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

4 files changed, 66 insertions, 13 deletions

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);