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2022-09-29net: dsa: hellcreek: refactor hellcreek_port_setup_tc() to use switch/caseVladimir Oltean
The following patch will need to make this function also respond to TC_QUERY_BASE, so make the processing more structured around the tc_setup_type. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Reviewed-by: Kurt Kanzenbach <kurt@linutronix.de> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net: dsa: felix: offload per-tc max SDU from tc-taprioVladimir Oltean
Our current vsc9959_tas_guard_bands_update() algorithm has a limitation imposed by the hardware design. To avoid packet overruns between one gate interval and the next (which would add jitter for scheduled traffic in the next gate), we configure the switch to use guard bands. These are as large as the largest packet which is possible to be transmitted. The problem is that at tc-taprio intervals of sizes comparable to a guard band, there isn't an obvious place in which to split the interval between the useful portion (for scheduling) and the guard band portion (where scheduling is blocked). For example, a 10 us interval at 1Gbps allows 1225 octets to be transmitted. We currently split the interval between the bare minimum of 33 ns useful time (required to schedule a single packet) and the rest as guard band. But 33 ns of useful scheduling time will only allow a single packet to be sent, be that packet 1200 octets in size, or 60 octets in size. It is impossible to send 2 60 octets frames in the 10 us window. Except that if we reduced the guard band (and therefore the maximum allowable SDU size) to 5 us, the useful time for scheduling is now also 5 us, so more packets could be scheduled. The hardware inflexibility of not scheduling according to individual packet lengths must unfortunately propagate to the user, who needs to tune the queueMaxSDU values if he wants to fit more small packets into a 10 us interval, rather than one large packet. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net/sched: taprio: allow user input of per-tc max SDUVladimir Oltean
IEEE 802.1Q clause 12.29.1.1 "The queueMaxSDUTable structure and data types" and 8.6.8.4 "Enhancements for scheduled traffic" talk about the existence of a per traffic class limitation of maximum frame sizes, with a fallback on the port-based MTU. As far as I am able to understand, the 802.1Q Service Data Unit (SDU) represents the MAC Service Data Unit (MSDU, i.e. L2 payload), excluding any number of prepended VLAN headers which may be otherwise present in the MSDU. Therefore, the queueMaxSDU is directly comparable to the device MTU (1500 means L2 payload sizes are accepted, or frame sizes of 1518 octets, or 1522 plus one VLAN header). Drivers which offload this are directly responsible of translating into other units of measurement. To keep the fast path checks optimized, we keep 2 arrays in the qdisc, one for max_sdu translated into frame length (so that it's comparable to skb->len), and another for offloading and for dumping back to the user. Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net/sched: query offload capabilities through ndo_setup_tc()Vladimir Oltean
When adding optional new features to Qdisc offloads, existing drivers must reject the new configuration until they are coded up to act on it. Since modifying all drivers in lockstep with the changes in the Qdisc can create problems of its own, it would be nice if there existed an automatic opt-in mechanism for offloading optional features. Jakub proposes that we multiplex one more kind of call through ndo_setup_tc(): one where the driver populates a Qdisc-specific capability structure. First user will be taprio in further changes. Here we are introducing the definitions for the base functionality. Link: https://patchwork.kernel.org/project/netdevbpf/patch/20220923163310.3192733-3-vladimir.oltean@nxp.com/ Suggested-by: Jakub Kicinski <kuba@kernel.org> Co-developed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net/tipc: Remove unused struct distr_queue_itemYuan Can
After commit 09b5678c778f("tipc: remove dead code in tipc_net and relatives"), struct distr_queue_item is not used any more and can be removed as well. Signed-off-by: Yuan Can <yuancan@huawei.com> Acked-by: Jon Maloy <jmaloy@redhat.com> Link: https://lore.kernel.org/r/20220928085636.71749-1-yuancan@huawei.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net: skb: introduce and use a single page frag cachePaolo Abeni
