[ Upstream commit 2fd895842d ]
When a call is released, rxrpc takes the spinlock and removes it from
->recvmsg_q in an effort to prevent racing recvmsg() invocations from
seeing the same call. Now, rxrpc_recvmsg() only takes the spinlock when
actually removing a call from the queue; it doesn't, however, take it in
the lead up to that when it checks to see if the queue is empty. It *does*
hold the socket lock, which prevents a recvmsg/recvmsg race - but this
doesn't prevent sendmsg from ending the call because sendmsg() drops the
socket lock and relies on the call->user_mutex.
Fix this by firstly removing the bit in rxrpc_release_call() that dequeues
the released call and, instead, rely on recvmsg() to simply discard
released calls (done in a preceding fix).
Secondly, rxrpc_notify_socket() is abandoned if the call is already marked
as released rather than trying to be clever by setting both pointers in
call->recvmsg_link to NULL to trick list_empty(). This isn't perfect and
can still race, resulting in a released call on the queue, but recvmsg()
will now clean that up.
Fixes: 17926a7932 ("[AF_RXRPC]: Provide secure RxRPC sockets for use by userspace and kernel both")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250717074350.3767366-4-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: e66f8f32f5 ("rxrpc: Fix socket notification race")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c73370c677 ]
The trace event btrfs_sync_file() is called in an atomic context (all trace
events are) and its call to dput(), which is needed due to the call to
dget_parent(), can sleep, triggering a kernel splat.
This can be reproduced by enabling the trace event and running btrfs/056
from fstests for example. The splat shown in dmesg is the following:
[53.919] BUG: sleeping function called from invalid context at fs/dcache.c:970
[53.947] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 32773, name: xfs_io
[53.988] preempt_count: 2, expected: 0
[53.967] RCU nest depth: 0, expected: 0
[53.943] Preemption disabled at:
[53.944] [<0000000000000000>] 0x0
[54.078] CPU: 0 UID: 0 PID: 32773 Comm: xfs_io Tainted: G W 7.1.0-rc1-btrfs-next-232+ #1 PREEMPT(full)
[54.070] Tainted: [W]=WARN
[54.071] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.2-0-gea1b7a073390-prebuilt.qemu.org 04/01/2014
[54.072] Call Trace:
[54.074] <TASK>
[54.076] dump_stack_lvl+0x56/0x80
[54.079] __might_resched.cold+0xd6/0x10f
[54.072] dput.part.0+0x24/0x110
[54.078] trace_event_raw_event_btrfs_sync_file+0x75/0x140 [btrfs]
[54.089] btrfs_sync_file+0x1ed/0x530 [btrfs]
[54.087] ? __handle_mm_fault+0x8ae/0xed0
[54.089] btrfs_do_write_iter+0x172/0x210 [btrfs]
[54.091] vfs_write+0x21f/0x450
[54.094] __x64_sys_pwrite64+0x8d/0xc0
[54.096] ? do_user_addr_fault+0x20c/0x670
[54.099] do_syscall_64+0x60/0xf20
[54.092] ? clear_bhb_loop+0x60/0xb0
[54.094] entry_SYSCALL_64_after_hwframe+0x76/0x7e
So stop using dget_parent() and dput() and access the parent dentry
directly as dentry->d_parent. This is also what ext4 is doing in
its equivalent trace event ext4_sync_file_enter().
Fixes: a85b46db14 ("btrfs: tracepoints: get correct superblock from dentry in event btrfs_sync_file()")
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f2e388a019 ]
hrtimer_start() when invoked with an already armed timer traces like:
<comm>-.. [032] d.h2. 5.002263: hrtimer_cancel: hrtimer= ....
<comm>-.. [032] d.h1. 5.002263: hrtimer_start: hrtimer= ....
Which is incorrect as the timer doesn't get canceled. Just the expiry time
changes. The internal dequeue operation which is required for that is not
really interesting for trace analysis. But it makes it tedious to keep real
cancellations and the above case apart.
Remove the cancel tracing in hrtimer_start() and add a 'was_armed'
indicator to the hrtimer start tracepoint, which clearly indicates what the
state of the hrtimer is when hrtimer_start() is invoked:
<comm>-.. [032] d.h1. 6.200103: hrtimer_start: hrtimer= .... was_armed=0
<comm>-.. [032] d.h1. 6.200558: hrtimer_start: hrtimer= .... was_armed=1
Fixes: c6a2a17702 ("hrtimer: Add tracepoint for hrtimers")
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260224163430.208491877@kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1f2740150f ]
If skb_unshare() fails to unshare a packet due to allocation failure in
rxrpc_input_packet(), the skb pointer in the parent (rxrpc_io_thread())
will be NULL'd out. This will likely cause the call to
trace_rxrpc_rx_done() to oops.
Fix this by moving the unsharing down to where rxrpc_input_call_event()
calls rxrpc_input_call_packet(). There are a number of places prior to
that where we ignore DATA packets for a variety of reasons (such as the
call already being complete) for which an unshare is then avoided.
