8122937: [JEP 245] Validate JVM Command-Line Flag Arguments.
Summary: Validate the arguments to all JVM command-line flags so as to avoid crashes, and ensure that appropriate error messages are displayed when they are invalid.
Reviewed-by: ddmitriev, dholmes, kbarrett, drwhite, brutisso, coleenp
/*
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#include "precompiled.hpp"
#include "runtime/arguments.hpp"
#include "runtime/commandLineFlagConstraintsRuntime.hpp"
#include "runtime/globals.hpp"
#include "utilities/defaultStream.hpp"
Flag::Error ObjectAlignmentInBytesConstraintFunc(bool verbose, intx* value) {
if (!is_power_of_2(*value)) {
if (verbose == true) {
jio_fprintf(defaultStream::error_stream(),
"ObjectAlignmentInBytes=" INTX_FORMAT " must be power of 2\n",
*value);
}
return Flag::VIOLATES_CONSTRAINT;
}
// In case page size is very small.
if (*value >= (intx)os::vm_page_size()) {
if (verbose == true) {
jio_fprintf(defaultStream::error_stream(),
"ObjectAlignmentInBytes=" INTX_FORMAT " must be less than page size " INTX_FORMAT "\n",
*value, (intx)os::vm_page_size());
}
return Flag::VIOLATES_CONSTRAINT;
}
return Flag::SUCCESS;
}
// Need to enforce the padding not to break the existing field alignments.
// It is sufficient to check against the largest type size.
Flag::Error ContendedPaddingWidthConstraintFunc(bool verbose, intx* value) {
if ((*value != 0) && ((*value % BytesPerLong) != 0)) {
if (verbose == true) {
jio_fprintf(defaultStream::error_stream(),
"ContendedPaddingWidth=" INTX_FORMAT " must be a multiple of %d\n",
*value, BytesPerLong);
}
return Flag::VIOLATES_CONSTRAINT;
} else {
return Flag::SUCCESS;
}
}