kernel.git/drivers/s390/char/sclp.c, branch master

s390/sclp: Fix SCCB present check

2025-08-20T14:37:27Z

Tracing code called by the SCLP interrupt handler contains early exits if the SCCB address associated with an interrupt is NULL. This check is performed after physical to virtual address translation. If the kernel identity mapping does not start at address zero, the resulting virtual address is never zero, so that the NULL checks won't work. Subsequently this may result in incorrect accesses to the first page of the identity mapping. Fix this by introducing a function that handles the NULL case before address translation. Fixes: ada1da31ce34 ("s390/sclp: sort out physical vs virtual pointers usage") Cc: stable@vger.kernel.org Reviewed-by: Alexander Gordeev Signed-off-by: Peter Oberparleiter Signed-off-by: Alexander Gordeev

s390/sclp: Use monotonic clock in sclp_sync_wait()

2025-07-21T10:41:55Z

sclp_sync_wait() should use the monotonic clock for the delay loop. Otherwise the code won't work correctly when the clock is changed. Signed-off-by: Sven Schnelle Reviewed-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/drivers: Explicitly include

2025-06-17T16:18:02Z

Explicitly include in files which contain an EXPORT_SYMBOL(). See commit a934a57a42f6 ("scripts/misc-check: check missing #include when W=1") for more details. Acked-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12Z

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

s390/sclp: Initialize sclp subsystem via arch_cpu_finalize_init()

2025-01-28T16:38:46Z

With the switch to GENERIC_CPU_DEVICES an early call to the sclp subsystem was added to smp_prepare_cpus(). This will usually succeed since the sclp subsystem is implicitly initialized early enough if an sclp based console is present. If no such console is present the initialization happens with an arch_initcall(); in such cases calls to the sclp subsystem will fail. For CPU detection this means that the fallback sigp loop will be used permanently to detect CPUs instead of the preferred READ_CPU_INFO sclp request. Fix this by adding an explicit early sclp_init() call via arch_cpu_finalize_init(). Reported-by: Sheshu Ramanandan Fixes: 4a39f12e753d ("s390/smp: Switch to GENERIC_CPU_DEVICES") Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/sclp: Deactivate sclp after all its users

2024-10-16T09:32:32Z

On reboot the SCLP interface is deactivated through a reboot notifier. This happens before other components using SCLP have the chance to run their own reboot notifiers. Two of those components are the SCLP console and tty drivers which try to flush the last outstanding messages. At that point the SCLP interface is already unusable and the messages are discarded. Execute sclp_deactivate() as late as possible to avoid this issue. Fixes: 4ae46db99cd8 ("s390/consoles: improve panic notifiers reliability") Cc: stable@vger.kernel.org Signed-off-by: Thomas Weißschuh Reviewed-by: Sven Schnelle Link: https://lore.kernel.org/r/20241014-s390-kunit-v1-1-941defa765a6@linutronix.de Signed-off-by: Heiko Carstens

s390/irqflags: do not instrument arch_local_irq_*() with KMSAN

2024-07-04T02:30:25Z

Lockdep generates the following false positives with KMSAN on s390x: [ 6.063666] DEBUG_LOCKS_WARN_ON(lockdep_hardirqs_enabled()) [ ...] [ 6.577050] Call Trace: [ 6.619637] [<000000000690d2de>] check_flags+0x1fe/0x210 [ 6.665411] ([<000000000690d2da>] check_flags+0x1fa/0x210) [ 6.707478] [<00000000006cec1a>] lock_acquire+0x2ca/0xce0 [ 6.749959] [<00000000069820ea>] _raw_spin_lock_irqsave+0xea/0x190 [ 6.794912] [<00000000041fc988>] __stack_depot_save+0x218/0x5b0 [ 6.838420] [<000000000197affe>] __msan_poison_alloca+0xfe/0x1a0 [ 6.882985] [<0000000007c5827c>] start_kernel+0x70c/0xd50 [ 6.927454] [<0000000000100036>] startup_continue+0x36/0x40 Between trace_hardirqs_on() and `stosm __mask, 3` lockdep thinks that interrupts are on, but on the CPU they are still off. KMSAN instrumentation takes spinlocks, giving lockdep a chance to see and complain about this discrepancy. KMSAN instrumentation is inserted in order to poison the __mask variable. Disable instrumentation in the respective functions. They are very small and it's easy to see that no important metadata updates are lost because of this. Link: https://lkml.kernel.org/r/20240621113706.315500-31-iii@linux.ibm.com Signed-off-by: Ilya Leoshkevich Reviewed-by: Alexander Potapenko Cc: Alexander Gordeev Cc: Christian Borntraeger Cc: Christoph Lameter Cc: David Rientjes Cc: Dmitry Vyukov Cc: Heiko Carstens Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com> Cc: Joonsoo Kim Cc: Cc: Marco Elver Cc: Mark Rutland Cc: Masami Hiramatsu (Google) Cc: Pekka Enberg Cc: Roman Gushchin Cc: Steven Rostedt (Google) Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Signed-off-by: Andrew Morton

s390/sclp: Fix sclp_init() cleanup on failure

2024-06-24T09:07:06Z

If sclp_init() fails it only partially cleans up: if there are multiple failing calls to sclp_init() sclp_state_change_event will be added several times to sclp_reg_list, which results in the following warning: ------------[ cut here ]------------ list_add double add: new=000003ffe1598c10, prev=000003ffe1598bf0, next=000003ffe1598c10. WARNING: CPU: 0 PID: 1 at lib/list_debug.c:35 __list_add_valid_or_report+0xde/0xf8 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 6.10.0-rc3 Krnl PSW : 0404c00180000000 000003ffe0d6076a (__list_add_valid_or_report+0xe2/0xf8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 ... Call Trace: [<000003ffe0d6076a>] __list_add_valid_or_report+0xe2/0xf8 ([<000003ffe0d60766>] __list_add_valid_or_report+0xde/0xf8) [<000003ffe0a8d37e>] sclp_init+0x40e/0x450 [<000003ffe00009f2>] do_one_initcall+0x42/0x1e0 [<000003ffe15b77a6>] do_initcalls+0x126/0x150 [<000003ffe15b7a0a>] kernel_init_freeable+0x1ba/0x1f8 [<000003ffe0d6650e>] kernel_init+0x2e/0x180 [<000003ffe000301c>] __ret_from_fork+0x3c/0x60 [<000003ffe0d759ca>] ret_from_fork+0xa/0x30 Fix this by removing sclp_state_change_event from sclp_reg_list when sclp_init() fails. Reviewed-by: Peter Oberparleiter Signed-off-by: Heiko Carstens Signed-off-by: Alexander Gordeev

s390/sclp: replace deprecated strncpy with strtomem

2023-10-25T13:08:30Z

Let's move away from using strncpy() as it is deprecated [1]. Instead use strtomem() as `e.id` is already marked as nonstring: | char id[4] __nonstring; We don't need strtomem_pad() because `e` is already memset to 0 -- rendering any additional NUL-padding useless. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strncpy-on-nul-terminated-strings [1] Link: https://github.com/KSPP/linux/issues/90 Cc: linux-hardening@vger.kernel.org Signed-off-by: Justin Stitt Reviewed-by: Kees Cook Link: https://lore.kernel.org/r/20231023-strncpy-drivers-s390-char-sclp-c-v1-1-eaeef80522bb@google.com Signed-off-by: Vasily Gorbik

s390/ctlreg: add struct ctlreg

2023-09-19T11:26:56Z

Add struct ctlreg to enforce strict type checking / usage for control register functions. Reviewed-by: Alexander Gordeev Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik