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Diffstat (limited to 'src/cmd/ld')
-rw-r--r--src/cmd/ld/data.c102
-rw-r--r--src/cmd/ld/elf.c12
-rw-r--r--src/cmd/ld/lib.c11
-rw-r--r--src/cmd/ld/lib.h8
4 files changed, 106 insertions, 27 deletions
diff --git a/src/cmd/ld/data.c b/src/cmd/ld/data.c
index 547494866..c48e1392b 100644
--- a/src/cmd/ld/data.c
+++ b/src/cmd/ld/data.c
@@ -1040,6 +1040,7 @@ dodata(void)
int32 n;
vlong datsize;
Section *sect;
+ Segment *segro;
Sym *s, *last, **l;
Sym *gcdata1, *gcbss1;
@@ -1130,7 +1131,7 @@ dodata(void)
sect->vaddr = datsize;
s->sect = sect;
s->type = SDATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
sect->len = datsize - sect->vaddr;
}
@@ -1146,7 +1147,7 @@ dodata(void)
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SDATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
@@ -1163,7 +1164,7 @@ dodata(void)
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SDATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
@@ -1184,7 +1185,7 @@ dodata(void)
s->sect = sect;
s->type = SDATA;
datsize = aligndatsize(datsize, s);
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
gcaddsym(gcdata1, s, datsize - sect->vaddr); // gc
growdatsize(&datsize, s);
}
@@ -1203,7 +1204,7 @@ dodata(void)
for(; s != nil && s->type < SNOPTRBSS; s = s->next) {
s->sect = sect;
datsize = aligndatsize(datsize, s);
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
gcaddsym(gcbss1, s, datsize - sect->vaddr); // gc
growdatsize(&datsize, s);
}
@@ -1222,7 +1223,7 @@ dodata(void)
for(; s != nil && s->type == SNOPTRBSS; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
@@ -1241,7 +1242,7 @@ dodata(void)
for(; s != nil && s->type == STLSBSS; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize;
@@ -1252,27 +1253,56 @@ dodata(void)
diag("unexpected symbol type %d for %s", s->type, s->name);
}
- /* we finished segdata, begin segtext */
+ /*
+ * We finished data, begin read-only data.
+ * Not all systems support a separate read-only non-executable data section.
+ * ELF systems do.
+ * OS X and Plan 9 do not.
+ * Windows PE may, but if so we have not implemented it.
+ * And if we're using external linking mode, the point is moot,
+ * since it's not our decision; that code expects the sections in
+ * segtext.
+ */
+ if(iself && linkmode == LinkInternal)
+ segro = &segrodata;
+ else
+ segro = &segtext;
+
s = datap;
+
+ datsize = 0;
+
+ /* read-only executable ELF, Mach-O sections */
+ for(; s != nil && s->type < STYPE; s = s->next) {
+ sect = addsection(&segtext, s->name, 04);
+ sect->align = symalign(s);
+ datsize = rnd(datsize, sect->align);
+ sect->vaddr = datsize;
+ s->sect = sect;
+ s->type = SRODATA;
+ s->value = datsize - sect->vaddr;
+ growdatsize(&datsize, s);
+ sect->len = datsize - sect->vaddr;
+ }
/* read-only data */
- sect = addsection(&segtext, ".rodata", 04);
+ sect = addsection(segro, ".rodata", 04);
sect->align = maxalign(s, STYPELINK-1);
+ datsize = rnd(datsize, sect->align);
sect->vaddr = 0;
lookup("rodata", 0)->sect = sect;
lookup("erodata", 0)->sect = sect;
- datsize = 0;
for(; s != nil && s->type < STYPELINK; s = s->next) {
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* typelink */
- sect = addsection(&segtext, ".typelink", 04);
+ sect = addsection(segro, ".typelink", 04);
sect->align = maxalign(s, STYPELINK);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
@@ -1282,13 +1312,13 @@ dodata(void)
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* gosymtab */
- sect = addsection(&segtext, ".gosymtab", 04);
+ sect = addsection(segro, ".gosymtab", 04);
sect->align = maxalign(s, SPCLNTAB-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
@@ -1298,13 +1328,13 @@ dodata(void)
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* gopclntab */
- sect = addsection(&segtext, ".gopclntab", 04);
+ sect = addsection(segro, ".gopclntab", 04);
sect->align = maxalign(s, SELFROSECT-1);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
@@ -1314,33 +1344,35 @@ dodata(void)
datsize = aligndatsize(datsize, s);
s->sect = sect;
s->type = SRODATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
}
sect->len = datsize - sect->vaddr;
/* read-only ELF, Mach-O sections */
for(; s != nil && s->type < SELFSECT; s = s->next) {
- sect = addsection(&segtext, s->name, 04);
+ sect = addsection(segro, s->name, 04);
sect->align = symalign(s);
datsize = rnd(datsize, sect->align);
sect->vaddr = datsize;
s->sect = sect;
s->type = SRODATA;
- s->value = datsize;
+ s->value = datsize - sect->vaddr;
growdatsize(&datsize, s);
sect->len = datsize - sect->vaddr;
}
// 6g uses 4-byte relocation offsets, so the entire segment must fit in 32 bits.