After commit 3226b158e67c ("net: avoid 32 x truesize under-estimation for tiny skbs") we are observing 10-20% regressions in performance tests with small packets. The perf trace points to high pressure on the slab allocator. This change tries to improve the allocation schema for small packets using an idea originally suggested by Eric: a new per CPU page frag is introduced and used in __napi_alloc_skb to cope with small allocation requests. To ensure that the above does not lead to excessive truesize underestimation, the frag size for small allocation is inflated to 1K and all the above is restricted to build with 4K page size. Note that we need to update accordingly the run-time check introduced with commit fd9ea57f4e95 ("net: add napi_get_frags_check() helper"). Alex suggested a smart page refcount schema to reduce the number of atomic operations and deal properly with pfmemalloc pages. Under small packet UDP flood, I measure a 15% peak tput increases. Suggested-by: Eric Dumazet <eric.dumazet@gmail.com> Suggested-by: Alexander H Duyck <alexanderduyck@fb.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com> Link: https://lore.kernel.org/r/6b6f65957c59f86a353fc09a5127e83a32ab5999.1664350652.git.pabeni@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29net: sched: cls_u32: Avoid memcpy() false-positive warningKees Cook
To work around a misbehavior of the compiler's ability to see into composite flexible array structs (as detailed in the coming memcpy() hardening series[1]), use unsafe_memcpy(), as the sizing, bounds-checking, and allocation are all very tightly coupled here. This silences the false-positive reported by syzbot: memcpy: detected field-spanning write (size 80) of single field "&n->sel" at net/sched/cls_u32.c:1043 (size 16) [1] https://lore.kernel.org/linux-hardening/20220901065914.1417829-2-keescook@chromium.org Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Jiri Pirko <jiri@resnulli.us> Reported-by: syzbot+a2c4601efc75848ba321@syzkaller.appspotmail.com Link: https://lore.kernel.org/lkml/000000000000a96c0b05e97f0444@google.com/ Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://lore.kernel.org/r/20220927153700.3071688-1-keescook@chromium.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29dt-bindings: net: snps,dwmac: Document stmmac-axi-config subnodeMarek Vasut
The stmmac-axi-config subnode is present in multiple dwmac instance DTs, document its content per snps,axi-config property description which is a phandle to this subnode. Signed-off-by: Marek Vasut <marex@denx.de> Reviewed-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20220927012449.698915-1-marex@denx.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29docs: netlink: clarify the historical baggage of Netlink flagsJakub Kicinski
nlmsg_flags are full of historical baggage, inconsistencies and strangeness. Try to document it more thoroughly. Explain the meaning of the ECHO flag (and while at it clarify the comment in the uAPI). Handwave a little about the NEW request flags and how they make sense on the surface but cater to really old paradigm before commands were a thing. I will add more notes on how to make use of ECHO and discouragement for reuse of flags to the kernel-side documentation. Link: https://lore.kernel.org/r/20220927212306.823862-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29vhost/vsock: Use kvmalloc/kvfree for larger packets.Junichi Uekawa
When copying a large file over sftp over vsock, data size is usually 32kB, and kmalloc seems to fail to try to allocate 32 32kB regions. vhost-5837: page allocation failure: order:4, mode:0x24040c0 Call Trace: [<ffffffffb6a0df64>] dump_stack+0x97/0xdb [<ffffffffb68d6aed>] warn_alloc_failed+0x10f/0x138 [<ffffffffb68d868a>] ? __alloc_pages_direct_compact+0x38/0xc8 [<ffffffffb664619f>] __alloc_pages_nodemask+0x84c/0x90d [<ffffffffb6646e56>] alloc_kmem_pages+0x17/0x19 [<ffffffffb6653a26>] kmalloc_order_trace+0x2b/0xdb [<ffffffffb66682f3>] __kmalloc+0x177/0x1f7 [<ffffffffb66e0d94>] ? copy_from_iter+0x8d/0x31d [<ffffffffc0689ab7>] vhost_vsock_handle_tx_kick+0x1fa/0x301 [vhost_vsock] [<ffffffffc06828d9>] vhost_worker+0xf7/0x157 [vhost] [<ffffffffb683ddce>] kthread+0xfd/0x105 [<ffffffffc06827e2>] ? vhost_dev_set_owner+0x22e/0x22e [vhost] [<ffffffffb683dcd1>] ? flush_kthread_worker+0xf3/0xf3 [<ffffffffb6eb332e>] ret_from_fork+0x4e/0x80 [<ffffffffb683dcd1>] ? flush_kthread_worker+0xf3/0xf3 Work around by doing kvmalloc instead. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Signed-off-by: Junichi Uekawa <uekawa@chromium.org> Reviewed-by: Stefano Garzarella <sgarzare@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Link: https://lore.kernel.org/r/20220928064538.667678-1-uekawa@chromium.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-30drm/msm: Fix build break with recent mm treeRob Clark