And with that, rxrpc_input_packet() doesn't need to take a pointer to the
pointer to the packet, so change that to just a pointer.
Fixes: 2d1faf7a0c ("rxrpc: Simplify skbuff accounting in receive path")
Closes: https://sashiko.dev/#/patchset/20260408121252.2249051-1-dhowells%40redhat.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jeffrey Altman <jaltman@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/20260422161438.2593376-4-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Relocated the unshare/skb_copy block from rxrpc_input_call_event()'s rx_queue dequeue loop to existing `if (skb) rxrpc_input_call_packet()` site, and substituted rxrpc_skb_put_call_rx with rxrpc_skb_put_input. ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Readd rxrpc_skb_put_response_copy() or will cause a build fail with commit 24481a7f57 ("rxrpc: Fix conn-level packet handling to unshare RESPONSE packets") ]
Signed-off-by: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a85b46db14 ]
If overlay is used on top of btrfs, dentry->d_sb translates to overlay's
super block and fsid assignment will lead to a crash.
Use file_inode(file)->i_sb to always get btrfs_sb.
Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 2c28769a51 ]
If rxrpc_recvmsg() fails because MSG_DONTWAIT was specified but the call at
the front of the recvmsg queue already has its mutex locked, it requeues
the call - whether or not the call is already queued. The call may be on
the queue because MSG_PEEK was also passed and so the call was not dequeued
or because the I/O thread requeued it.
The unconditional requeue may then corrupt the recvmsg queue, leading to
things like UAFs or refcount underruns.
Fix this by only requeuing the call if it isn't already on the queue - and
moving it to the front if it is already queued. If we don't queue it, we
have to put the ref we obtained by dequeuing it.
Also, MSG_PEEK doesn't dequeue the call so shouldn't call
rxrpc_notify_socket() for the call if we didn't use up all the data on the
queue, so fix that also.
Fixes: 540b1c48c3 ("rxrpc: Fix deadlock between call creation and sendmsg/recvmsg")
Reported-by: Faith <faith@zellic.io>
Reported-by: Pumpkin Chang <pumpkin@devco.re>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Marc Dionne <marc.dionne@auristor.com>
cc: Nir Ohfeld <niro@wiz.io>
cc: Willy Tarreau <w@1wt.eu>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: stable@kernel.org
Link: https://patch.msgid.link/95163.1768428203@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[Use spin_unlock instead of spin_unlock_irq to maintain context consistency.]
Signed-off-by: Robert Garcia <rob_garcia@163.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit f157dd6613 ]
When evicting an inode the first thing we do is to setup tracing for it,
which implies fetching the root's id. But in btrfs_evict_inode() the
root might be NULL, as implied in the next check that we do in
btrfs_evict_inode().
Hence, we either should set the ->root_objectid to 0 in case the root is
NULL, or we move tracing setup after checking that the root is not
NULL. Setting the rootid to 0 at least gives us the possibility to trace
this call even in the case when the root is NULL, so that's the solution
taken here.
Fixes: 1abe9b8a13 ("Btrfs: add initial tracepoint support for btrfs")
Reported-by: syzbot+d991fea1b4b23b1f6bf8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d991fea1b4b23b1f6bf8
Signed-off-by: Miquel Sabaté Solà <mssola@mssola.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[ Adjust context ]
Signed-off-by: Bin Lan <lanbincn@139.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 079c24d569 upstream.
The rss_stat trace event allows userspace tools, like Perfetto [1], to
inspect per-process RSS metric changes over time.
The curr field was introduced to rss_stat in commit e4dcad204d
("rss_stat: add support to detect RSS updates of external mm"). Its
intent is to indicate whether the RSS update is for the mm_struct of the
current execution context; and is set to false when operating on a remote
mm_struct (e.g., via kswapd or a direct reclaimer).
However, an issue arises when a kernel thread temporarily adopts a user
process's mm_struct. Kernel threads do not have their own mm_struct and
normally have current->mm set to NULL. To operate on user memory, they
can "borrow" a memory context using kthread_use_mm(), which sets
current->mm to the user process's mm.
This can be observed, for example, in the USB Function Filesystem (FFS)
driver. The ffs_user_copy_worker() handles AIO completions and uses
kthread_use_mm() to copy data to a user-space buffer. If a page fault
occurs during this copy, the fault handler executes in the kthread's
context.
At this point, current is the kthread, but current->mm points to the user
process's mm. Since the rss_stat event (from the page fault) is for that
same mm, the condition current->mm == mm becomes true, causing curr to be
incorrectly set to true when the trace event is emitted.
This is misleading because it suggests the mm belongs to the kthread,
confusing userspace tools that track per-process RSS changes and
corrupting their mm_id-to-process association.
Fix this by ensuring curr is always false when the trace event is emitted
from a kthread context by checking for the PF_KTHREAD flag.
