All pf->create implementations have been fixed now to clear sock->sk on
error, when they deallocate the allocated sk object.
Put a warning in place to make sure we don't break this promise in the
future.
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-9-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sock_init_data() attaches the allocated sk pointer to the provided sock
object. If inet6_create() fails later, the sk object is released, but the
sock object retains the dangling sk pointer, which may cause use-after-free
later.
Clear the sock sk pointer on error.
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-8-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sock_init_data() attaches the allocated sk object to the provided sock
object. If inet_create() fails later, the sk object is freed, but the
sock object retains the dangling pointer, which may create use-after-free
later.
Clear the sk pointer in the sock object on error.
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-7-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sock_init_data() attaches the allocated sk object to the provided sock
object. If ieee802154_create() fails later, the allocated sk object is
freed, but the dangling pointer remains in the provided sock object, which
may allow use-after-free.
Clear the sk pointer in the sock object on error.
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Miquel Raynal <miquel.raynal@bootlin.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-6-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On error can_create() frees the allocated sk object, but sock_init_data()
has already attached it to the provided sock object. This will leave a
dangling sk pointer in the sock object and may cause use-after-free later.
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Marc Kleine-Budde <mkl@pengutronix.de>
Link: https://patch.msgid.link/20241014153808.51894-5-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bt_sock_alloc() attaches allocated sk object to the provided sock object.
If rfcomm_dlc_alloc() fails, we release the sk object, but leave the
dangling pointer in the sock object, which may cause use-after-free.
Fix this by swapping calls to bt_sock_alloc() and rfcomm_dlc_alloc().
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-4-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
bt_sock_alloc() allocates the sk object and attaches it to the provided
sock object. On error l2cap_sock_alloc() frees the sk object, but the
dangling pointer is still attached to the sock object, which may create
use-after-free in other code.
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-3-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
After sock_init_data() the allocated sk object is attached to the provided
sock object. On error, packet_create() frees the sk object leaving the
dangling pointer in the sock object on return. Some other code may try
to use this pointer and cause use-after-free.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Ignat Korchagin <ignat@cloudflare.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241014153808.51894-2-ignat@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Similar to the situation described for sja1105 in commit 1f9fc48fd3
("net: dsa: sja1105: fix reception from VLAN-unaware bridges"), the
vsc73xx driver uses tag_8021q and doesn't need the ds->untag_bridge_pvid
request. In fact, this option breaks packet reception.
The ds->untag_bridge_pvid option strips VLANs from packets received on
VLAN-unaware bridge ports. But those VLANs should already be stripped
by tag_vsc73xx_8021q.c as part of vsc73xx_rcv() - they are not VLANs in
VLAN-unaware mode, but DSA tags. Thus, dsa_software_vlan_untag() tries
to untag a VLAN that doesn't exist, corrupting the packet.
Fixes: 93e4649efa ("net: dsa: provide a software untagging function on RX for VLAN-aware bridges")
Tested-by: Pawel Dembicki <paweldembicki@gmail.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://patch.msgid.link/20241014153041.1110364-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Recent work moving the reporting of Rx software timestamps to the core
[1] highlighted an issue where hardware time stamping was advertised
for the platforms where it is not supported.
Fix this by covering advertising support for hardware timestamps only if
the hardware supports it. Due to the Tx implementation in RAVB software
Tx timestamping is also only considered if the hardware supports
hardware timestamps. This should be addressed in future, but this fix
only reflects what the driver currently implements.
1. Commit 277901ee3a ("ravb: Remove setting of RX software timestamp")
Fixes: 7e09a052dc ("ravb: Exclude gPTP feature support for RZ/G2L")
Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Reviewed-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Tested-by: Paul Barker <paul.barker.ct@bp.renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Link: https://patch.msgid.link/20241014124343.3875285-1-niklas.soderlund+renesas@ragnatech.se
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The subsequent calculation of port_rate = speed * 1000 * BYTES_PER_KBIT,
where the BYTES_PER_KBIT is of type LL, may cause an overflow.
