linux-stable.git/drivers/dpll, branch linux-6.8.y Linux kernel stable tree dpll: fix return value check for kmemdup 2024-05-30T07:49:27+00:00 Chen Ni nichen@iscas.ac.cn 2024-05-13T03:28:24+00:00 0864dce79928ff3e34cd70ca28b01115a6bcf1a5 [ Upstream commit ad506586cb69292b6ac59ab95468aadd54b19ab7 ] The return value of kmemdup() is dst->freq_supported, not src->freq_supported. Update the check accordingly. Fixes: 830ead5fb0c5 ("dpll: fix pin dump crash for rebound module") Signed-off-by: Chen Ni <nichen@iscas.ac.cn> Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com> Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240513032824.2410459-1-nichen@iscas.ac.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ad506586cb69292b6ac59ab95468aadd54b19ab7 ]

The return value of kmemdup() is dst->freq_supported, not
src->freq_supported. Update the check accordingly.

Fixes: 830ead5fb0c5 ("dpll: fix pin dump crash for rebound module")
Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240513032824.2410459-1-nichen@iscas.ac.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dpll: fix dpll_pin_on_pin_register() for multiple parent pins 2024-05-02T14:35:22+00:00 Arkadiusz Kubalewski arkadiusz.kubalewski@intel.com 2024-04-24T10:16:36+00:00 f3e1cf62d18220a3aa97e084e7a3552debece9fc [ Upstream commit 38d7b94e81d068b8d8c8392f421cfd2c3bbfd1a6 ] In scenario where pin is registered with multiple parent pins via dpll_pin_on_pin_register(..), all belonging to the same dpll device. A second call to dpll_pin_on_pin_unregister(..) would cause a call trace, as it tries to use already released registration resources (due to fix introduced in b446631f355e). In this scenario pin was registered twice, so resources are not yet expected to be release until each registered pin/pin pair is unregistered. Currently, the following crash/call trace is produced when ice driver is removed on the system with installed E810T NIC which includes dpll device: WARNING: CPU: 51 PID: 9155 at drivers/dpll/dpll_core.c:809 dpll_pin_ops+0x20/0x30 RIP: 0010:dpll_pin_ops+0x20/0x30 Call Trace: ? __warn+0x7f/0x130 ? dpll_pin_ops+0x20/0x30 dpll_msg_add_pin_freq+0x37/0x1d0 dpll_cmd_pin_get_one+0x1c0/0x400 ? __nlmsg_put+0x63/0x80 dpll_pin_event_send+0x93/0x140 dpll_pin_on_pin_unregister+0x3f/0x100 ice_dpll_deinit_pins+0xa1/0x230 [ice] ice_remove+0xf1/0x210 [ice] Fix by adding a parent pointer as a cookie when creating a registration, also when searching for it. For the regular pins pass NULL, this allows to create separated registration for each parent the pin is registered with. Fixes: b446631f355e ("dpll: fix dpll_xa_ref_*_del() for multiple registrations") Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240424101636.1491424-1-arkadiusz.kubalewski@intel.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 38d7b94e81d068b8d8c8392f421cfd2c3bbfd1a6 ]

In scenario where pin is registered with multiple parent pins via
dpll_pin_on_pin_register(..), all belonging to the same dpll device.
A second call to dpll_pin_on_pin_unregister(..) would cause a call trace,
as it tries to use already released registration resources (due to fix
introduced in b446631f355e). In this scenario pin was registered twice,
so resources are not yet expected to be release until each registered
pin/pin pair is unregistered.

Currently, the following crash/call trace is produced when ice driver is
removed on the system with installed E810T NIC which includes dpll device:

WARNING: CPU: 51 PID: 9155 at drivers/dpll/dpll_core.c:809 dpll_pin_ops+0x20/0x30
RIP: 0010:dpll_pin_ops+0x20/0x30
Call Trace:
 ? __warn+0x7f/0x130
 ? dpll_pin_ops+0x20/0x30
 dpll_msg_add_pin_freq+0x37/0x1d0
 dpll_cmd_pin_get_one+0x1c0/0x400
 ? __nlmsg_put+0x63/0x80
 dpll_pin_event_send+0x93/0x140
 dpll_pin_on_pin_unregister+0x3f/0x100
 ice_dpll_deinit_pins+0xa1/0x230 [ice]
 ice_remove+0xf1/0x210 [ice]

Fix by adding a parent pointer as a cookie when creating a registration,
also when searching for it. For the regular pins pass NULL, this allows to
create separated registration for each parent the pin is registered with.

