5l, 6l, 8l, runtime: make -s binaries work

5l, 6l, 8l: change ELF header so that strip doesn't destroy binary

Fixes issue 261.

R=iant, r
CC=golang-dev
http://codereview.appspot.com/994044

16 files changed, 235 insertions, 59 deletions

diff --git a/src/cmd/5l/asm.c b/src/cmd/5l/asm.c
index 79050a9d0..62c2a07ad 100644
--- a/src/cmd/5l/asm.c
+++ b/src/cmd/5l/asm.c
@@ -184,6 +184,7 @@ enum {
 	ElfStrText,
 	ElfStrData,
 	ElfStrBss,
+	ElfStrGosymcounts,
 	ElfStrGosymtab,
 	ElfStrGopclntab,
 	ElfStrShstrtab,
@@ -224,7 +225,8 @@ doelf(void)
 	elfstr[ElfStrText] = addstring(shstrtab, ".text");
 	elfstr[ElfStrData] = addstring(shstrtab, ".data");
 	elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
-	if(!debug['s']) {
+	if(!debug['s']) {	
+		elfstr[ElfStrGosymcounts] = addstring(shstrtab, ".gosymcounts");
 		elfstr[ElfStrGosymtab] = addstring(shstrtab, ".gosymtab");
 		elfstr[ElfStrGopclntab] = addstring(shstrtab, ".gopclntab");
 	}
@@ -243,36 +245,45 @@ doelf(void)
 		/* interpreter string */
 		s = lookup(".interp", 0);
 		s->reachable = 1;
-		s->type = SDATA;	// TODO: rodata
+		s->type = SELFDATA;	// TODO: rodata
 
 		/* dynamic symbol table - first entry all zeros */
 		s = lookup(".dynsym", 0);
-		s->type = SDATA;
+		s->type = SELFDATA;
 		s->reachable = 1;
 		s->value += ELF32SYMSIZE;
 
 		/* dynamic string table */
 		s = lookup(".dynstr", 0);
+		s->type = SELFDATA;
+		s->reachable = 1;
 		addstring(s, "");
 		dynstr = s;
 
 		/* relocation table */
 		s = lookup(".rel", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* global offset table */
 		s = lookup(".got", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* got.plt - ??? */
 		s = lookup(".got.plt", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
+		
+		/* hash */
+		s = lookup(".hash", 0);
+		s->reachable = 1;
+		s->type = SELFDATA;
 
 		/* define dynamic elf table */
 		s = lookup(".dynamic", 0);
+		s->reachable = 1;
+		s->type = SELFDATA;
 		dynamic = s;
 
 		/*
@@ -664,7 +675,7 @@ asmb(void)
 		if(!debug['s']) {
 			ph = newElfPhdr();
 			ph->type = PT_LOAD;
-			ph->flags = PF_W+PF_R;
+			ph->flags = PF_R;
 			ph->off = symo;
 			ph->vaddr = symdatva;
 			ph->paddr = symdatva;
@@ -757,13 +768,19 @@ asmb(void)
 		va = startva + fo;
 		w = textsize;
 
+		/*
+		 * The alignments are bigger than they really need
+		 * to be here, but they are necessary to keep the
+		 * arm strip from moving everything around.
+		 */
+
 		sh = newElfShdr(elfstr[ElfStrText]);
 		sh->type = SHT_PROGBITS;
 		sh->flags = SHF_ALLOC+SHF_EXECINSTR;
 		sh->addr = va;
 		sh->off = fo;
 		sh->size = w;
-		sh->addralign = 4;
+		sh->addralign = ELFRESERVE;
 
 		fo = rnd(fo+w, INITRND);
 		va = rnd(va+w, INITRND);
@@ -772,10 +789,10 @@ asmb(void)
 		sh = newElfShdr(elfstr[ElfStrData]);
 		sh->type = SHT_PROGBITS;
 		sh->flags = SHF_WRITE+SHF_ALLOC;
-		sh->addr = va;
-		sh->off = fo;
-		sh->size = w;
-		sh->addralign = 4;
+		sh->addr = va + elfdatsize;
+		sh->off = fo + elfdatsize;
+		sh->size = w - elfdatsize;
+		sh->addralign = INITRND;
 
 		fo += w;
 		va += w;
@@ -790,23 +807,38 @@ asmb(void)
 		sh->addralign = 4;
 
 		if (!debug['s']) {
-			fo = symo+8;
+			fo = symo;
+			w = 8;
+
+			sh = newElfShdr(elfstr[ElfStrGosymtab]);
+			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
+			sh->off = fo;
+			sh->size = w;
+			sh->addralign = INITRND;
+			sh->addr = symdatva;
+
+			fo += w;
 			w = symsize;
 
 			sh = newElfShdr(elfstr[ElfStrGosymtab]);
 			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
 			sh->off = fo;
 			sh->size = w;
 			sh->addralign = 1;
+			sh->addr = symdatva + 8;
 
 			fo += w;
 			w = lcsize;
 
 			sh = newElfShdr(elfstr[ElfStrGopclntab]);
 			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
 			sh->off = fo;
 			sh->size = w;
 			sh->addralign = 1;
+			sh->addr = symdatva + 8 + lcsize;
 		}
 
 		sh = newElfShstrtab(elfstr[ElfStrShstrtab]);
@@ -987,6 +1019,7 @@ asmsym(void)
 				continue;
 
 			case SDATA:
+			case SELFDATA:
 				putsymb(s->name, 'D', s->value+INITDAT, s->version);
 				continue;
 
@@ -994,6 +1027,10 @@ asmsym(void)
 				putsymb(s->name, 'B', s->value+INITDAT, s->version);
 				continue;
 
+			case SFIXED:
+				putsymb(s->name, 'B', s->value, s->version);
+				continue;
+
 			case SSTRING:
 				putsymb(s->name, 'T', s->value, s->version);
 				continue;
diff --git a/src/cmd/5l/l.h b/src/cmd/5l/l.h
index 44bd923a9..c6659cfab 100644
--- a/src/cmd/5l/l.h
+++ b/src/cmd/5l/l.h
@@ -199,6 +199,9 @@ enum
 
 	SIMPORT,
 	SEXPORT,
+	
+	SFIXED,
+	SELFDATA,
 
 	LFROM		= 1<<0,
 	LTO		= 1<<1,
@@ -317,6 +320,7 @@ EXTERN	Prog*	curp;
 EXTERN	Prog*	curtext;
 EXTERN	Prog*	datap;
 EXTERN	int32	datsize;
+EXTERN	int32 	elfdatsize;
 EXTERN	char	debug[128];
 EXTERN	Prog*	edatap;
 EXTERN	Prog*	etextp;
diff --git a/src/cmd/5l/pass.c b/src/cmd/5l/pass.c
index fcdee6944..06b1792b4 100644
--- a/src/cmd/5l/pass.c
+++ b/src/cmd/5l/pass.c
@@ -48,7 +48,7 @@ dodata(void)
 			s->value = dtype;
 		if(s->type == SBSS)
 			s->type = SDATA;
-		if(s->type != SDATA)
+		if(s->type != SDATA && s->type != SELFDATA)
 			diag("initialize non-data (%d): %s\n%P",
 				s->type, s->name, p);
 		v = p->from.offset + p->reg;
@@ -72,6 +72,24 @@ dodata(void)
 				s->type = SSTRING;
 		}
 	}
+	
+	/*
+	 * pass 0
+	 * assign elf data - must be segregated from real data
+	 */
+	orig = 0;
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		if(!s->reachable || s->type != SELFDATA)
+			continue;
+		v = s->value;
+		while(v & 3)
+			v++;
+		s->size = v;
+		s->value = orig;
+		orig += v;
+	}
+	elfdatsize = orig;
 
 	/*
 	 * pass 1
@@ -79,7 +97,6 @@ dodata(void)
 	 *	(rational is that data segment is more easily
 	 *	 addressed through offset on R12)
 	 */
-	orig = 0;
 	for(i=0; i<NHASH; i++)
 	for(s = hash[i]; s != S; s = s->link) {
 		t = s->type;
@@ -146,6 +163,11 @@ dodata(void)
 	xdefine("edata", SDATA, datsize);
 	xdefine("end", SBSS, datsize+bsssize);
 	xdefine("etext", STEXT, 0L);
+
+	if(debug['s'])
+		xdefine("symdat", SFIXED, 0);
+	else
+		xdefine("symdat", SFIXED, SYMDATVA);
 }
 
