--- a/toolkit/content/aboutSupport.js
+++ b/toolkit/content/aboutSupport.js
@@ -582,21 +582,46 @@ var snapshotFormatters = {
     let strings = stringBundle();
     let tbody = $("sandbox-tbody");
     for (let key in data) {
       // Simplify the display a little in the common case.
       if (key === "hasPrivilegedUserNamespaces" &&
           data[key] === data["hasUserNamespaces"]) {
         continue;
       }
+      if (key === "syscallLog") {
+	// Not in this table.
+	continue;
+      }
       tbody.appendChild($.new("tr", [
         $.new("th", strings.GetStringFromName(key), "column"),
-        $.new("td", data[key])
+        $.new("td", data[key]),
       ]));
     }
+
+    let syscallBody = $("sandbox-syscalls-tbody");
+    let argsHead = $("sandbox-syscalls-argshead");
+    for (let syscall of data.syscallLog) {
+      if (argsHead.colSpan < syscall.args.length) {
+	argsHead.colSpan = syscall.args.length;
+      }
+      let cells = [
+	$.new("td", syscall.index, "integer"),
+	$.new("td", syscall.msecAgo / 1000),
+	$.new("td", syscall.pid, "integer"),
+	$.new("td", syscall.tid, "integer"),
+	$.new("td", strings.GetStringFromName("sandboxProcType." +
+					      syscall.procType)),
+	$.new("td", syscall.syscall, "integer"),
+      ];
+      for (let arg of syscall.args) {
+	cells.push($.new("td", arg, "integer"));
+      }
+      syscallBody.appendChild($.new("tr", cells));
+    }
   },
 };
 
 var $ = document.getElementById.bind(document);
 
 $.new = function $_new(tag, textContentOrChildren, className, attributes) {
   let elt = document.createElement(tag);
   if (className)

--- a/toolkit/content/aboutSupport.xhtml
+++ b/toolkit/content/aboutSupport.xhtml
@@ -543,15 +543,48 @@
       <h2 class="major-section" id="sandbox">
 	&aboutSupport.sandboxTitle;
       </h2>
 
       <table>
 	<tbody id="sandbox-tbody">
 	</tbody>
       </table>
+
+#if defined(XP_LINUX)
+      <h4>&aboutSupport.sandboxSyscallLogTitle;</h4>
+      <table>
+	<thead>
+	  <tr>
+	    <th>
+	      &aboutSupport.sandboxSyscallIndex;
+	    </th>
+	    <th>
+	      &aboutSupport.sandboxSyscallAge;
+	    </th>
+	    <th>
+	      &aboutSupport.sandboxSyscallPID;
+	    </th>
+	    <th>
+	      &aboutSupport.sandboxSyscallTID;
+	    </th>
+	    <th>
+	      &aboutSupport.sandboxSyscallProcType;
+	    </th>
+	    <th>
+	      &aboutSupport.sandboxSyscallNumber;
+	    </th>
+	    <th id="sandbox-syscalls-argshead">
+	      &aboutSupport.sandboxSyscallArgs;
+	    </th>
+	    </tr>
+	</thead>
+	<tbody id="sandbox-syscalls-tbody">
+	</tbody>
+      </table>
+#endif
 #endif
 
     </div>
 
   </body>
 
 </html>

--- a/toolkit/locales/en-US/chrome/global/aboutSupport.dtd
+++ b/toolkit/locales/en-US/chrome/global/aboutSupport.dtd
@@ -105,16 +105,24 @@ variant of aboutSupport.showDir.label. -
 
 <!ENTITY aboutSupport.installationHistoryTitle "Installation History">
 <!ENTITY aboutSupport.updateHistoryTitle "Update History">
 
 <!ENTITY aboutSupport.copyTextToClipboard.label "Copy text to clipboard">
 <!ENTITY aboutSupport.copyRawDataToClipboard.label "Copy raw data to clipboard">
 
 <!ENTITY aboutSupport.sandboxTitle "Sandbox">
+<!ENTITY aboutSupport.sandboxSyscallLogTitle "Rejected System Calls">
+<!ENTITY aboutSupport.sandboxSyscallIndex "#">
+<!ENTITY aboutSupport.sandboxSyscallAge "Seconds Ago">
+<!ENTITY aboutSupport.sandboxSyscallPID "PID">
+<!ENTITY aboutSupport.sandboxSyscallTID "TID">
+<!ENTITY aboutSupport.sandboxSyscallProcType "Process Type">
+<!ENTITY aboutSupport.sandboxSyscallNumber "Syscall">
+<!ENTITY aboutSupport.sandboxSyscallArgs "Arguments">
 
 <!ENTITY aboutSupport.safeModeTitle "Try Safe Mode">
 <!ENTITY aboutSupport.restartInSafeMode.label "Restart with Add-ons Disabled…">
 
