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| author | Olivier Martin <olivier.martin@arm.com> | 2014-11-11 00:52:46 +0000 |
|---|---|---|
| committer | oliviermartin <oliviermartin@Edk2> | 2014-11-11 00:52:46 +0000 |
| commit | 4a2928934b37e798a15ecc8546b8432057d090bf (patch) | |
| tree | 4f75680e6237af289c9d2945f25d90672b6f6207 | |
| parent | 284fb5c811fb7784ee3afa753dbdf5b389c4cdce (diff) | |
| download | edk2-platforms-4a2928934b37e798a15ecc8546b8432057d090bf.tar.xz | |
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 <olivier.martin@arm.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16329 6f19259b-4bc3-4df7-8a09-765794883524
| -rw-r--r-- | ArmPkg/Library/ArmArchTimerLib/ArmArchTimerLib.c | 2 |
1 files changed, 1 insertions, 1 deletions
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 ();
|