Sigsegv when calling a virtual method via UnsafeAccessor #101643

Closed
#101648
Closed
Sigsegv when calling a virtual method via UnsafeAccessor#101643
#101648
Assignees
AaronRobinsonMSFT
Labels
area-System.Runtime.CompilerServices
Milestone
9.0.0

Description

@andriivitiv
andriivitiv
opened on Apr 27, 2024

Description

Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.

Reproduction Steps

dotnet run -c Release
usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}

Expected behavior

Prints:

Program started
Success - no crash

Exit code: 0

Actual behavior

Prints:

Program started

Exit code: 139

Regression?

No. Crashes on both .NET 8 and 9.

Known Workarounds

Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.

Configuration

Happens on both linux-x64 and osx-x64.

.NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

Other information

No response

Activity

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    , 'i'); if (__m === '*' || __re.test(location.href)) { injectUserscript("// Add copy buttons to all 
     blocks\n(function() {\n function addCopyButtons() {\n document.querySelectorAll('pre code').forEach(function(codeBlock) {\n if (codeBlock.parentElement.hasAttribute('data-copy-added')) return;\n codeBlock.parentElement.setAttribute('data-copy-added', 'true');\n \n var btn = document.createElement('button');\n btn.textContent = 'Copy';\n btn.style.cssText = 'position:absolute;top:4px;right:4px;padding:2px 8px;font-size:11px;background:#4ecdc4;border:none;border-radius:4px;color:#1a1a2e;cursor:pointer;opacity:0.7;transition:opacity 0.2s;';\n btn.onmouseover = function() { this.style.opacity = '1'; };\n btn.onmouseout = function() { this.style.opacity = '0.7'; };\n btn.onclick = function() {\n navigator.clipboard.writeText(codeBlock.textContent).then(function() {\n btn.textContent = 'Copied!';\n setTimeout(function() { btn.textContent = 'Copy'; }, 1500);\n });\n };\n codeBlock.parentElement.style.position = 'relative';\n codeBlock.parentElement.appendChild(btn);\n });\n }\n \n addCopyButtons();\n \n // Re-run on dynamic content\n var observer = new MutationObserver(addCopyButtons);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Add Copy Buttons to Code Blocks");
}
} catch(__e) { console.warn('[Userscript:Add Copy Buttons to Code Blocks]', __e); }
})();
(function(){
try {
var __m = "github.com";
var __re = new RegExp('^' + "github\\.com" + '

    Skip to content
    Sigsegv when calling a virtual method via UnsafeAccessor #101643
    Closed
    #101648
    Closed
    Sigsegv when calling a virtual method via UnsafeAccessor#101643
    #101648
    Assignees
    AaronRobinsonMSFT
    Labels
    area-System.Runtime.CompilerServices
    Milestone
    9.0.0
    Description
    @andriivitiv
    andriivitiv
    opened on Apr 27, 2024
    Description
    Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
    Reproduction Steps
    dotnet run -c Release
    usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
    Expected behavior
    Prints:
    Program started
Success - no crash

    Exit code: 0
    Actual behavior
    Prints:
    Program started

    Exit code: 139
    Regression?
    No. Crashes on both .NET 8 and 9.
    Known Workarounds
    Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
    Configuration
    Happens on both linux-x64 and osx-x64.
    .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

    Other information
    No response
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Force GitHub README to respect dark mode\n(function() {\n var style = document.createElement('style');\n style.textContent = '\n .markdown-body {\n color-scheme: dark light;\n }\n .markdown-body pre { background: #161b22 !important; }\n .markdown-body code { background: rgba(110, 118, 129, 0.4) !important; }\n .markdown-body table th, .markdown-body table td { border-color: #30363d !important; }\n .markdown-body img { background: #0d1117; }\n .markdown-body blockquote { border-left-color: #8b949e; }\n .markdown-body hr { border-color: #30363d; }\n ';\n document.head.appendChild(style);\n})();", "GitHub Dark Mode README Fix");
}
} catch(__e) { console.warn('[Userscript:GitHub Dark Mode README Fix]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

