get_perf_callchain() returns a per-CPU perf_callchain_entry buffer and
releases its recursion slot via put_callchain_entry() before returning,
so nothing keeps the entry reserved while __bpf_get_stack() consumes
it below.
A preemptible BPF program (e.g. a non-sleepable raw tracepoint program
on a PREEMPT kernel, which runs under migrate_disable() but not
preempt_disable()) can be scheduled out between obtaining the entry
and the copy. Another task scheduled on the same CPU then reuses the
same per-CPU buffer and overwrites trace->nr with a larger value.
copy_len is then computed from the inflated trace->nr and can exceed
the caller's buffer, causing an out-of-bounds write in the memcpy()
and in the build_id path.
The rcu_read_lock() taken here alone does not prevent this. It is
only taken on the may_fault path, and under CONFIG_PREEMPT_RCU it does
not disable preemption; it merely keeps perf's callchain buffer array
alive (freed via call_rcu()) and does nothing to stop another task
from reusing the entry.
Disable preemption around obtaining the callchain entry and copying
it into the caller's buffer, so the entry cannot be reused underneath
us and trace->nr stays bounded by max_depth. Build ID resolution may
fault and is therefore deferred until after preemption is re-enabled;
by then the instruction pointers have already been copied into buf,
so it operates only on that private copy. Note, preempt_disable() also
subsumes the buffer-lifetime guarantee the rcu_read_lock() provided,
since a preempt-disabled section is an RCU read-side critical section
for the callchain buffers' call_rcu() reclaim.
Fixes: c195651e56 ("bpf: add bpf_get_stack helper")
Reported-by: Tao Chen <chen.dylane@linux.dev>
Reported-by: STAR Labs SG <info@starlabs.sg>
Signed-off-by: Daniel Borkmann <borkmann@iogearbox.net>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20260803210149.296496-11-jolsa@kernel.org
Closes: https://lore.kernel.org/bpf/20260206090653.1336687-1-chen.dylane@linux.dev/
[ changed Fixes: commit ]
Both bpf_get_task_stack and bpf_get_task_stack_sleepable helpers that
use __bpf_get_task_stack have buf defined as ARG_PTR_TO_UNINIT_MEM
argument and we should initialize the buf on every return path.
Adding missing buf memset for __bpf_get_task_stack fail paths. This
provides deterministic buffer contents, which is useful when the buffer
is used directly as a map key.
Fixes: 06ab134ce8 ("bpf: Refcount task stack in bpf_get_task_stack")
Fixes: b992f01e66 ("bpf: Guard against accessing NULL pt_regs in bpf_get_task_stack()")
Reported-by: Sashiko <sashiko-bot@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-10-jolsa@kernel.org
Now with the new callchain_* helper functions we can process trace_in
case directly in bpf_get_stack_pe function and remove it from
__bpf_get_stack which makes things easier for preemption fix in
following change.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-9-jolsa@kernel.org
The new callchain_finalize function calls the build-id retrieval
(if needed) and zeroes the buffer. This makes things easier for
preemption fix in following change.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-8-jolsa@kernel.org
The new callchain_store function stores trace entries buffer into
user supplied buffer. It covers both just-ip and buildid data.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-7-jolsa@kernel.org
Replacing __bpf_get_stackid calls with sequence of following functions:
stackid_fastpath
stackid_new_bucket
stackid_install
This makes code more structured and allows us to easily disable
preemption only in bpf_get_stackid in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-5-jolsa@kernel.org
The new stackid_fastpath does the fast stack hash and trace check, that
does not need new bucket allocation. It covers both just-ip and buildid
code paths.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-3-jolsa@kernel.org
The new stackid_init function stores all the necessary bits for stackid
trace and it will be used by other functions in following changes.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260803210149.296496-2-jolsa@kernel.org
dma_req_free() acquires buf_mutex through req->map, drops the mapping
reference with kref_put(), and then dereferences req->map again to unlock
the mutex.
If kref_put() drops the last reference, mport_release_mapping() frees the
mapping, and the subsequent mutex_unlock() dereferences a freed object.
This is a use-after-free.
Fix this by caching map and md before kref_put(), clearing req->map while
holding buf_mutex, and using the cached md for mutex unlocking.
The bug is reachable from userspace via the RapidIO mport character device
interface.
Link: https://lore.kernel.org/20260723235220.588424-1-james010kim@gmail.com
Fixes: e8de370188 ("rapidio: add mport char device driver")
Signed-off-by: James Kim <james010kim@gmail.com>
Reviewed-by: Dan Carpenter <error27@gmail.com>
Cc: Alexandre Bounine <alex.bou9@gmail.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Heartbeat regions publish struct o2hb_region as the private data for the
NEGO_TIMEOUT and NEGO_APPROVE o2net handlers as soon as make_item()
creates the configfs region. The approve handler can call
o2hb_arm_timeout(), so a peer can touch the region timeout work before
dev_store() has finished building the heartbeat runtime, or after teardown
has started to shut that runtime back down.
The final configfs put also has to keep reg alive until the last in-flight
o2net callback drops its handler reference.
o2net_unregister_handler_list() blocks future handler lookups, but it does
not wait for sc_rx_work that already passed o2net_handler_get(). That
drain needs to cover local listener teardown as well, where the o2net
ordered workqueue may already be inside destroy_workqueue().
Fix the lifetime rule in both directions. Initialize the region delayed
works before publishing reg through the o2net handler table, keep new or
stopping regions non-armable with hr_stopping, and quiesce both delayed
works on failed-start and teardown paths even when no heartbeat thread is
left to call o2hb_disarm_timeout(). Then unregister handlers before
tearing down handler-visible region state and make the drain wait for the
active or destroying o2net ordered workqueue before release frees reg.
The buggy scenario involves two paths, with each column showing the order
within that path:
region lifecycle: late negotiate callback:
1. make_item() registers the 1. o2net_process_message() gets a
region handlers before heartbeat handler for reg.
dev_store() has built a 2. The callback runs after the lookup
runnable heartbeat context. lock is dropped and dereferences reg.
