| Summary: | Mips R_MIPS_16 relocation incorrectly handled | ||
|---|---|---|---|
| Product: | binutils | Reporter: | Carl van Schaik <navlrac> |
| Component: | ld | Assignee: | unassigned |
| Status: | RESOLVED FIXED | ||
| Severity: | critical | CC: | bug-binutils |
| Priority: | P2 | ||
| Version: | 2.15 | ||
| Target Milestone: | --- | ||
| Host: | ia32-linux | Target: | mips-linux |
| Build: | Last reconfirmed: | ||
The master branch has been updated by Alan Modra <amodra@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=d712f2768ac5e71027657d85b921fc0e85d94bcd commit d712f2768ac5e71027657d85b921fc0e85d94bcd Author: Alan Modra <amodra@gmail.com> Date: Sun Jun 12 16:29:05 2022 +0930 BFD_RELOC_MIPS_16 MIPS should not be using BFD_RELOC_16 for its R_MIPS_16 relocation, since R_MIPS_16 specifies a 16-bit field in a 32-bit word. BFD_RELOC_16, emitted by generic code to handle fixups on 16-bit data directives, expects fixups to operate on the whole of a 16-bit word. This patch corrects the problem by using BFD_RELOC_MIPS_16, a new bfd reloc that is used to generate R_MIPS_16. BFD_RELOC_16 is handled in md_apply_fix for cases where the fixup can be applied at assembly time. Like BFD_RELOC_8, BFD_RELOC_16 now has no corresponding object file relocation, and thus .half, .hword, .short and .dc.w must be resolved at assembly time. BFD_RELOC_MIPS_REL16 is removed by this patch since it isn't used. PR 3243 PR 26542 * reloc.c (BFD_RELOC_MIPS_16): Rename from BFD_RELOC_MIPS_REL16. * elf32-mips.c (mips_reloc_map): Map BFD_RELOC_MIPS_16 to R_MIPS_16. * elf64-mips.c (mips_reloc_map): Likewise, delete BFD_RELOC_MIPS_REL16. * elfn32-mips.c (mips_reloc_map): Likewise. * libbfd.h: Regenerate. * bfd-in2.h: Regenerate. gas/ * config/tc-mips.c (append_insn): Handle BFD_RELOC_MIPS_16. (macro_build): Likewise. (mips_percent_op <%half>): Generate BFD_RELOC_MIPS_16. (md_apply_fix): Handle BFD_RELOC_16 and BFD_RELOC_MIPS_16 when fx_done. ld/ * testsuite/ld-mips-elf/reloc-local-overflow.d, * testsuite/ld-mips-elf/reloc-local-overflow.s: Rewrite. Fixed, you now can't use R_MIPS_16 on data. |
R_MIPS_16 is incorrectly handled when at a half-word offset: See below: 00000000 <structure>: 8: 00000001 movf zero,zero,$fcc0 c: 00000130 tge zero,zero,0x4 ... 10: R_MIPS_32 kdebug_init() 14: R_MIPS_32 kdebug_entry(void*) 50: R_MIPS_32 _memory_descriptors_offset 56: R_MIPS_16 _memory_descriptors_size a4: 0000003f 0x3f After linking, the values that should be at offset 0x56, is actually placed at 0x60 in the elf output.