Enable more SOS commands for Linux/MacOS

Allows more SOS on Linux/MacOS and Linux core dumps on Windows under Windbg.

Issue: dotnet#3169

src/SOS/SOS.Hosting/Commands/SOSCommand.cs

@@ -10,6 +10,7 @@
 
 namespace SOS.Hosting
 {
+    [Command(Name = "analyzeoom",       DefaultOptions = "AnalyzeOOM",          Help = "Displays the info of the last OOM occurred on an allocation request to the GC heap.")]
     [Command(Name = "clrstack",         DefaultOptions = "ClrStack",            Help = "Provides a stack trace of managed code only.")]
     [Command(Name = "clrthreads",       DefaultOptions = "Threads",             Help = "List the managed threads running.")]
     [Command(Name = "dbgout",           DefaultOptions = "dbgout",              Help = "Enable/disable (-off) internal SOS logging.")]
@@ -26,11 +27,15 @@ namespace SOS.Hosting
     [Command(Name = "dumpmodule",       DefaultOptions = "DumpModule",          Help = "Displays information about a EE module structure at the specified address.")]
     [Command(Name = "dumpmt",           DefaultOptions = "DumpMT",              Help = "Displays information about a method table at the specified address.")]
     [Command(Name = "dumpobj",          DefaultOptions = "DumpObj",             Aliases = new string[] { "do" }, Help = "Displays info about an object at the specified address.")]
-    [Command(Name = "dumpvc",           DefaultOptions = "DumpVC",              Help = "Displays info about the fields of a value class.")]
+    [Command(Name = "dumpruntimetypes", DefaultOptions = "DumpRuntimeTypes",    Help = "Finds all System.RuntimeType objects in the gc heap and prints the type name and MethodTable they refer too.")]
     [Command(Name = "dumpstackobjects", DefaultOptions = "DumpStackObjects",    Aliases = new string[] { "dso" }, Help = "Displays all managed objects found within the bounds of the current stack.")]
+    [Command(Name = "dumpsig",          DefaultOptions = "DumpSig",             Help = "This command dumps the signature of a method or field given by <sigaddr> <moduleaddr>.")]
+    [Command(Name = "dumpsigelem",      DefaultOptions = "DumpSigElem",         Help = "This command dumps a single element of a signature object.")]
+    [Command(Name = "dumpvc",           DefaultOptions = "DumpVC",              Help = "Displays info about the fields of a value class.")]
     [Command(Name = "eeheap",           DefaultOptions = "EEHeap",              Help = "Displays info about process memory consumed by internal runtime data structures.")]
     [Command(Name = "eeversion",        DefaultOptions = "EEVersion",           Help = "Displays information about the runtime version.")]
     [Command(Name = "finalizequeue",    DefaultOptions = "FinalizeQueue",       Help = "Displays all objects registered for finalization.")]
+    [Command(Name = "gchandles",        DefaultOptions = "GCHandles",           Help = "Provides statistics about GCHandles in the process.")]
     [Command(Name = "gcroot",           DefaultOptions = "GCRoot",              Help = "Displays info about references (or roots) to an object at the specified address.")]
     [Command(Name = "gcwhere",          DefaultOptions = "GCWhere",             Help = "Displays the location in the GC heap of the argument passed in.")]
     [Command(Name = "ip2md",            DefaultOptions = "IP2MD",               Help = "Displays the MethodDesc structure at the specified address in code that has been JIT-compiled.")]
@@ -42,20 +47,18 @@ namespace SOS.Hosting
     [Command(Name = "histobj",          DefaultOptions = "HistObj",             Help = "Examines all stress log relocation records and displays the chain of garbage collection relocations that may have led to the address passed in as an argument.")]
     [Command(Name = "histobjfind",      DefaultOptions = "HistObjFind",         Help = "Displays all the log entries that reference an object at the specified address.")]
     [Command(Name = "histroot",         DefaultOptions = "HistRoot",            Help = "Displays information related to both promotions and relocations of the specified root.")]
-    [Command(Name = "verifyheap",       DefaultOptions = "VerifyHeap",          Help = "Checks the GC heap for signs of corruption.")]
+    [Command(Name = "listnearobj",      DefaultOptions = "ListNearObj",         Help = "Displays the object preceding and succeeding the address specified.")]
     [Command(Name = "threadpool",       DefaultOptions = "ThreadPool",          Help = "Lists basic information about the thread pool.")]
     [Command(Name = "soshelp",          DefaultOptions = "Help",                Help = "Displays help for a specific SOS command.")]
+    [Command(Name = "verifyheap",       DefaultOptions = "VerifyHeap",          Help = "Checks the GC heap for signs of corruption.")]
+    [Command(Name = "verifyobj",        DefaultOptions = "VerifyObj",           Help = "Checks the object for signs of corruption.")]
     [Command(Name = "dumprcw",          DefaultOptions = "DumpRCW",             Platform = CommandPlatform.Windows, Help = "Displays information about a Runtime Callable Wrapper.")]
     [Command(Name = "dumpccw",          DefaultOptions = "DumpCCW",             Platform = CommandPlatform.Windows, Help = "Displays information about a COM Callable Wrapper.")]
     [Command(Name = "dumppermissionset",DefaultOptions = "DumpPermissionSet",   Platform = CommandPlatform.Windows, Help = "Displays a PermissionSet object (debug build only).")]
     [Command(Name = "traverseheap",     DefaultOptions = "TraverseHeap",        Platform = CommandPlatform.Windows, Help = "Writes out a file in a format understood by the CLR Profiler.")]
-    [Command(Name = "analyzeoom",       DefaultOptions = "AnalyzeOOM",          Platform = CommandPlatform.Windows, Help = "Displays the info of the last OOM occurred on an allocation request to the GC heap.")]
-    [Command(Name = "verifyobj",        DefaultOptions = "VerifyObj",           Platform = CommandPlatform.Windows, Help = "Checks the object for signs of corruption.")]
-    [Command(Name = "listnearobj",      DefaultOptions = "ListNearObj",         Platform = CommandPlatform.Windows, Help = "Displays the object preceding and succeeding the address specified.")]
     [Command(Name = "gcheapstat",       DefaultOptions = "GCHeapStat",          Platform = CommandPlatform.Windows, Help = "Display various GC heap stats.")]
     [Command(Name = "watsonbuckets",    DefaultOptions = "WatsonBuckets",       Platform = CommandPlatform.Windows, Help = "Displays the Watson buckets.")]
     [Command(Name = "comstate",         DefaultOptions = "COMState",            Platform = CommandPlatform.Windows, Help = "Lists the COM apartment model for each thread.")]
-    [Command(Name = "gchandles",        DefaultOptions = "GCHandles",           Help = "Provides statistics about GCHandles in the process.")]
     [Command(Name = "objsize",          DefaultOptions = "ObjSize",             Platform = CommandPlatform.Windows, Help = "Lists the sizes of the all the objects found on managed threads.")]
     [Command(Name = "gchandleleaks",    DefaultOptions = "GCHandleLeaks",       Platform = CommandPlatform.Windows, Help = "Helps in tracking down GCHandle leaks")]
     public class SOSCommand : CommandBase