At least when speed = SPEED_20000, the expression to the left of port_rate
will be greater than INT_MAX.
Found by Linux Verification Center (linuxtesting.org) with SVACE.
Signed-off-by: Elena Salomatkina <esalomatkina@ispras.ru>
Link: https://patch.msgid.link/20241013124529.1043-1-esalomatkina@ispras.ru
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If:
1) the user requested USO, but
2) there is not enough payload for GSO to kick in, and
3) the egress device doesn't offer checksum offload, then
we want to compute the L4 checksum in software early on.
In the case when we are not taking the GSO path, but it has been requested,
the software checksum fallback in skb_segment doesn't get a chance to
compute the full checksum, if the egress device can't do it. As a result we
end up sending UDP datagrams with only a partial checksum filled in, which
the peer will discard.
Fixes: 10154dbded ("udp: Allow GSO transmit from devices with no checksum offload")
Reported-by: Ivan Babrou <ivan@cloudflare.com>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20241011-uso-swcsum-fixup-v2-1-6e1ddc199af9@cloudflare.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
According to the Marvell datasheet the 88E6361 has two VTU pages
(4k VIDs per page) so the max_vid should be 8191, not 4095.
In the current implementation mv88e6xxx_vtu_walk() gives unexpected
results because of this error. I verified that mv88e6xxx_vtu_walk()
works correctly on the MV88E6361 with this patch in place.
Fixes: 12899f2998 ("net: dsa: mv88e6xxx: enable support for 88E6361 switch")
Signed-off-by: Peter Rashleigh <peter@rashleigh.ca>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://patch.msgid.link/20241014204342.5852-1-peter@rashleigh.ca
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Martin KaFai Lau reported use-after-free [0] in reqsk_timer_handler().
"""
We are seeing a use-after-free from a bpf prog attached to
trace_tcp_retransmit_synack. The program passes the req->sk to the
bpf_sk_storage_get_tracing kernel helper which does check for null
before using it.
"""
The commit 83fccfc394 ("inet: fix potential deadlock in
reqsk_queue_unlink()") added timer_pending() in reqsk_queue_unlink() not
to call del_timer_sync() from reqsk_timer_handler(), but it introduced a
small race window.
Before the timer is called, expire_timers() calls detach_timer(timer, true)
to clear timer->entry.pprev and marks it as not pending.
If reqsk_queue_unlink() checks timer_pending() just after expire_timers()
calls detach_timer(), TCP will miss del_timer_sync(); the reqsk timer will
continue running and send multiple SYN+ACKs until it expires.
The reported UAF could happen if req->sk is close()d earlier than the timer
expiration, which is 63s by default.
