• Heiko Carstens's avatar
    s390/spinlock: avoid yield to non existent cpu · 84976952
    Heiko Carstens authored
    arch_spin_lock_wait_flags() checks if a spinlock is not held before
    trying a compare and swap instruction. If the lock is unlocked it
    tries the compare and swap instruction, however if a different cpu
    grabbed the lock in the meantime the instruction will fail as
    expected.
    
    Subsequently the arch_spin_lock_wait_flags() incorrectly tries to
    figure out if the cpu that holds the lock is running. However it is
    using the wrong cpu number for this (-1) and then will also yield the
    current cpu to the wrong cpu.
    
    Fix this by adding a missing continue statement.
    
    Fixes: 470ada6b ("s390/spinlock: refactor arch_spin_lock_wait[_flags]")
    Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
    Acked-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
    84976952
spinlock.c 6.34 KB