2. A failed start or rmdir 3. An approve or timeout path tries to
stops the heartbeat thread, queue reg's delayed work, or release
quiesces existing work, and races the callback body after handler
drops the final configfs ref. unregister.
3. region_release() must drain 4. The callback or delayed work can
handler-visible o2net rx work outlive reg unless lifecycle code
before freeing reg. keeps the region non-armable and
drains the active-or-destroying
o2net workqueue.
Validation reproduced this kernel report:
KASAN slab-use-after-free in __run_timers+0x22c/0x5b0
Write of size 8
Call trace:
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
__run_timers+0x22c/0x5b0
kasan_report+0xe0/0x110
_raw_spin_unlock_irqrestore+0x27/0x60
try_to_wake_up+0x191/0xf70
timer_expire_remote+0xae/0xf0
run_timer_softirq+0x19b/0x1a0
handle_softirqs+0x156/0x660
__irq_exit_rcu+0xc4/0x160
irq_exit_rcu+0xe/0x20
sysvec_apic_timer_interrupt+0x6c/0x80
asm_sysvec_apic_timer_interrupt+0x1a/0x20
Allocated by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
o2hb_heartbeat_group_make_item+0x3c/0x600
Link: https://lore.kernel.org/20260624095310.763763-3-zzzccc427@gmail.com
Fixes: 34069b886f ("ocfs2: o2hb: add NEGO_TIMEOUT message")
Fixes: e76f8237a2 ("ocfs2: o2hb: add NEGOTIATE_APPROVE message")
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
Assisted-by: Codex:gpt-5.5
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "ocfs2: harden heartbeat teardown races".
This series fixes two OCFS2 heartbeat/o2net teardown races found by
KASAN.
This patch (of 2):
Heartbeat callbacks stay registered while configfs local-node teardown
enters o2net_stop_listening(). A node-down event can still run through
o2net_disconnect_node() and o2net_set_nn_state() while teardown is
destroying o2net_wq, so the later queue/flush operations can hit a dead
workqueue. KASAN has caught this as a slab-use-after-free in
__queue_work() with the call chain:
KASAN slab-use-after-free in __queue_work+0x56/0xa90
Read of size 4
Call trace:
dump_stack_lvl+0x66/0xa0
print_report+0xce/0x630
__queue_work+0x56/0xa90
srso_alias_return_thunk+0x5/0xfbef5
__virt_addr_valid+0x19f/0x330
kasan_report+0xe0/0x110
__queue_delayed_work+0x58/0x1e0
queue_delayed_work_on+0xb4/0xc0
o2net_set_nn_state+0x467/0x840
o2net_disconnect_node+0x7b/0xe0
o2net_hb_node_down_cb+0x54/0x60
o2hb_run_event_list+0x236/0x2d0
o2hb_check_slot+0xad4/0xbc0
lock_release+0xc8/0x290
o2hb_check_slot+0x9ea/0xbc0
trace_hardirqs_on+0x18/0x130
o2hb_do_disk_heartbeat+0x646/0xb30 (fs/ocfs2/cluster/heartbeat.c:1079)
__lock_acquire+0x466/0x2260
lockdep_hardirqs_on_prepare+0xea/0x1a0
ktime_get_with_offset+0xe9/0x230
o2hb_thread+0x14e/0x770
kthread+0x1ad/0x1f0
ret_from_fork+0x3c9/0x540
__switch_to+0x2e9/0x730
ret_from_fork_asm+0x1a/0x30
Allocated by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
__kasan_kmalloc+0xaa/0xb0
__kmalloc_noprof+0x292/0x760
__alloc_workqueue+0x736/0xc60
alloc_workqueue_noprof+0xb1/0x110
o2net_start_listening+0xe5/0x430
o2nm_node_local_store+0x184/0x310
configfs_write_iter+0x18a/0x210
vfs_write+0x469/0x810
ksys_write+0xd2/0x170
do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task stack:
kasan_save_stack+0x33/0x60
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x5f/0x80
kfree+0x313/0x590
rcu_core+0x4f4/0x1320
handle_softirqs+0x156/0x660
queue_delayed_work_on
o2net_set_nn_state
o2net_disconnect_node
o2net_hb_node_down_cb
o2hb_run_event_list
Keep heartbeat callbacks registered so quorum state still tracks node
state, but stop them from driving o2net reconnect/disconnect work once
local teardown starts. Mark the transport offline before destroying
o2net_wq, wait for any in-flight heartbeat callback to finish, and delay
bring-up replay until the new local node is published through
o2nm_this_node().
The replay also has to stay serialized with heartbeat callback delivery.
Otherwise a live-node snapshot can be copied, a real hb_down callback
can install -ENOTCONN for a peer, and the stale replay can call
o2net_hb_node_up() for that same peer and queue reconnect work even
though heartbeat is already down.
The buggy scenario involves two paths, with each column showing the order
within that path:
local-node teardown: heartbeat node-down callback:
1. configfs local-off enters 1. o2hb_run_event_list() invokes
o2net_stop_listening(). o2net_hb_node_down_cb().
2. teardown heads for 2. the callback reaches
destroy_workqueue(o2net_wq). o2net_disconnect_node() and
o2net_set_nn_state().
3. teardown destroys and NULLs 3. the callback flushes or queues
o2net_wq. work through o2net_wq.
Link: https://lore.kernel.org/20260624095310.763763-1-zzzccc427@gmail.com
Link: https://lore.kernel.org/20260624095310.763763-2-zzzccc427@gmail.com
Fixes: 98211489d4 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Signed-off-by: Cen Zhang <zzzccc427@gmail.com>
Assisted-by: Codex:gpt-5.5
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
alloc_skb() with the __GFP_NOFAIL flag will never return NULL, so the
subsequent NULL checks and error handling are unreachable dead code.
Remove them.
