cd247eae16
In commit b88cfee90268cad we defined masks for the IBRD and FBRD integer and fractional baud rate divider registers, to prevent the guest from writing invalid values which could cause division-by-zero. Unfortunately we got the mask values the wrong way around: the FBRD register is six bits and the IBRD register is 16 bits, not vice-versa. You would only run into this bug if you programmed the UART to a baud rate of less than 9600, because for 9600 baud and above the IBRD value will fit into 6 bits, as per the table in https://developer.arm.com/documentation/ddi0183/g/programmers-model/register-descriptions/fractional-baud-rate-register--uartfbrd The only visible effects would be that the value read back from the register by the guest would be truncated, and we would print an incorrect baud rate in the debug logs. Cc: qemu-stable@nongnu.org Fixes: b88cfee90268 ("hw/char/pl011: Avoid division-by-zero in pl011_get_baudrate()") Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2610 Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org> Reviewed-by: Gavin Shan <gshan@redhat.com> Message-id: 20241007144732.2491331-1-peter.maydell@linaro.org