linux-stable.git/arch/s390/include, branch linux-rolling-lts Linux kernel stable tree s390: Revert support for DCACHE_WORD_ACCESS 2026-07-18T14:53:20+00:00 Heiko Carstens hca@linux.ibm.com 2026-06-11T15:37:46+00:00 be79d285bea70d0edd5015bd487311bfa8cbebc9 commit 37540b8c287fc817bdbd0c62bb75ad6eab0e5d03 upstream. load_unaligned_zeropad() reads eight bytes from unaligned addresses and may cross page boundaries. It handles exceptions which may happen if reading from the second page results in an exception. For pages which are donated to the Ultravisor for secure execution purposes the do_secure_storage_access() exception handler however does not handle such exceptions correctly. Such an exception may result in an endless exception loop which will never be resolved. An attempt to fix this [1] turned out to be not sufficient. For now revert load_unaligned_zeropad() until this problem has been resolved in a proper way. Note that the implementation of load_unaligned_zeropad() itself is correct. The revert is just a temporary workaround until there is complete fix for secure storage access exceptions. [1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory") Fixes: 802ba53eefc5 ("s390: add support for DCACHE_WORD_ACCESS") Cc: stable@vger.kernel.org Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 37540b8c287fc817bdbd0c62bb75ad6eab0e5d03 upstream.

load_unaligned_zeropad() reads eight bytes from unaligned addresses and may
cross page boundaries. It handles exceptions which may happen if reading
from the second page results in an exception.

For pages which are donated to the Ultravisor for secure execution purposes
the do_secure_storage_access() exception handler however does not handle
such exceptions correctly. Such an exception may result in an endless
exception loop which will never be resolved.

An attempt to fix this [1] turned out to be not sufficient. For now revert
load_unaligned_zeropad() until this problem has been resolved in a proper
way.

Note that the implementation of load_unaligned_zeropad() itself is
correct. The revert is just a temporary workaround until there is complete
fix for secure storage access exceptions.

[1] commit b00be77302d7 ("s390/mm: Add missing secure storage access fixups for donated memory")

Fixes: 802ba53eefc5 ("s390: add support for DCACHE_WORD_ACCESS")
Cc: stable@vger.kernel.org
Acked-by: Christian Borntraeger <borntraeger@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ring-buffer: Flush and stop persistent ring buffer on panic 2026-06-01T15:50:44+00:00 Masami Hiramatsu (Google) mhiramat@kernel.org 2026-04-30T03:28:16+00:00 2bc60c175568ecf0e8b7803dcbf54bd61f3cf76e commit a494d3c8d5392bcdff83c2a593df0c160ff9f322 upstream. On real hardware, panic and machine reboot may not flush hardware cache to memory. This means the persistent ring buffer, which relies on a coherent state of memory, may not have its events written to the buffer and they may be lost. Moreover, there may be inconsistency with the counters which are used for validation of the integrity of the persistent ring buffer which may cause all data to be discarded. To avoid this issue, stop recording of the ring buffer on panic and flush the cache of the ring buffer's memory. Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance") Cc: stable@vger.kernel.org Cc: Will Deacon <will@kernel.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Ian Rogers <irogers@google.com> Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit a494d3c8d5392bcdff83c2a593df0c160ff9f322 upstream.

On real hardware, panic and machine reboot may not flush hardware cache
to memory. This means the persistent ring buffer, which relies on a
coherent state of memory, may not have its events written to the buffer
and they may be lost. Moreover, there may be inconsistency with the
counters which are used for validation of the integrity of the
persistent ring buffer which may cause all data to be discarded.

To avoid this issue, stop recording of the ring buffer on panic and
flush the cache of the ring buffer's memory.