      Skip to content
      Sigsegv when calling a virtual method via UnsafeAccessor #101643
      Closed
      #101648
      Closed
      Sigsegv when calling a virtual method via UnsafeAccessor#101643
      #101648
      Assignees
      AaronRobinsonMSFT
      Labels
      area-System.Runtime.CompilerServices
      Milestone
      9.0.0
      Description
      @andriivitiv
      andriivitiv
      opened on Apr 27, 2024
      Description
      Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
      Reproduction Steps
      dotnet run -c Release
      usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
      Expected behavior
      Prints:
      Program started
Success - no crash

      Exit code: 0
      Actual behavior
      Prints:
      Program started

      Exit code: 139
      Regression?
      No. Crashes on both .NET 8 and 9.
      Known Workarounds
      Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
      Configuration
      Happens on both linux-x64 and osx-x64.
      .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

      Other information
      No response
      Activity
      Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
      Metadata
      Metadata
      Assignees
      Labels
      area-System.Runtime.CompilerServices
      Type
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      No projects
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        Relationships
        None yet
        Development
        No branches or pull requests
        Issue actions
        
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Highlight search terms from Google/DuckDuckGo/Bing referrer\n(function() {\n var ref = document.referrer;\n var terms = [];\n \n if (ref.includes('google.com') || ref.includes('duckduckgo.com') || ref.includes('bing.com')) {\n var url = new URL(ref);\n var q = url.searchParams.get('q') || url.searchParams.get('p');\n if (q) {\n terms = q.split(/\\s+/).filter(function(t) { return t.length > 2; });\n }\n }\n \n if (terms.length === 0) return;\n \n var style = document.createElement('style');\n style.textContent = '.userscript-highlight { background: #fbbf24; color: #1a1a2e; padding: 1px 3px; border-radius: 2px; }';\n document.head.appendChild(style);\n \n function highlight(node) {\n if (node.nodeType === 3) { // text node\n var text = node.textContent;\n var found = false;\n terms.forEach(function(term) {\n var regex = new RegExp('(' + term.replace(/[.*+?^${}()|[\\]\\\\]/g, '\\\\') + ')', 'gi');\n if (regex.test(text)) {\n found = true;\n var frag = document.createDocumentFragment();\n var parts = text.split(regex);\n parts.forEach(function(part, i) {\n if (i % 2 === 0) {\n frag.appendChild(document.createTextNode(part));\n } else {\n var span = document.createElement('span');\n span.className = 'userscript-highlight';\n span.textContent = part;\n frag.appendChild(span);\n }\n });\n node.parentNode.replaceChild(frag, node);\n }\n });\n } else if (node.nodeType === 1 && node.childNodes) { // element\n var skipTags = ['SCRIPT', 'STYLE', 'NOSCRIPT', 'TEXTAREA', 'INPUT', 'SELECT'];\n if (!skipTags.includes(node.tagName)) {\n Array.from(node.childNodes).forEach(highlight);\n }\n }\n }\n \n highlight(document.body);\n \n // Re-highlight on dynamic content\n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1 || node.nodeType === 3) highlight(node);\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Highlight Search Terms");
}
} catch(__e) { console.warn('[Userscript:Highlight Search Terms]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

        Skip to content
        Sigsegv when calling a virtual method via UnsafeAccessor #101643
        Closed
        #101648
        Closed
        Sigsegv when calling a virtual method via UnsafeAccessor#101643
        #101648
        Assignees
        AaronRobinsonMSFT
        Labels
        area-System.Runtime.CompilerServices
        Milestone
        9.0.0
        Description
        @andriivitiv
        andriivitiv
        opened on Apr 27, 2024
        Description
        Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
        Reproduction Steps
        dotnet run -c Release
        usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
        Expected behavior
        Prints:
        Program started
Success - no crash

        Exit code: 0
        Actual behavior
        Prints:
        Program started

        Exit code: 139
        Regression?
        No. Crashes on both .NET 8 and 9.
        Known Workarounds
        Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
        Configuration
        Happens on both linux-x64 and osx-x64.
        .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

        Other information
        No response
        Activity
        Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
        Metadata
        Metadata
        Assignees
        Labels
        area-System.Runtime.CompilerServices
        Type
        No type
        Projects
        No projects
          Milestone
          Relationships
          None yet
          Development
          No branches or pull requests
          Issue actions
          