Link: https://lkml.kernel.org/r/20260219233708.1971199-1-kaleshsingh@google.com
Link: https://perfetto.dev/ [1]
Fixes: e4dcad204d ("rss_stat: add support to detect RSS updates of external mm")
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Pedro Falcato <pfalcato@suse.de>
Cc: "David Hildenbrand (Arm)" <david@kernel.org>
Cc: Joel Fernandes <joel@joelfernandes.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: <stable@vger.kernel.org> [5.10+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c6c209ceb8 ]
I haven't found an NFSERR_EAGAIN in RFCs 1094, 1813, 7530, or 8881.
None of these RFCs have an NFS status code that match the numeric
value "11".
Based on the meaning of the EAGAIN errno, I presume the use of this
status in NFSD means NFS4ERR_DELAY. So replace the one usage of
nfserr_eagain, and remove it from NFSD's NFS status conversion
tables.
As far as I can tell, NFSERR_EAGAIN has existed since the pre-git
era, but was not actually used by any code until commit f4e44b3933
("NFSD: delay unmount source's export after inter-server copy
completed."), at which time it become possible for NFSD to return
a status code of 11 (which is not valid NFS protocol).
Fixes: f4e44b3933 ("NFSD: delay unmount source's export after inter-server copy completed.")
Cc: stable@vger.kernel.org
Reviewed-by: NeilBrown <neil@brown.name>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit ca283ea992 ]
Continue adding const to parameters. This is for clarity and minor
addition to safety. There are some minor effects, in the assembly code
and .ko measured on release config.
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 962fb1f651 ]
If a call receives an event (such as incoming data), the call gets placed
on the socket's queue and a thread in recvmsg can be awakened to go and
process it. Once the thread has picked up the call off of the queue,
further events will cause it to be requeued, and once the socket lock is
dropped (recvmsg uses call->user_mutex to allow the socket to be used in
parallel), a second thread can come in and its recvmsg can pop the call off
the socket queue again.
In such a case, the first thread will be receiving stuff from the call and
the second thread will be blocked on call->user_mutex. The first thread
can, at this point, process both the event that it picked call for and the
event that the second thread picked the call for and may see the call
terminate - in which case the call will be "released", decoupling the call
from the user call ID assigned to it (RXRPC_USER_CALL_ID in the control
message).
The first thread will return okay, but then the second thread will wake up
holding the user_mutex and, if it sees that the call has been released by
the first thread, it will BUG thusly:
kernel BUG at net/rxrpc/recvmsg.c:474!
Fix this by just dequeuing the call and ignoring it if it is seen to be
already released. We can't tell userspace about it anyway as the user call
ID has become stale.
Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Reported-by: Junvyyang, Tencent Zhuque Lab <zhuque@tencent.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: LePremierHomme <kwqcheii@proton.me>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20250717074350.3767366-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 87f3afd366 ]
This patch adds to support tracepoint for f2fs_vm_page_mkwrite(),
meanwhile it prints more details for trace_f2fs_filemap_fault().
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Stable-dep-of: ba8dac350f ("f2fs: fix to zero post-eof page")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit e52750fb14 ]
When printing a dynamic array in a trace event, the method is rather ugly.
It has the format of:
__print_array(__get_dynamic_array(array),
__get_dynmaic_array_len(array) / el_size, el_size)
Since dynamic arrays are known to the tracing infrastructure, create a
helper macro that does the above for you.
__print_dynamic_array(array, el_size)
Which would expand to the same output.
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Avadhut Naik <avadhut.naik@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Link: https://lore.kernel.org/r/20241022194158.110073-3-avadhut.naik@amd.com
Stable-dep-of: ea8d7647f9 ("tracing: Verify event formats that have "%*p.."")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit db3efdcf70 ]
Introduce a tracepoint for icmp_send, which can help users to get more
detail information conveniently when icmp abnormal events happen.
1. Giving an usecase example:
=============================
When an application experiences packet loss due to an unreachable UDP
destination port, the kernel will send an exception message through the
icmp_send function. By adding a trace point for icmp_send, developers or
system administrators can obtain detailed information about the UDP
packet loss, including the type, code, source address, destination address,
source port, and destination port. This facilitates the trouble-shooting
of UDP packet loss issues especially for those network-service
applications.
2. Operation Instructions:
==========================
Switch to the tracing directory.
cd /sys/kernel/tracing
Filter for destination port unreachable.
echo "type==3 && code==3" > events/icmp/icmp_send/filter
Enable trace event.
echo 1 > events/icmp/icmp_send/enable
3. Result View:
================
udp_client_erro-11370 [002] ...s.12 124.728002:
icmp_send: icmp_send: type=3, code=3.