Link: https://lore.kernel.org/20260724022851.466017-7-gouhao@uniontech.com
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Cc: Bharat Potnuri <bharat@chelsio.com>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: jiazhenyuan <jiazhenyuan@uniontech.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Wentao Guan <guanwentao@uniontech.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kvcalloc with the __GFP_NOFAIL flag will never return NULL, so the
subsequent NULL checks are unreachable dead code. Remove them.
Link: https://lore.kernel.org/20260724022851.466017-6-gouhao@uniontech.com
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Bharat Potnuri <bharat@chelsio.com>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: jiazhenyuan <jiazhenyuan@uniontech.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Wentao Guan <guanwentao@uniontech.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
kzalloc_obj with the __GFP_NOFAIL flag will never return NULL, so the
subsequent WARN_ON(!ctx) is unreachable dead code. Remove it.
Link: https://lore.kernel.org/20260724022851.466017-5-gouhao@uniontech.com
Signed-off-by: Gou Hao <gouhao@uniontech.com>
Cc: Bharat Potnuri <bharat@chelsio.com>
Cc: Cédric Le Goater <clg@kaod.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: jiazhenyuan <jiazhenyuan@uniontech.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nam Cao <namcao@linutronix.de>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Nilay Shroff <nilay@linux.ibm.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Wentao Guan <guanwentao@uniontech.com>
Cc: Alistair Popple <apopple@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
syzbot is reporting KCOV state corruption on PREEMPT_RT kernels, for the
temporary storage used for saving/restoring remote KCOV state is currently
allocated as the per-CPU area.
On PREEMPT_RT kernels, softirq handlers run as preemptible task threads
(e.g., ksoftirqd). If a softirq context preempts a task running a remote
KCOV session, it safely saves the task's state into the per-CPU area.
However, if that softirq thread is subsequently preempted by a higher-
priority softirq thread on the same CPU, the second softirq will overwrite
the same per-CPU area, permanently destroying the original task's KCOV
state.
Fix this data corruption by moving the temporary storage from the per-CPU
area to the per-thread area. Since each softirq thread now owns its own
task context, nested softirq preemption no longer causes data overwrites.
Note that while the temporary storage is now on a per-thread basis, the
per-CPU kcov_percpu_data.lock must be retained, for we need to ensure that
kcov_remote_start() and kcov_remote_stop() operate atomically without
racing against asynchronous interrupts that manipulate the current task's
KCOV state.
It is likely that GFP_KERNEL allocation by vmalloc_node() in kcov_init()
has already called panic() before returning NULL, for there will be no
OOM-killable userspace processes when __init function of built-in module
runs. But this patch also fixes crashing the kernel when vmalloc_node()
in kcov_init() returned NULL, for kcov_init() left per-CPU irq_area == NULL
but kcov_remote_start() depends on per-CPU irq_area != NULL, resulting in
(1) doing vmalloc() in kcov_remote_start() despite !in_task() context
(2) out-of-array-bounds access if (1) succeeded but
kcov->remote_size < CONFIG_KCOV_IRQ_AREA_SIZE
(3) always leak memory allocated by (1), eventually killing all
OOM-killable userspace processes
problems.
Link: https://lore.kernel.org/43552d09-2ce2-4b19-b0d3-a2d1ab952145@I-love.SAKURA.ne.jp
Reported-by: syzbot+3f51ad7ac3ae57a6fdcc@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=3f51ad7ac3ae57a6fdcc
Reported-by: syzbot+47cf95ca1f9dcca872c8@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=47cf95ca1f9dcca872c8
Reported-by: syzbot+8a173e13208949931dc7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=8a173e13208949931dc7
Reported-by: syzbot+90984d3713722683112e@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=90984d3713722683112e
Analyzed-by: AI Mode in Google Search (no mail address)
Fixes: 5ff3b30ab5 ("kcov: collect coverage from interrupts")
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Alexander Potapenko <glider@google.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Clark Williams <williams@redhat.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Marco Elver <elver@google.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
[BUG]
lsetxattr() panics the kernel when setting a large xattr value on a
fragmented filesystem where the file already has an external xattr
block.
[CAUSE]
ocfs2_calc_xattr_set_need() never reserves metadata blocks for a new
xattr value's extent tree when the file already has an external xattr
block. The not_found path leaves meta_add at zero, so meta_ac is NULL
when ocfs2_xattr_extend_allocation() runs.
A new value root has room for a single extent record. On a fragmented
filesystem, the allocator cannot satisfy the xattr value in one
contiguous run, so each non-contiguous run requires its own extent
record. When the value root's extent list is full and meta_ac is NULL,
ocfs2_add_clusters_in_btree() returns RESTART_META, and
ocfs2_xattr_extend_allocation() hits BUG_ON(why == RESTART_META).
[FIX]
The case where no xattr block exists yet already calls
ocfs2_extend_meta_needed(&def_xv.xv.xr_list) to reserve value tree
metadata. Add the same reservation to the case where an xattr block
already exists, making the two cases consistent.
Replace the BUG_ON with a -ENOSPC return so that if RESTART_META is
returned despite the reservation, the error propagates to userspace
instead of panicking the kernel.
Link: https://lore.kernel.org/amLwn3i9tET8yhG7@dev
Fixes: a78f9f4668 ("ocfs2: make xattr extension work with new local alloc reservation.")
Signed-off-by: Ian Bridges <icb@fastmail.org>
Reported-by: syzbot+e538032956b1157914a3@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=e538032956b1157914a3
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- use the "typedef" keyword when describing a typedef
- add a Returns: section
to prevent these kernel-doc warnings:
Warning: include/linux/stacktrace.h:20 function parameter
'stack_trace_consume_fn' not described in 'bool'
Warning: include/linux/stacktrace.h:20 expecting prototype for
stack_trace_consume_fn(). Prototype was for bool() instead
Warning: include/linux/stacktrace.h:58 No description found for
return value of 'arch_stack_walk_reliable'
Link: https://lore.kernel.org/20260723161831.138237-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Correct the function parameter name to avoid kernel-doc warnings:
Warning: ./include/linux/llist.h:71 function parameter 'list' not described in 'init_llist_head'
Warning: ./include/linux/llist.h:71 Excess function parameter 'head' description in 'init_llist_head'
Link: https://lore.kernel.org/20260723165113.225098-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
parse() hands nla_strscpy() len as dstsize, and nla_strscpy() copies at
most dstsize - 1 bytes. When the attr payload comes in without a trailing
NUL, srclen == len >= dstsize and the last character of the cpumask string
gets cut off. Register "0-15" and you are silently listening on "0-1",
exit data for the rest never shows up.