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Strip utm_, fbclid, gclid, etc. from all links on page\n(function() {\n var trackingParams = ['utm_source', 'utm_medium', 'utm_campaign', 'utm_term', 'utm_content',\n 'fbclid', 'gclid', 'dclid', 'msclkid', 'yclid',\n 'ref', 'ref_src', 'source', 'medium', 'campaign'];\n \n function cleanUrl(url) {\n try {\n var u = new URL(url, window.location.origin);\n var changed = false;\n trackingParams.forEach(function(p) {\n if (u.searchParams.has(p)) {\n u.searchParams.delete(p);\n changed = true;\n }\n });\n return changed ? u.toString() : url;\n } catch (e) {\n return url;\n }\n }\n \n function cleanLinks() {\n document.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n \n cleanLinks();\n \n var observer = new MutationObserver(function(mutations) {\n mutations.forEach(function(m) {\n m.addedNodes.forEach(function(node) {\n if (node.nodeType === 1) {\n if (node.tagName === 'A') cleanLinks();\n node.querySelectorAll('a[href]').forEach(function(a) {\n var clean = cleanUrl(a.href);\n if (clean !== a.href) a.href = clean;\n });\n }\n });\n });\n });\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "Remove Tracking Parameters from Links");
}
} catch(__e) { console.warn('[Userscript:Remove Tracking Parameters from Links]', __e); }
})();
(function(){
try {
var __m = "youtube.com";
var __re = new RegExp('^' + "youtube\\.com" + '

          Skip to content
          Sigsegv when calling a virtual method via UnsafeAccessor #101643
          Closed
          #101648
          Closed
          Sigsegv when calling a virtual method via UnsafeAccessor#101643
          #101648
          Assignees
          AaronRobinsonMSFT
          Labels
          area-System.Runtime.CompilerServices
          Milestone
          9.0.0
          Description
          @andriivitiv
          andriivitiv
          opened on Apr 27, 2024
          Description
          Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
          Reproduction Steps
          dotnet run -c Release
          usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
          Expected behavior
          Prints:
          Program started
Success - no crash

          Exit code: 0
          Actual behavior
          Prints:
          Program started

          Exit code: 139
          Regression?
          No. Crashes on both .NET 8 and 9.
          Known Workarounds
          Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
          Configuration
          Happens on both linux-x64 and osx-x64.
          .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

          Other information
          No response
          Activity
          Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
          Metadata
          Metadata
          Assignees
          Labels
          area-System.Runtime.CompilerServices
          Type
          No type
          Projects
          No projects
            Milestone
            Relationships
            None yet
            Development
            No branches or pull requests
            Issue actions
            
, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Auto-enable theater mode on YouTube\n(function() {\n function tryTheater() {\n var btn = document.querySelector('button[aria-label=\"Theater mode\"], ytd-player #player button[title=\"Theater mode\"]');\n if (btn && !btn.classList.contains('activated')) {\n btn.click();\n }\n }\n \n // Try immediately\n tryTheater();\n \n // Try after navigation (SPA)\n var lastUrl = location.href;\n setInterval(function() {\n if (location.href !== lastUrl) {\n lastUrl = location.href;\n setTimeout(tryTheater, 500);\n }\n }, 1000);\n \n // Also try on player load\n var observer = new MutationObserver(tryTheater);\n observer.observe(document.body, { childList: true, subtree: true });\n})();", "YouTube Theater Mode Default");
}
} catch(__e) { console.warn('[Userscript:YouTube Theater Mode Default]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

            Skip to content
            Sigsegv when calling a virtual method via UnsafeAccessor #101643
            Closed
            #101648
            Closed
            Sigsegv when calling a virtual method via UnsafeAccessor#101643
            #101648
            Assignees
            AaronRobinsonMSFT
            Labels
            area-System.Runtime.CompilerServices
            Milestone
            9.0.0
            Description
            @andriivitiv
            andriivitiv
            opened on Apr 27, 2024
            Description
            Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
            Reproduction Steps
            dotnet run -c Release
            usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
            Expected behavior
            Prints:
            Program started
Success - no crash

            Exit code: 0
            Actual behavior
            Prints:
            Program started