9178e3dcb121 ("mm: discard __GFP_ATOMIC") removed __GFP_ATOMIC, replacing it with a check for not __GFP_DIRECT_RECLAIM. Reported-by: Randy Dunlap <rdunlap@infradead.org> Reported-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Rob Clark <robdclark@chromium.org> Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested Signed-off-by: Dave Airlie <airlied@redhat.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220929161404.2769414-1-robdclark@gmail.com
2022-09-29sbitmap: fix lockup while swappingHugh Dickins
Commit 4acb83417cad ("sbitmap: fix batched wait_cnt accounting") is a big improvement: without it, I had to revert to before commit 040b83fcecfb ("sbitmap: fix possible io hung due to lost wakeup") to avoid the high system time and freezes which that had introduced. Now okay on the NVME laptop, but 4acb83417cad is a disaster for heavy swapping (kernel builds in low memory) on another: soon locking up in sbitmap_queue_wake_up() (into which __sbq_wake_up() is inlined), cycling around with waitqueue_active() but wait_cnt 0 . Here is a backtrace, showing the common pattern of outer sbitmap_queue_wake_up() interrupted before setting wait_cnt 0 back to wake_batch (in some cases other CPUs are idle, in other cases they're spinning for a lock in dd_bio_merge()): sbitmap_queue_wake_up < sbitmap_queue_clear < blk_mq_put_tag < __blk_mq_free_request < blk_mq_free_request < __blk_mq_end_request < scsi_end_request < scsi_io_completion < scsi_finish_command < scsi_complete < blk_complete_reqs < blk_done_softirq < __do_softirq < __irq_exit_rcu < irq_exit_rcu < common_interrupt < asm_common_interrupt < _raw_spin_unlock_irqrestore < __wake_up_common_lock < __wake_up < sbitmap_queue_wake_up < sbitmap_queue_clear < blk_mq_put_tag < __blk_mq_free_request < blk_mq_free_request < dd_bio_merge < blk_mq_sched_bio_merge < blk_mq_attempt_bio_merge < blk_mq_submit_bio < __submit_bio < submit_bio_noacct_nocheck < submit_bio_noacct < submit_bio < __swap_writepage < swap_writepage < pageout < shrink_folio_list < evict_folios < lru_gen_shrink_lruvec < shrink_lruvec < shrink_node < do_try_to_free_pages < try_to_free_pages < __alloc_pages_slowpath < __alloc_pages < folio_alloc < vma_alloc_folio < do_anonymous_page < __handle_mm_fault < handle_mm_fault < do_user_addr_fault < exc_page_fault < asm_exc_page_fault See how the process-context sbitmap_queue_wake_up() has been interrupted, after bringing wait_cnt down to 0 (and in this example, after doing its wakeups), before advancing wake_index and refilling wake_cnt: an interrupt-context sbitmap_queue_wake_up() of the same sbq gets stuck. I have almost no grasp of all the possible sbitmap races, and their consequences: but __sbq_wake_up() can do nothing useful while wait_cnt 0, so it is better if sbq_wake_ptr() skips on to the next ws in that case: which fixes the lockup and shows no adverse consequence for me. The check for wait_cnt being 0 is obviously racy, and ultimately can lead to lost wakeups: for example, when there is only a single waitqueue with waiters. However, lost wakeups are unlikely to matter in these cases, and a proper fix requires redesign (and benchmarking) of the batched wakeup code: so let's plug the hole with this bandaid for now. Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Keith Busch <kbusch@kernel.org> Link: https://lore.kernel.org/r/9c2038a7-cdc5-5ee-854c-fbc6168bf16@google.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-29io_uring/net: fix notif cqe reorderingPavel Begunkov
send zc is not restricted to !IO_URING_F_UNLOCKED anymore and so we can't use task-tw ordering trick to order notification cqes with requests completions. In this case leave it alone and let io_send_zc_cleanup() flush it. Cc: stable@vger.kernel.org Fixes: 53bdc88aac9a2 ("io_uring/notif: order notif vs send CQEs") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/0031f3a00d492e814a4a0935a2029a46d9c9ba06.1664486545.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-29io_uring/net: don't update msg_name if not providedPavel Begunkov