From 127.0.0.1:41895 to 127.0.0.1:6666 ulen=23
skbaddr=00000000589b167a
Signed-off-by: Peilin He <he.peilin@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Yunkai Zhang <zhang.yunkai@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Liu Chun <liu.chun2@zte.com.cn>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5bbd6e863b ]
If rpc_signal_task() is called while a task is in an rpc_call_done()
callback function, and the latter calls rpc_restart_call(), the task can
end up looping due to the RPC_TASK_SIGNALLED flag being set without the
tk_rpc_status being set.
Removing the redundant mechanism for signalling the task fixes the
looping behaviour.
Reported-by: Li Lingfeng <lilingfeng3@huawei.com>
Fixes: 39494194f9 ("SUNRPC: Fix races with rpc_killall_tasks()")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Anna Schumaker <anna.schumaker@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 72ba14deb4 ]
The current implementation of the mark_victim tracepoint provides only the
process ID (pid) of the victim process. This limitation poses challenges
for userspace tools requiring real-time OOM analysis and intervention.
Although this information is available from the kernel logs, it’s not
the appropriate format to provide OOM notifications. In Android, BPF
programs are used with the mark_victim trace events to notify userspace of
an OOM kill. For consistency, update the trace event to include the same
information about the OOMed victim as the kernel logs.
- UID
In Android each installed application has a unique UID. Including
the `uid` assists in correlating OOM events with specific apps.
- Process Name (comm)
Enables identification of the affected process.
- OOM Score
Will allow userspace to get additional insight of the relative kill
priority of the OOM victim. In Android, the oom_score_adj is used to
categorize app state (foreground, background, etc.), which aids in
analyzing user-perceptible impacts of OOM events [1].
- Total VM, RSS Stats, and pgtables
Amount of memory used by the victim that will, potentially, be freed up
by killing it.
[1] https://cs.android.com/android/platform/superproject/main/+/246dc8fc95b6d93afcba5c6d6c133307abb3ac2e:frameworks/base/services/core/java/com/android/server/am/ProcessList.java;l=188-283
Signed-off-by: Carlos Galo <carlosgalo@google.com>
Reviewed-by: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Stable-dep-of: ade81479c7 ("memcg: fix soft lockup in the OOM process")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4241a702e0 ]
The rxrpc_connection attend queue is never used because conn::attend_link
is never initialised and so is always NULL'd out and thus always appears to
be busy. This requires the following fix:
(1) Fix this the attend queue problem by initialising conn::attend_link.
And, consequently, two further fixes for things masked by the above bug:
(2) Fix rxrpc_input_conn_event() to handle being invoked with a NULL
sk_buff pointer - something that can now happen with the above change.
(3) Fix the RXRPC_SKB_MARK_SERVICE_CONN_SECURED message to carry a pointer
to the connection and a ref on it.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Jakub Kicinski <kuba@kernel.org>
cc: "David S. Miller" <davem@davemloft.net>
cc: Eric Dumazet <edumazet@google.com>
cc: Paolo Abeni <pabeni@redhat.com>
cc: Simon Horman <horms@kernel.org>
cc: linux-afs@lists.infradead.org
cc: netdev@vger.kernel.org
Fixes: f2cce89a07 ("rxrpc: Implement a mechanism to send an event notification to a connection")
Link: https://patch.msgid.link/20250203110307.7265-3-dhowells@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0e56ebde24 ]
Fix the handling of a connection abort that we've received. Though the
abort is at the connection level, it needs propagating to the calls on that
connection. Whilst the propagation bit is performed, the calls aren't then
woken up to go and process their termination, and as no further input is
forthcoming, they just hang.
Also add some tracing for the logging of connection aborts.
Fixes: 248f219cb8 ("rxrpc: Rewrite the data and ack handling code")
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Link: https://patch.msgid.link/20241204074710.990092-3-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9750be93b2 ]
If we manage to begin an async call, but fail to transmit any data on it
due to a signal, we then abort it which causes a race between the
notification of call completion from rxrpc and our attempt to cancel the
notification. The notification will be necessary, however, for async
FetchData to terminate the netfs subrequest.
However, since we get a notification from rxrpc upon completion of a call
(aborted or otherwise), we can just leave it to that.
This leads to calls not getting cleaned up, but appearing in
/proc/net/rxrpc/calls as being aborted with code 6.
Fix this by making the "error_do_abort:" case of afs_make_call() abort the
call and then abandon it to the notification handler.
Fixes: 34fa47612b ("afs: Fix race in async call refcounting")
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/r/20241216204124.3752367-25-dhowells@redhat.com
cc: linux-afs@lists.infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5fe6ec8f6a ]
Tracing the runtime delta makes sense, observer can sum over time.
Tracing the absolute vruntime makes less sense, inconsistent:
absolute-vs-delta, but also vruntime delta can be computed from
runtime delta.
Removing the vruntime thing also makes the two tracepoint sites
identical, allowing to unify the code in a later patch.
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Stable-dep-of: 0664e2c311 ("sched/deadline: Fix warning in migrate_enable for boosted tasks")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit fc9de52de3 ]
If a call gets aborted (e.g. because kafs saw a signal) between it being
queued for connection and the I/O thread picking up the call, the abort
will be prioritised over the connection and it will be removed from
local->new_client_calls by rxrpc_disconnect_client_call() without a lock
being held. This may cause other calls on the list to disappear if a race
occurs.