The scenario would be
1. inet_csk_complete_hashdance() calls inet_csk_reqsk_queue_drop(),
but del_timer_sync() is missed
2. reqsk timer is executed and scheduled again
3. req->sk is accept()ed and reqsk_put() decrements rsk_refcnt, but
reqsk timer still has another one, and inet_csk_accept() does not
clear req->sk for non-TFO sockets
4. sk is close()d
5. reqsk timer is executed again, and BPF touches req->sk
Let's not use timer_pending() by passing the caller context to
__inet_csk_reqsk_queue_drop().
Note that reqsk timer is pinned, so the issue does not happen in most
use cases. [1]
[0]
BUG: KFENCE: use-after-free read in bpf_sk_storage_get_tracing+0x2e/0x1b0
Use-after-free read at 0x00000000a891fb3a (in kfence-#1):
bpf_sk_storage_get_tracing+0x2e/0x1b0
bpf_prog_5ea3e95db6da0438_tcp_retransmit_synack+0x1d20/0x1dda
bpf_trace_run2+0x4c/0xc0
tcp_rtx_synack+0xf9/0x100
reqsk_timer_handler+0xda/0x3d0
run_timer_softirq+0x292/0x8a0
irq_exit_rcu+0xf5/0x320
sysvec_apic_timer_interrupt+0x6d/0x80
asm_sysvec_apic_timer_interrupt+0x16/0x20
intel_idle_irq+0x5a/0xa0
cpuidle_enter_state+0x94/0x273
cpu_startup_entry+0x15e/0x260
start_secondary+0x8a/0x90
secondary_startup_64_no_verify+0xfa/0xfb
kfence-#1: 0x00000000a72cc7b6-0x00000000d97616d9, size=2376, cache=TCPv6
allocated by task 0 on cpu 9 at 260507.901592s:
sk_prot_alloc+0x35/0x140
sk_clone_lock+0x1f/0x3f0
inet_csk_clone_lock+0x15/0x160
tcp_create_openreq_child+0x1f/0x410
tcp_v6_syn_recv_sock+0x1da/0x700
tcp_check_req+0x1fb/0x510
tcp_v6_rcv+0x98b/0x1420
ipv6_list_rcv+0x2258/0x26e0
napi_complete_done+0x5b1/0x2990
mlx5e_napi_poll+0x2ae/0x8d0
net_rx_action+0x13e/0x590
irq_exit_rcu+0xf5/0x320
common_interrupt+0x80/0x90
asm_common_interrupt+0x22/0x40
cpuidle_enter_state+0xfb/0x273
cpu_startup_entry+0x15e/0x260
start_secondary+0x8a/0x90
secondary_startup_64_no_verify+0xfa/0xfb
freed by task 0 on cpu 9 at 260507.927527s:
rcu_core_si+0x4ff/0xf10
irq_exit_rcu+0xf5/0x320
sysvec_apic_timer_interrupt+0x6d/0x80
asm_sysvec_apic_timer_interrupt+0x16/0x20
cpuidle_enter_state+0xfb/0x273
cpu_startup_entry+0x15e/0x260
start_secondary+0x8a/0x90
secondary_startup_64_no_verify+0xfa/0xfb
Fixes: 83fccfc394 ("inet: fix potential deadlock in reqsk_queue_unlink()")
Reported-by: Martin KaFai Lau <martin.lau@kernel.org>
Closes: https://lore.kernel.org/netdev/eb6684d0-ffd9-4bdc-9196-33f690c25824@linux.dev/
Link: https://lore.kernel.org/netdev/b55e2ca0-42f2-4b7c-b445-6ffd87ca74a0@linux.dev/ [1]
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://patch.msgid.link/20241014223312.4254-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since commit 1202cdd665 ("Remove DECnet support from kernel"),
NEIGH_DN_TABLE is no longer used.
MPLS has implicit dependency on it in nla_put_via(), but nla_get_via()
does not support DECnet.
Let's remove NEIGH_DN_TABLE.
Now, neigh_tables[] has only 2 elements and no extra iteration
for DECnet in many places.
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20241014235216.10785-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The CP_SMMU_TABLE_UPDATE _should_ be waiting for idle, but on some
devices (x1-85, possibly others), it seems to pass that barrier while
there are still things in the event completion FIFO waiting to be
written back to memory.
Work around that by adding a fence wait before context switch. The
CP_EVENT_WRITE that writes the fence is the last write from a submit,
so seeing this value hit memory is a reliable indication that it is
safe to proceed with the context switch.
v2: Only emit CP_WAIT_TIMESTAMP on a7xx, as it is not supported on a6xx.
Conversely, I've not been able to reproduce this issue on a6xx, so
hopefully it is limited to a7xx, or perhaps just certain a7xx
devices.