io_sendmsg_copy_hdr() may clear msg->msg_name if the userspace didn't provide it, we should retain NULL in this case. Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Link: https://lore.kernel.org/r/97d49f61b5ec76d0900df658cfde3aa59ff22121.1664486545.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-30Merge tag 'drm-intel-next-fixes-2022-09-29' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-intel into drm-next - Fix release build bug in 'remove GuC log size module parameters' (John Harrison) - Remove ipc_enabled from struct drm_i915_private (Jani Nikula) - Do not cleanup obj with NULL bo->resource (Nirmoy Das) - Fix device info for devices without display (Jani Nikula) - Force DPLL calculation for TC ports after readout (Ville Syrjälä) - Use i915_vm_put on ppgtt_create error paths (Chris Wilson) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/YzWqtwPNxAe+r9FO@tursulin-desk
2022-09-29binfmt: remove taso from linux_binprm structLukas Bulwahn
With commit 987f20a9dcce ("a.out: Remove the a.out implementation"), the use of the special taso flag for alpha architectures in the linux_binprm struct is gone. Remove the definition of taso in the linux_binprm struct. No functional change. Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20220929203903.9475-1-lukas.bulwahn@gmail.com
2022-09-30Merge tag 'drm-intel-fixes-2022-09-29' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-intel into drm-fixes - Restrict forced preemption to the active context (Chris) - Restrict perf_limit_reasons to the supported platforms - gen11+ (Ashutosh) Signed-off-by: Dave Airlie <airlied@redhat.com> From: Rodrigo Vivi <rodrigo.vivi@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/YzXAkH1a32pYJD33@intel.com
2022-09-30Merge tag 'amd-drm-fixes-6.0-2022-09-29' of ↵Dave Airlie
https://gitlab.freedesktop.org/agd5f/linux into drm-fixes amd-drm-fixes-6.0-2022-09-29: amdgpu: - GC 11.x fixes - SMU 13.x fixes - DCN 3.1.4 fixes - DCN 3.2.x fixes - GC 9.x fix - Fence fix - SR-IOV supend/resume fix - PSR regression fix Signed-off-by: Dave Airlie <airlied@redhat.com> From: Alex Deucher <alexander.deucher@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220929144003.8363-1-alexander.deucher@amd.com
2022-09-30Merge tag 'drm-misc-fixes-2022-09-29' of ↵Dave Airlie
git://anongit.freedesktop.org/drm/drm-misc into drm-fixes Short summary of fixes pull: * bridge/analogix: Revert earlier suspend fix * bridge/lt8912b: Fix corrupt display output Signed-off-by: Dave Airlie <airlied@redhat.com> From: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patchwork.freedesktop.org/patch/msgid/YzWvHhaqHhYirn4L@linux-uq9g
2022-09-29io_uring: don't gate task_work run on TIF_NOTIFY_SIGNALJens Axboe
This isn't a reliable mechanism to tell if we have task_work pending, we really should be looking at whether we have any items queued. This is problematic if forward progress is gated on running said task_work. One such example is reading from a pipe, where the write side has been closed right before the read is started. The fput() of the file queues TWA_RESUME task_work, and we need that task_work to be run before ->release() is called for the pipe. If ->release() isn't called, then the read will sit forever waiting on data that will never arise. Fix this by io_run_task_work() so it checks if we have task_work pending rather than rely on TIF_NOTIFY_SIGNAL for that. The latter obviously doesn't work for task_work that is queued without TWA_SIGNAL. Reported-by: Christiano Haesbaert <haesbaert@haesbaert.org> Cc: stable@vger.kernel.org Link: https://github.com/axboe/liburing/issues/665 Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-09-29Merge tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds
Pull coredump fix from Al Viro: "Fix for breakage in dump_user_range()" * tag 'pull-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [coredump] don't use __kernel_write() on kmap_local_page()
2022-09-29Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2022-09-29drm/panel: simple: Use dev_err_probe() to simplify codeYuan Can
In the probe path, dev_err() can be replaced with dev_err_probe() which will check if error code is -EPROBE_DEFER and prints the error name. It also sets the defer probe reason which can be checked later through debugfs. Signed-off-by: Yuan Can <yuancan@huawei.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220929015503.17301-3-yuancan@huawei.com
