internal static Version GetClosestCompilerVersionWithSpectreMitigations(BinaryAnalyzerContext context, ExtendedMachine machine, Version omVersion)
{
var compilerMitigationData = LoadCompilerDataFromConfig(context.Policy);
var machineFamily = machine.GetMachineFamily();
if (!compilerMitigationData.ContainsKey(machineFamily))
{
// Mitigations are not supported on this platform at all. No appropriate 'closest compiler version'.
return(null);
}
else
{
var listOfMitigatedCompilers = compilerMitigationData[machineFamily];
// If the compiler version is not supported, then either:
// 1) it is earlier than any supported compiler version
// 2) it is in-between two supported compiler versions (e.x. VS2017.1-4)--it is larger than some supported version numbers and smaller than others.
// 3) it's greater than any of them.
// We want to give users the 'next greatest' compiler version that supports the spectre mitigations--this should be the "smallest available upgrade."
Version previousMaximum = new Version(0, 0, 0, 0);
for (int i = 0; i < listOfMitigatedCompilers.Length; i++)
{
if (omVersion > previousMaximum &&
omVersion <= listOfMitigatedCompilers[i].MinimalSupportedVersion &&
(listOfMitigatedCompilers[i].SupportedMitigations
& (CompilerMitigations.QSpectreAvailable
| CompilerMitigations.D2GuardSpecLoadAvailable)) != 0)
{
return(listOfMitigatedCompilers[i].MinimalSupportedVersion);
}
else
{
previousMaximum = listOfMitigatedCompilers[i].MaximumSupportedVersion;
}
}
// If we're here, we're in situation (3)--the compiler is greater than any we recognize. We'll return the largest compiler we know supports Spectre mitigations.
// With appropriate configuration (i.e. a catch-all entry with a maximum of *.*.*.* is present), we should never really hit this case.
return(listOfMitigatedCompilers[listOfMitigatedCompilers.Length - 1].MinimalSupportedVersion);
}
}
/// <summary>
/// Get the Spectre compiler compiler mitigations available for a particular compiler version and machine type.
/// </summary>
internal static CompilerMitigations GetAvailableMitigations(BinaryAnalyzerContext context, ExtendedMachine machine, Version omVersion)
{
var compilerMitigationData = LoadCompilerDataFromConfig(context.Policy);
var machineFamily = machine.GetMachineFamily();
if (!compilerMitigationData.ContainsKey(machineFamily))
{
return(CompilerMitigations.None);
}
else
{
var listOfMitigatedCompilers = compilerMitigationData[machineFamily];
for (int i = 0; i < listOfMitigatedCompilers.Length; i++)
{
if (omVersion >= listOfMitigatedCompilers[i].MinimalSupportedVersion && omVersion < listOfMitigatedCompilers[i].MaximumSupportedVersion)
{
return(listOfMitigatedCompilers[i].SupportedMitigations);
}
}
}
return(CompilerMitigations.None);
}