Fixes: e645535a954a ("tracing: Add option to use memmapped memory for trace boot instance")
Cc: stable@vger.kernel.org
Cc: Will Deacon <will@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Ian Rogers <irogers@google.com>
Link: https://patch.msgid.link/177751969602.2136606.12031934362587643488.stgit@mhiramat.tok.corp.google.com
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s390/barrier: Make array_index_mask_nospec() __always_inline 2026-04-02T11:23:16+00:00 Vasily Gorbik gor@linux.ibm.com 2026-03-26T13:38:44+00:00 3d39a4ec6380835edd7f097f24c4bbef31ca3b80 commit c5c0a268b38adffbb2e70e6957017537ff54c157 upstream. Mark array_index_mask_nospec() as __always_inline to guarantee the mitigation is emitted inline regardless of compiler inlining decisions. Fixes: e2dd833389cc ("s390: add optimized array_index_mask_nospec") Cc: stable@kernel.org Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c5c0a268b38adffbb2e70e6957017537ff54c157 upstream.

Mark array_index_mask_nospec() as __always_inline to guarantee the
mitigation is emitted inline regardless of compiler inlining decisions.

Fixes: e2dd833389cc ("s390: add optimized array_index_mask_nospec")
Cc: stable@kernel.org
Reviewed-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s390/stackleak: Fix __stackleak_poison() inline assembly constraint 2026-03-19T15:08:38+00:00 Heiko Carstens hca@linux.ibm.com 2026-03-02T13:35:00+00:00 a547ffcb9b1d58f885ee9078c0da94acdbc464ee commit 674c5ff0f440a051ebf299d29a4c013133d81a65 upstream. The __stackleak_poison() inline assembly comes with a "count" operand where the "d" constraint is used. "count" is used with the exrl instruction and "d" means that the compiler may allocate any register from 0 to 15. If the compiler would allocate register 0 then the exrl instruction would not or the value of "count" into the executed instruction - resulting in a stackframe which is only partially poisoned. Use the correct "a" constraint, which excludes register 0 from register allocation. Fixes: 2a405f6bb3a5 ("s390/stackleak: provide fast __stackleak_poison() implementation") Cc: stable@vger.kernel.org Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Reviewed-by: Vasily Gorbik <gor@linux.ibm.com> Link: https://lore.kernel.org/r/20260302133500.1560531-4-hca@linux.ibm.com Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 674c5ff0f440a051ebf299d29a4c013133d81a65 upstream.

The __stackleak_poison() inline assembly comes with a "count" operand where
the "d" constraint is used. "count" is used with the exrl instruction and
"d" means that the compiler may allocate any register from 0 to 15.

If the compiler would allocate register 0 then the exrl instruction would
not or the value of "count" into the executed instruction - resulting in a
stackframe which is only partially poisoned.

Use the correct "a" constraint, which excludes register 0 from register
allocation.

Fixes: 2a405f6bb3a5 ("s390/stackleak: provide fast __stackleak_poison() implementation")
Cc: stable@vger.kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Reviewed-by: Vasily Gorbik <gor@linux.ibm.com>
Link: https://lore.kernel.org/r/20260302133500.1560531-4-hca@linux.ibm.com
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s390/idle: Fix cpu idle exit cpu time accounting 2026-03-12T11:09:17+00:00 Heiko Carstens hca@linux.ibm.com 2026-02-18T14:20:04+00:00 d30168b0cbc132626807341538fe5ae4b9b90d2d [ Upstream commit 0d785e2c324c90662baa4fe07a0d02233ff92824 ] With the conversion to generic entry [1] cpu idle exit cpu time accounting was converted from assembly to C. This introduced an reversed order of cpu time accounting. On cpu idle exit the current accounting happens with the following call chain: -> do_io_irq()/do_ext_irq() -> irq_enter_rcu() -> account_hardirq_enter() -> vtime_account_irq() -> vtime_account_kernel() vtime_account_kernel() accounts the passed cpu time since last_update_timer as system time, and updates last_update_timer to the current cpu timer value. However the subsequent call of -> account_idle_time_irq() will incorrectly subtract passed cpu time from timer_idle_enter to the updated last_update_timer value from system_timer. Then last_update_timer is updated to a sys_enter_timer, which means that last_update_timer goes back in time. Subsequently account_hardirq_exit() will account too much cpu time as hardirq time. The sum of all accounted cpu times is still correct, however some cpu time which was previously accounted as system time is now accounted as hardirq time, plus there is the oddity that last_update_timer goes back in time. Restore previous behavior by extracting cpu time accounting code from account_idle_time_irq() into a new update_timer_idle() function and call it before irq_enter_rcu(). Fixes: 56e62a737028 ("s390: convert to generic entry") [1] Reviewed-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0d785e2c324c90662baa4fe07a0d02233ff92824 ]

With the conversion to generic entry [1] cpu idle exit cpu time accounting
was converted from assembly to C. This introduced an reversed order of cpu
time accounting.

