[CoreCLR][Signal] Bump shutdown notif and crashdump before prev handler

src/coreclr/dlls/mscoree/exports.cpp

@@ -297,6 +297,13 @@ int coreclr_initialize(
     // This will take ownership of propertyKeysWTemp and propertyValuesWTemp
     Configuration::InitializeConfigurationKnobs(propertyCount, propertyKeysW, propertyValuesW);
 
+#ifdef TARGET_UNIX
+    if (Configuration::GetKnobBooleanValue(W("System.Runtime.CrashReportBeforeSignalChaining"), CLRConfig::INTERNAL_CrashReportBeforeSignalChaining))
+    {
+        PAL_EnableCrashReportBeforeSignalChaining();
+    }
+#endif
+
     STARTUP_FLAGS startupFlags;
     InitializeStartupFlags(&startupFlags);
 

src/coreclr/inc/clrconfigvalues.h

@@ -572,6 +572,7 @@ RETAIL_CONFIG_DWORD_INFO(INTERNAL_DbgEnableMiniDump, W("DbgEnableMiniDump"), 0,
 RETAIL_CONFIG_STRING_INFO(INTERNAL_DbgMiniDumpName, W("DbgMiniDumpName"), "Crash dump name")
 RETAIL_CONFIG_DWORD_INFO(INTERNAL_DbgMiniDumpType, W("DbgMiniDumpType"), 0, "Crash dump type: 1 normal, 2 withheap, 3 triage, 4 full")
 RETAIL_CONFIG_DWORD_INFO(INTERNAL_CreateDumpDiagnostics, W("CreateDumpDiagnostics"), 0, "Enable crash dump generation diagnostic logging")
+RETAIL_CONFIG_DWORD_INFO(INTERNAL_CrashReportBeforeSignalChaining, W("CrashReportBeforeSignalChaining"), 0, "Enable crash report generation before chaining to previous signal handler")
 
 ///
 /// R2R

src/coreclr/pal/inc/pal.h

@@ -252,6 +252,12 @@ PALAPI
 PAL_SetCreateDumpCallback(
     IN PCREATEDUMP_CALLBACK callback);
 
+PALIMPORT
+VOID
+PALAPI
+PAL_EnableCrashReportBeforeSignalChaining(
+    void);
+
 PALIMPORT
 BOOL
 PALAPI

src/coreclr/pal/src/exception/signal.cpp

@@ -103,6 +103,8 @@ bool g_registered_signal_handlers = false;
 #if !HAVE_MACH_EXCEPTIONS
 bool g_enable_alternate_stack_check = false;
 #endif // !HAVE_MACH_EXCEPTIONS
+// When true, generate crash dump before invoking previously registered signal handler
+static bool g_crash_report_before_signal_chaining = false;
 
 static bool g_registered_sigterm_handler = false;
 static bool g_registered_activation_handler = false;
@@ -133,6 +135,22 @@ const int StackOverflowFlag = 0x40000000;
 
 /* public function definitions ************************************************/
 
+/*++
+Function:
+  PAL_EnableCrashReportBeforeSignalChaining
+
+Abstract:
+  Enables generating a crash report before the signal is chained to previous handlers.
+--*/
+PALIMPORT
+VOID
+PALAPI
+PAL_EnableCrashReportBeforeSignalChaining(
+    void)
+{
+    g_crash_report_before_signal_chaining = true;
+}
+
 /*++
 Function :
     SEHInitializeSignals
@@ -447,7 +465,16 @@ static void invoke_previous_action(struct sigaction* action, int code, siginfo_t
             PROCAbort(code, siginfo, context);
         }
     }
-    else if (IsSaSigInfo(action))
+
+    _ASSERTE(!IsSigDfl(action) && !IsSigIgn(action));
+
+    if (g_crash_report_before_signal_chaining)
+    {
+        PROCNotifyProcessShutdown(IsRunningOnAlternateStack(context));
+        PROCCreateCrashDumpIfEnabled(code, siginfo, context, true);
+    }
+
+    if (IsSaSigInfo(action))
     {
         // Directly call the previous handler.
         _ASSERTE(action->sa_sigaction != NULL);
@@ -460,9 +487,11 @@ static void invoke_previous_action(struct sigaction* action, int code, siginfo_t
         action->sa_handler(code);
     }
 
-    PROCNotifyProcessShutdown(IsRunningOnAlternateStack(context));
-
-    PROCCreateCrashDumpIfEnabled(code, siginfo, context, true);
+    if (!g_crash_report_before_signal_chaining)
+    {
+        PROCNotifyProcessShutdown(IsRunningOnAlternateStack(context));
+        PROCCreateCrashDumpIfEnabled(code, siginfo, context, true);
+    }
 }
 
 /*++

src/tasks/AndroidAppBuilder/Templates/monodroid-coreclr.c

@@ -190,6 +190,7 @@ mono_droid_runtime_init (const char* executable)
 #ifdef DIAGNOSTIC_PORTS
     setenv ("DOTNET_DiagnosticPorts", DIAGNOSTIC_PORTS, true);
 #endif
+    setenv ("DOTNET_CrashReportBeforeSignalChaining", "1", true);
 
     if (bundle_executable_path(executable, g_bundle_path, &g_executable_path) < 0)
     {