2022-09-29drm/panel: panel-edp: Use dev_err_probe() to simplify codeYuan Can
In the probe path, dev_err() can be replaced with dev_err_probe() which will check if error code is -EPROBE_DEFER and prints the error name. It also sets the defer probe reason which can be checked later through debugfs. Signed-off-by: Yuan Can <yuancan@huawei.com> Reviewed-by: Douglas Anderson <dianders@chromium.org> Signed-off-by: Douglas Anderson <dianders@chromium.org> Link: https://patchwork.freedesktop.org/patch/msgid/20220929015503.17301-2-yuancan@huawei.com Link: https://patchwork.freedesktop.org/patch/msgid/20220929015503.17301-2-yuancan@huawei.com
2022-09-29Bluetooth: L2CAP: Fix user-after-freeLuiz Augusto von Dentz
This uses l2cap_chan_hold_unless_zero() after calling __l2cap_get_chan_blah() to prevent the following trace: Bluetooth: l2cap_core.c:static void l2cap_chan_destroy(struct kref *kref) Bluetooth: chan 0000000023c4974d Bluetooth: parent 00000000ae861c08 ================================================================== BUG: KASAN: use-after-free in __mutex_waiter_is_first kernel/locking/mutex.c:191 [inline] BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:671 [inline] BUG: KASAN: use-after-free in __mutex_lock+0x278/0x400 kernel/locking/mutex.c:729 Read of size 8 at addr ffff888006a49b08 by task kworker/u3:2/389 Link: https://lore.kernel.org/lkml/20220622082716.478486-1-lee.jones@linaro.org Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sungwoo Kim <iam@sung-woo.kim>
2022-09-29checkpatch: warn on usage of VM_BUG_ON() and other BUG variantsDavid Hildenbrand
checkpatch does not point out that VM_BUG_ON() and friends should be avoided, however, Linus notes: VM_BUG_ON() has the exact same semantics as BUG_ON. It is literally no different, the only difference is "we can make the code smaller because these are less important". [1] So let's warn on VM_BUG_ON() and other BUG variants as well. While at it, make it clearer that the kernel really shouldn't be crashed. As there are some subsystem BUG macros that actually don't end up crashing the kernel -- for example, KVM_BUG_ON() -- exclude these manually. [1] https://lore.kernel.org/r/CAHk-=wg40EAZofO16Eviaj7mfqDhZ2gVEbvfsMf6gYzspRjYvw@mail.gmail.com Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20220923113426.52871-3-david@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29coding-style.rst: document BUG() and WARN() rules ("do not crash the kernel")David Hildenbrand
Linus notes [1] that the introduction of new code that uses VM_BUG_ON() is just as bad as BUG_ON(), because it will crash the kernel on distributions that enable CONFIG_DEBUG_VM (like Fedora): VM_BUG_ON() has the exact same semantics as BUG_ON. It is literally no different, the only difference is "we can make the code smaller because these are less important". [2] This resulted in a more generic discussion about usage of BUG() and friends. While there might be corner cases that still deserve a BUG_ON(), most BUG_ON() cases should simply use WARN_ON_ONCE() and implement a recovery path if reasonable: The only possible case where BUG_ON can validly be used is "I have some fundamental data corruption and cannot possibly return an error". [2] As a very good approximation is the general rule: "absolutely no new BUG_ON() calls _ever_" [2] ... not even if something really shouldn't ever happen and is merely for documenting that an invariant always has to hold. However, there are sill exceptions where BUG_ON() may be used: If you have a "this is major internal corruption, there's no way we can continue", then BUG_ON() is appropriate. [3] There is only one good BUG_ON(): Now, that said, there is one very valid sub-form of BUG_ON(): BUILD_BUG_ON() is absolutely 100% fine. [2] While WARN will also crash the machine with panic_on_warn set, that's exactly to be expected: So we have two very different cases: the "virtual machine with good logging where a dead machine is fine" - use 'panic_on_warn'. And the actual real hardware with real drivers, running real loads by users. [4] The basic idea is that warnings will similarly get reported by users and be found during testing. However, in contrast to a BUG(), there is a way to actually influence the expected behavior (e.g., panic_on_warn) and to eventually keep the machine alive to extract some debug info. Ingo notes that not all WARN_ON_ONCE cases need recovery. If we don't ever expect this code to trigger in any case, recovery