On cpu idle exit the current accounting happens with the following call
chain:

-> do_io_irq()/do_ext_irq()
 -> irq_enter_rcu()
  -> account_hardirq_enter()
   -> vtime_account_irq()
    -> vtime_account_kernel()

vtime_account_kernel() accounts the passed cpu time since last_update_timer
as system time, and updates last_update_timer to the current cpu timer
value.

However the subsequent call of

 -> account_idle_time_irq()

will incorrectly subtract passed cpu time from timer_idle_enter to the
updated last_update_timer value from system_timer. Then last_update_timer
is updated to a sys_enter_timer, which means that last_update_timer goes
back in time.

Subsequently account_hardirq_exit() will account too much cpu time as
hardirq time. The sum of all accounted cpu times is still correct, however
some cpu time which was previously accounted as system time is now
accounted as hardirq time, plus there is the oddity that last_update_timer
goes back in time.

Restore previous behavior by extracting cpu time accounting code from
account_idle_time_irq() into a new update_timer_idle() function and call it
before irq_enter_rcu().

Fixes: 56e62a737028 ("s390: convert to generic entry") [1]
Reviewed-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
s390/ipl: Clear SBP flag when bootprog is set 2026-01-02T11:57:25+00:00 Sven Schnelle svens@linux.ibm.com 2025-12-05T09:58:57+00:00 0f5940176ad6f43b7a182612460b4df84368a09a commit b1aa01d31249bd116b18c7f512d3e46b4b4ad83b upstream. With z16 a new flag 'search boot program' was introduced for list-directed IPL (SCSI, NVMe, ECKD DASD). If this flag is set, e.g. via selecting the "Automatic" value for the "Boot program selector" control on an HMC load panel, it is copied to the reipl structure from the initial ipl structure. When a user now sets a boot prog via sysfs, the flag is not cleared and the bootloader will again automatically select the boot program, ignoring user configuration. To avoid that, clear the SBP flag when a bootprog sysfs file is written. Cc: stable@vger.kernel.org Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com> Reviewed-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sven Schnelle <svens@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b1aa01d31249bd116b18c7f512d3e46b4b4ad83b upstream.

With z16 a new flag 'search boot program' was introduced for
list-directed IPL (SCSI, NVMe, ECKD DASD). If this flag is set,
e.g. via selecting the "Automatic" value for the "Boot program
selector" control on an HMC load panel, it is copied to the reipl
structure from the initial ipl structure. When a user now sets a
boot prog via sysfs, the flag is not cleared and the bootloader
will again automatically select the boot program, ignoring user
configuration.

To avoid that, clear the SBP flag when a bootprog sysfs file is
written.