Fix this by taking the client_call_lock when removing a call from whatever
list its ->wait_link happens to be on.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-afs@lists.infradead.org
Reported-by: Marc Dionne <marc.dionne@auristor.com>
Fixes: 9d35d880e0 ("rxrpc: Move client call connection to the I/O thread")
Link: https://patch.msgid.link/726660.1730898202@warthog.procyon.org.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 247d65fb12 ]
When rename moves an AFS subdirectory between parent directories, the
subdir also needs a bit of editing: the ".." entry needs updating to point
to the new parent (though I don't make use of the info) and the DV needs
incrementing by 1 to reflect the change of content. The server also sends
a callback break notification on the subdirectory if we have one, but we
can take care of recovering the promise next time we access the subdir.
This can be triggered by something like:
mount -t afs %example.com:xfstest.test20 /xfstest.test/
mkdir /xfstest.test/{aaa,bbb,aaa/ccc}
touch /xfstest.test/bbb/ccc/d
mv /xfstest.test/{aaa/ccc,bbb/ccc}
touch /xfstest.test/bbb/ccc/e
When the pathwalk for the second touch hits "ccc", kafs spots that the DV
is incorrect and downloads it again (so the fix is not critical).
Fix this, if the rename target is a directory and the old and new
parents are different, by:
(1) Incrementing the DV number of the target locally.
(2) Editing the ".." entry in the target to refer to its new parent's
vnode ID and uniquifier.
Link: https://lore.kernel.org/r/3340431.1729680010@warthog.procyon.org.uk
Fixes: 63a4681ff3 ("afs: Locally edit directory data for mkdir/create/unlink/...")
cc: David Howells <dhowells@redhat.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: linux-afs@lists.infradead.org
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 37f0b47c51 ]
The "addr" and "is_shmem" arguments have different order in TP_PROTO and
TP_ARGS. This resulted in the incorrect trace result:
text-hugepage-644429 [276] 392092.878683: mm_khugepaged_collapse_file:
mm=0xffff20025d52c440, hpage_pfn=0x200678c00, index=512, addr=1, is_shmem=0,
filename=text-hugepage, nr=512, result=failed
The value of "addr" is wrong because it was treated as bool value, the
type of is_shmem.
Fix the order in TP_PROTO to keep "addr" is before "is_shmem" since the
original patch review suggested this order to achieve best packing.
And use "lx" for "addr" instead of "ld" in TP_printk because address is
typically shown in hex.
After the fix, the trace result looks correct:
text-hugepage-7291 [004] 128.627251: mm_khugepaged_collapse_file:
mm=0xffff0001328f9500, hpage_pfn=0x20016ea00, index=512, addr=0x400000,
is_shmem=0, filename=text-hugepage, nr=512, result=failed
Link: https://lkml.kernel.org/r/20241012011702.1084846-1-yang@os.amperecomputing.com
Fixes: 4c9473e87e ("mm/khugepaged: add tracepoint to collapse_file()")
Signed-off-by: Yang Shi <yang@os.amperecomputing.com>
Cc: Gautam Menghani <gautammenghani201@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: <stable@vger.kernel.org> [6.2+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit aaf8c0b9ae ]
We may trigger high frequent checkpoint for below case:
1. mkdir /mnt/dir1; set dir1 encrypted
2. touch /mnt/file1; fsync /mnt/file1
3. mkdir /mnt/dir2; set dir2 encrypted
4. touch /mnt/file2; fsync /mnt/file2
...
Although, newly created dir and file are not related, due to
commit bbf156f7af ("f2fs: fix lost xattrs of directories"), we will
trigger checkpoint whenever fsync() comes after a new encrypted dir
created.
In order to avoid such performance regression issue, let's record an
entry including directory's ino in global cache whenever we update
directory's xattr data, and then triggerring checkpoint() only if
xattr metadata of target file's parent was updated.
This patch updates to cover below no encryption case as well:
1) parent is checkpointed
2) set_xattr(dir) w/ new xnid
3) create(file)
4) fsync(file)
Fixes: bbf156f7af ("f2fs: fix lost xattrs of directories")
Reported-by: wangzijie <wangzijie1@honor.com>
Reported-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Tested-by: Zhiguo Niu <zhiguo.niu@unisoc.com>
Reported-by: Yunlei He <heyunlei@hihonor.com>
Signed-off-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f169c62ff7 ]
VMAs are skipped if there is no recent fault activity but this represents
a chicken-and-egg problem as there may be no fault activity if the PTEs
are never updated to trap NUMA hints. There is an indirect reliance on
scanning to be forced early in the lifetime of a task but this may fail
to detect changes in phase behaviour. Force inactive VMAs to be scanned
when all other eligible VMAs have been updated within the same scan
sequence.
