From 4a2928934b37e798a15ecc8546b8432057d090bf Mon Sep 17 00:00:00 2001 From: Olivier Martin Date: Tue, 11 Nov 2014 00:52:46 +0000 Subject: [PATCH] ArmPkg/ArmArchTimerLib: Promotes 32bit value to prevent overflow Both MicroSeconds and PcdArmArchTimerFreqInHz are 32-bit values on AArch32 so their multiplication produces 32-bit result that might cause wrong calculation. Example: With MicroSeconds = 200 us, PcdArmArchTimerFreqInHz = 24MHz. 200*24000000 = 0x1_1E1A_3000 => So 0x1E1A_3000 when the type is UINT32. Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Olivier Martin git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16329 6f19259b-4bc3-4df7-8a09-765794883524 --- ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c index 5d8e006cc9..c0ab4a4433 100644 --- a/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c +++ b/ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c @@ -85,7 +85,7 @@ MicroSecondDelay ( // Calculate counter ticks that can represent requested delay: // = MicroSeconds x TICKS_PER_MICRO_SEC // = MicroSeconds x Frequency.10^-6 - TimerTicks64 = (MicroSeconds * PcdGet32 (PcdArmArchTimerFreqInHz)) / 1000000U; + TimerTicks64 = ((UINT64)MicroSeconds * PcdGet32 (PcdArmArchTimerFreqInHz)) / 1000000U; // Read System Counter value SystemCounterVal = ArmGenericTimerGetSystemCount (); -- 2.39.2