The bug only bites when the sender doesn't NUL terminate the payload;
senders that include the NUL were always fine (srclen gets decremented for
the trailing NUL, so srclen < dstsize). Thats probably why this survived
20 years. And the policy is NLA_STRING, not NLA_NUL_STRING, so a payload
without the trailing NUL is legit input here.
Skip the kmalloc/nla_strscpy dance entirely and use nla_strdup(), which
already allocates srclen + 1 and terminates. The nla_len() bounds checks
stay as they were.
Link: https://lore.kernel.org/EC49FE41-7F5F-41E0-A07A-ABEB8ECA514D@grrlz.net
Fixes: f9fd8914c1 ("[PATCH] per-task delay accounting taskstats interface: control exit data through cpumasks")
Signed-off-by: Bradley Morgan <include@grrlz.net>
Reported-by: Oleg Deomi <oleg.deomi@gmail.com>
Closes: https://lore.kernel.org/CAByWkfZ6b1=3H9pwkz-dDQOs9cZaF-HYQ6b9Yb0=Hq2r1Vv_Pw@mail.gmail.com
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Balbir Singh <bsingharora@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
checkpatch.pl reports a total of 18 incorrect use of spaces instead of
tabulations in lib/ucs2_string.c.
Apply
./scripts/checkpatch.pl --fix-inplace lib/ucs2_string.c
to fix them all.
Link: https://lore.kernel.org/20260723-fix-ucs2_strnlen-v2-2-9ea94e32a358@kernel.org
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "lib/ucs2_string.c: fix out-of-bounds read in
ucs2_strnlen()", v2.
This series fixes an off-by-one out-of-bounds read in ucs2_strnlen().
The first patch is the real fix, the second patch comes as a bonus and
fixes the code indentation.
This patch (of 2):
ucs2_strnlen() checks the current character before checking whether the
caller-provided maximum length has been reached. If the input is not
NUL-terminated within that bound, the loop can read one ucs2_char_t past
the limit.
Test the length before dereferencing to prevent an off-by-one
out-of-bounds read.
Link: https://lore.kernel.org/20260723-fix-ucs2_strnlen-v2-0-9ea94e32a358@kernel.org
Link: https://lore.kernel.org/20260723-fix-ucs2_strnlen-v2-1-9ea94e32a358@kernel.org
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Vincent Mailhol <mailhol@kernel.org>
Cc: Kees Cook <kees@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Use the correct function parameter name in rb_next_match(). Use the
struct keyword when describing struct latch_tree_ops.
Prevents the following kernel-doc warnings:
Warning: ./include/linux/rbtree.h:510 function parameter 'node' not
described in 'rb_next_match'
Warning: ./include/linux/rbtree.h:510 Excess function parameter 'tree'
description in 'rb_next_match'
Warning: ./include/linux/rbtree_latch.h:63 cannot understand function
prototype: 'struct latch_tree_ops'
Link: https://lore.kernel.org/20260722050759.3892887-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: "Peter Zijlstra (Intel)" <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
In o2hb_region_inc_user(), o2hb_dependent_users is incremented
unconditionally before calling o2hb_region_pin(). If the pin fails, the
counter is never decremented and any partially-pinned regions are never
unpinned, since the caller does not call o2hb_region_dec_user() on error.
The leaked counter causes subsequent o2hb_region_inc_user() calls to skip
pinning entirely (the > 1 check), leaving heartbeat regions unprotected.
Fix by rolling back on failure: call o2hb_region_unpin(NULL) to release
any partially-pinned regions and decrement o2hb_dependent_users to restore
the pre-increment state.
Link: https://lore.kernel.org/20260722124933.430554-4-joseph.qi@linux.alibaba.com
Fixes: 58a3158a5d ("ocfs2/cluster: Pin/unpin o2hb regions")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
o2hb_heartbeat_group_drop_item() is called from configfs rmdir with the
parent directory's inode_lock held. It calls o2hb_region_pin() ->
o2nm_depend_item() -> configfs_depend_item(), which acquires the configfs
root inode_lock. This creates a parent -> root inode_lock nesting that
could deadlock against paths taking root -> parent (e.g. subsystem
unregistration).
Fix this by using configfs_depend_item_unlocked() when o2hb_region_pin()
is called from a configfs callback context. This variant skips the root
inode_lock when caller and target are in the same subsystem, which is safe
because VFS already holds a lock preventing unregistration.
Add o2nm_depend_item_unlocked() wrapper and a from_callback parameter to
o2hb_region_pin() to select the appropriate variant.
Link: https://lore.kernel.org/20260722124933.430554-3-joseph.qi@linux.alibaba.com
Fixes: 58a3158a5d ("ocfs2/cluster: Pin/unpin o2hb regions")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "ocfs2: cluster: o2hb_region_pin() fixes", v2.
This series fixes three related issues in o2hb_region_pin(), all are from
the original implementation in commit: 58a3158a5d ("ocfs2/cluster:
Pin/unpin o2hb regions"):
1) It is called with o2hb_live_lock (a spinlock) held, but the
underlying configfs_depend_item() sleeps (takes inode rwsem and
pins the filesystem). This triggers BUG under
CONFIG_DEBUG_ATOMIC_SLEEP.
2) When called from the configfs drop_item callback, it creates a
lock order inversion: parent inode_lock -> configfs root
inode_lock, which can deadlock against subsystem unregistration
paths taking root -> parent.
3) If pinning fails partway through o2hb_region_inc_user(), the
o2hb_dependent_users counter is leaked and partially-pinned
regions are never released, leaving heartbeat regions
unprotected on subsequent mounts.