src/SOS/Strike/sos_unixexports.src

@@ -2,6 +2,7 @@
 ; The .NET Foundation licenses this file to you under the MIT license.
 ; See the LICENSE file in the project root for more information.
 
+AnalyzeOOM
 bpmd
 clrmodules
 ClrStack
@@ -45,6 +46,7 @@ HistObjFind
 HistRoot
 HistStats
 IP2MD
+ListNearObj
 logging
 Name2EE
 PrintException
@@ -63,6 +65,7 @@ ThreadState
 Token2EE
 u
 VerifyHeap
+VerifyObj
 
 SOSInitializeByHost
 SOSUninitializeByHost

src/SOS/Strike/sosdocsunix.txt

@@ -41,12 +41,12 @@ EEHeap (eeheap)                    FindAppDomain
 Name2EE (name2ee)                  DumpLog (dumplog)
 SyncBlk (syncblk)                  SuppressJitOptimization
 DumpMT (dumpmt)                    ThreadPool (threadpool)
-DumpClass (dumpclass)
-DumpMD (dumpmd)                    
+DumpClass (dumpclass)              AnalyzeOOM (analyzeoom)
+DumpMD (dumpmd)                    VerifyObj (verifyobj)
 Token2EE                           
 DumpModule (dumpmodule)
 DumpAssembly (dumpassembly)
-DumpRuntimeTypes
+DumpRuntimeTypes (dumpruntimetypes)
 DumpIL (dumpil)
 DumpSig
 DumpSigElem
@@ -1583,6 +1583,21 @@ is a simple example of the output for a dynamic method:
   IL_0010: stloc.0
   IL_0011: ldloc.0
   IL_0012: ret
+
+\\
+
+COMMAND: verifyobj.
+VerifyObj <object address>
+
+VerifyObj is a diagnostic tool that checks the object that is passed as an 
+argument for signs of corruption.
+
+    0:002> !verifyobj 028000ec
+    object 0x28000ec does not have valid method table
+
+    0:002> !verifyobj 0680017c 
+    object 0x680017c: bad member 00000001 at 06800184
+
 \\
 
