead of store_trace_args(). If we record an
array of string, this will fix to save fault access data on each
entry of the array correctly.
* tag 'probes-fixes-v6.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/probes: Fix to record 0-length data_loc in fetch_store_string*() if fails
Revert "tracing: Add "(fault)" name injection to kernel probes"
tracing/probes: Fix to update dynamic data counter if fetcharg uses it
tracing/probes: Fix not to count error code to total length
tracing/probes: Fix to avoid double count of the string length on the array
fprobes: Add a comment why fprobe_kprobe_handler exits if kprobe is running
Pull spi fixes from Mark Brown:
"A couple of fairly minor driver specific fixes here, plus a bunch of
maintainership and admin updates. Nothing too remarkable"
* tag 'spi-fix-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi:
mailmap: add entry for Jonas Gorski
MAINTAINERS: add myself for spi-bcm63xx
spi: s3c64xx: clear loopback bit after loopback test
spi: bcm63xx: fix max prepend length
MAINTAINERS: Add myself as a maintainer for Microchip SPI
Pull regmap fix from Mark Brown:
"One fix for an out of bounds access in the interupt code here"
* tag 'regmap-fix-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap:
regmap-irq: Fix out-of-bounds access when allocating config buffers
Pull iommu fixes from Joerg Roedel:
- Fix a regression causing a crash on sysfs access of iommu-group
specific files
- Fix signedness bug in SVA code
* tag 'iommu-fixes-v6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
iommu/sva: Fix signedness bug in iommu_sva_alloc_pasid()
iommu: Fix crash during syfs iommu_groups/N/type
Pull x86 CFI fixes from Peter Zijlstra:
"Fix kCFI/FineIBT weaknesses
The primary bug Alyssa noticed was that with FineIBT enabled function
prologues have a spurious ENDBR instruction:
__cfi_foo:
endbr64
subl $hash, %r10d
jz 1f
ud2
nop
1:
foo:
endbr64 <--- *sadface*
This means that any indirect call that fails to target the __cfi
symbol and instead targets (the regular old) foo+0, will succeed due
to that second ENDBR.
Fixing this led to the discovery of a single indirect call that was
still doing this: ret_from_fork(). Since that's an assembly stub the
compiler would not generate the proper kCFI indirect call magic and it
would not get patched.
Brian came up with the most comprehensive fix -- convert the thing to
C with only a very thin asm wrapper. This ensures the kernel thread
boostrap is a proper kCFI call.
While discussing all this, Kees noted that kCFI hashes could/should be
poisoned to seal all functions whose address is never taken, further
limiting the valid kCFI targets -- much like we already do for IBT.
So what was a 'simple' observation and fix cascaded into a bunch of
inter-related CFI infrastructure fixes"
* tag 'x86_urgent_for_6.5_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/cfi: Only define poison_cfi() if CONFIG_X86_KERNEL_IBT=y
x86/fineibt: Poison ENDBR at +0
x86: Rewrite ret_from_fork() in C
x86/32: Remove schedule_tail_wrapper()
x86/cfi: Extend ENDBR sealing to kCFI
x86/alternative: Rename apply_ibt_endbr()
x86/cfi: Extend {JMP,CAKK}_NOSPEC comment
Pull SCSI fixes from James Bottomley:
"This is a bunch of small driver fixes and a larger rework of zone disk
handling (which reaches into blk and nvme).
The aacraid array-bounds fix is now critical since the security people
turned on -Werror for some build tests, which now fail without it"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: storvsc: Handle SRB status value 0x30
scsi: block: Improve checks in blk_revalidate_disk_zones()
scsi: block: virtio_blk: Set zone limits before revalidating zones
scsi: block: nullblk: Set zone limits before revalidating zones
scsi: nvme: zns: Set zone limits before revalidating zones
scsi: sd_zbc: Set zone limits before revalidating zones
scsi: ufs: core: Add support for qTimestamp attribute
scsi: aacraid: Avoid -Warray-bounds warning
scsi: ufs: ufs-mediatek: Add dependency for RESET_CONTROLLER
scsi: ufs: core: Update contact email for monitor sysfs nodes
scsi: scsi_debug: Remove dead code
scsi: qla2xxx: Use vmalloc_array() and vcalloc()
scsi: fnic: Use vmalloc_array() and vcalloc()
scsi: qla2xxx: Fix error code in qla2x00_start_sp()
scsi: qla2xxx: Silence a static checker warning
scsi: lpfc: Fix a possible data race in lpfc_unregister_fcf_rescan()
Pull block fixes from Jens Axboe:
- NVMe pull request via Keith:
- Don't require quirk to use duplicate namespace identifiers
(Christoph, Sagi)
- One more BOGUS_NID quirk (Pankaj)
- IO timeout and error hanlding fixes for PCI (Keith)
- Enhanced metadata format mask fix (Ankit)
- Association race condition fix for fibre channel (Michael)
- Correct debugfs error checks (Minjie)
- Use PAGE_SECTORS_SHIFT where needed (Damien)
- Reduce kernel logs for legacy nguid attribute (Keith)
- Use correct dma direction when unmapping metadata (Ming)
- Fix for a flush handling regression in this release (Christoph)
- Fix for batched request time stamping (Chengming)
- Fix for a regression in the mq-deadline position calculation (Bart)
- Lockdep fix for blk-crypto (Eric)
- Fix for a regression in the Amiga partition handling changes
(Michael)
* tag 'block-6.5-2023-07-14' of git://git.kernel.dk/linux:
block: queue data commands from the flush state machine at the head
blk-mq: fix start_time_ns and alloc_time_ns for pre-allocated rq
nvme-pci: fix DMA direction of unmapping integrity data
nvme: don't reject probe due to duplicate IDs for single-ported PCIe devices
block/mq-deadline: Fix a bug in deadline_from_pos()
nvme: ensure disabling pairs with unquiesce
nvme-fc: fix race between error recovery and creating association
nvme-fc: return non-zero status code when fails to create association
nvme: fix parameter check in nvme_fault_inject_init()
nvme: warn only once for legacy uuid attribute
block: remove dead struc request->completion_data field
nvme: fix the NVME_ID_NS_NVM_STS_MASK definition
nvmet: use PAGE_SECTORS_SHIFT
nvme: add BOGUS_NID quirk for Samsung SM953
blk-crypto: use dynamic lock class for blk_crypto_profile::lock
block/partition: fix signedness issue for Amiga partitions
Pull io_uring fix from Jens Axboe:
"Just a single tweak for the wait logic in io_uring"
* tag 'io_uring-6.5-2023-07-14' of git://git.kernel.dk/linux:
io_uring: Use io_schedule* in cqring wait