Patch 1 reworks o2hb_region_pin() to drop o2hb_live_lock across each
sleeping configfs_depend_item() call, using a config_item reference to
keep the region alive while unlocked.
Patch 2 adds a from_callback parameter to select
configfs_depend_item_unlocked() when called from configfs context,
avoiding the inode_lock nesting.
Patch 3 fixes the error path in o2hb_region_inc_user() to unpin and
decrement the counter on failure.
This patch (of 3):
o2hb_region_pin() is always called with the o2hb_live_lock spinlock held
(from o2hb_region_inc_user() and o2hb_heartbeat_group_drop_item()), but it
calls o2nm_depend_item() -> configfs_depend_item(), which sleeps: it pins
the configfs filesystem and takes the configfs root inode rwsem. Under
CONFIG_DEBUG_ATOMIC_SLEEP this triggers:
BUG: sleeping function called from invalid context at kernel/locking/rwsem.c
in_atomic(): 1, ... name: mount.ocfs2
down_write
configfs_depend_item
o2hb_region_pin
o2hb_region_inc_user
o2hb_register_callback
dlm_register_domain_handlers
...
ocfs2_dlm_init
ocfs2_mount_volume
ocfs2_fill_super
Rework o2hb_region_pin() to pin one region at a time with the lock dropped
across the sleeping call: under o2hb_live_lock find the next eligible
region and take a config_item reference to keep it alive, drop the lock,
call o2nm_depend_item(), then retake the lock and record the pin. The
config_item_put() is done with the lock released as well, since
o2hb_region_release() also acquires o2hb_live_lock and can sleep. The
region list may change while unlocked, so the scan restarts from the top
after each pin. Local heartbeat still pins only the matching region;
global heartbeat pins all eligible regions.
The unpin path is unaffected: configfs_undepend_item() only takes a
spinlock and does not sleep.
Link: https://lore.kernel.org/20260722124933.430554-1-joseph.qi@linux.alibaba.com
Link: https://lore.kernel.org/20260722124933.430554-2-joseph.qi@linux.alibaba.com
Fixes: 58a3158a5d ("ocfs2/cluster: Pin/unpin o2hb regions")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
symbol__disassemble_bpf_libbfd() has four resource management bugs:
1. free(prog_linfo) leaks internal arrays. bpf_prog_linfo contains
raw_linfo, raw_jited_linfo, nr_jited_linfo_per_func, and
jited_linfo_func_idx pointers that are only freed by the proper
destructor bpf_prog_linfo__free().
2. open_memstream(&buf, &buf_size) allocates a dynamic buffer that the
caller must free after fclose(). The function calls fclose(s) but
never free(buf), leaking the stream buffer on every call.
3. args->line = strdup(srcline) is immediately consumed by
disasm_line__new(args) which internally calls strdup(args->line)
again via annotation_line__init(). The first strdup result is then
overwritten by args->line = buf + prev_buf_size without being freed.
4. If open_memstream() fails, the error path jumps to 'out:' which
calls fclose(s) with s == NULL — undefined behavior.
Fix by using bpf_prog_linfo__free(), initializing buf to NULL, adding
free(buf) after fclose(s), guarding fclose() against NULL, and removing
the redundant strdup since annotation_line__init() makes its own copy.
Fixes: 6987561c9e ("perf annotate: Enable annotation of BPF programs")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
synthesize_bpf_prog_name() unconditionally dereferences prog_tags[sub_id]
(line: u8 (*prog_tags)[BPF_TAG_SIZE] = (void *)(uintptr_t)(info->prog_tags))
but __bpf_event__print_bpf_prog_info() only requires JITED_KSYMS and
JITED_FUNC_LENS in its required_arrays bitmask.
If a crafted perf.data has the PROG_TAGS bit cleared (or the array was
invalidated by bpil_offs_to_addr() bounds checking), info->prog_tags
contains either zero or a raw file offset. Dereferencing it causes a
NULL pointer dereference or an arbitrary memory read.
Add PERF_BPIL_PROG_TAGS to required_arrays so the function returns early
when prog_tags was not present or failed validation.
Fixes: f8dfeae009 ("perf bpf: Show more BPF program info in print_bpf_prog_info()")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
write_bpf_prog_info() holds a read lock while temporarily mutating
info_linear via bpil_addr_to_offs()/bpil_offs_to_addr(). Between these
two calls, the pointers in info_linear contain file offsets instead of
heap addresses. Concurrent readers holding the same read lock see the
file offsets and dereference them as pointers.
Use down_write()/up_write() instead of down_read()/up_read() to exclude
concurrent readers during the addr-to-offset-to-addr translation window.
Fixes: 63ac7968a1fb ("perf bpf: Save bpf_prog_info information as headers to perf.data")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
symbol__disassemble_bpf_libbfd() casts info_linear->info.jited_prog_insns
and info_linear->info.jited_ksyms to pointers without checking whether
bpil_offs_to_addr() actually converted the file offsets. A crafted
perf.data with PERF_BPIL_* bits unset but non-zero counts causes raw
file offsets to be dereferenced as pointers.
Add bitmask checks for PERF_BPIL_JITED_INSNS and PERF_BPIL_JITED_KSYMS
before the casts, matching the validation added to bpf-event.c call
sites.
Fixes: 6987561c9e ("perf annotate: Enable annotation of BPF programs")
Reported-by: sashiko-bot <sashiko-bot@kernel.org>
Cc: Song Liu <songliubraving@fb.com>
Reviewed-by: Ian Rogers <irogers@google.com>
Assisted-by: Claude:claude-opus-4.6
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Currently, when a probe event is added using perf probe --add with a
hexadecimal type cast (e.g., var:x64 and var:x32), the kernel traceprobe
subsystem sets the field type to "u64" in the event's format file, yet
generates a print format specifier of "var=0x%Lx" or "0x%x".
