From: Cherry Mui <cherryyz@google.com>
Date: Thu, 8 Jun 2023 17:23:39 +0000 (-0400)
Subject: cmd/link: clean up some relocation handling
X-Git-Tag: go1.22rc1~1580
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=66c8410c7331edc2762bae3babb58e6e715eb066;p=gostls13.git

cmd/link: clean up some relocation handling

We don't use R_PCREL for calls to dynamic symbols (we use R_CALL
instead). Don't handle R_PCREL as a call.

We don't use R_CALL on ARM64 (we use R_CALLARM64 instead).

Remove those cases, which we don't expect to see.

Change-Id: Idd99022a8eeb65750ffc2936ffdccf8bb0405e30
Reviewed-on: https://go-review.googlesource.com/c/go/+/501859
Run-TryBot: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Than McIntosh <thanm@google.com>
---

diff --git a/src/cmd/link/internal/amd64/asm.go b/src/cmd/link/internal/amd64/asm.go
index c4134262c5..7082c839ee 100644
--- a/src/cmd/link/internal/amd64/asm.go
+++ b/src/cmd/link/internal/amd64/asm.go
@@ -245,13 +245,25 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade
 	r = relocs.At(rIdx)
 
 	switch r.Type() {
-	case objabi.R_CALL,
-		objabi.R_PCREL:
+	case objabi.R_CALL:
 		if targType != sym.SDYNIMPORT {
 			// nothing to do, the relocation will be laid out in reloc
 			return true
 		}
-		if r.Type() == objabi.R_PCREL && ldr.SymType(s) == sym.STEXT && target.IsDarwin() {
+		if target.IsExternal() {
+			// External linker will do this relocation.
+			return true
+		}
+		// Internal linking, for both ELF and Mach-O.
+		// Build a PLT entry and change the relocation target to that entry.
+		addpltsym(target, ldr, syms, targ)
+		su := ldr.MakeSymbolUpdater(s)
+		su.SetRelocSym(rIdx, syms.PLT)
+		su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ)))
+		return true
+
+	case objabi.R_PCREL:
+		if targType == sym.SDYNIMPORT && ldr.SymType(s) == sym.STEXT && target.IsDarwin() {
 			// Loading the address of a dynamic symbol. Rewrite to use GOT.
 			// turn LEAQ symbol address to MOVQ of GOT entry
 			if r.Add() != 0 {
@@ -272,19 +284,7 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade
 				return true
 			}
 			ldr.Errorf(s, "unexpected R_PCREL reloc for dynamic symbol %s: not preceded by LEAQ instruction", ldr.SymName(targ))
-			return false
-		}
-		if target.IsExternal() {
-			// External linker will do this relocation.
-			return true
 		}
-		// Internal linking, for both ELF and Mach-O.
-		// Build a PLT entry and change the relocation target to that entry.
-		addpltsym(target, ldr, syms, targ)
-		su := ldr.MakeSymbolUpdater(s)
-		su.SetRelocSym(rIdx, syms.PLT)
-		su.SetRelocAdd(rIdx, int64(ldr.SymPlt(targ)))
-		return true
 
 	case objabi.R_ADDR:
 		if ldr.SymType(s) == sym.STEXT && target.IsElf() {
diff --git a/src/cmd/link/internal/arm64/asm.go b/src/cmd/link/internal/arm64/asm.go
index e3fc1c4dd4..f2a2b32232 100644
--- a/src/cmd/link/internal/arm64/asm.go
+++ b/src/cmd/link/internal/arm64/asm.go
@@ -284,9 +284,7 @@ func adddynrel(target *ld.Target, ldr *loader.Loader, syms *ld.ArchSyms, s loade
 	r = relocs.At(rIdx)
 
 	switch r.Type() {
-	case objabi.R_CALL,
-		objabi.R_PCREL,
-		objabi.R_CALLARM64:
+	case objabi.R_CALLARM64:
 		if targType != sym.SDYNIMPORT {
 			// nothing to do, the relocation will be laid out in reloc
 			return true