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8152182: Possible overflow in initialzation of _rescan_task_size and _marking_task_size

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Add constraints for CMSRescanMultiple and CMSConcMarkMultiple flags

Reviewed-by: jwilhelm, jmasa
This commit is contained in:
Sangheon Kim 2016-04-07 15:34:21 -07:00
parent 10c7cac93e
commit 25f35cda7d
5 changed files with 60 additions and 2 deletions
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5
hotspot/src/share/vm/gc/cms/compactibleFreeListSpace.cpp
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@ -2836,6 +2836,11 @@ void CompactibleFreeListSpace:: par_get_chunk_of_blocks(size_t word_sz, size_t n
par_get_chunk_of_blocks_dictionary(word_sz, n, fl);
}
const size_t CompactibleFreeListSpace::max_flag_size_for_task_size() const {
const size_t ergo_max = _old_gen->reserved().word_size() / (CardTableModRefBS::card_size_in_words * BitsPerWord);
return ergo_max;
}
// Set up the space's par_seq_tasks structure for work claiming
// for parallel rescan. See CMSParRemarkTask where this is currently used.
// XXX Need to suitably abstract and generalize this and the next

2
hotspot/src/share/vm/gc/cms/compactibleFreeListSpace.hpp
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@ -345,6 +345,8 @@ class CompactibleFreeListSpace: public CompactibleSpace {
// Support for parallelization of rescan and marking.
const size_t rescan_task_size() const { return _rescan_task_size; }
const size_t marking_task_size() const { return _marking_task_size; }
// Return ergonomic max size for CMSRescanMultiple and CMSConcMarkMultiple.
const size_t max_flag_size_for_task_size() const;
SequentialSubTasksDone* conc_par_seq_tasks() {return &_conc_par_seq_tasks; }
void initialize_sequential_subtasks_for_rescan(int n_threads);
void initialize_sequential_subtasks_for_marking(int n_threads,

45
hotspot/src/share/vm/runtime/commandLineFlagConstraintsGC.cpp
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@ -457,6 +457,51 @@ Flag::Error MarkStackSizeConstraintFunc(size_t value, bool verbose) {
}
}
static Flag::Error CMSReservedAreaConstraintFunc(const char* name, size_t value, bool verbose) {
#if INCLUDE_ALL_GCS
if (UseConcMarkSweepGC) {
ConcurrentMarkSweepGeneration* cms = (ConcurrentMarkSweepGeneration*)GenCollectedHeap::heap()->old_gen();
const size_t ergo_max = cms->cmsSpace()->max_flag_size_for_task_size();
if (value > ergo_max) {
CommandLineError::print(verbose,
"%s (" SIZE_FORMAT ") must be "
"less than or equal to ergonomic maximum (" SIZE_FORMAT ") "
"which is based on the maximum size of the old generation of the Java heap\n",
name, value, ergo_max);
return Flag::VIOLATES_CONSTRAINT;
}
}
#endif
return Flag::SUCCESS;
}
Flag::Error CMSRescanMultipleConstraintFunc(size_t value, bool verbose) {
Flag::Error status = CMSReservedAreaConstraintFunc("CMSRescanMultiple", value, verbose);
#if INCLUDE_ALL_GCS
if (status == Flag::SUCCESS && UseConcMarkSweepGC) {
// CMSParRemarkTask::do_dirty_card_rescan_tasks requires CompactibleFreeListSpace::rescan_task_size()
// to be aligned to CardTableModRefBS::card_size * BitsPerWord.
// Note that rescan_task_size() will be aligned if CMSRescanMultiple is a multiple of 'HeapWordSize'
// because rescan_task_size() is CardTableModRefBS::card_size / HeapWordSize * BitsPerWord.
if (value % HeapWordSize != 0) {
CommandLineError::print(verbose,
"CMSRescanMultiple (" SIZE_FORMAT ") must be "
"a multiple of " SIZE_FORMAT "\n",
value, HeapWordSize);
status = Flag::VIOLATES_CONSTRAINT;
}
}
#endif
return status;
}
Flag::Error CMSConcMarkMultipleConstraintFunc(size_t value, bool verbose) {
return CMSReservedAreaConstraintFunc("CMSConcMarkMultiple", value, verbose);
}
Flag::Error CMSPrecleanDenominatorConstraintFunc(uintx value, bool verbose) {
#if INCLUDE_ALL_GCS
if (UseConcMarkSweepGC && (value <= CMSPrecleanNumerator)) {

2
hotspot/src/share/vm/runtime/commandLineFlagConstraintsGC.hpp
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@ -60,6 +60,8 @@ Flag::Error ParGCCardsPerStrideChunkConstraintFunc(intx value, bool verbose);
Flag::Error CMSOldPLABMinConstraintFunc(size_t value, bool verbose);
Flag::Error CMSOldPLABMaxConstraintFunc(size_t value, bool verbose);
Flag::Error MarkStackSizeConstraintFunc(size_t value, bool verbose);
Flag::Error CMSRescanMultipleConstraintFunc(size_t value, bool verbose);
Flag::Error CMSConcMarkMultipleConstraintFunc(size_t value, bool verbose);
Flag::Error CMSPrecleanDenominatorConstraintFunc(uintx value, bool verbose);
Flag::Error CMSPrecleanNumeratorConstraintFunc(uintx value, bool verbose);
Flag::Error CMSSamplingGrainConstraintFunc(uintx value, bool verbose);

8
hotspot/src/share/vm/runtime/globals.hpp
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@ -1806,13 +1806,17 @@ public:
"enough work per iteration") \
range(0, max_intx) \
\
/* 4096 = CardTableModRefBS::card_size_in_words * BitsPerWord */ \
product(size_t, CMSRescanMultiple, 32, \
"Size (in cards) of CMS parallel rescan task") \
range(1, max_uintx) \
range(1, SIZE_MAX / 4096) \
constraint(CMSRescanMultipleConstraintFunc,AfterMemoryInit) \
\
/* 4096 = CardTableModRefBS::card_size_in_words * BitsPerWord */ \
product(size_t, CMSConcMarkMultiple, 32, \
"Size (in cards) of CMS concurrent MT marking task") \
range(1, max_uintx) \
range(1, SIZE_MAX / 4096) \
constraint(CMSConcMarkMultipleConstraintFunc,AfterMemoryInit) \
\
product(bool, CMSAbortSemantics, false, \
"Whether abort-on-overflow semantics is implemented") \