 <!ENTITY aboutSupport.graphicsFeaturesTitle "Features">
 <!ENTITY aboutSupport.graphicsDiagnosticsTitle "Diagnostics">
 <!ENTITY aboutSupport.graphicsFailureLogTitle "Failure Log">
 <!ENTITY aboutSupport.graphicsGPU1Title "GPU #1">

--- a/toolkit/locales/en-US/chrome/global/aboutSupport.properties
+++ b/toolkit/locales/en-US/chrome/global/aboutSupport.properties
@@ -99,16 +99,18 @@ loadedLibVersions = Version in use
 
 hasSeccompBPF = Seccomp-BPF (System Call Filtering)
 hasSeccompTSync = Seccomp Thread Synchronization
 hasUserNamespaces = User Namespaces
 hasPrivilegedUserNamespaces = User Namespaces for privileged processes
 canSandboxContent = Content Process Sandboxing
 canSandboxMedia = Media Plugin Sandboxing
 contentSandboxLevel = Content Process Sandbox Level
+sandboxProcType.content = content
+sandboxProcType.mediaPlugin = media plugin
 
 # LOCALIZATION NOTE %1$S and %2$S will be replaced with the number of remote and the total number
 # of windows, respectively, while %3$S will be replaced with one of the status strings below,
 # which contains a description of the multi-process preference and status.
 # Note: multiProcessStatus.3 doesn't exist because status=3 was deprecated.
 multiProcessWindows = %1$S/%2$S (%3$S)
 multiProcessStatus.0 = Enabled by user
 multiProcessStatus.1 = Enabled by default

--- a/toolkit/modules/Troubleshoot.jsm
+++ b/toolkit/modules/Troubleshoot.jsm
@@ -564,16 +564,31 @@ if (AppConstants.MOZ_SANDBOX) {
 
       let sysInfo = Cc["@mozilla.org/system-info;1"].
                     getService(Ci.nsIPropertyBag2);
       for (let key of keys) {
         if (sysInfo.hasKey(key)) {
           data[key] = sysInfo.getPropertyAsBool(key);
         }
       }
+
+      let reporter = Cc["@mozilla.org/sandbox/syscall-reporter;1"].
+                     getService(Ci.mozISandboxReporter);
+      const snapshot = reporter.snapshot();
+      let syscalls = [];
+      for (let index = snapshot.begin; index < snapshot.end; ++index) {
+        let report = snapshot.getElement(index);
+        let { msecAgo, pid, tid, procType, syscall } = report;
+        let args = []
+        for (let i = 0; i < report.numArgs; ++i) {
+          args.push(report.getArg(i));
+        }
+        syscalls.push({ index, msecAgo, pid, tid, procType, syscall, args });
+      }
+      data.syscallLog = syscalls;
     }
 
     if (AppConstants.MOZ_CONTENT_SANDBOX) {
       data.contentSandboxLevel =
         Services.prefs.getIntPref("security.sandbox.content.level");
     }
 
     done(data);

--- a/toolkit/modules/tests/browser/browser_Troubleshoot.js
+++ b/toolkit/modules/tests/browser/browser_Troubleshoot.js
@@ -482,16 +482,52 @@ const SNAPSHOT_SCHEMA = {
         canSandboxMedia: {
           required: false,
           type: "boolean"
         },
         contentSandboxLevel: {
           required: AppConstants.MOZ_CONTENT_SANDBOX,
           type: "number"
         },
+	syscallLog: {
+	  required: AppConstants.platform == "linux",
+	  type: "array",
+	  items: {
+	    type: "object",
+	    properties: {
+	      index: {
+		required: true,
+		type: "number",
+	      },
+	      pid: {
+		required: true,
+		type: "number",
+	      },
+	      tid: {
+		required: true,
+		type: "number",
+	      },
+	      procType: {
+		required: true,
+		type: "string",
+	      },
+	      syscall: {
+		required: true,
+		type: "number",
+	      },
+	      args: {
+		required: true,
+		type: "array",
+		items: {
+		  type: "string",
+		},
+	      },
+	    },
+	  },
+	},
       },
     },
   },
 };
 
 /**
  * Throws an Error if obj doesn't conform to schema.  That way you get a nice
  * error message and a stack to help you figure out what went wrong, which you

--- a/toolkit/themes/shared/aboutSupport.css
+++ b/toolkit/themes/shared/aboutSupport.css
@@ -64,16 +64,21 @@ th.column {
   width: 0px;
 }
 
 td {
   text-align: start;
   border-color: var(--in-content-table-border-dark-color);
 }
 
+td.integer {
+  text-align: end;
+  font-family: monospace;
+}
+
 .prefs-table {
   width: 100%;
   table-layout: fixed;
 }
 
 .pref-name {
   width: 70%;
   white-space: nowrap;