            Exit code: 139
            Regression?
            No. Crashes on both .NET 8 and 9.
            Known Workarounds
            Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
            Configuration
            Happens on both linux-x64 and osx-x64.
            .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Remove or un-stick sticky/fixed headers that block content\n(function() {\n function unstick() {\n document.querySelectorAll('header, nav, [role=\"banner\"], .header, .navbar, .sticky, .fixed-top, [style*=\"position: fixed\"], [style*=\"position:sticky\"]').forEach(function(el) {\n if (el.style.position === 'fixed' || el.style.position === 'sticky' || \n getComputedStyle(el).position === 'fixed' || getComputedStyle(el).position === 'sticky') {\n el.style.position = 'static';\n el.style.top = 'auto';\n el.style.zIndex = 'auto';\n }\n });\n }\n \n unstick();\n \n var observer = new MutationObserver(unstick);\n observer.observe(document.body, { childList: true, subtree: true, attributes: true, attributeFilter: ['style', 'class'] });\n})();", "Kill Sticky Headers");
}
} catch(__e) { console.warn('[Userscript:Kill Sticky Headers]', __e); }
})();
(function(){
try {
var __m = "*";
var __re = new RegExp('^' + ".*" + '

              Skip to content
              Sigsegv when calling a virtual method via UnsafeAccessor #101643
              Closed
              #101648
              Closed
              Sigsegv when calling a virtual method via UnsafeAccessor#101643
              #101648
              Assignees
              AaronRobinsonMSFT
              Labels
              area-System.Runtime.CompilerServices
              Milestone
              9.0.0
              Description
              @andriivitiv
              andriivitiv
              opened on Apr 27, 2024
              Description
              Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
              Reproduction Steps
              dotnet run -c Release
              usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
              Expected behavior
              Prints:
              Program started
Success - no crash

              Exit code: 0
              Actual behavior
              Prints:
              Program started

              Exit code: 139
              Regression?
              No. Crashes on both .NET 8 and 9.
              Known Workarounds
              Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
              Configuration
              Happens on both linux-x64 and osx-x64.
              .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

              Other information
              No response
              Activity
              Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
              Metadata
              Metadata
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              Labels
              area-System.Runtime.CompilerServices
              Type
              No type
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              No projects
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                None yet
                Development
                No branches or pull requests
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, 'i');
if (__m === '*' || __re.test(location.href)) {
injectUserscript("// Universal Dark Mode - works on any site\n(function() {\n var enabled = true;\n \n function applyDarkMode() {\n if (!enabled) return;\n \n // Create style element if it doesn't exist\n var style = document.getElementById('universal-dark-mode-style');\n if (!style) {\n style = document.createElement('style');\n style.id = 'universal-dark-mode-style';\n document.head.appendChild(style);\n }\n \n // Dark mode CSS - inverts colors but preserves images/video\n style.textContent = '\n /* Invert everything except media */\n html {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #1a1a2e !important;\n }\n \n /* Restore images, videos, iframes, canvas */\n img, video, iframe, canvas, svg, picture, [style*=\"background-image\"] {\n filter: invert(1) hue-rotate(180deg) !important;\n }\n \n /* Preserve specific elements that should not be inverted */\n .no-dark-mode, .no-dark-mode *,\n [data-theme=\"light\"], [data-theme=\"light\"],\n .ace_editor, .ace_editor *,\n .CodeMirror, .CodeMirror *,\n .monaco-editor, .monaco-editor *,\n .markdown-body pre, .markdown-body pre *,\n .highlight, .highlight *,\n pre code, pre code * {\n filter: none !important;\n }\n \n /* Fix common UI elements */\n .modal, .popup, .dropdown-menu, .tooltip, .popover {\n filter: invert(1) hue-rotate(180deg) !important;\n background: #2d2d44 !important;\n border-color: #444 !important;\n }\n \n /* Scrollbars */\n ::-webkit-scrollbar { background: #1a1a2e !important; }\n ::-webkit-scrollbar-thumb { background: #444 !important; }\n ::-webkit-scrollbar-thumb:hover { background: #555 !important; }\n \n /* Selection */\n ::selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ::-moz-selection { background: #4ecdc4 !important; color: #1a1a2e !important; }\n ';\n }\n \n function removeDarkMode() {\n var style = document.getElementById('universal-dark-mode-style');\n if (style) style.remove();\n }\n \n // Toggle with Alt+Shift+D\n document.addEventListener('keydown', function(e) {\n if (e.altKey && e.shiftKey && e.key === 'D') {\n e.preventDefault();\n enabled = !enabled;\n if (enabled) {\n applyDarkMode();\n console.log('[Universal Dark Mode] Enabled');\n } else {\n removeDarkMode();\n console.log('[Universal Dark Mode] Disabled');\n }\n }\n });\n \n // Apply on load\n applyDarkMode();\n \n // Re-apply on dynamic content\n var observer = new MutationObserver(function(mutations) {\n if (enabled && !document.getElementById('universal-dark-mode-style')) {\n applyDarkMode();\n }\n });\n observer.observe(document.head, { childList: true });\n \n console.log('[Universal Dark Mode] Loaded - Press Alt+Shift+D to toggle');\n})();", "Universal Dark Mode");
}
} catch(__e) { console.warn('[Userscript:Universal Dark Mode]', __e); }
})();
})();

