• Colin Ian King's avatar
    liquidio: Fix unintented sign extension of a left shift of a u16 · 298b58f0
    Colin Ian King authored
    The macro CN23XX_PEM_BAR1_INDEX_REG is being used to shift oct->pcie_port
    (a u16) left 24 places. There are two subtle issues here, first the
    shift gets promoted to an signed int and then sign extended to a u64.
    If oct->pcie_port is 0x80 or more then the upper bits get sign extended
    to 1. Secondly shfiting a u16 24 bits will lead to an overflow so it
    needs to be cast to a u64 for all the bits to not overflow.
    
    It is entirely possible that the u16 port value is never large enough
    for this to fail, but it is useful to fix unintended overflows such
    as this.
    
    Fix this by casting the port parameter to the macro to a u64 before
    the shift.
    
    Addresses-Coverity: ("Unintended sign extension")
    Fixes: 5bc67f58 ("liquidio: CN23XX register definitions")
    Signed-off-by: default avatarColin Ian King <colin.king@canonical.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    298b58f0
cn23xx_pf_regs.h 23.3 KB