From: Fangrui Song Date: Mon, 17 Oct 2022 18:57:17 +0000 (-0700) Subject: [ELF] Move ELFT-agnostic relocation code to processAux X-Git-Tag: upstream/17.0.6~30334 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d8af31ecede0c54ec667ab687784149e806c9e4c;p=platform%2Fupstream%2Fllvm.git [ELF] Move ELFT-agnostic relocation code to processAux --- diff --git a/lld/ELF/Relocations.cpp b/lld/ELF/Relocations.cpp index a1377b2..285b268 100644 --- a/lld/ELF/Relocations.cpp +++ b/lld/ELF/Relocations.cpp @@ -1035,9 +1035,30 @@ bool RelocationScanner::isStaticLinkTimeConstant(RelExpr e, RelType type, // space for the extra PT_LOAD even if we end up not using it. void RelocationScanner::processAux(RelExpr expr, RelType type, uint64_t offset, Symbol &sym, int64_t addend) const { + // If non-ifunc non-preemptible, change PLT to direct call and optimize GOT + // indirection. + const bool isIfunc = sym.isGnuIFunc(); + if (!sym.isPreemptible && (!isIfunc || config->zIfuncNoplt)) { + if (expr != R_GOT_PC) { + // The 0x8000 bit of r_addend of R_PPC_PLTREL24 is used to choose call + // stub type. It should be ignored if optimized to R_PC. + if (config->emachine == EM_PPC && expr == R_PPC32_PLTREL) + addend &= ~0x8000; + // R_HEX_GD_PLT_B22_PCREL (call a@GDPLT) is transformed into + // call __tls_get_addr even if the symbol is non-preemptible. + if (!(config->emachine == EM_HEXAGON && + (type == R_HEX_GD_PLT_B22_PCREL || + type == R_HEX_GD_PLT_B22_PCREL_X || + type == R_HEX_GD_PLT_B32_PCREL_X))) + expr = fromPlt(expr); + } else if (!isAbsoluteValue(sym)) { + expr = + target->adjustGotPcExpr(type, addend, sec->rawData.data() + offset); + } + } + // We were asked not to generate PLT entries for ifuncs. Instead, pass the // direct relocation on through. - const bool isIfunc = sym.isGnuIFunc(); if (LLVM_UNLIKELY(isIfunc) && config->zIfuncNoplt) { std::lock_guard lock(relocMutex); sym.exportDynamic = true; @@ -1428,30 +1449,6 @@ template void RelocationScanner::scanOne(RelTy *&i) { } } - // If we know that a PLT entry will be resolved within the same ELF module, we - // can skip PLT access and directly jump to the destination function. For - // example, if we are linking a main executable, all dynamic symbols that can - // be resolved within the executable will actually be resolved that way at - // runtime, because the main executable is always at the beginning of a search - // list. We can leverage that fact. - if (!sym.isPreemptible && (!sym.isGnuIFunc() || config->zIfuncNoplt)) { - if (expr != R_GOT_PC) { - // The 0x8000 bit of r_addend of R_PPC_PLTREL24 is used to choose call - // stub type. It should be ignored if optimized to R_PC. - if (config->emachine == EM_PPC && expr == R_PPC32_PLTREL) - addend &= ~0x8000; - // R_HEX_GD_PLT_B22_PCREL (call a@GDPLT) is transformed into - // call __tls_get_addr even if the symbol is non-preemptible. - if (!(config->emachine == EM_HEXAGON && - (type == R_HEX_GD_PLT_B22_PCREL || - type == R_HEX_GD_PLT_B22_PCREL_X || - type == R_HEX_GD_PLT_B32_PCREL_X))) - expr = fromPlt(expr); - } else if (!isAbsoluteValue(sym)) { - expr = target->adjustGotPcExpr(type, addend, relocatedAddr); - } - } - processAux(expr, type, offset, sym, addend); }