By default, perf trace uses its internal beautifiers which only inspect
field->type and field->flags. Because traceprobe events declare
primitive integer field types ("u64") without a C pointer asterisk
(i.e., "*"), perf trace defaults to printing the field's value as a
decimal unsigned long ("%ld"), ignoring the hexadecimal intent.
Introduce field_has_hex_fmt() to inspect the tracepoint's print_fmt
format string. If a field's print format assignment uses hexadecimal
specifiers (i.e., "=0x", "=%#", or "=%p"), assign SCA_PTR formatting so
perf trace displays the value in hexadecimal by default without
requiring --libtraceevent. For example:
❯ sudo ./perf probe --add 'enqueue_task_fair rq=rq:x64 p=p:x64 flags=flags:x32'
Added new event:
probe:enqueue_task_fair (on enqueue_task_fair with rq=rq:x64 p=p:x64 flags=flags:x32)
You can now use it in all perf tools, such as:
perf record -e probe:enqueue_task_fair -aR sleep 1
❯ sudo ./perf trace --show-cpu --event probe:enqueue_task_fair --max-event 3
0.000 [000] :0/0 probe:enqueue_task_fair(rq: 0xffff8ac632233180, p: 0xffff8ac2c1240000, flags: 0x100009)
0.006 [004] :0/0 probe:enqueue_task_fair(rq: 0xffff8ac632433180, p: 0xffff8ac624cf8000, flags: 0x9)
0.069 [001] :0/0 probe:enqueue_task_fair(rq: 0xffff8ac6322b3180, p: 0xffff8ac4c4212c40, flags: 0x9)
Signed-off-by: Aaron Tomlin <atomlin@atomlin.com>
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Puranjay Mohan says:
====================
bpf: Inline the numeric open-coded iterator kfuncs
The bpf_for(i, start, end) macro is BPF's open-coded numeric iterator. It
expands into calls to three kfuncs: bpf_iter_num_new() to set the iterator
up, bpf_iter_num_next() once per iteration, and bpf_iter_num_destroy() to
tear it down. The verifier emits these as ordinary kfunc calls, so a
bpf_for() loop pays function-call overhead on setup, teardown, and -- most
importantly -- on every single iteration via bpf_iter_num_next().
All three kfuncs are tiny and only touch the 8-byte on-stack iterator state
(struct bpf_iter_num_kern { int cur; int end; }). That makes them good
candidates for inlining, the same way several other special kfuncs are
already open-coded in bpf_fixup_kfunc_call(). This series replaces each of
the three calls with an equivalent inline BPF instruction sequence:
- bpf_iter_num_new(): the end - start range check is done with 32-bit
arithmetic (start <= end is checked first, so the distance fits in a
u32) and range-checked against BPF_MAX_LOOPS as unsigned. This avoids
the cpuv4 sign-extension insns that some JITs do not implement. Returns
the same -EINVAL / -E2BIG / 0 as the kfunc.
- bpf_iter_num_next(): the hot path. cur and end are int, so the kfunc's
s->cur + 1 >= s->end test is an ordinary signed 32-bit compare and the
inlined code needs no sign extension.
- bpf_iter_num_destroy(): the stack slot is no longer tracked as iterator
state once destroy() returns, so nothing needs to be written to it.
Both the kfunc and the inlined form become a no-op, which just drops the
call.
The emitted instructions are plain BPF and remain valid for the
interpreter, so interpreter fallback stays correct and no jit_required
marking is needed.
Benchmark (./bench -p 1 --nr_loops 1000000 {bpf-loop,bpf-for}):
+--------+---------------------+---------------------+---------------------+
| arch | bpf_loop | bpf_for non-inlined | bpf_for inlined |
+--------+---------------------+---------------------+---------------------+
| x86-64 | 4252 M/s (0.24 ns) | 3608 M/s (0.28 ns) | 7417 M/s (0.13 ns) |
+--------+---------------------+---------------------+---------------------+
| arm64 | 649 M/s (1.54 ns) | 548 M/s (1.82 ns) | 546 M/s (1.83 ns) |
+--------+---------------------+---------------------+---------------------+
On x86-64 removing the per-iteration call roughly doubles bpf_for()
throughput. On arm64 it is neutral, and rather than guess why this was
checked with perf: inlining removes ~28% of the executed instructions (the
call) but leaves the cycle count unchanged -- IPC drops from ~4.2 to ~3.0
and backend stalls rise from ~50% to ~66%. The loop is bound by the latency
of the iterator's on-stack counter, not by call overhead:
bpf_iter_num_next() loads s->cur from the stack, increments it and stores it
back each iteration, and the next iteration's load depends on that store.
The removed call instructions were executing in the shadow of that
store->load stall and were never on the critical path.
A small userspace microbenchmark isolates the effect: a same-address
store->load->add round-trip (the shape of the on-stack counter) costs
~6 cycles/iteration on the tested arm64 core but ~1 cycle on x86-64, where
the core collapses the same-address round-trip into a register move (memory
renaming / store-to-load-forwarding elimination). So on x86-64 the loop is
not latency-bound and the per-iteration call dominates -- removing it is the
~2x win -- whereas on arm64 the call fits entirely inside the store->load
stall the loop already has, so adding or removing it changes nothing.
bpf_loop() is shown for reference only; it is a different construct (a
callback invoked per iteration) and this series does not change it. Its
counter lives in a register rather than on the stack, so on arm64 it avoids
the store->load latency above and is faster than bpf_for() there.