                Skip to content
                Sigsegv when calling a virtual method via UnsafeAccessor #101643
                Closed
                #101648
                Closed
                Sigsegv when calling a virtual method via UnsafeAccessor#101643
                #101648
                Assignees
                AaronRobinsonMSFT
                Labels
                area-System.Runtime.CompilerServices
                Milestone
                9.0.0
                Description
                @andriivitiv
                andriivitiv
                opened on Apr 27, 2024
                Description
                Calling a virtual method via UnsafeAccessor many times crashes the runtime with exit code 139. This is likely caused by a JIT optimization.
                Reproduction Steps
                dotnet run -c Release
                usingSystem.Runtime.CompilerServices;Console.WriteLine("Program started");varobj=newFoo();for(vari=0;i<1_000_000;i++){FooAccessor.Func(obj);// There must be another call after the call to UnsafeAccessor otherwise no crash.// Any of the below will cause the crash but methods like// GC.KeepAlive(obj), Console.Write("") or await Task.Delay(0) won't.// Don't know why.awaitTask.Delay(1);//GC.Collect();//Console.WriteLine(0);}Console.WriteLine("Success - no crash");internalclassFoo{// Only crashes on virtual methodspublicvirtualvoidFunc(){}}internalclassFooAccessor{[UnsafeAccessor(UnsafeAccessorKind.Method,Name=nameof(Foo.Func))]publicstaticexternvoidFunc(Foob);}
                Expected behavior
                Prints:
                Program started
Success - no crash

                Exit code: 0
                Actual behavior
                Prints:
                Program started

                Exit code: 139
                Regression?
                No. Crashes on both .NET 8 and 9.
                Known Workarounds
                Apply [MethodImpl(MethodImplOptions.NoOptimization)] to the UnsafeAccessor method.
                Configuration
                Happens on both linux-x64 and osx-x64.
                .NET SDK:
Version: 9.0.100-preview.3.24204.13
Commit: 81f61d8290
Workload version: 9.0.100-manifests.77bb7ba9
MSBuild version: 17.11.0-preview-24178-16+7ca3c98fa
Runtime Environment:
OS Name: ubuntu
OS Version: 22.04
OS Platform: Linux
RID: linux-x64
Base Path: /home/andrii/dev/dotnet/runtime/.dotnet/sdk/9.0.100-preview.3.24204.13/
.NET workloads installed:
There are no installed workloads to display.
Host:
Version: 9.0.0-preview.3.24172.9
Architecture: x64
Commit: 9e6ba1f68c
.NET SDKs installed:
9.0.100-preview.3.24204.13 [/home/andrii/dev/dotnet/runtime/.dotnet/sdk]
.NET runtimes installed:
Microsoft.AspNetCore.App 9.0.0-preview.3.24172.13 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.AspNetCore.App]
Microsoft.NETCore.App 9.0.0-preview.3.24172.9 [/home/andrii/dev/dotnet/runtime/.dotnet/shared/Microsoft.NETCore.App]

                Other information
                No response
                Activity
                Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
                Metadata
                Metadata
                Assignees
                Labels
                area-System.Runtime.CompilerServices
                Type
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                Projects
                No projects
                  Milestone
                  Relationships
                  None yet
                  Development
                  No branches or pull requests
                  Issue actions