code is not really helpful. I'd prefer to keep all these warnings 'simple' - i.e. no attempted recovery & control flow, unless we ever expect these to trigger. [5] There have been different rules floating around that were never properly documented. Let's try to clarify. [1] https://lkml.kernel.org/r/CAHk-=wiEAH+ojSpAgx_Ep=NKPWHU8AdO3V56BXcCsU97oYJ1EA@mail.gmail.com [2] https://lore.kernel.org/r/CAHk-=wg40EAZofO16Eviaj7mfqDhZ2gVEbvfsMf6gYzspRjYvw@mail.gmail.com [3] https://lkml.kernel.org/r/CAHk-=wit-DmhMfQErY29JSPjFgebx_Ld+pnerc4J2Ag990WwAA@mail.gmail.com [4] https://lore.kernel.org/r/CAHk-=wgF7K2gSSpy=m_=K3Nov4zaceUX9puQf1TjkTJLA2XC_g@mail.gmail.com [5] https://lore.kernel.org/r/YwIW+mVeZoTOxn%2F4@gmail.com Reviewed-by: John Hubbard <jhubbard@nvidia.com> Signed-off-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/r/20220923113426.52871-2-david@redhat.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29Documentation: devres: add missing IO helperYang Yingliang
Add missing devm_request_free_mem_region() to devres.rst. It's introduced by commit 0092908d16c6 ("mm: factor out a devm_request_free_mem_region helper"). Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20220927080215.1359979-1-yangyingliang@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29Documentation: devres: update IRQ helperYang Yingliang
devm_irq_sim_init() has been changed to devm_irq_domain_create_sim() in commit 337cbeb2c13e ("genirq/irq_sim: Simplify the API"). Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Link: https://lore.kernel.org/r/20220927083819.12484-1-yangyingliang@huawei.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29Documentation/mm: modify page_referenced to folio_referencedVernon Yang
Since commit b3ac04132c4b ("mm/rmap: Turn page_referenced() into folio_referenced()") the page_referenced function name was modified, so fix it up to use the correct one. Signed-off-by: Vernon Yang <vernon2gm@gmail.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Link: https://lore.kernel.org/r/20220926152032.74621-1-vernon2gm@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29Documentation/CoC: Reflect current CoC interpretation and practicesKristen Carlson Accardi
The Code of Conduct interpretation does not reflect the current practices of the CoC committee or the TAB. Update the documentation to remove references to initial committees and boot strap periods since it is past that time, and note that the this document does serve as the documentation for the CoC committee processes. Signed-off-by: Kristen Carlson Accardi <kristen@linux.intel.com> Reviewed-by: Shuah Khan <skhan@linuxfoundation.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Link: https://lore.kernel.org/r/20220926211149.2278214-1-kristen@linux.intel.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs/doc-guide: Add documentation on SPHINX_IMGMATHAkira Yokosawa
Now that building html docs with math expressions does not need texlive packages, remove the note on the requirement in the "Sphinx Install" section. Instead, add sections of "Math Expressions in HTML" and "Choice of Math Renderer". Describe the effect of setting SPHINX_IMGMATH in the latter section. Signed-off-by: Akira Yokosawa <akiyks@gmail.com> Cc: Mauro Carvalho Chehab <mchehab@kernel.org> Cc: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/a67e3279-6bc7-ee2c-2b49-9275252460b0@gmail.com Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: process/5.Posting.rst: clarify use of Reported-by: tagThorsten Leemhuis
Bring the description on when to use the Reported-by: tag found in Documentation/process/5.Posting.rst more in line with the description in Documentation/process/submitting-patches.rst: before this change the two were contradicting each other, as the latter is way more permissive and only states '[...] if the bug was reported in private, then ask for permission first before using the Reported-by tag.' Signed-off-by: Thorsten Leemhuis <linux@leemhuis.info> Link: https://lore.kernel.org/r/2fc7162dfb76e04da5ea903c9c170d913e735dad.1664372256.git.linux@leemhuis.info Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs, kprobes: Fix the wrong location of KprobesTiezhu Yang
After commit 22471e1313f2 ("kconfig: use a menu in arch/Kconfig to reduce clutter"), the location of Kprobes is under "General architecture-dependent options" rather than "General setup". Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org> Fixes: 22471e1313f2 ("kconfig: use a menu in arch/Kconfig to reduce clutter") Link: https://lore.kernel.org/r/1663322106-12178-1-git-send-email-yangtiezhu@loongson.cn Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29drm/amdgpu: Enable sram on vcn_4_0_2Sonny Jiang