Changelog:
v4: https://lore.kernel.org/all/20260729203633.213973-1-puranjay@kernel.org/
Changes in v5:
- Inline the new()/next()/destroy() sequences directly in
bpf_fixup_kfunc_call() instead of via helper functions (Andrii Nakryiko)
- Trim the code comments; keep the explanation in the bpf_iter.c kfuncs and
leave only brief comments at the inline sites, and shorten the
bpf_iter_num_destroy() kfunc to /* no-op */ (Andrii Nakryiko)
- Reword the patch 1 comment so it no longer forward-references the inlined
bpf_iter_num_next(), which is only added later in the series (bpf-ci)
- Switch the bpf_iter_num_next() comment to the networking multi-line style
v3: https://lore.kernel.org/all/20260722132424.450230-1-puranjay@kernel.org/
Changes in v4:
- Drop the "elide range checks for constant bounds" patch (Andrii Nakryiko)
- bpf_iter_num_new(): range-check the distance against BPF_MAX_LOOPS with an
unsigned compare (Andrii Nakryiko)
- bpf_iter_num_destroy(): make it a no-op in both the kfunc and the inlined
form instead of zeroing the iterator state (Andrii Nakryiko)
- New patch: fix the misleading overflow comment in bpf_iter_num_next() and
drop the redundant (s64) cast; the int wraparound is intentional and
load-bearing (Andrii Nakryiko)
- bpf_for benchmark: nr_loops is int, matching what bpf_for() expects
(Andrii Nakryiko)
- Corroborate the arm64/x86 benchmark difference with perf counters and a
store-to-load-forwarding microbenchmark (Kumar Kartikeya Dwivedi,
Andrii Nakryiko)
v2: https://lore.kernel.org/bpf/20260717120215.2171057-1-puranjay@kernel.org/
Changes in v3:
- Elide the range checks in bpf_iter_num_new() when start and end are
constant, marking the registers precise so paths reaching the call with
different constants are not pruned (Eduard Zingerman)
- Add __xlated selftests pinning the inlined new()/next()/destroy() shapes
(Eduard Zingerman)
- Use the insn_buf[i++] idiom in the inline helpers (Eduard Zingerman)
- Pick up Acked-by on patch 3
v1: https://lore.kernel.org/all/20260715130430.318421-1-puranjay@kernel.org/
Changes in v2:
- Don't emit sign-extending (movsx) moves; some JITs (e.g. x86-32, mips32,
sparc64) decode them as a plain move and would miscompile the range check
====================
Link: https://patch.msgid.link/20260804134601.2305303-1-puranjay@kernel.org
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Add a bpf_for() benchmark modelled on bench_bpf_loop so the per-iteration
iterator cost can be measured and compared against bpf_loop. It runs an
empty bpf_for(i, 0, nr_loops) loop 1000 times per trigger and accounts
nr_loops hits per outer iteration:
$ ./bench -p 1 --nr_loops 1000 bpf-for
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260804134601.2305303-7-puranjay@kernel.org
Add an __xlated test pinning the inlined bpf_iter_num_{new,next,destroy}()
shapes. The program is __naked, so there is no compiler glue and the whole
sequence is matched instruction for instruction.
Gate it to x86_64 and arm64 (bpf_jit_needs_zext() == false); elsewhere the
verifier interleaves "wN = wN" zero-extensions that would not match. The
inlining is arch independent, so these two are enough.
Suggested-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260804134601.2305303-6-puranjay@kernel.org
Once destroy() returns the stack slot is no longer tracked as iterator
state, so zeroing it is dead work. Make the kfunc a no-op and inline the
call to a single BPF_JA 0 (the fixup can't drop the instruction outright,
so emit a nop; the JITs elide it).
Suggested-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260804134601.2305303-5-puranjay@kernel.org
bpf_iter_num_next() runs on every bpf_for() iteration, so inlining it
drops a call from the loop body. R1 points to the iterator; the returned
pointer to s->cur is R1 itself, since s->cur is first.
s->cur and s->end are int, so the kfunc's s->cur + 1 >= s->end is a
signed 32-bit compare and the inlined code needs no sign extension.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260804134601.2305303-4-puranjay@kernel.org
bpf_for() expands to the bpf_iter_num_{new,next,destroy}() kfuncs, which
the verifier emits as regular calls. They are tiny and only touch the
8-byte on-stack iterator state, so open-code them in bpf_fixup_kfunc_call()
like the other special kfuncs there.
Start with bpf_iter_num_new(): R1 points to the iterator, R2/R3 hold
start/end. The inlined sequence mirrors the kfunc and returns the same
-EINVAL / -E2BIG / 0.
start > end is rejected first, so end - start fits in a u32; range-check
it as u32 on both sides ((u32)(end - start) in the kfunc). A movsx-based
check would emit a cpuv4 instruction that some JITs (x86-32, mips32,
sparc64) decode as a plain move and get wrong.
The emitted instructions are plain BPF, so the interpreter path stays
correct and no jit_required marking is needed.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260804134601.2305303-3-puranjay@kernel.org
The comment on the s->cur + 1 >= s->end check claims the (s64) cast is
needed to avoid overflow when s->cur == s->end == INT_MAX. It isn't:
s->cur + 1 is computed in int and wraps before the cast, so the cast
changes nothing (INT_MAX + 1 compares the same either way).
The wraparound is the point. bpf_iter_num_new() sets s->cur = start - 1,
which wraps to INT_MAX for start == INT_MIN, and the wrapping s->cur + 1
brings it back to start. (s64)s->cur + 1 would instead break iterators
starting at INT_MIN.
Drop the cast and reword the comment. No functional change; the wrap is
well-defined under -fno-strict-overflow.
Signed-off-by: Puranjay Mohan <puranjay@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20260804134601.2305303-2-puranjay@kernel.org
The Acer Nitro AN515-46 is a hybrid graphics laptop whose internal
panel is driven by the AMD GPU (Radeon 680M); the discrete NVIDIA GPU
only drives external outputs. The firmware nevertheless advertises the
NVIDIA WMI EC backlight GUID, so the backlight type resolves to
nvidia_wmi_ec. The nvidia-wmi-ec-backlight driver however fails to
probe ("EC backlight control failed: AE_NOT_FOUND") and, since the
backlight type is still nvidia_wmi_ec, amdgpu skips registering its
own backlight device. The result is no backlight device at all,
leaving the brightness keys and the desktop brightness slider
non-functional.
Booting with acpi_backlight=native makes amdgpu register its backlight
interface and brightness control works. Add a DMI quirk to use the
native backlight on this model by default.