Cc: stable@vger.kernel.org
Reviewed-by: Peter Oberparleiter <oberpar@linux.ibm.com>
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
s390/fpu: Fix false-positive kmsan report in fpu_vstl() 2025-12-18T13:03:00+00:00 Aleksei Nikiforov aleksei.nikiforov@linux.ibm.com 2025-11-07T15:59:16+00:00 13dcd6308cb8f67134ee5d5d762b2a66363c695b [ Upstream commit 14e4e4175b64dd9216b522f6ece8af6997d063b2 ] A false-positive kmsan report is detected when running ping command. An inline assembly instruction 'vstl' can write varied amount of bytes depending on value of 'index' argument. If 'index' > 0, 'vstl' writes at least 2 bytes. clang generates kmsan write helper call depending on inline assembly constraints. Constraints are evaluated compile-time, but value of 'index' argument is known only at runtime. clang currently generates call to __msan_instrument_asm_store with 1 byte as size. Manually call kmsan function to indicate correct amount of bytes written and fix false-positive report. This change fixes following kmsan reports: [ 36.563119] ===================================================== [ 36.563594] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70 [ 36.563852] virtqueue_add+0x35c6/0x7c70 [ 36.564016] virtqueue_add_outbuf+0xa0/0xb0 [ 36.564266] start_xmit+0x288c/0x4a20 [ 36.564460] dev_hard_start_xmit+0x302/0x900 [ 36.564649] sch_direct_xmit+0x340/0xea0 [ 36.564894] __dev_queue_xmit+0x2e94/0x59b0 [ 36.565058] neigh_resolve_output+0x936/0xb40 [ 36.565278] __neigh_update+0x2f66/0x3a60 [ 36.565499] neigh_update+0x52/0x60 [ 36.565683] arp_process+0x1588/0x2de0 [ 36.565916] NF_HOOK+0x1da/0x240 [ 36.566087] arp_rcv+0x3e4/0x6e0 [ 36.566306] __netif_receive_skb_list_core+0x1374/0x15a0 [ 36.566527] netif_receive_skb_list_internal+0x1116/0x17d0 [ 36.566710] napi_complete_done+0x376/0x740 [ 36.566918] virtnet_poll+0x1bae/0x2910 [ 36.567130] __napi_poll+0xf4/0x830 [ 36.567294] net_rx_action+0x97c/0x1ed0 [ 36.567556] handle_softirqs+0x306/0xe10 [ 36.567731] irq_exit_rcu+0x14c/0x2e0 [ 36.567910] do_io_irq+0xd4/0x120 [ 36.568139] io_int_handler+0xc2/0xe8 [ 36.568299] arch_cpu_idle+0xb0/0xc0 [ 36.568540] arch_cpu_idle+0x76/0xc0 [ 36.568726] default_idle_call+0x40/0x70 [ 36.568953] do_idle+0x1d6/0x390 [ 36.569486] cpu_startup_entry+0x9a/0xb0 [ 36.569745] rest_init+0x1ea/0x290 [ 36.570029] start_kernel+0x95e/0xb90 [ 36.570348] startup_continue+0x2e/0x40 [ 36.570703] [ 36.570798] Uninit was created at: [ 36.571002] kmem_cache_alloc_node_noprof+0x9e8/0x10e0 [ 36.571261] kmalloc_reserve+0x12a/0x470 [ 36.571553] __alloc_skb+0x310/0x860 [ 36.571844] __ip_append_data+0x483e/0x6a30 [ 36.572170] ip_append_data+0x11c/0x1e0 [ 36.572477] raw_sendmsg+0x1c8c/0x2180 [ 36.572818] inet_sendmsg+0xe6/0x190 [ 36.573142] __sys_sendto+0x55e/0x8e0 [ 36.573392] __s390x_sys_socketcall+0x19ae/0x2ba0 [ 36.573571] __do_syscall+0x12e/0x240 [ 36.573823] system_call+0x6e/0x90 [ 36.573976] [ 36.574017] Byte 35 of 98 is uninitialized [ 36.574082] Memory access of size 98 starts at 0000000007aa0012 [ 36.574218] [ 36.574325] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G B N 6.17.0-dirty #16 NONE [ 36.574541] Tainted: [B]=BAD_PAGE, [N]=TEST [ 36.574617] Hardware name: IBM 3931 A01 703 (KVM/Linux) [ 36.574755] ===================================================== [ 63.532541] ===================================================== [ 63.533639] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70 [ 63.533989] virtqueue_add+0x35c6/0x7c70 [ 63.534940] virtqueue_add_outbuf+0xa0/0xb0 [ 63.535861] start_xmit+0x288c/0x4a20 [ 63.536708] dev_hard_start_xmit+0x302/0x900 [ 63.537020] sch_direct_xmit+0x340/0xea0 [ 63.537997] __dev_queue_xmit+0x2e94/0x59b0 [ 63.538819] neigh_resolve_output+0x936/0xb40 [ 63.539793] ip_finish_output2+0x1ee2/0x2200 [ 63.540784] __ip_finish_output+0x272/0x7a0 [ 63.541765] ip_finish_output+0x4e/0x5e0 [ 63.542791] ip_output+0x166/0x410 [ 63.543771] ip_push_pending_frames+0x1a2/0x470 [ 63.544753] raw_sendmsg+0x1f06/0x2180 [ 63.545033] inet_sendmsg+0xe6/0x190 [ 63.546006] __sys_sendto+0x55e/0x8e0 [ 63.546859] __s390x_sys_socketcall+0x19ae/0x2ba0 [ 63.547730] __do_syscall+0x12e/0x240 [ 63.548019] system_call+0x6e/0x90 [ 63.548989] [ 63.549779] Uninit was created at: [ 63.550691] kmem_cache_alloc_node_noprof+0x9e8/0x10e0 [ 63.550975] kmalloc_reserve+0x12a/0x470 [ 63.551969] __alloc_skb+0x310/0x860 [ 63.552949] __ip_append_data+0x483e/0x6a30 [ 63.553902] ip_append_data+0x11c/0x1e0 [ 63.554912] raw_sendmsg+0x1c8c/0x2180 [ 63.556719] inet_sendmsg+0xe6/0x190 [ 63.557534] __sys_sendto+0x55e/0x8e0 [ 63.557875] __s390x_sys_socketcall+0x19ae/0x2ba0 [ 63.558869] __do_syscall+0x12e/0x240 [ 63.559832] system_call+0x6e/0x90 [ 63.560780] [ 63.560972] Byte 35 of 98 is uninitialized [ 63.561741] Memory access of size 98 starts at 0000000005704312 [ 63.561950] [ 63.562824] CPU: 3 UID: 0 PID: 192 Comm: ping Tainted: G B N 6.17.0-dirty #16 NONE [ 63.563868] Tainted: [B]=BAD_PAGE, [N]=TEST [ 63.564751] Hardware name: IBM 3931 A01 703 (KVM/Linux) [ 63.564986] ===================================================== Fixes: dcd3e1de9d17 ("s390/checksum: provide csum_partial_copy_nocheck()") Signed-off-by: Aleksei Nikiforov <aleksei.nikiforov@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 14e4e4175b64dd9216b522f6ece8af6997d063b2 ]