Test results in general look good with some changes in performance, both
negative and positive, depending on whether the additional scanning and
faulting was beneficial or not to the workload. The autonuma benchmark
workload NUMA01_THREADLOCAL was picked for closer examination. The workload
creates two processes with numerous threads and thread-local storage that
is zero-filled in a loop. It exercises the corner case where unrelated
threads may skip VMAs that are thread-local to another thread and still
has some VMAs that inactive while the workload executes.
The VMA skipping activity frequency with and without the patch:
6.6.0-rc2-sched-numabtrace-v1
=============================
649 reason=scan_delay
9,094 reason=unsuitable
48,915 reason=shared_ro
143,919 reason=inaccessible
193,050 reason=pid_inactive
6.6.0-rc2-sched-numabselective-v1
=============================
146 reason=seq_completed
622 reason=ignore_pid_inactive
624 reason=scan_delay
6,570 reason=unsuitable
16,101 reason=shared_ro
27,608 reason=inaccessible
41,939 reason=pid_inactive
Note that with the patch applied, the PID activity is ignored
(ignore_pid_inactive) to ensure a VMA with some activity is completely
scanned. In addition, a small number of VMAs are scanned when no other
eligible VMA is available during a single scan window (seq_completed).
The number of times a VMA is skipped due to no PID activity from the
scanning task (pid_inactive) drops dramatically. It is expected that
this will increase the number of PTEs updated for NUMA hinting faults
as well as hinting faults but these represent PTEs that would otherwise
have been missed. The tradeoff is scan+fault overhead versus improving
locality due to migration.
On a 2-socket Cascade Lake test machine, the time to complete the
workload is as follows;
6.6.0-rc2 6.6.0-rc2
sched-numabtrace-v1 sched-numabselective-v1
Min elsp-NUMA01_THREADLOCAL 174.22 ( 0.00%) 117.64 ( 32.48%)
Amean elsp-NUMA01_THREADLOCAL 175.68 ( 0.00%) 123.34 * 29.79%*
Stddev elsp-NUMA01_THREADLOCAL 1.20 ( 0.00%) 4.06 (-238.20%)
CoeffVar elsp-NUMA01_THREADLOCAL 0.68 ( 0.00%) 3.29 (-381.70%)
Max elsp-NUMA01_THREADLOCAL 177.18 ( 0.00%) 128.03 ( 27.74%)
The time to complete the workload is reduced by almost 30%:
6.6.0-rc2 6.6.0-rc2
sched-numabtrace-v1 sched-numabselective-v1 /
Duration User 91201.80 63506.64
Duration System 2015.53 1819.78
Duration Elapsed 1234.77 868.37
In this specific case, system CPU time was not increased but it's not
universally true.
From vmstat, the NUMA scanning and fault activity is as follows;
6.6.0-rc2 6.6.0-rc2
sched-numabtrace-v1 sched-numabselective-v1
Ops NUMA base-page range updates 64272.00 26374386.00
Ops NUMA PTE updates 36624.00 55538.00
Ops NUMA PMD updates 54.00 51404.00
Ops NUMA hint faults 15504.00 75786.00
Ops NUMA hint local faults % 14860.00 56763.00
Ops NUMA hint local percent 95.85 74.90
Ops NUMA pages migrated 1629.00 6469222.00
Both the number of PTE updates and hint faults is dramatically
increased. While this is superficially unfortunate, it represents
ranges that were simply skipped without the patch. As a result
of the scanning and hinting faults, many more pages were also
migrated but as the time to completion is reduced, the overhead
is offset by the gain.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Link: https://lore.kernel.org/r/20231010083143.19593-7-mgorman@techsingularity.net
Stable-dep-of: f22cde4371 ("sched/numa: Fix the vma scan starving issue")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b7a5b537c5 ]
NUMA Balancing skips VMAs when the current task has not trapped a NUMA
fault within the VMA. If the VMA is skipped then mm->numa_scan_offset
advances and a task that is trapping faults within the VMA may never
fully update PTEs within the VMA.
Force tasks to update PTEs for partially scanned PTEs. The VMA will
be tagged for NUMA hints by some task but this removes some of the
benefit of tracking PID activity within a VMA. A follow-on patch
will mitigate this problem.
The test cases and machines evaluated did not trigger the corner case so
the performance results are neutral with only small changes within the
noise from normal test-to-test variance. However, the next patch makes
the corner case easier to trigger.
Signed-off-by: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Raghavendra K T <raghavendra.kt@amd.com>
Link: https://lore.kernel.org/r/20231010083143.19593-6-mgorman@techsingularity.net
Stable-dep-of: f22cde4371 ("sched/numa: Fix the vma scan starving issue")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit b6a66e521a upstream.
The 'mptcp_subflow_context' structure has two items related to the
backup flags:
- 'backup': the subflow has been marked as backup by the other peer
- 'request_bkup': the backup flag has been set by the host
Before this patch, the scheduler was only looking at the 'backup' flag.