Signed-off-by: Marcos Paulo Medeiros <maarcospm1996@gmail.com>
Link: https://patch.msgid.link/20260727132151.12792-1-maarcospm1996@gmail.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Previously, rmi_f54_buffer_queue() waited for the worker thread to
finish but ignored whether it succeeded. If the worker failed (e.g.,
due to a timeout or register read failure), the queue thread would
silently return success, delivering stale or uninitialized memory to
userspace.
Add a 'report_error' field to struct f54_data to store the worker's exit
status. Check this field in rmi_f54_buffer_queue() after the worker
finishes, and mark the buffer as VB2_BUF_STATE_ERROR if an error
occurred.
Fixes: 3a762dbd53 ("[media] Input: synaptics-rmi4 - add support for F54 diagnostics")
Reported-by: sashiko-bot@kernel.org
Cc: stable@vger.kernel.org
Assisted-by: Antigravity:gemini-3.5-flash
Link: https://patch.msgid.link/20260626051802.4033172-6-dmitry.torokhov@gmail.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Add myself as a reviewer for overall KVM, as I have been helping shepherd
a decent chunk of the virt/kvm commits into the kernel over the last few
years, and I expect to continue doing so. Of the 270 non-merge commits
that have been made to virt/kvm since v6.6, I have committed 127 (~47%)
and Paolo has committed 117 (~43.3%), with all but 5 of the remaining 26
coming from non-KVM folks, e.g. from treewide changes.
Note, this intended to purely be an efficiency and quality of life
improvement, for both contributors and myself. There is no implied right
of succession or anything of the sort.
Cc: Marc Zyngier <maz@kernel.org>
Cc: Oliver Upton <oupton@kernel.org>
Cc: Tianrui Zhao <zhaotianrui@loongson.cn>
Cc: Bibo Mao <maobibo@loongson.cn>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Anup Patel <anup@brainfault.org>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Acked-by: Janosch Frank <frankja@linux.ibm.com>
Acked-by: Anup Patel <anup@brainfault.org>
Acked-by: Bibo Mao <maobibo@loongson.cn>
Acked-by: Paolo Bonzini <pbonzini@redhat.com>
Link: https://patch.msgid.link/20260731173842.2649391-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Officially "reward" David with guest_memfd responsibilities and authority,
as he's been instrumental in pushing guest_memfd forward, and his ongoing
input and feedback, especially from an mm/ perspective, is and will be
critical to keeping us virtualization folks from going too far off the
rails.
Cc: David Hildenbrand <david@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Link: https://patch.msgid.link/20260731173842.2649391-5-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
To better reflect how guest_memfd has been maintained for the last few
years, and to prepare for significant upcoming growth and expansion, add a
dedicated MAINTAINERS entry for KVM's guest_memfd, with Paolo and myself
(Sean) as co-maintainers.
List both the KVM and KVM x86 git trees as authoritative repositories, as
any given guest_memfd change has a equal odds of hitting KVM x86 or not.
Link: https://patch.msgid.link/20260731173842.2649391-4-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Extract the gmem function declarations out of kvm_mm.h and into a dedicated
header, guest_memfd.h. This will allow creating a MAINTAINERS entry for
guest_memfd without having to rely on content pattern matching.
Reviewed-by: Ackerley Tng <ackerleytng@google.com>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Link: https://patch.msgid.link/20260731173842.2649391-3-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Add the kvm-x86 tree to all KVM x86 entries so that humans, bots, and
everything in between can more easily find KVM x86 (and some broader KVM)
patches that are targeted for the next kernel release, but haven't yet made
their way to the main KVM tree. While the KVM x86 patch flow is documented
in Documentation/process/maintainer-kvm-x86.rst, that's very much one-off
documentation; random passersbys likely don't know it exists, and it's not
suitable for any workflow that's at all automated.
Reported-by: Yosry Ahmed <yosry@kernel.org>
Link: https://patch.msgid.link/20260731173842.2649391-2-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
reg_defaults must be sorted by ascending register address, as
regcache_lookup_reg() locates entries in it with bsearch(). See commit
fd80df352b ("regcache: Add support for sorting defaults arrays").
The table lists the ADAU1761 specific registers (0x4008 and up) before
the block shared with the ADAU1381/ADAU1781, which starts at
ADAU17X1_CLOCK_CONTROL (0x4000), so bsearch() descends into the wrong
half and 28 of the 52 entries are unreachable.
regcache_reg_needs_sync() then cannot compare them against their default
and reports that a sync is needed, so they are written to the device on
every regcache_sync() even when they were never touched.
Sort the table by register address.
Fixes: dab464b60b ("ASoC: Add ADAU1361/ADAU1761 audio CODEC support")
Cc: stable@vger.kernel.org
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@linux.intel.com>
Acked-by: Nuno Sá <nuno.sa@analog.com>
Link: https://patch.msgid.link/20260805122713.11376-1-peter.ujfalusi@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
vfio_pci_core_map_bars() calls pci_iomap() to set up BAR resources, but not
all devices support having their BARs mapped by the CPU. The
non_mappable_bars flag indicates that a PCI device's BARs cannot be
accessed by the CPU. The ISM device on s390 is one such device. The BAR
size for an ISM device is 256 TiB, and attempting to map the BAR will lead
to warnings:
vmalloc_node_range for size 281474976714752 failed: Address range
restricted to 0x2110bab00000 - 0x21903ab00000
Use pdev->non_mappable_bars to skip pci_iomap() for such devices. This flag
is set by the PCI core at enumeration time and already serves the same
purpose in vfio_pci_probe_mmaps().
Fixes: 05f2a68b40 ("vfio/pci: Set up BAR resources and maps in vfio_pci_core_enable()")
Reported-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Link: https://lore.kernel.org/r/20260729181116.1373-1-alifm@linux.ibm.com
Signed-off-by: Alex Williamson <alex@shazbot.org>
As per discussion between the developers in the mail thread
linked, expand the comment in __switch_to so that readers
of the code understand what is going on.
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Linus Walleij <linusw@kernel.org>>
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