Fixes: af66706acc ("drm/msm/a6xx: Add skeleton A7xx support")
Closes: https://gitlab.freedesktop.org/drm/msm/-/issues/63
Signed-off-by: Rob Clark <robdclark@chromium.org>
Reviewed-by: Akhil P Oommen <quic_akhilpo@quicinc.com>
Signed-off-by: Abhinav Kumar <quic_abhinavk@quicinc.com>
VDSO time functions do not call any other function, so they don't
need to save/restore LR. However, retrieving the address of VDSO data
page requires using LR hence saving then restoring it, which can be
heavy on some CPUs. On the other hand, VDSO functions on powerpc are
not standard functions and require a wrapper function to call C VDSO
functions. And that wrapper has to save and restore LR in order to
call the C VDSO function, so retrieving VDSO data page address in that
wrapper doesn't require additional save/restore of LR.
For random VDSO functions it is a bit different. Because the function
calls __arch_chacha20_blocks_nostack(), it saves and restores LR.
Retrieving VDSO data page address can then be done there without
additional save/restore of LR.
So lets implement __arch_get_vdso_rng_data() and simplify the wrapper.
It starts paving the way for the day powerpc will implement a more
standard ABI for VDSO functions.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/a1a9bd0df508f1b5c04684b7366940577dfc6262.1727858295.git.christophe.leroy@csgroup.eu
The bcmasp_xmit() returns NETDEV_TX_OK without freeing skb
in case of mapping fails, add dev_kfree_skb() to fix it.
Fixes: 490cb41200 ("net: bcmasp: Add support for ASP2.0 Ethernet controller")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Link: https://patch.msgid.link/20241014145901.48940-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The page containing VDSO time data is swapped with the one containing
TIME namespace data when a process uses a non-root time namespace.
For other data like powerpc specific data and RNG data, it means
tracking whether time namespace is the root one or not to know which
page to use.
Simplify the logic behind by moving time data out of first data page
so that the first data page which contains everything else always
remains the first page. Time data is in the second or third page
depending on selected time namespace.
While we are playing with get_datapage macro, directly take into
account the data offset inside the macro instead of adding that offset
afterwards.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/0557d3ec898c1d0ea2fc59fa8757618e524c5d94.1727858295.git.christophe.leroy@csgroup.eu
cxgb3_alloc_stid() and cxgb3_free_stid() have been unused since
commit 30e0f6cf5a ("RDMA/iw_cxgb3: Remove the iw_cxgb3 module
from kernel")
Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://patch.msgid.link/20241013012946.284721-1-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Dr. David Alan Gilbert says:
====================
cxgb4: Deadcode removal
This is a bunch of deadcode removal in cxgb4.
It's all complete function removal rather than any actual change to
logic.
Build and boot tested, but I don't have the hardware to test
the actual card.
====================
Link: https://patch.msgid.link/20241013203831.88051-1-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
t4_free_ofld_rxqs() has been unused since
commit 0fbc81b3ad ("chcr/cxgb4i/cxgbit/RDMA/cxgb4: Allocate resources
dynamically for all cxgb4 ULD's")
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241013203831.88051-7-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
cxgb4_l2t_alloc_switching() has been unused since it was added in
commit f7502659ce ("cxgb4: Add API to alloc l2t entry; also update
existing ones")
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241013203831.88051-6-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
cxgb4_iscsi_init() has been unused since 2016's commit
5999299f1c ("cxgb3i,cxgb4i,libcxgbi: remove iSCSI DDP support")
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241013203831.88051-5-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
cxgb4_get_srq_entry() has been unused since 2018's commit
e47094751d ("cxgb4: Add support to initialise/read SRQ entries")
which added it.
Remove it.
Note: I'm a bit suspicious whether any of the srq code in there
actually does anything useful; without this get I can't see anything
that reads the data, so perhaps the whole thing should go?
But that however would remove one of the opcode handlers, and I have
no way to test that.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241013203831.88051-4-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
cxgb4_alloc_raw_mac_filt() and cxgb4_free_raw_mac_filt() have been
unused since they were added in 2019 commit
5fab51581f ("cxgb4: Add MPS TCAM refcounting for raw mac filters")
Remove them.
This was also the last use of cxgb4_mps_ref_dec().
