cmd/link: support R_PPC64_REL24_P9NOTOC

This can be treated identically to R_PPC64_REL24_NOTOC as stubs
are generated based on GOPPC64 and -buildmode.

Change-Id: I3c42a9bf3c08d107fb656e6bf59b2307783bd9af
Reviewed-on: https://go-review.googlesource.com/c/go/+/497915
Reviewed-by: Michael Knyszek <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>
Reviewed-by: Lynn Boger <[email protected]>
Reviewed-by: Ian Lance Taylor <[email protected]>
Run-TryBot: Paul Murphy <[email protected]>

Author: pmur

src/cmd/link/internal/loadelf/ldelf.go

@@ -1066,6 +1066,7 @@ func relSize(arch *sys.Arch, pn string, elftype uint32) (uint8, uint8, error) {
 		I386 | uint32(elf.R_386_GOT32X)<<16,
 		PPC64 | uint32(elf.R_PPC64_REL24)<<16,
 		PPC64 | uint32(elf.R_PPC64_REL24_NOTOC)<<16,
+		PPC64 | uint32(elf.R_PPC64_REL24_P9NOTOC)<<16,
 		PPC64 | uint32(elf.R_PPC_REL32)<<16,
 		S390X | uint32(elf.R_390_32)<<16,
 		S390X | uint32(elf.R_390_PC32)<<16,

src/cmd/link/internal/ppc64/asm.go

@@ -304,6 +304,10 @@ func genstubs(ctxt *ld.Link, ldr *loader.Loader) {
 					}
 				}
 
+			case objabi.ElfRelocOffset + objabi.RelocType(elf.R_PPC64_REL24_P9NOTOC):
+				// This can be treated identically to R_PPC64_REL24_NOTOC, as stubs are determined by
+				// GOPPC64 and -buildmode.
+				fallthrough
 			case objabi.ElfRelocOffset + objabi.RelocType(elf.R_PPC64_REL24_NOTOC):
 				switch ldr.SymType(r.Sym()) {
 				case sym.SDYNIMPORT:
@@ -602,13 +606,14 @@ func addelfdynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s lo
 		}
 
 		// Handle relocations found in ELF object files.
-	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_PPC64_REL24_NOTOC):
+	case objabi.ElfRelocOffset + objabi.RelocType(elf.R_PPC64_REL24_NOTOC),
+		objabi.ElfRelocOffset + objabi.RelocType(elf.R_PPC64_REL24_P9NOTOC):
 		su := ldr.MakeSymbolUpdater(s)
 		su.SetRelocType(rIdx, objabi.R_CALLPOWER)
 
 		if targType == sym.SDYNIMPORT {
 			// Should have been handled in elfsetupplt
-			ldr.Errorf(s, "unexpected R_PPC64_REL24_NOTOC for dyn import")
+			ldr.Errorf(s, "unexpected R_PPC64_REL24_NOTOC/R_PPC64_REL24_P9NOTOC for dyn import")
 		}
 		return true