The VS2017 compiler reports 'warning C4244: '=': conversion from 'UINT64' to 'UINT32', possible loss of data' for the calculation of the UART Divisor value.
Fix this warning by adding appropriate typecast and a validation that ensures that the UART divisor value generated does not exceed MAX_UINT32. Signed-off-by: Sami Mujawar <sami.muja...@arm.com> --- ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c index 801990d9551a638c17d560d4226137b8a3ee47bb..2d3c279cce49304959953ec4a34b50e09a7d0045 100644 --- a/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c +++ b/ArmPlatformPkg/Library/PL011UartLib/PL011UartLib.c @@ -2,7 +2,7 @@ Serial I/O Port library functions with no library constructor/destructor Copyright (c) 2008 - 2010, Apple Inc. All rights reserved.<BR> - Copyright (c) 2011 - 2016, ARM Ltd. All rights reserved.<BR> + Copyright (c) 2011 - 2019, ARM Ltd. All rights reserved.<BR> SPDX-License-Identifier: BSD-2-Clause-Patent @@ -78,6 +78,7 @@ PL011UartInitializePort ( UINT32 Integer; UINT32 Fractional; UINT32 HardwareFifoDepth; + UINT64 DivisorValue; HardwareFifoDepth = (PL011_UARTPID2_VER (MmioRead32 (UartBase + UARTPID2)) \ > PL011_VER_R1P4) \ @@ -188,7 +189,12 @@ PL011UartInitializePort ( return RETURN_INVALID_PARAMETER; } - Divisor = (UartClkInHz * 4) / *BaudRate; + DivisorValue = (((UINT64)UartClkInHz * 4) / *BaudRate); + if (DivisorValue > MAX_UINT32) { + return RETURN_INVALID_PARAMETER; + } + + Divisor = (UINT32)DivisorValue; Integer = Divisor >> FRACTION_PART_SIZE_IN_BITS; Fractional = Divisor & FRACTION_PART_MASK; } -- 'Guid(CE165669-3EF3-493F-B85D-6190EE5B9759)' -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#46279): https://edk2.groups.io/g/devel/message/46279 Mute This Topic: https://groups.io/mt/32999802/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-