That can make sense in some cases, but it looks like that's not what we
wanted for the general use, because either the path-manager was setting
both of them when sending an MP_PRIO, or the receiver was duplicating
the 'backup' flag in the subflow request.
Note that the use of these two flags in the path-manager are going to be
fixed in the next commits, but this change here is needed not to modify
the behaviour.
Fixes: f296234c98 ("mptcp: Add handling of incoming MP_JOIN requests")
Cc: stable@vger.kernel.org
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 8cd44dd1d1 upstream.
When btrfs makes a block group read-only, it adds all free regions in the
block group to space_info->bytes_readonly. That free space excludes
reserved and pinned regions. OTOH, when btrfs makes the block group
read-write again, it moves all the unused regions into the block group's
zone_unusable. That unused region includes reserved and pinned regions.
As a result, it counts too much zone_unusable bytes.
Fortunately (or unfortunately), having erroneous zone_unusable does not
affect the calculation of space_info->bytes_readonly, because free
space (num_bytes in btrfs_dec_block_group_ro) calculation is done based on
the erroneous zone_unusable and it reduces the num_bytes just to cancel the
error.
This behavior can be easily discovered by adding a WARN_ON to check e.g,
"bg->pinned > 0" in btrfs_dec_block_group_ro(), and running fstests test
case like btrfs/282.
Fix it by properly considering pinned and reserved in
btrfs_dec_block_group_ro(). Also, add a WARN_ON and introduce
btrfs_space_info_update_bytes_zone_unusable() to catch a similar mistake.
Fixes: 169e0da91a ("btrfs: zoned: track unusable bytes for zones")
CC: stable@vger.kernel.org # 5.15+
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 522018a0de ]
We got the following issue in our fault injection stress test:
==================================================================
BUG: KASAN: slab-use-after-free in fscache_withdraw_volume+0x2e1/0x370
Read of size 4 at addr ffff88810680be08 by task ondemand-04-dae/5798
CPU: 0 PID: 5798 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #565
Call Trace:
kasan_check_range+0xf6/0x1b0
fscache_withdraw_volume+0x2e1/0x370
cachefiles_withdraw_volume+0x31/0x50
cachefiles_withdraw_cache+0x3ad/0x900
cachefiles_put_unbind_pincount+0x1f6/0x250
cachefiles_daemon_release+0x13b/0x290
__fput+0x204/0xa00
task_work_run+0x139/0x230
Allocated by task 5820:
__kmalloc+0x1df/0x4b0
fscache_alloc_volume+0x70/0x600
__fscache_acquire_volume+0x1c/0x610
erofs_fscache_register_volume+0x96/0x1a0
erofs_fscache_register_fs+0x49a/0x690
erofs_fc_fill_super+0x6c0/0xcc0
vfs_get_super+0xa9/0x140
vfs_get_tree+0x8e/0x300
do_new_mount+0x28c/0x580
[...]
Freed by task 5820:
kfree+0xf1/0x2c0
fscache_put_volume.part.0+0x5cb/0x9e0
erofs_fscache_unregister_fs+0x157/0x1b0
erofs_kill_sb+0xd9/0x1c0
deactivate_locked_super+0xa3/0x100
vfs_get_super+0x105/0x140
vfs_get_tree+0x8e/0x300
do_new_mount+0x28c/0x580
[...]
==================================================================
Following is the process that triggers the issue:
mount failed | daemon exit
------------------------------------------------------------
deactivate_locked_super cachefiles_daemon_release
erofs_kill_sb
erofs_fscache_unregister_fs
fscache_relinquish_volume
__fscache_relinquish_volume
fscache_put_volume(fscache_volume, fscache_volume_put_relinquish)
zero = __refcount_dec_and_test(&fscache_volume->ref, &ref);
cachefiles_put_unbind_pincount
cachefiles_daemon_unbind
cachefiles_withdraw_cache
cachefiles_withdraw_volumes
list_del_init(&volume->cache_link)
fscache_free_volume(fscache_volume)
cache->ops->free_volume
cachefiles_free_volume
list_del_init(&cachefiles_volume->cache_link);
kfree(fscache_volume)
cachefiles_withdraw_volume
fscache_withdraw_volume
fscache_volume->n_accesses
// fscache_volume UAF !!!
The fscache_volume in cache->volumes must not have been freed yet, but its
reference count may be 0. So use the new fscache_try_get_volume() helper
function try to get its reference count.
If the reference count of fscache_volume is 0, fscache_put_volume() is
freeing it, so wait for it to be removed from cache->volumes.
If its reference count is not 0, call cachefiles_withdraw_volume() with
reference count protection to avoid the above issue.
