https://sourceware.org/bugzilla/show_bug.cgi?id=27169
--- Comment #10 from Fangrui Song <i at maskray dot me> --- (In reply to H.J. Lu from comment #9) > ld uses R_386_PC32 to tell if call site supports PIC PLT. Calling an IFUNC > function in static PIE requires PLT. If call site doesn't support PIC PLT, > linker will issue an error: > > https://sourceware.org/bugzilla/show_bug.cgi?id=20515 Let me rephrase what PR20515 is about: For a call to a hidden function declaration, the compiler produces an R_386_PC32 relocation. The relocation is an indicator that EBX may not be set up. If the declaration refers to an ifunc definition, the linker will resolve the R_386_PC32 to an IPLT entry. For -pie and -shared links, the IPLT entry references EBX. If the call site does not set up EBX, the IPLT entry call will be incorrect. The resolution to PR20515 has implemented the diagnostic. If we change the compiler/assembler to use R_386_PLT32 for non-default visibility function declarations, this diagnostic will be lost. So unfortunately we cannot find a satisfactory relocation type for branches to undefined symbols: * R_386_PC32: canonical PLT entries (similar to copy relocations) which may break -Bsymbolic or --dynamic-list usage. * R_386_PLT32: lose a diagnostic for non-default ifunc in -pie/-shared modules. -- You are receiving this mail because: You are on the CC list for the bug.