A false-positive kmsan report is detected when running ping command.

An inline assembly instruction 'vstl' can write varied amount of bytes
depending on value of 'index' argument. If 'index' > 0, 'vstl' writes
at least 2 bytes.

clang generates kmsan write helper call depending on inline assembly
constraints. Constraints are evaluated compile-time, but value of
'index' argument is known only at runtime.

clang currently generates call to __msan_instrument_asm_store with 1 byte
as size. Manually call kmsan function to indicate correct amount of bytes
written and fix false-positive report.

This change fixes following kmsan reports:

[   36.563119] =====================================================
[   36.563594] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70
[   36.563852]  virtqueue_add+0x35c6/0x7c70
[   36.564016]  virtqueue_add_outbuf+0xa0/0xb0
[   36.564266]  start_xmit+0x288c/0x4a20
[   36.564460]  dev_hard_start_xmit+0x302/0x900
[   36.564649]  sch_direct_xmit+0x340/0xea0
[   36.564894]  __dev_queue_xmit+0x2e94/0x59b0
[   36.565058]  neigh_resolve_output+0x936/0xb40
[   36.565278]  __neigh_update+0x2f66/0x3a60
[   36.565499]  neigh_update+0x52/0x60
[   36.565683]  arp_process+0x1588/0x2de0
[   36.565916]  NF_HOOK+0x1da/0x240
[   36.566087]  arp_rcv+0x3e4/0x6e0
[   36.566306]  __netif_receive_skb_list_core+0x1374/0x15a0
[   36.566527]  netif_receive_skb_list_internal+0x1116/0x17d0
[   36.566710]  napi_complete_done+0x376/0x740
[   36.566918]  virtnet_poll+0x1bae/0x2910
[   36.567130]  __napi_poll+0xf4/0x830
[   36.567294]  net_rx_action+0x97c/0x1ed0
[   36.567556]  handle_softirqs+0x306/0xe10
[   36.567731]  irq_exit_rcu+0x14c/0x2e0
[   36.567910]  do_io_irq+0xd4/0x120
[   36.568139]  io_int_handler+0xc2/0xe8
[   36.568299]  arch_cpu_idle+0xb0/0xc0
[   36.568540]  arch_cpu_idle+0x76/0xc0
[   36.568726]  default_idle_call+0x40/0x70
[   36.568953]  do_idle+0x1d6/0x390
[   36.569486]  cpu_startup_entry+0x9a/0xb0
[   36.569745]  rest_init+0x1ea/0x290
[   36.570029]  start_kernel+0x95e/0xb90
[   36.570348]  startup_continue+0x2e/0x40
[   36.570703]
[   36.570798] Uninit was created at:
[   36.571002]  kmem_cache_alloc_node_noprof+0x9e8/0x10e0
[   36.571261]  kmalloc_reserve+0x12a/0x470
[   36.571553]  __alloc_skb+0x310/0x860
[   36.571844]  __ip_append_data+0x483e/0x6a30
[   36.572170]  ip_append_data+0x11c/0x1e0
[   36.572477]  raw_sendmsg+0x1c8c/0x2180
[   36.572818]  inet_sendmsg+0xe6/0x190
[   36.573142]  __sys_sendto+0x55e/0x8e0
[   36.573392]  __s390x_sys_socketcall+0x19ae/0x2ba0
[   36.573571]  __do_syscall+0x12e/0x240
[   36.573823]  system_call+0x6e/0x90
[   36.573976]
[   36.574017] Byte 35 of 98 is uninitialized
[   36.574082] Memory access of size 98 starts at 0000000007aa0012
[   36.574218]
[   36.574325] CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G    B            N  6.17.0-dirty #16 NONE
[   36.574541] Tainted: [B]=BAD_PAGE, [N]=TEST
[   36.574617] Hardware name: IBM 3931 A01 703 (KVM/Linux)
[   36.574755] =====================================================

[   63.532541] =====================================================
[   63.533639] BUG: KMSAN: uninit-value in virtqueue_add+0x35c6/0x7c70
[   63.533989]  virtqueue_add+0x35c6/0x7c70
[   63.534940]  virtqueue_add_outbuf+0xa0/0xb0
[   63.535861]  start_xmit+0x288c/0x4a20
[   63.536708]  dev_hard_start_xmit+0x302/0x900
[   63.537020]  sch_direct_xmit+0x340/0xea0
[   63.537997]  __dev_queue_xmit+0x2e94/0x59b0
[   63.538819]  neigh_resolve_output+0x936/0xb40
[   63.539793]  ip_finish_output2+0x1ee2/0x2200
[   63.540784]  __ip_finish_output+0x272/0x7a0
[   63.541765]  ip_finish_output+0x4e/0x5e0
[   63.542791]  ip_output+0x166/0x410
[   63.543771]  ip_push_pending_frames+0x1a2/0x470
[   63.544753]  raw_sendmsg+0x1f06/0x2180
[   63.545033]  inet_sendmsg+0xe6/0x190
[   63.546006]  __sys_sendto+0x55e/0x8e0
[   63.546859]  __s390x_sys_socketcall+0x19ae/0x2ba0
[   63.547730]  __do_syscall+0x12e/0x240
[   63.548019]  system_call+0x6e/0x90
[   63.548989]
[   63.549779] Uninit was created at:
[   63.550691]  kmem_cache_alloc_node_noprof+0x9e8/0x10e0
[   63.550975]  kmalloc_reserve+0x12a/0x470
[   63.551969]  __alloc_skb+0x310/0x860
[   63.552949]  __ip_append_data+0x483e/0x6a30
[   63.553902]  ip_append_data+0x11c/0x1e0
[   63.554912]  raw_sendmsg+0x1c8c/0x2180
[   63.556719]  inet_sendmsg+0xe6/0x190
[   63.557534]  __sys_sendto+0x55e/0x8e0
[   63.557875]  __s390x_sys_socketcall+0x19ae/0x2ba0
[   63.558869]  __do_syscall+0x12e/0x240
[   63.559832]  system_call+0x6e/0x90
[   63.560780]
[   63.560972] Byte 35 of 98 is uninitialized
[   63.561741] Memory access of size 98 starts at 0000000005704312
[   63.561950]
[   63.562824] CPU: 3 UID: 0 PID: 192 Comm: ping Tainted: G    B            N  6.17.0-dirty #16 NONE
[   63.563868] Tainted: [B]=BAD_PAGE, [N]=TEST
[   63.564751] Hardware name: IBM 3931 A01 703 (KVM/Linux)
[   63.564986] =====================================================

