.NET 4.6 Bug - Tail Call bug in RyuJIT - Quick Guid

UPDATE: Tail Call Bug has been fixed and here is the more details about it.
http://blogs.msdn.com/b/dotnet/archive/2015/07/28/ryujit-bug-advisory-in-the-net-framework-4-6.aspx

The following information has been collected from the below mentioned links and from my Friends.  This post is just a reference purpose and needs lot of testing to implement this solution.

Reference:
http://nickcraver.com/blog/2015/07/27/why-you-should-wait-on-dotnet-46/
https://github.com/dotnet/coreclr/issues/1296

What is Tail Call?

Wonder full Blog post on Tail Call is here: 
http://blogs.msdn.com/b/davbr/archive/2007/06/20/enter-leave-tailcall-hooks-part-2-tall-tales-of-tail-calls.aspx

Who should be worried about : 

-           .NET Framework 4.6 is installed on the machine running the application
-           The application targets the ‘Any CPU’ or ‘x64’ platform
-           The application targets the .NET 4.5 or .NET 4.6 framework (potentially even earlier .NET frameworks)
-           The CLR is running in 64-bit mode
-           Optimisations are enabled (i.e. the application is compiled in RELEASE configuration)
-           The application is running in IIS

Solution:

If you have already installed .NET 4.6, it is recommended to disable RyuJIT:

Via the registry:
Under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\.NETFramework
Add a useLegacyJit DWORD with a value of 1

Via Powershell:
Set-ItemProperty -Path HKLM:\Software\Microsoft\.NETFramework -Name useLegacyJit -Type DWord -Value 1

Sample Application to Test:

https://github.com/StackExchange/RyuJIT-TailCallBug

Note: When you download and open this application with .Net Version 4.5 or lesser then the following steps need to be applied to run the application.

In CorruptionRepro project

1. Web.config 

Under System.codedom -> Compilers -> Compiler -> CompilerOptions : Change the languageVersion:6 to languageVersion:5

2. Index.html

In Views -> Home -> Index.cshtml Line no:73
Change to
<td>@(test.RawSetDuration.HasValue ? test.RawSetDuration.ToString() : "(null)")</td>



Comments

Post a Comment

Popular posts from this blog

Error : ID4243: Could not create a SecurityToken.

For persons who worked on WIF Programming would encounter the following error, ID4243: Could not create a SecurityToken. A token was not found in the token cache and no cookie was found in the context We will be getting this error when the browser sends the cookie to the server and when sever validates the token and it fails then we may get this error. The end user can't do anything since the browser sends the token to the server always until the user manually clears the cookie from the browser. To handle this scenario we can srite the below list of code in the Global.asax.cs Basically, what it does is it will check for the excetion type and then it tries to sign out the user (delete the cookie informations) and redirect to the requested page. It is as simple as it is :) protected void Application_OnError() { var ex = Context.Error; if (!(ex is SecurityTokenException)) return; Context.ClearError(); if (FederatedAuthenticati...
Read more

MVC - Looping through the model properties from cshtml

When ever we are struck with the values being not properly filled in the model and need to print all the properties of the model or dto of the page then we can use the below lines of code to loop through the model or dto and write all the items in the page. foreach (var result in Model)             {                                   var type = result.GetType();                     var properties = type.GetProperties();                     <ul>                         @foreach (var property in properties)                         {                         <li>     ...
Read more