 void
diff --git a/src/cmd/5l/span.c b/src/cmd/5l/span.c
index 1272b05ec..a97af07f9 100644
--- a/src/cmd/5l/span.c
+++ b/src/cmd/5l/span.c
@@ -708,6 +708,10 @@ aclass(Adr *a)
 					s->name, TNAME);
 				s->type = SDATA;
 			}
+			if(s->type == SFIXED) {
+				instoffset = s->value + a->offset;
+				return C_LCON;
+			}
 			instoffset = s->value + a->offset + INITDAT;
 			if(s->type == STEXT || s->type == SLEAF || s->type == SUNDEF) {
 				instoffset = s->value + a->offset;
@@ -756,6 +760,9 @@ aclass(Adr *a)
 					s->name, TNAME);
 				s->type = SDATA;
 				break;
+			case SFIXED:
+				instoffset = s->value + a->offset;
+				return C_LCON;
 			case SUNDEF:
 			case STEXT:
 			case SSTRING:
diff --git a/src/cmd/6l/asm.c b/src/cmd/6l/asm.c
index b83cec68f..c104d23d4 100644
--- a/src/cmd/6l/asm.c
+++ b/src/cmd/6l/asm.c
@@ -254,6 +254,7 @@ enum {
 	ElfStrText,
 	ElfStrData,
 	ElfStrBss,
+	ElfStrGosymcounts,
 	ElfStrGosymtab,
 	ElfStrGopclntab,
 	ElfStrShstrtab,
@@ -296,6 +297,7 @@ doelf(void)
 	elfstr[ElfStrData] = addstring(shstrtab, ".data");
 	elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
 	if(!debug['s']) {
+		elfstr[ElfStrGosymcounts] = addstring(shstrtab, ".gosymcounts");
 		elfstr[ElfStrGosymtab] = addstring(shstrtab, ".gosymtab");
 		elfstr[ElfStrGopclntab] = addstring(shstrtab, ".gopclntab");
 		if(debug['e']) {
@@ -317,32 +319,42 @@ doelf(void)
 
 		/* dynamic symbol table - first entry all zeros */
 		s = lookup(".dynsym", 0);
-		s->type = SDATA;
+		s->type = SELFDATA;
 		s->reachable = 1;
 		s->value += ELF64SYMSIZE;
 
 		/* dynamic string table */
 		s = lookup(".dynstr", 0);
+		s->type = SELFDATA;
+		s->reachable = 1;
+		s->value += ELF64SYMSIZE;
 		addstring(s, "");
 		dynstr = s;
 
 		/* relocation table */
 		s = lookup(".rela", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* global offset table */
 		s = lookup(".got", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* got.plt - ??? */
 		s = lookup(".got.plt", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
+		
+		/* hash */
+		s = lookup(".hash", 0);
+		s->reachable = 1;
+		s->type = SELFDATA;
 
 		/* define dynamic elf table */
 		s = lookup(".dynamic", 0);
+		s->reachable = 1;
+		s->type = SELFDATA;
 		dynamic = s;
 
 		/*
@@ -737,7 +749,7 @@ asmb(void)
 		if(!debug['s']) {
 			ph = newElfPhdr();
 			ph->type = PT_LOAD;
-			ph->flags = PF_W+PF_R;
+			ph->flags = PF_R;
 			ph->off = symo;
 			ph->vaddr = symdatva;
 			ph->paddr = symdatva;
@@ -835,9 +847,9 @@ asmb(void)
 		sh = newElfShdr(elfstr[ElfStrData]);
 		sh->type = SHT_PROGBITS;
 		sh->flags = SHF_WRITE+SHF_ALLOC;
-		sh->addr = va;
-		sh->off = fo;
-		sh->size = w;
+		sh->addr = va + elfdatsize;
+		sh->off = fo + elfdatsize;
+		sh->size = w - elfdatsize;
 		sh->addralign = 8;
 
 		fo += w;
@@ -853,23 +865,38 @@ asmb(void)
 		sh->addralign = 8;
 
 		if (!debug['s']) {
-			fo = symo+8;
+			fo = symo;
+			w = 8;
+
+			sh = newElfShdr(elfstr[ElfStrGosymcounts]);
+			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
+			sh->off = fo;
+			sh->size = w;
+			sh->addralign = 1;
+			sh->addr = symdatva;
+
+			fo += w;
 			w = symsize;
 
 			sh = newElfShdr(elfstr[ElfStrGosymtab]);
 			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
 			sh->off = fo;
 			sh->size = w;
 			sh->addralign = 1;
+			sh->addr = symdatva + 8;
 
