ld: fix freebsd build reverting .interp move

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4794046

src/cmd/5l/asm.c

@@ -185,14 +185,6 @@ doelf(void)
 		elfstr[ElfStrRelPlt] = addstring(shstrtab, ".rel.plt");
 		elfstr[ElfStrPlt] = addstring(shstrtab, ".plt");
 
-		/* interpreter string */
-		if(interpreter == nil)
-			interpreter = linuxdynld;
-		s = lookup(".interp", 0);
-		s->type = SELFROSECT;
-		s->reachable = 1;
-		addstring(s, interpreter);
-
 		/* dynamic symbol table - first entry all zeros */
 		s = lookup(".dynsym", 0);
 		s->type = SELFROSECT;
@@ -492,7 +484,9 @@ asmb(void)
 			sh->type = SHT_PROGBITS;
 			sh->flags = SHF_ALLOC;
 			sh->addralign = 1;
-			shsym(sh, lookup(".interp", 0));
+			if(interpreter == nil)
+				interpreter = linuxdynld;
+			elfinterp(sh, startva, interpreter);
 
 			ph = newElfPhdr();
 			ph->type = PT_INTERP;
@@ -638,7 +632,7 @@ asmb(void)
 		a += elfwritephdrs();
 		a += elfwriteshdrs();
 		cflush();
-		if(a > ELFRESERVE)	
+		if(a+elfwriteinterp() > ELFRESERVE)	
 			diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
 		break;
 	}

src/cmd/6l/asm.c

@@ -591,22 +591,6 @@ doelf(void)
 		elfstr[ElfStrGnuVersion] = addstring(shstrtab, ".gnu.version");
 		elfstr[ElfStrGnuVersionR] = addstring(shstrtab, ".gnu.version_r");
 
-		/* interpreter string */
-		if(interpreter == nil) {
-			switch(HEADTYPE) {
-			case Hlinux:
-				interpreter = linuxdynld;
-				break;
-			case Hfreebsd:
-				interpreter = freebsddynld;
-				break;
-			}
-		}
-		s = lookup(".interp", 0);
-		s->type = SELFROSECT;
-		s->reachable = 1;
-		addstring(s, interpreter);
-
 		/* dynamic symbol table - first entry all zeros */
 		s = lookup(".dynsym", 0);
 		s->type = SELFROSECT;
@@ -909,7 +893,7 @@ asmb(void)
 					break;
 				}
 			}
-			shsym(sh, lookup(".interp", 0));
+			elfinterp(sh, startva, interpreter);
 
 			ph = newElfPhdr();
 			ph->type = PT_INTERP;
@@ -1088,7 +1072,7 @@ asmb(void)
 		a += elfwritephdrs();
 		a += elfwriteshdrs();
 		cflush();
-		if(a > ELFRESERVE)	
+		if(a+elfwriteinterp() > ELFRESERVE)	
 			diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
 		break;
 	case Hwindows:

src/cmd/8l/asm.c

@@ -551,22 +551,6 @@ doelf(void)
 		elfstr[ElfStrGnuVersion] = addstring(shstrtab, ".gnu.version");
 		elfstr[ElfStrGnuVersionR] = addstring(shstrtab, ".gnu.version_r");
 
-		/* interpreter string */
-		if(interpreter == nil) {
-			switch(HEADTYPE) {
-			case Hlinux:
-				interpreter = linuxdynld;
-				break;
-			case Hfreebsd:
-				interpreter = freebsddynld;
-				break;
-			}
-		}
-		s = lookup(".interp", 0);
-		s->type = SELFROSECT;
-		s->reachable = 1;
-		addstring(s, interpreter);
-
 		/* dynamic symbol table - first entry all zeros */
 		s = lookup(".dynsym", 0);
 		s->type = SELFROSECT;
@@ -964,7 +948,17 @@ asmb(void)
 			sh->type = SHT_PROGBITS;
 			sh->flags = SHF_ALLOC;
 			sh->addralign = 1;
-			shsym(sh, lookup(".interp", 0));
+			if(interpreter == nil) {
+				switch(HEADTYPE) {
+				case Hlinux:
+					interpreter = linuxdynld;
+					break;
+				case Hfreebsd:
+					interpreter = freebsddynld;
+					break;
+				}
+			}
+			elfinterp(sh, startva, interpreter);
 
 			ph = newElfPhdr();
 			ph->type = PT_INTERP;
@@ -1148,7 +1142,7 @@ asmb(void)
 		a += elfwritephdrs();
 		a += elfwriteshdrs();
 		cflush();
-		if(a > ELFRESERVE)	
+		if(a+elfwriteinterp() > ELFRESERVE)	
 			diag("ELFRESERVE too small: %d > %d", a, ELFRESERVE);
 		break;
 

src/cmd/ld/data.c

@@ -871,7 +871,7 @@ dodata(void)
 
 	/* data */
 	sect = addsection(&segdata, ".data", 06);
-	sect->vaddr = 0;
+	sect->vaddr = datsize;
 	for(; s != nil && s->type < SBSS; s = s->next) {
 		s->type = SDATA;
 		t = s->size;

src/cmd/ld/elf.c

@@ -19,6 +19,7 @@ static	int	elf64;
 static	ElfEhdr	hdr;
 static	ElfPhdr	*phdr[NSECT];
 static	ElfShdr	*shdr[NSECT];
+static	char	*interp;
 
 typedef struct Elfstring Elfstring;
 struct Elfstring
@@ -303,6 +304,32 @@ elfwritedynentsymsize(Sym *s, int tag, Sym *t)
 	addsize(s, t);
 }
 
+int
+elfwriteinterp(void)
+{
+	int n;
+
+	if(interp == nil)
+		return 0;
+
+	n = strlen(interp)+1;
+	cseek(ELFRESERVE-n);
+	cwrite(interp, n);
+	return n;
+}
+
+void
+elfinterp(ElfShdr *sh, uint64 startva, char *p)
+{
+	int n;
+
+	interp = p;
+	n = strlen(interp)+1;
+	sh->addr = startva + ELFRESERVE - n;
+	sh->off = ELFRESERVE - n;
+	sh->size = n;
+}
+
 extern int nelfsym;
 int elfverneed;