 COMMAND: verifyheap.
@@ -1623,6 +1638,65 @@ in the CLR. In user code, an error in constructing PInvoke calls can cause
 this problem, and running with Managed Debugging Assistants is advised. If that
 possibility is eliminated, consider contacting Microsoft Product Support for
 help.
+
+\\
+
+COMMAND: analyzeoom.
+AnalyzeOOM
+
+AnalyzeOOM displays the info of the last OOM occurred on an allocation request to
+the GC heap (in Server GC it displays OOM, if any, on each GC heap). 
+
+To see the managed exception(s) use the clrthreads command which will show you 
+managed exception(s), if any, on each managed thread. If you do see an 
+OutOfMemoryException exception you can use the !PrintException command on it.
+To get the full callstack use the "kb" command in the debugger for that thread.
+For example, to display thread 3's stack use ~3kb.
+
+OOM exceptions could be because of the following reasons:
+
+1) allocation request to GC heap 
+   in which case you will see JIT_New* on the call stack because managed code called new.
+2) other runtime allocation failure
+   for example, failure to expand the finalize queue when GC.ReRegisterForFinalize is
+   called.
+3) some other code you use throws a managed OOM exception 
+   for example, some .NET framework code converts a native OOM exception to managed 
+   and throws it.
+
+The !AnalyzeOOM command aims to help you with investigating 1) which is the most
+difficult because it requires some internal info from GC. The only exception is
+we don't support allocating objects larger than 2GB on CLR v2.0 or prior. And this
+command will not display any managed OOM because we will throw OOM right away 
+instead of even trying to allocate it on the GC heap.
+
+There are 2 legitimate scenarios where GC would return OOM to allocation requests - 
+one is if the process is running out of VM space to reserve a segment; the other
+is if the system is running out physical memory (+ page file if you have one) so
+GC can not commit memory it needs. You can look at these scenarios by using performance
+counters or debugger commands. For example for the former scenario the "!address 
+-summary" debugger command will show you the largest free region in the VM. For
+the latter scenario you can look at the "Memory% Committed Bytes In Use" see
+if you are running low on commit space. One important thing to keep in mind is
+when you do this kind of memory analysis it could an aftereffect and doesn't 
+completely agree with what this command tells you, in which case the command should
+be respected because it truly reflects what happened during GC.
+
+The other cases should be fairly obvious from the callstack.
+
+Sample output:
+
+0:011> !analyzeoom
+---------Heap 2 ---------
+Managed OOM occurred after GC #28 (Requested to allocate 1234 bytes)
+Reason: Didn't have enough memory to commit
+Detail: SOH: Didn't have enough memory to grow the internal GC datastructures (800000 bytes) - 
+        on GC entry available commit space was 500 MB
+---------Heap 4 ---------
+Managed OOM occurred after GC #12 (Requested to allocate 100000 bytes)
+Reason: Didn't have enough memory to allocate an LOH segment
+Detail: LOH: Failed to reserve memory (16777216 bytes)
+
 \\
 
 COMMAND: gcwhere.
@@ -1642,6 +1716,40 @@ the "size" is displayed as 0:
     0280003c 2    0   02800000 02800038 0282b740  0
 \\
 
+COMMAND: listnearobj.
+ListNearObj <object address>
+
+ListNearObj is a diagnostic tool that displays the object preceeding and 
+succeeding the address passed in:
+
+The command looks for the address in the GC heap that looks like a valid 
+beginning of a managed object (based on a valid method table) and the object 
+following the argument address.
+
+    0:002> listnearobj 028000ec
+    Before: 0x28000a4           72 (0x48      ) System.StackOverflowException
+    After:  0x2800134           72 (0x48      ) System.Threading.ThreadAbortException
+    Heap local consistency confirmed.
+
+    0:002> listnearobj 028000f0
+    Before: 0x28000ec           72 (0x48      ) System.ExecutionEngineException
+    After:  0x2800134           72 (0x48      ) System.Threading.ThreadAbortException
+    Heap local consistency confirmed.
+
+The command considers the heap as "locally consistent" if:
+    prev_obj_addr + prev_obj_size = arg_addr && arg_obj + arg_size = next_obj_addr
+OR
+    prev_obj_addr + prev_obj_size = next_obj_addr
+
+When the condition is not satisfied:
+
+    0:002> listnearobj 028000ec
+    Before: 0x28000a4           72 (0x48      ) System.StackOverflowException
+    After:  0x2800134           72 (0x48      ) System.Threading.ThreadAbortException
+    Heap local consistency not confirmed.
+
+\\
+
 COMMAND: dumplog.
 DumpLog [-addr <addressOfStressLog>] [<Filename>]
 