Enable sram on vcn_4_0_2 Signed-off-by: Sonny Jiang <sonny.jiang@amd.com> Reviewed-by: James Zhu <James.Zhu@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2022-09-29drm/amdgpu: Enable VCN DPG for GC11_0_1Sonny Jiang
Enable VCN DPG on GC11_0_1 Signed-off-by: Sonny Jiang <sonny.jiang@amd.com> Reviewed-by: James Zhu <James.Zhu@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
2022-09-29perf build: Fixup disabling of -Wdeprecated-declarations for the python ↵Arnaldo Carvalho de Melo
scripting engine A brown paper bag where -Wno-error=deprecated-declarations was added from compiler output when the right thing is to add -Wno-deprecated-declarations, fix it. Fixes: 4ee3c4da8b1b9c22 ("perf scripting python: Do not build fail on deprecation warnings") Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-09-29Merge branch 'fp' into docs-mwJonathan Corbet
The top-level index.rst file is the entry point for the kernel's documentation, especially for readers of the HTML output. It is currently a mess containing everything we thought to throw in there. Firefox says it would require 26 pages of paper to print it. That is not a user-friendly introduction. This series aims to improve our documentation entry point with a focus on rewriting index.rst. The result is, IMO, simpler and more approachable. For anybody who wants to see the rendered results without building the docs, have a look at: https://static.lwn.net/kerneldoc/ This time around I've rendered the pages using the "Read The Docs" theme, since that's what everybody will get by default. That theme ignores the directives regarding the left column, so the results are not as good there. I have a series proposing a default-theme change in the works, but that's a separate topic. This is only a beginning; I think this kind of organizational effort has to be pushed down into the lower layers of the docs tree itself. But one has to start somewhere.
2022-09-29docs: add a man-pages link to the front pageJonathan Corbet
Readers looking for user-oriented information may benefit from it. Signed-off-by: Jonathan Corbet <corbet@lwn.net> Reviewed-by: David Vernet <void@manifault.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-8-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: put atomic*.txt and memory-barriers.txt into the core-api bookJonathan Corbet
These files describe part of the core API, but have never been converted to RST due to ... let's say local oppposition. So, create a set of special-purpose wrappers to ..include these files into a separate page so that they can be a part of the htmldocs build. Then link them into the core-api manual and remove them from the "staging" dumping ground. Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Reviewed-by: David Vernet <void@manifault.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-7-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: move asm-annotations.rst into core-apiJonathan Corbet
This one file should not really be in the top-level documentation directory. core-api/ may not be a perfect fit but seems to be best, so move it there. Adjust a couple of internal document references to make them location-independent, and point checkpatch.pl at the new location. Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Joe Perches <joe@perches.com> Reviewed-by: David Vernet <void@manifault.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-6-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: remove some index.rst cruftJonathan Corbet
There is some useless boilerplate text that was added by sphinx when this file was first created; take it out. Reviewed-by: David Vernet <void@manifault.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-5-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: reconfigure the HTML left columnJonathan Corbet
Use the html_sidebars directive to get a more useful set of links in the left column. Unfortunately, this is a no-op with the default RTD theme, but others observe it. Reviewed-by: David Vernet <void@manifault.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-4-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: Rewrite the front pageJonathan Corbet