 			fo += w;
 			w = lcsize;
 
 			sh = newElfShdr(elfstr[ElfStrGopclntab]);
 			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
 			sh->off = fo;
 			sh->size = w;
 			sh->addralign = 1;
+			sh->addr = symdatva + 8 + symsize;
 			
 			if(debug['e']) {
 				sh = newElfShdr(elfstr[ElfStrSymtab]);
@@ -1102,7 +1129,7 @@ datblk(int32 s, int32 n)
 			for(j=l+(c-i)-1; j>=l; j--)
 				if(buf.dbuf[j]) {
 					print("%P\n", p);
-					diag("multiple initialization");
+					diag("multiple initialization for %d %d", s, j);
 					break;
 				}
 		}
diff --git a/src/cmd/6l/l.h b/src/cmd/6l/l.h
index 5f99e9a51..3db0b450a 100644
--- a/src/cmd/6l/l.h
+++ b/src/cmd/6l/l.h
@@ -167,6 +167,8 @@ enum
 	SEXPORT,
 
 	SMACHO,
+	SFIXED,
+	SELFDATA,
 
 	NHASH		= 10007,
 	NHUNK		= 100000,
@@ -314,6 +316,7 @@ EXTERN	Prog*	curtext;
 EXTERN	Prog*	datap;
 EXTERN	Prog*	edatap;
 EXTERN	vlong	datsize;
+EXTERN	vlong	elfdatsize;
 EXTERN	char	debug[128];
 EXTERN	char	literal[32];
 EXTERN	Prog*	etextp;
diff --git a/src/cmd/6l/pass.c b/src/cmd/6l/pass.c
index 44dcb0710..f86942926 100644
--- a/src/cmd/6l/pass.c
+++ b/src/cmd/6l/pass.c
@@ -56,7 +56,7 @@ dodata(void)
 			s->value = dtype;
 		if(s->type == SBSS)
 			s->type = SDATA;
-		if(s->type != SDATA)
+		if(s->type != SDATA && s->type != SELFDATA)
 			diag("initialize non-data (%d): %s\n%P",
 				s->type, s->name, p);
 		t = p->from.offset + p->width;
@@ -64,12 +64,27 @@ dodata(void)
 			diag("initialize bounds (%lld): %s\n%P",
 				s->value, s->name, p);
 	}
-	/* allocate small guys */
+
+	/* allocate elf guys - must be segregated from real data */
 	datsize = 0;
 	for(i=0; i<NHASH; i++)
 	for(s = hash[i]; s != S; s = s->link) {
 		if(!s->reachable)
 			continue;
+		if(s->type != SELFDATA)
+			continue;
+		t = rnd(s->value, 8);
+		s->size = t;
+		s->value = datsize;
+		datsize += t;
+	}
+	elfdatsize = datsize;
+
+	/* allocate small guys */
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		if(!s->reachable)
+			continue;
 		if(s->type != SDATA)
 		if(s->type != SBSS)
 			continue;
@@ -167,6 +182,11 @@ dobss(void)
 	xdefine("data", SBSS, 0);
 	xdefine("edata", SBSS, datsize);
 	xdefine("end", SBSS, dynptrsize + bsssize + datsize);
+
+	if(debug['s'])
+		xdefine("symdat", SFIXED, 0);
+	else
+		xdefine("symdat", SFIXED, SYMDATVA);
 }
 
 Prog*
diff --git a/src/cmd/6l/span.c b/src/cmd/6l/span.c
index 237a81fff..15f931bcb 100644
--- a/src/cmd/6l/span.c
+++ b/src/cmd/6l/span.c
@@ -234,6 +234,7 @@ genasmsym(void (*put)(char*, int, vlong, vlong, int, Sym*))
 				continue;
 
 			case SDATA:
+			case SELFDATA:
 				if(!s->reachable)
 					continue;
 				put(s->name, 'D', s->value+INITDAT, s->size, s->version, s->gotype);
@@ -251,6 +252,10 @@ genasmsym(void (*put)(char*, int, vlong, vlong, int, Sym*))
 				put(s->name, 'B', s->value+INITDAT, s->size, s->version, s->gotype);
 				continue;
 
