en Copyright 2015 Java http://172.16.0.5:8080/history/freebsd-14.2/contrib/elftoolchain/libelf/Makefile#eb81f38a Fix objcopy for little-endian MIPS64 objects.MIPS64 does not store the 'r_info' field of a relocation table entry asa 64-bit value consisting of a 32-bit symbol index in the high 32 bitsand a 32-bit type in the low 32 bits as on other architectures. Instead,the 64-bit 'r_info' field is really a 32-bit symbol index followed by fourindividual byte type fields. For big-endian MIPS64, treating this as a64-bit integer happens to be compatible with the layout expected by otherarchitectures (symbol index in upper 32-bits of resulting "native" 64-bitinteger). However, for little-endian MIPS64 the parsed 64-bit integercontains the symbol index in the low 32 bits and the 4 individual bytetype fields in the upper 32-bits (but as if the upper 32-bits werebyte-swapped).To cope, add two helper routines in gelf_getrel.c to translate between thecorrect native 'r_info' value and the value obtained after the normalbyte-swap translation. Use these routines in gelf_getrel(), gelf_getrela(),gelf_update_rel(), and gelf_update_rela(). This fixes 'readelf -r' onlittle-endian MIPS64 objects which was previously decoding incorrectrelocations as well as 'objcopy: invalid symbox index' warnings fromobjcopy when extracting debug symbols from kernel modules.Even with this fixed, objcopy was still crashing when trying to extractdebug symbols from little-endian MIPS64 modules. The workaround ingelf_*rel*() depends on the current ELF object having a valid ELF headerso that the 'e_machine' field can be compared against EM_MIPS. objcopywas parsing the relocation entries to possibly rewrite the 'r_info' fieldsin the update_relocs() function before writing the initial ELF header tothe destination object file. Move the initial write of the ELF headerearlier before copy_contents() so that update_relocs() uses the correctsymbol index values.Note that this change should really go upstream. The binutils readelfsource has a similar hack for MIPS64EL though I implemented this versionfrom scratch using the MIPS64 ABI PDF as a reference.Discussed with: jkoshyReviewed by: emaste, impApproved by: re (gjb, kib)MFC after: 1 monthDifferential Revision: https://reviews.freebsd.org/D15734 List of files: /freebsd-14.2/contrib/elftoolchain/libelf/Makefile Wed, 05 Sep 2018 20:51:53 +0000 John Baldwin <jhb@FreeBSD.org>