Fixes: dcd3e1de9d17 ("s390/checksum: provide csum_partial_copy_nocheck()")
Signed-off-by: Aleksei Nikiforov <aleksei.nikiforov@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
s390/mm: Fix __ptep_rdp() inline assembly 2025-11-14T14:58:20+00:00 Heiko Carstens hca@linux.ibm.com 2025-11-13T12:21:47+00:00 31475b88110c4725b4f9a79c3a0d9bbf97e69e1c When a zero ASCE is passed to the __ptep_rdp() inline assembly, the generated instruction should have the R3 field of the instruction set to zero. However the inline assembly is written incorrectly: for such cases a zero is loaded into a register allocated by the compiler and this register is then used by the instruction. This means that selected TLB entries may not be flushed since the specified ASCE does not match the one which was used when the selected TLB entries were created. Fix this by removing the asce and opt parameters of __ptep_rdp(), since all callers always pass zero, and use a hard-coded register zero for the R3 field. Fixes: 0807b856521f ("s390/mm: add support for RDP (Reset DAT-Protection)") Cc: stable@vger.kernel.org Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
When a zero ASCE is passed to the __ptep_rdp() inline assembly, the
generated instruction should have the R3 field of the instruction set to
zero. However the inline assembly is written incorrectly: for such cases a
zero is loaded into a register allocated by the compiler and this register
is then used by the instruction.

This means that selected TLB entries may not be flushed since the specified
ASCE does not match the one which was used when the selected TLB entries
were created.

Fix this by removing the asce and opt parameters of __ptep_rdp(), since
all callers always pass zero, and use a hard-coded register zero for
the R3 field.

Fixes: 0807b856521f ("s390/mm: add support for RDP (Reset DAT-Protection)")
Cc: stable@vger.kernel.org
Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
s390/pci: Restore IRQ unconditionally for the zPCI device 2025-10-24T13:25:43+00:00 Farhan Ali alifm@linux.ibm.com 2025-10-22T16:47:26+00:00 b45873c3f09153d1ad9b3a7bf9e5c0b0387fd2ea Commit c1e18c17bda6 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()"), introduced the zpci_set_irq() and zpci_clear_irq(), to be used while resetting a zPCI device. Commit da995d538d3a ("s390/pci: implement reset_slot for hotplug slot"), mentions zpci_clear_irq() being called in the path for zpci_hot_reset_device(). But that is not the case anymore and these functions are not called outside of this file. Instead zpci_hot_reset_device() relies on zpci_disable_device() also clearing the IRQs, but misses to reset the zdev->irqs_registered flag. However after a CLP disable/enable reset, the device's IRQ are unregistered, but the flag zdev->irq_registered does not get cleared. It creates an inconsistent state and so arch_restore_msi_irqs() doesn't correctly restore the device's IRQ. This becomes a problem when a PCI driver tries to restore the state of the device through pci_restore_state(). Restore IRQ unconditionally for the device and remove the irq_registered flag as its redundant. Fixes: c1e18c17bda6 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()") Cc: stable@vger.kernnel.org Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com> Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com> Signed-off-by: Farhan Ali <alifm@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> 
Commit c1e18c17bda6 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()"),
introduced the zpci_set_irq() and zpci_clear_irq(), to be used while
resetting a zPCI device.