Remove it.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241013203831.88051-3-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
cxgb4_alloc_encap_mac_filt() and cxgb4_free_encap_mac_filt() have been
unused since
commit 28b3870578 ("cxgb4: Re-work the logic for mps refcounting")
Remove them.
Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Reviewed-by: Kalesh AP <kalesh-anakkur.purayil@broadcom.com>
Link: https://patch.msgid.link/20241013203831.88051-2-linux@treblig.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since SLOB was removed and since
commit 6c6c47b063 ("mm, slab: call kvfree_rcu_barrier() from kmem_cache_destroy()"),
it is not necessary to use call_rcu when the callback only performs
kmem_cache_free. Use kfree_rcu() directly.
The changes were made using Coccinelle.
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Acked-by: Paul E. McKenney <paulmck@kernel.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://patch.msgid.link/20241013201704.49576-14-Julia.Lawall@inria.fr
This is a real driver and dev_err_probe will hide the distinction between
EPROBE_DEFER and other errors automatically, so there is no need to
open-code this.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20240906082511.2963890-4-heiko@sntech.de
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The main documentation block seems to be from a time before the driver
handled sleeping and non-sleeping gpios and with that change it seems
updating the doc was overlooked. So do that now.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20240906082511.2963890-3-heiko@sntech.de
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
In contrast to fixed clocks that are described as ungateable, boards
sometimes use additional oscillators for things like PCIe reference
clocks, that need actual supplies to get enabled and enable-gpios to be
toggled for them to work.
This adds a binding for such oscillators that are not configurable
themself, but need to handle supplies for them to work.
In schematics they often can be seen as
----------------
Enable - | 100MHz,3.3V, | - VDD
| 3225 |
GND - | | - OUT
----------------
or similar. The enable pin might be separate but can also just be tied
to the vdd supply, hence it is optional in the binding.
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20240906082511.2963890-2-heiko@sntech.de
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
The documentation which tries to give advices how to properly inserting
delays or sleeps is outdated. The file name is 'timers-howto.rst' which
might be misleading as it is only about delay and sleep mechanisms and not
how to use timers.
Update the documentation by integrating the important parts from the
related function descriptions and move it all into a self explaining file
with the name "delay_sleep_functions.rst".
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-15-dc8b907cb62f@linutronix.de
anysee driver was transformed to use usbv2 years ago. The comments in
anysee_ctrl_msg() still are referencing the old interfaces where msleep()
was used. The v2 interfaces also changed over the years and with commit
1162c7b383 ("[media] dvb_usb_v2: refactor dvb_usbv2_generic_rw()") the
usage of msleep() was gone anyway.
Remove FIXME comment and update also comment before call to
dvb_usbv2_generic_rw_locked().
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-14-dc8b907cb62f@linutronix.de
When commit 38f7b7067d ("powerpc/rtas: rtas_busy_delay() improvements")
was introduced, documentation about proper usage of sleep related functions
was outdated.
The commit message references the usage of a HZ=100 system. When using a
20ms sleep duration on such a system and therefore using msleep(), the
possible additional slack will be +10ms.
When the system is configured with HZ=100 the granularity of a jiffy and of
a bucket of the lowest timer wheel level is 10ms. To make sure a timer will
not expire early (when queueing of the timer races with an concurrent
update of jiffies), timers are always queued into the next bucket. This is
the reason for the maximal possible slack of 10ms.
fsleep() limits the maximal possible slack to 25% by making threshold
between usleep_range() and msleep() HZ dependent. As soon as the accuracy
of msleep() is sufficient, the less expensive timer list timer based
sleeping function is used instead of the more expensive hrtimer based
usleep_range() function. The udelay() will not be used in this specific
usecase as the lowest sleep length is larger than 1 millisecond.
Use fsleep() directly instead of using an own heuristic for the best
sleeping mechanism to use.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-13-dc8b907cb62f@linutronix.de
Function descriptions in iopoll.h, regmap.h, phy.h and sound/soc/sof/ops.h
copied all the same outdated documentation about sleep/delay function
limitations. In those comments, the generic (and still outdated) timer
documentation file is referenced.
