• Ilya Leoshkevich's avatar
    s390/irqflags: do not instrument arch_local_irq_*() with KMSAN · 1b301f5f
    Ilya Leoshkevich authored
    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.comSigned-off-by: default avatarIlya Leoshkevich <iii@linux.ibm.com>
    Reviewed-by: default avatarAlexander Potapenko <glider@google.com>
    Cc: Alexander Gordeev <agordeev@linux.ibm.com>
    Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
    Cc: Christoph Lameter <cl@linux.com>
    Cc: David Rientjes <rientjes@google.com>
    Cc: Dmitry Vyukov <dvyukov@google.com>
    Cc: Heiko Carstens <hca@linux.ibm.com>
    Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
    Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
    Cc: <kasan-dev@googlegroups.com>
    Cc: Marco Elver <elver@google.com>
    Cc: Mark Rutland <mark.rutland@arm.com>
    Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
    Cc: Pekka Enberg <penberg@kernel.org>
    Cc: Roman Gushchin <roman.gushchin@linux.dev>
    Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
    Cc: Sven Schnelle <svens@linux.ibm.com>
    Cc: Vasily Gorbik <gor@linux.ibm.com>
    Cc: Vlastimil Babka <vbabka@suse.cz>
    Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
    1b301f5f
irqflags.h 2.07 KB