Fixes: b446631f355e ("dpll: fix dpll_xa_ref_*_del() for multiple registrations")
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240424101636.1491424-1-arkadiusz.kubalewski@intel.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dpll: check that pin is registered in __dpll_pin_unregister() 2024-05-02T14:35:22+00:00 Jiri Pirko jiri@nvidia.com 2024-02-06T07:48:53+00:00 11cbb7a5a3f39dc33f2465ed657780c17a183388 [ Upstream commit 9736c648370d237f61065a7e45e668e2db4374e9 ] Similar to what is done in dpll_device_unregister(), add assertion to __dpll_pin_unregister() to make sure driver does not try to unregister non-registered pin. Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Link: https://lore.kernel.org/r/20240206074853.345744-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 38d7b94e81d0 ("dpll: fix dpll_pin_on_pin_register() for multiple parent pins") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 9736c648370d237f61065a7e45e668e2db4374e9 ]

Similar to what is done in dpll_device_unregister(), add assertion to
__dpll_pin_unregister() to make sure driver does not try to unregister
non-registered pin.

Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Link: https://lore.kernel.org/r/20240206074853.345744-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 38d7b94e81d0 ("dpll: fix dpll_pin_on_pin_register() for multiple parent pins")
Signed-off-by: Sasha Levin <sashal@kernel.org>
dpll: indent DPLL option type by a tab 2024-04-10T14:37:56+00:00 Prasad Pandit pjp@fedoraproject.org 2024-03-22T11:48:19+00:00 63ea013a3f493fda5a80e86127b768409cf589fb [ Upstream commit cc2699268152d8e0386a36fe7c9271d7e23668f2 ] Indent config option type by a tab. It helps Kconfig parsers to read file without error. Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions") Signed-off-by: Prasad Pandit <pjp@fedoraproject.org> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240322114819.1801795-1-ppandit@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit cc2699268152d8e0386a36fe7c9271d7e23668f2 ]

Indent config option type by a tab. It helps Kconfig parsers
to read file without error.

Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions")
Signed-off-by: Prasad Pandit <pjp@fedoraproject.org>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240322114819.1801795-1-ppandit@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dpll: fix dpll_xa_ref_*_del() for multiple registrations 2024-03-26T22:16:56+00:00 Jiri Pirko jiri@nvidia.com 2024-03-06T15:12:40+00:00 b27e32e9367dac024cd6f61f22655714f483fd67 [ Upstream commit b446631f355ece73b13c311dd712c47381a23172 ] Currently, if there are multiple registrations of the same pin on the same dpll device, following warnings are observed: WARNING: CPU: 5 PID: 2212 at drivers/dpll/dpll_core.c:143 dpll_xa_ref_pin_del.isra.0+0x21e/0x230 WARNING: CPU: 5 PID: 2212 at drivers/dpll/dpll_core.c:223 __dpll_pin_unregister+0x2b3/0x2c0 The problem is, that in both dpll_xa_ref_dpll_del() and dpll_xa_ref_pin_del() registration is only removed from list in case the reference count drops to zero. That is wrong, the registration has to be removed always. To fix this, remove the registration from the list and free it unconditionally, instead of doing it only when the ref reference counter reaches zero. Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b446631f355ece73b13c311dd712c47381a23172 ]

Currently, if there are multiple registrations of the same pin on the
same dpll device, following warnings are observed:
WARNING: CPU: 5 PID: 2212 at drivers/dpll/dpll_core.c:143 dpll_xa_ref_pin_del.isra.0+0x21e/0x230
WARNING: CPU: 5 PID: 2212 at drivers/dpll/dpll_core.c:223 __dpll_pin_unregister+0x2b3/0x2c0

The problem is, that in both dpll_xa_ref_dpll_del() and
dpll_xa_ref_pin_del() registration is only removed from list in case the
reference count drops to zero. That is wrong, the registration has to
be removed always.

To fix this, remove the registration from the list and free
it unconditionally, instead of doing it only when the ref reference
counter reaches zero.

Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Rahul Rameshbabu <rrameshbabu@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
dpll: move all dpll<>netdev helpers to dpll code 2024-03-06T02:36:42+00:00 Jakub Kicinski kuba@kernel.org 2024-03-05T01:35:32+00:00 289e922582af5b4721ba02e86bde4d9ba918158a Older versions of GCC really want to know the full definition of the type involved in rcu_assign_pointer(). struct dpll_pin is defined in a local header, net/core can't reach it. Move all the netdev <> dpll code into dpll, where the type is known. Otherwise we'd need multiple function calls to jump between the compilation units. This is the same problem the commit under fixes was trying to address, but with rcu_assign_pointer() not rcu_dereference(). Some of the exports are not needed, networking core can't be a module, we only need exports for the helpers used by drivers. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Link: https://lore.kernel.org/all/35a869c8-52e8-177-1d4d-e57578b99b6@linux-m68k.org/ Fixes: 640f41ed33b5 ("dpll: fix build failure due to rcu_dereference_check() on unknown type") Reviewed-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240305013532.694866-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Older versions of GCC really want to know the full definition
of the type involved in rcu_assign_pointer().

struct dpll_pin is defined in a local header, net/core can't
reach it. Move all the netdev <> dpll code into dpll, where
the type is known. Otherwise we'd need multiple function calls
to jump between the compilation units.

This is the same problem the commit under fixes was trying to address,
but with rcu_assign_pointer() not rcu_dereference().

Some of the exports are not needed, networking core can't
be a module, we only need exports for the helpers used by
drivers.

Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Link: https://lore.kernel.org/all/35a869c8-52e8-177-1d4d-e57578b99b6@linux-m68k.org/
Fixes: 640f41ed33b5 ("dpll: fix build failure due to rcu_dereference_check() on unknown type")
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240305013532.694866-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dpll: fix build failure due to rcu_dereference_check() on unknown type 2024-02-29T20:18:37+00:00 Eric Dumazet edumazet@google.com 2024-02-29T19:05:15+00:00 640f41ed33b5a420e05daf395afae85e6b20c003 Tasmiya reports that their compiler complains that we deref a pointer to unknown type with rcu_dereference_rtnl(): include/linux/rcupdate.h:439:9: error: dereferencing pointer to incomplete type ‘struct dpll_pin’ Unclear what compiler it is, at the moment, and we can't report but since DPLL can't be a module - move the code from the header into the source file. Fixes: 0d60d8df6f49 ("dpll: rely on rcu for netdev_dpll_pin()") Reported-by: Tasmiya Nalatwad <tasmiya@linux.vnet.ibm.com> Link: https://lore.kernel.org/all/3fcf3a2c-1c1b-42c1-bacb-78fdcd700389@linux.vnet.ibm.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/r/20240229190515.2740221-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Tasmiya reports that their compiler complains that we deref
a pointer to unknown type with rcu_dereference_rtnl():

include/linux/rcupdate.h:439:9: error: dereferencing pointer to incomplete type ‘struct dpll_pin’

Unclear what compiler it is, at the moment, and we can't report
but since DPLL can't be a module - move the code from the header
into the source file.

Fixes: 0d60d8df6f49 ("dpll: rely on rcu for netdev_dpll_pin()")
Reported-by: Tasmiya Nalatwad <tasmiya@linux.vnet.ibm.com>
Link: https://lore.kernel.org/all/3fcf3a2c-1c1b-42c1-bacb-78fdcd700389@linux.vnet.ibm.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20240229190515.2740221-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dpll: rely on rcu for netdev_dpll_pin() 2024-02-27T02:39:34+00:00 Eric Dumazet edumazet@google.com 2024-02-23T12:32:08+00:00 0d60d8df6f493bb46bf5db40d39dd60a1bafdd4e This fixes a possible UAF in if_nlmsg_size(), which can run without RTNL. Add rcu protection to "struct dpll_pin" Move netdev_dpll_pin() from netdevice.h to dpll.h to decrease name pollution. Note: This looks possible to no longer acquire RTNL in netdev_dpll_pin_assign() later in net-next. v2: do not force rcu_read_lock() in rtnl_dpll_pin_size() (Jiri Pirko) Fixes: 5f1842692880 ("netdev: expose DPLL pin handle for netdevice") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://lore.kernel.org/r/20240223123208.3543319-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
This fixes a possible UAF in if_nlmsg_size(),
which can run without RTNL.

Add rcu protection to "struct dpll_pin"

Move netdev_dpll_pin() from netdevice.h to dpll.h to
decrease name pollution.

Note: This looks possible to no longer acquire RTNL in
netdev_dpll_pin_assign() later in net-next.

v2: do not force rcu_read_lock() in rtnl_dpll_pin_size() (Jiri Pirko)

Fixes: 5f1842692880 ("netdev: expose DPLL pin handle for netdevice")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Cc: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Link: https://lore.kernel.org/r/20240223123208.3543319-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dpll: fix possible deadlock during netlink dump operation 2024-02-09T02:29:21+00:00 Jiri Pirko jiri@nvidia.com 2024-02-07T11:59:02+00:00 53c0441dd2c44ee93fddb5473885fd41e4bc2361 Recently, I've been hitting following deadlock warning during dpll pin dump: [52804.637962] ====================================================== [52804.638536] WARNING: possible circular locking dependency detected [52804.639111] 6.8.0-rc2jiri+ #1 Not tainted [52804.639529] ------------------------------------------------------ [52804.640104] python3/2984 is trying to acquire lock: [52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780 [52804.641417] but task is already holding lock: [52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20 [52804.642747] which lock already depends on the new lock. [52804.643551] the existing dependency chain (in reverse order) is: [52804.644259] -> #1 (dpll_lock){+.+.}-{3:3}: [52804.644836] lock_acquire+0x174/0x3e0 [52804.645271] __mutex_lock+0x119/0x1150 [52804.645723] dpll_lock_dumpit+0x13/0x20 [52804.646169] genl_start+0x266/0x320 [52804.646578] __netlink_dump_start+0x321/0x450 [52804.647056] genl_family_rcv_msg_dumpit+0x155/0x1e0 [52804.647575] genl_rcv_msg+0x1ed/0x3b0 [52804.648001] netlink_rcv_skb+0xdc/0x210 [52804.648440] genl_rcv+0x24/0x40 [52804.648831] netlink_unicast+0x2f1/0x490 [52804.649290] netlink_sendmsg+0x36d/0x660 [52804.649742] __sock_sendmsg+0x73/0xc0 [52804.650165] __sys_sendto+0x184/0x210 [52804.650597] __x64_sys_sendto+0x72/0x80 [52804.651045] do_syscall_64+0x6f/0x140 [52804.651474] entry_SYSCALL_64_after_hwframe+0x46/0x4e [52804.652001] -> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}: [52804.652650] check_prev_add+0x1ae/0x1280 [52804.653107] __lock_acquire+0x1ed3/0x29a0 [52804.653559] lock_acquire+0x174/0x3e0 [52804.653984] __mutex_lock+0x119/0x1150 [52804.654423] netlink_dump+0xb3/0x780 [52804.654845] __netlink_dump_start+0x389/0x450 [52804.655321] genl_family_rcv_msg_dumpit+0x155/0x1e0 [52804.655842] genl_rcv_msg+0x1ed/0x3b0 [52804.656272] netlink_rcv_skb+0xdc/0x210 [52804.656721] genl_rcv+0x24/0x40 [52804.657119] netlink_unicast+0x2f1/0x490 [52804.657570] netlink_sendmsg+0x36d/0x660 [52804.658022] __sock_sendmsg+0x73/0xc0 [52804.658450] __sys_sendto+0x184/0x210 [52804.658877] __x64_sys_sendto+0x72/0x80 [52804.659322] do_syscall_64+0x6f/0x140 [52804.659752] entry_SYSCALL_64_after_hwframe+0x46/0x4e [52804.660281] other info that might help us debug this: [52804.661077] Possible unsafe locking scenario: [52804.661671] CPU0 CPU1 [52804.662129] ---- ---- [52804.662577] lock(dpll_lock); [52804.662924] lock(nlk_cb_mutex-GENERIC); [52804.663538] lock(dpll_lock); [52804.664073] lock(nlk_cb_mutex-GENERIC); [52804.664490] The issue as follows: __netlink_dump_start() calls control->start(cb) with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken. Then nlk->cb_mutex is released and taken again in netlink_dump(), while dpll_lock still being held. That leads to ABBA deadlock when another CPU races with the same operation. Fix this by moving dpll_lock taking into dumpit() callback which ensures correct lock taking order. Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Link: https://lore.kernel.org/r/20240207115902.371649-1-jiri@resnulli.us Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Recently, I've been hitting following deadlock warning during dpll pin
dump:

[52804.637962] ======================================================
[52804.638536] WARNING: possible circular locking dependency detected
[52804.639111] 6.8.0-rc2jiri+ #1 Not tainted
[52804.639529] ------------------------------------------------------
[52804.640104] python3/2984 is trying to acquire lock:
[52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780
[52804.641417]
               but task is already holding lock:
[52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20
[52804.642747]
               which lock already depends on the new lock.

