changeset 49659:c42db4d81e33

8200366: SIGSEGV in CodeHeapState::print_names() Summary: Temporary removed the failing function in diagnostic command until investigation is complete. Added checks to validate code blobs. Reviewed-by: kvn, thartmann
author lucy
date Thu, 29 Mar 2018 14:53:01 -0700
parents 17c6ab93710e
children 1e11c8a238f7
files src/hotspot/share/code/codeHeapState.cpp src/hotspot/share/services/diagnosticCommand.cpp
diffstat 2 files changed, 19 insertions(+), 3 deletions(-) [+]
line wrap: on
line diff
--- a/src/hotspot/share/code/codeHeapState.cpp	Thu Mar 29 16:07:39 2018 -0400
+++ b/src/hotspot/share/code/codeHeapState.cpp	Thu Mar 29 14:53:01 2018 -0700
@@ -2084,9 +2084,17 @@
       ast->print_cr("--------------------------------------------------------------------");
       STRINGSTREAM_FLUSH_LOCKED("")
     }
+    // Only check granule if it contains at least one blob.
+    unsigned int nBlobs  = StatArray[ix].t1_count   + StatArray[ix].t2_count + StatArray[ix].tx_count +
+                           StatArray[ix].stub_count + StatArray[ix].dead_count;
+    if (nBlobs > 0 ) {
     for (unsigned int is = 0; is < granule_size; is+=(unsigned int)seg_size) {
+      // heap->find_start() is safe. Only working with _segmap. Returns NULL or void*. Returned CodeBlob may be uninitialized.
       CodeBlob* this_blob = (CodeBlob *)(heap->find_start(low_bound+ix*granule_size+is));
-      if ((this_blob != NULL) && (this_blob != last_blob)) {
+      bool blob_initialized = (this_blob != NULL) &&
+                              ((char*)this_blob + this_blob->header_size() == (char*)(this_blob->relocation_begin())) &&
+                              ((char*)this_blob + CodeBlob::align_code_offset(this_blob->header_size() + this_blob->relocation_size()) == (char*)(this_blob->content_begin()));
+      if (blob_initialized && (this_blob != last_blob)) {
         if (!name_in_addr_range) {
           name_in_addr_range = true;
           ast->fill_to(51);
@@ -2103,7 +2111,12 @@
         ast->fill_to(33);
 
         //---<  print size, name, and signature (for nMethods)  >---
-        const char *blob_name = this_blob->name();
+        // this_blob->name() could return NULL if no name is given to CTOR. Inlined, maybe not visible on stack
+        const char* blob_name = this_blob->name();
+        if (blob_name == 0) {
+          blob_name = "<unavailable>";
+        }
+        // this_blob->as_nmethod_or_null() is safe. Inlined, maybe not visible on stack.
         nmethod*           nm = this_blob->as_nmethod_or_null();
         blobType       cbType = noType;
         if (segment_granules) {
@@ -2145,8 +2158,11 @@
         }
         STRINGSTREAM_FLUSH_LOCKED("\n")
         last_blob          = this_blob;
+      } else if (!blob_initialized && (this_blob != NULL)) {
+        last_blob          = this_blob;
       }
     }
+    }
   }
   STRINGSTREAM_FLUSH_LOCKED("\n\n")
 }
--- a/src/hotspot/share/services/diagnosticCommand.cpp	Thu Mar 29 16:07:39 2018 -0400
+++ b/src/hotspot/share/services/diagnosticCommand.cpp	Thu Mar 29 14:53:01 2018 -0700
@@ -924,7 +924,7 @@
 //---<  BEGIN  >--- CodeHeap State Analytics.
 CodeHeapAnalyticsDCmd::CodeHeapAnalyticsDCmd(outputStream* output, bool heap) :
                                              DCmdWithParser(output, heap),
-  _function("function", "Function to be performed (aggregate, UsedSpace, FreeSpace, MethodCount, MethodSpace, MethodAge, MethodNames, discard", "STRING", false, "all"),
+  _function("function", "Function to be performed (aggregate, UsedSpace, FreeSpace, MethodCount, MethodSpace, MethodAge, discard", "STRING", false, "all"),
   _granularity("granularity", "Detail level - smaller value -> more detail", "STRING", false, "4096") {
   _dcmdparser.add_dcmd_argument(&_function);
   _dcmdparser.add_dcmd_argument(&_granularity);