Commit da995d538d3a ("s390/pci: implement reset_slot for hotplug
slot"), mentions zpci_clear_irq() being called in the path for
zpci_hot_reset_device().  But that is not the case anymore and these
functions are not called outside of this file. Instead
zpci_hot_reset_device() relies on zpci_disable_device() also clearing
the IRQs, but misses to reset the zdev->irqs_registered flag.

However after a CLP disable/enable reset, the device's IRQ are
unregistered, but the flag zdev->irq_registered does not get cleared. It
creates an inconsistent state and so arch_restore_msi_irqs() doesn't
correctly restore the device's IRQ. This becomes a problem when a PCI
driver tries to restore the state of the device through
pci_restore_state(). Restore IRQ unconditionally for the device and remove
the irq_registered flag as its redundant.

Fixes: c1e18c17bda6 ("s390/pci: add zpci_set_irq()/zpci_clear_irq()")
Cc: stable@vger.kernnel.org
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Reviewed-by: Matthew Rosato <mjrosato@linux.ibm.com>
Signed-off-by: Farhan Ali <alifm@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Merge tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux 2025-10-09T17:51:43+00:00 Linus Torvalds torvalds@linux-foundation.org 2025-10-09T17:51:43+00:00 9361cace0d07954ad8f2345c057976ab1bf44488 Pull more s390 updates from Alexander Gordeev: - Compile the decompressor with -Wno-pointer-sign flag to avoid a clang warning - Fix incomplete conversion to flag output macros in __xsch(), to avoid always zero return value instead of the expected condition code - Remove superfluous newlines from inline assemblies to improve compiler inlining decisions - Expose firmware provided UID Checking state in sysfs regardless of the device presence or state - CIO does not unregister subchannels when the attached device is invalid or unavailable. Update the purge function to remove I/O subchannels if the device number is found on cio_ignore list - Consolidate PAI crypto allocation and cleanup paths - The uv_get_secret_metadata() function has been removed some few months ago, remove also the function mention it in a comment * tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: s390/uv: Fix comment of uv_find_secret() function s390/pai_crypto: Consolidate PAI crypto allocation and cleanup paths s390/cio: Update purge function to unregister the unused subchannels s390/pci: Expose firmware provided UID Checking state in sysfs s390: Remove superfluous newlines from inline assemblies s390/cio/ioasm: Fix __xsch() condition code handling s390: Add -Wno-pointer-sign to KBUILD_CFLAGS_DECOMPRESSOR 
Pull more s390 updates from Alexander Gordeev:

 - Compile the decompressor with -Wno-pointer-sign flag to avoid a clang
   warning

 - Fix incomplete conversion to flag output macros in __xsch(), to avoid
   always zero return value instead of the expected condition code

 - Remove superfluous newlines from inline assemblies to improve
   compiler inlining decisions

 - Expose firmware provided UID Checking state in sysfs regardless of
   the device presence or state

 - CIO does not unregister subchannels when the attached device is
   invalid or unavailable. Update the purge function to remove I/O
   subchannels if the device number is found on cio_ignore list

 - Consolidate PAI crypto allocation and cleanup paths

 - The uv_get_secret_metadata() function has been removed some few
   months ago, remove also the function mention it in a comment

* tag 's390-6.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/uv: Fix comment of uv_find_secret() function
  s390/pai_crypto: Consolidate PAI crypto allocation and cleanup paths
  s390/cio: Update purge function to unregister the unused subchannels
  s390/pci: Expose firmware provided UID Checking state in sysfs
  s390: Remove superfluous newlines from inline assemblies
  s390/cio/ioasm: Fix __xsch() condition code handling
  s390: Add -Wno-pointer-sign to KBUILD_CFLAGS_DECOMPRESSOR