+			case SFIXED:
+				put(s->name, 'B', s->value, s->size, s->version, s->gotype);
+				continue;
+
 			case SFILE:
 				put(s->name, 'f', s->value, 0, s->version, 0);
 				continue;
@@ -792,6 +797,9 @@ vaddr(Adr *a)
 					v += INITTEXT;	/* TO DO */
 				v += s->value;
 				break;
+			case SFIXED:
+				v += s->value;
+				break;
 			case SMACHO:
 				if(!s->reachable)
 					sysfatal("unreachable symbol in vaddr - %s", s->name);
diff --git a/src/cmd/8l/asm.c b/src/cmd/8l/asm.c
index 0fca6fa0f..797209169 100644
--- a/src/cmd/8l/asm.c
+++ b/src/cmd/8l/asm.c
@@ -38,7 +38,7 @@
 
 char linuxdynld[] = "/lib/ld-linux.so.2";
 char freebsddynld[] = "/usr/libexec/ld-elf.so.1";
-uint32 symdatva = 0x99<<24;
+uint32 symdatva = SYMDATVA;
 
 int32
 entryvalue(void)
@@ -248,6 +248,7 @@ enum {
 	ElfStrText,
 	ElfStrData,
 	ElfStrBss,
+	ElfStrGosymcounts,
 	ElfStrGosymtab,
 	ElfStrGopclntab,
 	ElfStrShstrtab,
@@ -289,6 +290,7 @@ doelf(void)
 	elfstr[ElfStrData] = addstring(shstrtab, ".data");
 	elfstr[ElfStrBss] = addstring(shstrtab, ".bss");
 	if(!debug['s']) {
+		elfstr[ElfStrGosymcounts] = addstring(shstrtab, ".gosymcounts");
 		elfstr[ElfStrGosymtab] = addstring(shstrtab, ".gosymtab");
 		elfstr[ElfStrGopclntab] = addstring(shstrtab, ".gopclntab");
 	}
@@ -307,36 +309,40 @@ doelf(void)
 		/* interpreter string */
 		s = lookup(".interp", 0);
 		s->reachable = 1;
-		s->type = SDATA;	// TODO: rodata
+		s->type = SELFDATA;
 
 		/* dynamic symbol table - first entry all zeros */
 		s = lookup(".dynsym", 0);
-		s->type = SDATA;
+		s->type = SELFDATA;
 		s->reachable = 1;
 		s->value += ELF32SYMSIZE;
 
 		/* dynamic string table */
 		s = lookup(".dynstr", 0);
+		s->reachable = 1;
+		s->type = SELFDATA;
 		addstring(s, "");
 		dynstr = s;
 
 		/* relocation table */
 		s = lookup(".rel", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* global offset table */
 		s = lookup(".got", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* got.plt - ??? */
 		s = lookup(".got.plt", 0);
 		s->reachable = 1;
-		s->type = SDATA;
+		s->type = SELFDATA;
 
 		/* define dynamic elf table */
 		s = lookup(".dynamic", 0);
+		s->reachable = 1;
+		s->type = SELFDATA;
 		dynamic = s;
 
 		/*
@@ -874,7 +880,7 @@ asmb(void)
 		if(!debug['s'] && HEADTYPE != 8 && HEADTYPE != 11) {
 			ph = newElfPhdr();
 			ph->type = PT_LOAD;
-			ph->flags = PF_W+PF_R;
+			ph->flags = PF_R;
 			ph->off = symo;
 			ph->vaddr = symdatva;
 			ph->paddr = symdatva;
@@ -986,9 +992,9 @@ asmb(void)
 		sh = newElfShdr(elfstr[ElfStrData]);
 		sh->type = SHT_PROGBITS;
 		sh->flags = SHF_WRITE+SHF_ALLOC;
-		sh->addr = va;
-		sh->off = fo;
-		sh->size = w;
+		sh->addr = va + elfdatsize;
+		sh->off = fo + elfdatsize;
+		sh->size = w - elfdatsize;
 		sh->addralign = 4;
 
 		fo += w;
@@ -1004,23 +1010,38 @@ asmb(void)
 		sh->addralign = 4;
 
 		if (!debug['s']) {
-			fo = symo+8;
+			fo = symo;
+			w = 8;
+
+			sh = newElfShdr(elfstr[ElfStrGosymcounts]);
+			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
+			sh->off = fo;
+			sh->size = w;
+			sh->addralign = 1;
+			sh->addr = symdatva;
+
+			fo += w;
 			w = symsize;
 