The front page is the entry point to the documentation, especially for people who read it online. It's a big mess of everything we could think to toss into it. Rewrite the page with an eye toward simplicity and making it easy for readers to get going toward what they really want to find. This is only a beginning, but it makes our docs more approachable than before. Acked-by: Jani Nikula <jani.nikula@intel.com> Reviewed-by: David Vernet <void@manifault.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-3-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29docs: promote the title of process/index.rstJonathan Corbet
...otherwise Sphinx won't cooperate when trying to list it explicitly in the top-level index.rst file Reviewed-by: David Vernet <void@manifault.com> Acked-by: Jani Nikula <jani.nikula@intel.com> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Acked-by: Randy Dunlap <rdunlap@infradead.org> Link: https://lore.kernel.org/r/20220927160559.97154-2-corbet@lwn.net Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2022-09-29perf tests mmap-basic: Remove unused variable to address clang 15 warningJiri Olsa
A clang 15 build reveal several unused-but-set variables, removing the 'foo' variable in tests/mmap-basic.o object to address one of those cases. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: http://lore.kernel.org/lkml/20220929140514.226807-2-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-09-29perf parse-events: Ignore clang 15 warning about variable set but unused in ↵Jiri Olsa
bison produced code clang 15 now warns: 46 65.20 fedora:rawhide : FAIL clang version 15.0.0 (Fedora 15.0.0-3.fc38) util/parse-events-bison.c:1401:9: error: variable 'parse_events_nerrs' set but not used [-Werror,-Wunused-but-set-variable] int yynerrs = 0; ^ #define yynerrs parse_events_nerrs ^ 1 error generated. make[3]: *** [/git/perf-6.0.0-rc7/tools/build/Makefile.build:139: util] Error 2 Just ignore one more compiler warning for the bison generated C code. Committer notes: Older clangs don't know about -Wunused-but-set-variable, so we need to add -Wno-unknown-warning-option to avoid this: 37 44.92 fedora:32 : FAIL clang version 10.0.1 (Fedora 10.0.1-3.fc32) error: unknown warning option '-Wno-unused-but-set-variable'; did you mean '-Wno-unused-const-variable'? [-Werror,-Wunknown-warning-option] make[3]: *** [/git/perf-6.0.0-rc7/tools/build/Makefile.build:139: util] Error 2 Reported-by: Arnaldo Carvalho de Melo <acme@kernel.org> Signed-off-by: Jiri Olsa <jolsa@kernel.org> Tested-by: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Ian Rogers <irogers@google.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Link: https://lore.kernel.org/lkml/20220929140514.226807-1-jolsa@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
2022-09-29mfd: syscon: Remove repetition of the regmap_get_val_endian()Andy Shevchenko
Since the commit 0dbdb76c0ca8 ("regmap: mmio: Parse endianness definitions from DT") regmap MMIO parses DT itsef, no need to repeat this in the caller(s). Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee@kernel.org> Link: https://lore.kernel.org/r/20220808140811.26734-1-andriy.shevchenko@linux.intel.com
2022-09-29dmaengine: ioat: remove unused declarations in dma.hGaosheng Cui
ioat_ring_alloc_order and ioat_ring_max_alloc_order have been removed since commit cd60cd96137f ("dmaengine: IOATDMA: Removing descriptor ring reshape"), so remove them. Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com> Acked-by: Dave Jiang <dave.jiang@intel.com> Link: https://lore.kernel.org/r/20220911091817.3214271-1-cuigaosheng1@huawei.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
2022-09-29dmaengine: ti: k3-udma: Respond TX done if DMA_PREP_INTERRUPT is not requestedVaishnav Achath
If the DMA consumer driver does not expect the callback for TX done, then we need not perform the channel RT byte counter calculations and estimate the completion but return complete on first attempt itself.This assumes that the consumer who did not request DMA_PREP_INTERRUPT has its own mechanism for understanding TX completion, example: MCSPI EOW interrupt can be used as TX completion signal for a SPI transaction. Signed-off-by: Vaishnav Achath <vaishnav.a@ti.com> Acked-by: Peter Ujfalusi <peter.ujfalusi@gmail.com> Link: https://lore.kernel.org/r/20220914110049.5842-1-vaishnav.a@ti.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
generated by cgit (git 2.34.1) at 2025-09-15 10:00:49 +0000