Fixes: fe2140e2f5 ("cachefiles: Implement volume support")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240628062930.2467993-3-libaokun@huaweicloud.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit da4a827416 ]
We got the following issue in a fuzz test of randomly issuing the restore
command:
==================================================================
BUG: KASAN: slab-use-after-free in cachefiles_ondemand_daemon_read+0xb41/0xb60
Read of size 8 at addr ffff888122e84088 by task ondemand-04-dae/963
CPU: 13 PID: 963 Comm: ondemand-04-dae Not tainted 6.8.0-dirty #564
Call Trace:
kasan_report+0x93/0xc0
cachefiles_ondemand_daemon_read+0xb41/0xb60
vfs_read+0x169/0xb50
ksys_read+0xf5/0x1e0
Allocated by task 116:
kmem_cache_alloc+0x140/0x3a0
cachefiles_lookup_cookie+0x140/0xcd0
fscache_cookie_state_machine+0x43c/0x1230
[...]
Freed by task 792:
kmem_cache_free+0xfe/0x390
cachefiles_put_object+0x241/0x480
fscache_cookie_state_machine+0x5c8/0x1230
[...]
==================================================================
Following is the process that triggers the issue:
mount | daemon_thread1 | daemon_thread2
------------------------------------------------------------
cachefiles_withdraw_cookie
cachefiles_ondemand_clean_object(object)
cachefiles_ondemand_send_req
REQ_A = kzalloc(sizeof(*req) + data_len)
wait_for_completion(&REQ_A->done)
cachefiles_daemon_read
cachefiles_ondemand_daemon_read
REQ_A = cachefiles_ondemand_select_req
msg->object_id = req->object->ondemand->ondemand_id
------ restore ------
cachefiles_ondemand_restore
xas_for_each(&xas, req, ULONG_MAX)
xas_set_mark(&xas, CACHEFILES_REQ_NEW)
cachefiles_daemon_read
cachefiles_ondemand_daemon_read
REQ_A = cachefiles_ondemand_select_req
copy_to_user(_buffer, msg, n)
xa_erase(&cache->reqs, id)
complete(&REQ_A->done)
------ close(fd) ------
cachefiles_ondemand_fd_release
cachefiles_put_object
cachefiles_put_object
kmem_cache_free(cachefiles_object_jar, object)
REQ_A->object->ondemand->ondemand_id
// object UAF !!!
When we see the request within xa_lock, req->object must not have been
freed yet, so grab the reference count of object before xa_unlock to
avoid the above issue.
Fixes: 0a7e54c195 ("cachefiles: resend an open request if the read request's object is closed")
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://lore.kernel.org/r/20240522114308.2402121-5-libaokun@huaweicloud.com
Acked-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jia Zhu <zhujia.zj@bytedance.com>
Reviewed-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Stable-dep-of: 4b4391e77a ("cachefiles: defer exposing anon_fd until after copy_to_user() succeeds")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 58300f8d6a ]
The string SND_SOC_DAPM_DIR_OUT is printed in the snd_soc_dapm_path trace
event instead of its value:
(((REC->path_dir) == SND_SOC_DAPM_DIR_OUT) ? "->" : "<-")
User space cannot parse this, as it has no idea what SND_SOC_DAPM_DIR_OUT
is. Use TRACE_DEFINE_ENUM() to convert it to its value:
(((REC->path_dir) == 1) ? "->" : "<-")
So that user space tools, such as perf and trace-cmd, can parse it
correctly.
Reported-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Fixes: 6e588a0d83 ("ASoC: dapm: Consolidate path trace events")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20240416000303.04670cdf@rorschach.local.home
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit a4833e3aba upstream.
The rpcgss_context trace event acceptor field is a dynamically sized
string that records the "data" parameter. But this parameter is also
dependent on the "len" field to determine the size of the data.
It needs to use __string_len() helper macro where the length can be passed
in. It also incorrectly uses strncpy() to save it instead of
__assign_str(). As these macros can change, it is not wise to open code
them in trace events.
As of commit c759e60903 ("tracing: Remove __assign_str_len()"),
__assign_str() can be used for both __string() and __string_len() fields.
Before that commit, __assign_str_len() is required to be used. This needs
to be noted for backporting. (In actuality, commit c1fa617cae ("tracing:
Rework __assign_str() and __string() to not duplicate getting the string")
is the commit that makes __string_str_len() obsolete).
Cc: stable@vger.kernel.org
Fixes: 0c77668ddb ("SUNRPC: Introduce trace points in rpc_auth_gss.ko")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
David Howells
Filipe Manana
Thomas Gleixner
Goldwyn Rodrigues
Miquel Sabaté Solà
Kalesh Singh
Chuck Lever
Chen Hanxiao
Jeff Layton
David Sterba
Steven Rostedt
Chao Yu
Gao Xiang
Peilin He
Trond Myklebust
Carlos Galo
Peter Zijlstra
Mathieu Desnoyers
Yang Shi
Matthew Wilcox (Oracle)
Mel Gorman
Jithu Joseph
Matthieu Baerts (NGI0)
Naohiro Aota
Benjamin Coddington
Baokun Li
Yunseong Kim