 			sh = newElfShdr(elfstr[ElfStrGosymtab]);
 			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
 			sh->off = fo;
 			sh->size = w;
 			sh->addralign = 1;
+			sh->addr = symdatva + 8;
 
 			fo += w;
 			w = lcsize;
 
 			sh = newElfShdr(elfstr[ElfStrGopclntab]);
 			sh->type = SHT_PROGBITS;
+			sh->flags = SHF_ALLOC;
 			sh->off = fo;
 			sh->size = w;
 			sh->addralign = 1;
+			sh->addr = symdatva + 8 + symsize;
 		}
 
 		sh = newElfShstrtab(elfstr[ElfStrShstrtab]);
diff --git a/src/cmd/8l/l.h b/src/cmd/8l/l.h
index 5b0f30723..495c40d64 100644
--- a/src/cmd/8l/l.h
+++ b/src/cmd/8l/l.h
@@ -161,6 +161,9 @@ enum
 
 	SMACHO,	/* pointer to mach-o imported symbol */
 
+	SFIXED,
+	SELFDATA,
+
 	NHASH		= 10007,
 	NHUNK		= 100000,
 	MINSIZ		= 4,
@@ -280,6 +283,7 @@ EXTERN	Prog*	curtext;
 EXTERN	Prog*	datap;
 EXTERN	Prog*	edatap;
 EXTERN	int32	datsize;
+EXTERN	int32	elfdatsize;
 EXTERN	int32	dynptrsize;
 EXTERN	char	debug[128];
 EXTERN	char	literal[32];
diff --git a/src/cmd/8l/pass.c b/src/cmd/8l/pass.c
index 9c42c3ded..e8fda9b73 100644
--- a/src/cmd/8l/pass.c
+++ b/src/cmd/8l/pass.c
@@ -55,7 +55,7 @@ dodata(void)
 			s->value = dtype;
 		if(s->type == SBSS)
 			s->type = SDATA;
-		if(s->type != SDATA)
+		if(s->type != SDATA && s->type != SELFDATA)
 			diag("initialize non-data (%d): %s\n%P",
 				s->type, s->name, p);
 		t = p->from.offset + p->width;
@@ -63,12 +63,27 @@ dodata(void)
 			diag("initialize bounds (%ld): %s\n%P",
 				s->value, s->name, p);
 	}
-	/* allocate small guys */
+
+	/* allocate elf guys - must be segregated from real data */
 	datsize = 0;
 	for(i=0; i<NHASH; i++)
 	for(s = hash[i]; s != S; s = s->link) {
 		if(!s->reachable)
 			continue;
+		if(s->type != SELFDATA)
+			continue;
+		t = rnd(s->value, 4);
+		s->size = t;
+		s->value = datsize;
+		datsize += t;
+	}
+	elfdatsize = datsize;
+
+	/* allocate small guys */
+	for(i=0; i<NHASH; i++)
+	for(s = hash[i]; s != S; s = s->link) {
+		if(!s->reachable)
+			continue;
 		if(s->type != SDATA)
 		if(s->type != SBSS)
 			continue;
@@ -148,6 +163,11 @@ dodata(void)
 	xdefine("data", SBSS, 0);
 	xdefine("edata", SBSS, datsize);
 	xdefine("end", SBSS, dynptrsize + bsssize + datsize);
+
+	if(debug['s'])
+		xdefine("symdat", SFIXED, 0);
+	else
+		xdefine("symdat", SFIXED, SYMDATVA);
 }
 
 Prog*
diff --git a/src/cmd/8l/span.c b/src/cmd/8l/span.c
index 0245d72b9..99ba279da 100644
--- a/src/cmd/8l/span.c
+++ b/src/cmd/8l/span.c
@@ -214,6 +214,7 @@ asmsym(void)
 				continue;
 
 			case SDATA:
+			case SELFDATA:
 				if(!s->reachable)
 					continue;
 				putsymb(s->name, 'D', s->value+INITDAT, s->version, s->gotype);
@@ -231,6 +232,10 @@ asmsym(void)
 				putsymb(s->name, 'B', s->value+INITDAT, s->version, s->gotype);
 				continue;
 