[52804.643551]
               the existing dependency chain (in reverse order) is:
[52804.644259]
               -> #1 (dpll_lock){+.+.}-{3:3}:
[52804.644836]        lock_acquire+0x174/0x3e0
[52804.645271]        __mutex_lock+0x119/0x1150
[52804.645723]        dpll_lock_dumpit+0x13/0x20
[52804.646169]        genl_start+0x266/0x320
[52804.646578]        __netlink_dump_start+0x321/0x450
[52804.647056]        genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.647575]        genl_rcv_msg+0x1ed/0x3b0
[52804.648001]        netlink_rcv_skb+0xdc/0x210
[52804.648440]        genl_rcv+0x24/0x40
[52804.648831]        netlink_unicast+0x2f1/0x490
[52804.649290]        netlink_sendmsg+0x36d/0x660
[52804.649742]        __sock_sendmsg+0x73/0xc0
[52804.650165]        __sys_sendto+0x184/0x210
[52804.650597]        __x64_sys_sendto+0x72/0x80
[52804.651045]        do_syscall_64+0x6f/0x140
[52804.651474]        entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.652001]
               -> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}:
[52804.652650]        check_prev_add+0x1ae/0x1280
[52804.653107]        __lock_acquire+0x1ed3/0x29a0
[52804.653559]        lock_acquire+0x174/0x3e0
[52804.653984]        __mutex_lock+0x119/0x1150
[52804.654423]        netlink_dump+0xb3/0x780
[52804.654845]        __netlink_dump_start+0x389/0x450
[52804.655321]        genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.655842]        genl_rcv_msg+0x1ed/0x3b0
[52804.656272]        netlink_rcv_skb+0xdc/0x210
[52804.656721]        genl_rcv+0x24/0x40
[52804.657119]        netlink_unicast+0x2f1/0x490
[52804.657570]        netlink_sendmsg+0x36d/0x660
[52804.658022]        __sock_sendmsg+0x73/0xc0
[52804.658450]        __sys_sendto+0x184/0x210
[52804.658877]        __x64_sys_sendto+0x72/0x80
[52804.659322]        do_syscall_64+0x6f/0x140
[52804.659752]        entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.660281]
               other info that might help us debug this:

[52804.661077]  Possible unsafe locking scenario:

[52804.661671]        CPU0                    CPU1
[52804.662129]        ----                    ----
[52804.662577]   lock(dpll_lock);
[52804.662924]                                lock(nlk_cb_mutex-GENERIC);
[52804.663538]                                lock(dpll_lock);
[52804.664073]   lock(nlk_cb_mutex-GENERIC);
[52804.664490]

The issue as follows: __netlink_dump_start() calls control->start(cb)
with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken.
Then nlk->cb_mutex is released and taken again in netlink_dump(), while
dpll_lock still being held. That leads to ABBA deadlock when another
CPU races with the same operation.

Fix this by moving dpll_lock taking into dumpit() callback which ensures
correct lock taking order.

Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
Signed-off-by: Jiri Pirko <jiri@nvidia.com>
Reviewed-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Link: https://lore.kernel.org/r/20240207115902.371649-1-jiri@resnulli.us
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dpll: fix register pin with unregistered parent pin 2024-01-22T11:01:11+00:00 Arkadiusz Kubalewski arkadiusz.kubalewski@intel.com 2024-01-19T13:43:04+00:00 7dc5b18ff71bd6f948810ab8a08b6a6ff8b315c5 In case of multiple kernel module instances using the same dpll device: if only one registers dpll device, then only that one can register directly connected pins with a dpll device. When unregistered parent is responsible for determining if the muxed pin can be registered with it or not, the drivers need to be loaded in serialized order to work correctly - first the driver instance which registers the direct pins needs to be loaded, then the other instances could register muxed type pins. Allow registration of a pin with a parent even if the parent was not yet registered, thus allow ability for unserialized driver instance load order. Do not WARN_ON notification for unregistered pin, which can be invoked for described case, instead just return error. Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions") Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions") Reviewed-by: Jan Glaza <jan.glaza@intel.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> 
In case of multiple kernel module instances using the same dpll device:
if only one registers dpll device, then only that one can register
directly connected pins with a dpll device. When unregistered parent is
responsible for determining if the muxed pin can be registered with it
or not, the drivers need to be loaded in serialized order to work
correctly - first the driver instance which registers the direct pins
needs to be loaded, then the other instances could register muxed type
pins.

Allow registration of a pin with a parent even if the parent was not
yet registered, thus allow ability for unserialized driver instance
load order.
Do not WARN_ON notification for unregistered pin, which can be invoked
for described case, instead just return error.

Fixes: 9431063ad323 ("dpll: core: Add DPLL framework base functions")
Fixes: 9d71b54b65b1 ("dpll: netlink: Add DPLL framework base functions")
Reviewed-by: Jan Glaza <jan.glaza@intel.com>
Reviewed-by: Jiri Pirko <jiri@nvidia.com>
Signed-off-by: Arkadiusz Kubalewski <arkadiusz.kubalewski@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>