src/SOS/Strike/strike.cpp

@@ -1044,7 +1044,6 @@ DECLARE_API(DumpSig)
     INIT_API();
 
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
 
     //
     // Fetch arguments
@@ -1092,7 +1091,6 @@ DECLARE_API(DumpSigElem)
     INIT_API();
 
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
 
     //
     // Fetch arguments
@@ -3940,7 +3938,6 @@ DECLARE_API(DumpRuntimeTypes)
 {
     INIT_API();
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
 
     BOOL dml = FALSE;
 
@@ -4495,7 +4492,6 @@ DECLARE_API(VerifyHeap)
 {
     INIT_API();
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
 
     if (!g_snapshot.Build())
     {
@@ -4631,9 +4627,6 @@ DECLARE_API(AnalyzeOOM)
 {
     INIT_API();
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
-
-#ifndef FEATURE_PAL
 
     if (!InitializeHeapData ())
     {
@@ -4699,17 +4692,12 @@ DECLARE_API(AnalyzeOOM)
     }
 
     return S_OK;
-#else
-    _ASSERTE(false);
-    return E_FAIL;
-#endif // FEATURE_PAL
 }
 
 DECLARE_API(VerifyObj)
 {
     INIT_API();
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
 
     TADDR  taddrObj = 0;
     TADDR  taddrMT;
@@ -4772,9 +4760,6 @@ DECLARE_API(ListNearObj)
 {
     INIT_API();
     MINIDUMP_NOT_SUPPORTED();
-    ONLY_SUPPORTED_ON_WINDOWS_TARGET();
-
-#if !defined(FEATURE_PAL)
 
     TADDR taddrArg = 0;
     TADDR taddrObj = 0;
@@ -4946,13 +4931,6 @@ DECLARE_API(ListNearObj)
     }
 
     return Status;
-
-#else
-
-    _ASSERTE(false);
-    return E_FAIL;
-
-#endif // FEATURE_PAL
 }
 
 

src/SOS/lldbplugin/soscommand.cpp

@@ -181,6 +181,7 @@ sosCommandInitialize(lldb::SBDebugger debugger)
     g_services->AddCommand("gcroot", new sosCommand("GCRoot"), "Displays info about references (or roots) to an object at the specified address.");
     g_services->AddCommand("gcwhere", new sosCommand("GCWhere"), "Displays the location in the GC heap of the argument passed in.");
     g_services->AddCommand("ip2md", new sosCommand("IP2MD"), "Displays the MethodDesc structure at the specified address in code that has been JIT-compiled.");
+    g_services->AddCommand("listnearobj", new sosCommand("ListNearObj"), "displays the object preceeding and succeeding the address passed.");
     g_services->AddCommand("loadsymbols", new sosCommand("SetSymbolServer", "-loadsymbols"), "Load the .NET Core native module symbols.");
     g_services->AddCommand("name2ee", new sosCommand("Name2EE"), "Displays the MethodTable structure and EEClass structure for the specified type or method in the specified module.");
     g_services->AddCommand("pe", new sosCommand("PrintException"), "Displays and formats fields of any object derived from the Exception class at the specified address.");
@@ -201,5 +202,6 @@ sosCommandInitialize(lldb::SBDebugger debugger)
     g_services->AddCommand("threadstate", new sosCommand("ThreadState"), "Pretty prints the meaning of a threads state.");
     g_services->AddCommand("token2ee", new sosCommand("token2ee"), "Displays the MethodTable structure and MethodDesc structure for the specified token and module.");
     g_services->AddCommand("verifyheap", new sosCommand("VerifyHeap"), "Checks the GC heap for signs of corruption.");
+    g_services->AddCommand("verifyobj", new sosCommand("VerifyObj"), "Checks the object that is passed as an argument for signs of corruption.");
     return true;
 }