+			case SFIXED:
+				putsymb(s->name, 'B', s->value, s->version, s->gotype);
+				continue;
+
 			case SFILE:
 				putsymb(s->name, 'f', s->value, s->version, 0);
 				continue;
@@ -622,6 +627,9 @@ vaddr(Adr *a)
 					sysfatal("unreachable symbol in vaddr - %s", s->name);
 				v += INITDAT + datsize + s->value;
 				break;
+			case SFIXED:
+				v += s->value;
+				break;
 			default:
 				if(!s->reachable)
 					sysfatal("unreachable symbol in vaddr - %s", s->name);
diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index a0bcba35a..c5d58576d 100644
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -320,7 +320,7 @@ elfdynhash(int nsym)
 	uint32 *chain, *buckets;
 
 	s = lookup(".hash", 0);
-	s->type = SDATA;	// TODO: rodata
+	s->type = SELFDATA;	// TODO: rodata
 	s->reachable = 1;
 
 	i = nsym;
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index 3524bd1c4..18c425516 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -406,6 +406,10 @@ ldobj(Biobuf *f, char *pkg, int64 len, char *pn)
 	if(n != strlen(thestring) || strncmp(line, thestring, n) != 0) {
 		if(line)
 			line[n] = '\0';
+		if(strlen(pn) > 3 && strcmp(pn+strlen(pn)-3, ".go") == 0) {
+			print("%cl: input %s is not .%c file (use %cg to compile .go files)\n", thechar, pn, thechar, thechar);
+			errorexit();
+		}
 		diag("file not %s [%s]\n", thestring, line);
 		return;
 	}
diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index c89322e38..4307d2d41 100644
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -28,7 +28,7 @@
 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 // THE SOFTWARE.
 
-// This magic number also defined in src/pkg/runtime/symtab.c in SYMCOUNTS
+// Where symbol table data gets mapped into memory.
 #define SYMDATVA 0x99LL<<24
 
 typedef struct Library Library;
diff --git a/src/pkg/runtime/symtab.c b/src/pkg/runtime/symtab.c
index b571d21ec..4707b1537 100644
--- a/src/pkg/runtime/symtab.c
+++ b/src/pkg/runtime/symtab.c
@@ -17,10 +17,7 @@
 #include "os.h"
 #include "arch.h"
 
-// TODO(rsc): Move this *under* the text segment.
-// Then define names for these addresses instead of hard-coding magic ones.
-#define SYMCOUNTS ((int32*)(0x99LL<<24))   // known to 6l, 8l; see src/cmd/ld/lib.h
-#define SYMDATA ((byte*)(0x99LL<<24) + 8)
+extern int32 symdat[];
 
 typedef struct Sym Sym;
 struct Sym
@@ -39,18 +36,15 @@ walksymtab(void (*fn)(Sym*))
 	byte *p, *ep, *q;
 	Sym s;
 
-	// TODO(rsc): Remove once TODO at top of file is done.
-	if(goos != nil && strcmp((uint8*)goos, (uint8*)"nacl") == 0)
-		return;
-	if(goos != nil && strcmp((uint8*)goos, (uint8*)"pchw") == 0)
+	if(symdat == nil)
 		return;
 
 #ifdef __MINGW__
 	v = get_symdat_addr();
 	p = (byte*)v+8;
 #else
-	v = SYMCOUNTS;
-	p = SYMDATA;
+	v = symdat;
+	p = (byte*)(symdat+2);
 #endif
 	ep = p + v[0];
 	while(p < ep) {
@@ -248,7 +242,7 @@ splitpcln(void)
 	Func *f, *ef;
 	int32 *v;
 	int32 pcquant;
-	
+
 	switch(thechar) {
 	case '5':
 		pcquant = 4;
@@ -258,10 +252,7 @@ splitpcln(void)
 		break;
 	}
 
-	// TODO(rsc): Remove once TODO at top of file is done.
-	if(goos != nil && strcmp((uint8*)goos, (uint8*)"nacl") == 0)
-		return;
-	if(goos != nil && strcmp((uint8*)goos, (uint8*)"pchw") == 0)
+	if(symdat == nil)
 		return;
 
 	// pc/ln table bounds
@@ -269,8 +260,8 @@ splitpcln(void)
 	v = get_symdat_addr();
 	p = (byte*)v+8;
 #else
-	v = SYMCOUNTS;
-	p = SYMDATA;
+	v = symdat;
+	p = (byte*)(symdat+2);
 #endif
 	p += v[0];
 	ep = p+v[1];