diff -r 8fb16f199266 -r c7ec737733a6 src/share/vm/interpreter/bytecodes.cpp --- a/src/share/vm/interpreter/bytecodes.cpp Wed Oct 22 20:47:00 2008 -0700 +++ b/src/share/vm/interpreter/bytecodes.cpp Thu Oct 30 15:48:59 2008 -0400 @@ -54,13 +54,19 @@ return method->orig_bytecode_at(method->bci_from(bcp)); } -int Bytecodes::special_length_at(address bcp) { +int Bytecodes::special_length_at(address bcp, address end) { Code code = code_at(bcp); switch (code) { case _wide: + if (end != NULL && bcp + 1 >= end) { + return -1; // don't read past end of code buffer + } return wide_length_for(cast(*(bcp + 1))); case _tableswitch: { address aligned_bcp = (address)round_to((intptr_t)bcp + 1, jintSize); + if (end != NULL && aligned_bcp + 3*jintSize >= end) { + return -1; // don't read past end of code buffer + } jlong lo = (jint)Bytes::get_Java_u4(aligned_bcp + 1*jintSize); jlong hi = (jint)Bytes::get_Java_u4(aligned_bcp + 2*jintSize); jlong len = (aligned_bcp - bcp) + (3 + hi - lo + 1)*jintSize; @@ -73,6 +79,9 @@ case _fast_binaryswitch: // fall through case _fast_linearswitch: { address aligned_bcp = (address)round_to((intptr_t)bcp + 1, jintSize); + if (end != NULL && aligned_bcp + 2*jintSize >= end) { + return -1; // don't read past end of code buffer + } jlong npairs = (jint)Bytes::get_Java_u4(aligned_bcp + jintSize); jlong len = (aligned_bcp - bcp) + (2 + 2*npairs)*jintSize; // only return len if it can be represented as a positive int; @@ -90,14 +99,17 @@ // verifier when reading in bytecode to verify. Other mechanisms that // run at runtime (such as generateOopMaps) need to iterate over the code // and don't expect to see breakpoints: they want to see the instruction -// which was replaces so that they can get the correct length and find +// which was replaced so that they can get the correct length and find // the next bytecode. -int Bytecodes::raw_special_length_at(address bcp) { +// +// 'end' indicates the end of the code buffer, which we should not try to read +// past. +int Bytecodes::raw_special_length_at(address bcp, address end) { Code code = code_or_bp_at(bcp); if (code == _breakpoint) { return 1; } else { - return special_length_at(bcp); + return special_length_at(bcp, end); } }