В Thu, 14 Nov 2024 16:24:16 +0000 Mauricio Vargas Sepulveda <m.sepulv...@mail.utoronto.ca> пишет:
> After enabling the SAN flags, I cannot reproduce the gcc-san error > [2]. Can you use the rocker/r-devel-san container? It reproduces the problem for me. When reading galapagos/cg15.dic, FuzzyEntityParser::ParseEntities() keeps advancing over the file and failing to parse a single entity until it eventually calls stop() because it didn't find any entities. In a non-sanitized build, it first succeeds at 0-based offset 1095. In a sanitized build, it fails for all offsets. I think this is due to the ordering of the byte reads: https://github.com/pachadotdev/open-redatam/blob/bbb65242f1af5f601def1c0b971ed601d459b4f3/src/readers/ByteArrayReader.cpp#L176-L192 In C++, an operation like the following: static_cast<uint16_t>(ReadByte()) << 8 | static_cast<uint16_t>(ReadByte()); ...depends on the order in which the compiler will choose to evaluate the calls to static_cast<uint16_t>(ReadByte()), and this order is not guaranteed to be left-to-right: https://en.cppreference.com/w/cpp/language/eval_order I edited all four byte-reading functions and replaced the one-statement operations with separate statements for each of the byte reads: --- redatam.orig/src/redatamlib/readers/ByteArrayReader.cpp 2024-11-09 02:12:17.000000000 +0000 +++ redatam.new/src/redatamlib/readers/ByteArrayReader.cpp 2024-11-14 21:25:54.000000000 +0000 @@ -175,23 +175,27 @@ } uint16_t ByteArrayReader::ReadInt16LE() { - return static_cast<uint16_t>(ReadByte()) | - (static_cast<uint16_t>(ReadByte()) << 8); + uint16_t a = static_cast<uint16_t>(ReadByte()); + uint16_t b = static_cast<uint16_t>(ReadByte()) << 8; + return a | b; } uint32_t ByteArrayReader::ReadInt32LE() { - return static_cast<uint32_t>(ReadInt16LE()) | - static_cast<uint32_t>(ReadInt16LE()) << 16; + uint32_t a = static_cast<uint32_t>(ReadInt16LE()); + uint32_t b = static_cast<uint32_t>(ReadInt16LE()) << 16; + return a | b; } uint16_t ByteArrayReader::ReadInt16BE() { - return (static_cast<uint16_t>(ReadByte()) << 8) | - static_cast<uint16_t>(ReadByte()); + uint16_t a= (static_cast<uint16_t>(ReadByte()) << 8); + uint16_t b= static_cast<uint16_t>(ReadByte()); + return a| b; } uint32_t ByteArrayReader::ReadInt32BE() { - return (static_cast<uint32_t>(ReadInt16BE()) << 16) | - static_cast<uint32_t>(ReadInt16BE()); + uint32_t b = static_cast<uint32_t>(ReadInt16LE()) << 16; + uint32_t a = static_cast<uint32_t>(ReadInt16LE()); + return b | a; } } // namespace RedatamLib ...and this seems to make the error vanish. I think I see the misordering too. In the output of objdump -d redatam.Rcheck/redatam/libs/redatam.so, I see: 0000000000267010 <_ZN10RedatamLib15ByteArrayReader11ReadInt16LEEv>: 267028: e8 93 6f f5 ff call 1bdfc0 <_ZN10RedatamLib15ByteArrayReader8ReadByteEv@plt> first_byte <- ReadByte() 26702d: 41 89 c4 mov %eax,%r12d save first byte in r12 26703d: 41 c1 e4 08 shl $0x8,%r12d left-shift the first byte! 267041: e8 7a 6f f5 ff call 1bdfc0 <_ZN10RedatamLib15ByteArrayReader8ReadByteEv@plt> second byte in eax 26704a: 44 09 e0 or %r12d,%eax OR them together ...which is how you read big-endian numbers, not little-endian ones. -- Best regards, Ivan ______________________________________________ R-package-devel@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-package-devel
