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
--- 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);