As proper function descriptions for used delay and sleep functions are in
place, simply update the descriptions to reference to them. While at it fix
missing colon after "Returns" in function description and move return value
description to the end of the function description.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Andrew Lunn <andrew@lunn.ch> # for phy.h
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-12-dc8b907cb62f@linutronix.de
checkpatch.pl checks for several things related to sleep and delay
functions. In all warnings the outdated documentation is referenced. Also
in checkpatch kernel documentation the outdated documentation is
referenced.
Replace the links to the outdated documentation with links to the function
description.
Note: Update of the outdated checkpatch checks is done in a second step.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-10-dc8b907cb62f@linutronix.de
There is a warning in checkpatch script that triggers, when min and max
arguments of usleep_range_state() are in reverse order. This check does
only cover callsites which uses constants. Add this check into the code as
a WARN_ON_ONCE() to also cover callsites not using constants and fix the
mis-usage by resetting the delta to 0.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-9-dc8b907cb62f@linutronix.de
The upper bound for usleep_range_idle() was taken from the outdated
documentation. As a recommondation for the upper bound of usleep_range()
depends on HZ configuration it is not possible to hard code it.
Use the define "USLEEP_RANGE_UPPER_BOUND" instead.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-8-dc8b907cb62f@linutronix.de
fsleep() simply implements the recommendations of the outdated
documentation in "Documentation/timers/timers-howto.rst". This should be a
user friendly interface to choose always the best timeout function
approach:
- udelay() for very short sleep durations shorter than 10 microseconds
- usleep_range() for sleep durations until 20 milliseconds
- msleep() for the others
The actual implementation has several problems:
- It does not take into account that HZ resolution also has an impact on
granularity of jiffies and has also an impact on the granularity of the
buckets of timer wheel levels. This means that accuracy for the timeout
does not have an upper limit. When executing fsleep(20000) on a HZ=100
system, the possible additional slack will be 50% as the granularity of
the buckets in the lowest level is 10 milliseconds.
- The upper limit of usleep_range() is twice the requested timeout. When no
other interrupts occur in this range, the maximum value is used. This
means that the requested sleep length has then an additional delay of
100%.
Change the thresholds for the decisions in fsleep() to make sure the
maximum slack which is added to the sleep duration is 25%.
Note: Outdated documentation will be updated in a followup patch.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-7-dc8b907cb62f@linutronix.de
udelay() as well as ndelay() are defines and no functions and are using
constants to be able to transform a sleep time into loops and to prevent
too long udelays/ndelays. There was a compiler error with non-const 8 bit
arguments which was fixed by commit a87e553fab ("asm-generic: delay.h fix
udelay and ndelay for 8 bit args"). When using a function, the non-const 8
bit argument is type casted and the problem would be gone.
Transform udelay() and ndelay() into proper functions, remove the no longer
and confusing division, add defines for the magic values and add some
explanations as well.
Suggested-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-6-dc8b907cb62f@linutronix.de
A lot of commonly used functions for inserting a sleep or delay lack a
proper function description. Add function descriptions to all of them to
have important information in a central place close to the code.
No functional change.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-5-dc8b907cb62f@linutronix.de
usleep_idle_range() is a variant of usleep_range(). Both are using
usleep_range_state() as a base. To be able to find all the related
functions in one go, rename it usleep_idle_range() to usleep_range_idle().
No functional change.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-4-dc8b907cb62f@linutronix.de
schedule_timeout*() functions do not have proper kernel-doc formatted
function descriptions. schedule_hrtimeout() and schedule_hrtimeout_range()
have a almost identical description.
Add missing function descriptions. Remove copy of function description and
add a pointer to the existing description instead.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/all/20241014-devel-anna-maria-b4-timers-flseep-v3-3-dc8b907cb62f@linutronix.de