if(datsize != (uint32)datsize) {
- diag("text segment too large");
+ diag("read-only data segment too large");
}
/* number the sections */
n = 1;
for(sect = segtext.sect; sect != nil; sect = sect->next)
sect->extnum = n++;
+ for(sect = segrodata.sect; sect != nil; sect = sect->next)
+ sect->extnum = n++;
for(sect = segdata.sect; sect != nil; sect = sect->next)
sect->extnum = n++;
}
@@ -1402,6 +1434,7 @@ address(void)
segtext.vaddr = va;
segtext.fileoff = HEADR;
for(s=segtext.sect; s != nil; s=s->next) {
+//print("%s at %#llux + %#llux\n", s->name, va, (vlong)s->len);
va = rnd(va, s->align);
s->vaddr = va;
va += s->len;
@@ -1409,8 +1442,25 @@ address(void)
segtext.len = va - INITTEXT;
segtext.filelen = segtext.len;
- va = rnd(va, INITRND);
+ if(segrodata.sect != nil) {
+ // align to page boundary so as not to mix
+ // rodata and executable text.
+ va = rnd(va, INITRND);
+
+ segrodata.rwx = 04;
+ segrodata.vaddr = va;
+ segrodata.fileoff = va - segtext.vaddr + segtext.fileoff;
+ segrodata.filelen = 0;
+ for(s=segrodata.sect; s != nil; s=s->next) {
+ va = rnd(va, s->align);
+ s->vaddr = va;
+ va += s->len;
+ }
+ segrodata.len = va - segrodata.vaddr;
+ segrodata.filelen = segrodata.len;
+ }
+ va = rnd(va, INITRND);
segdata.rwx = 06;
segdata.vaddr = va;
segdata.fileoff = va - segtext.vaddr + segtext.fileoff;
@@ -1445,17 +1495,17 @@ address(void)
segdata.filelen = bss->vaddr - segdata.vaddr;
text = segtext.sect;
- rodata = text->next;
+ if(segrodata.sect)
+ rodata = segrodata.sect;
+ else
+ rodata = text->next;
typelink = rodata->next;
symtab = typelink->next;
pclntab = symtab->next;
for(sym = datap; sym != nil; sym = sym->next) {
cursym = sym;
- if(sym->type < SNOPTRDATA)
- sym->value += rodata->vaddr;
- else
- sym->value += segdata.sect->vaddr;
+ sym->value += sym->sect->vaddr;
for(sub = sym->sub; sub != nil; sub = sub->sub)
sub->value += sym->value;
}
diff --git a/src/cmd/ld/elf.c b/src/cmd/ld/elf.c
index e0a522ad7..51a48c518 100644
--- a/src/cmd/ld/elf.c
+++ b/src/cmd/ld/elf.c
@@ -864,6 +864,8 @@ elfemitreloc(void)
elfrelocsect(segtext.sect, textp);
for(sect=segtext.sect->next; sect!=nil; sect=sect->next)
elfrelocsect(sect, datap);
+ for(sect=segrodata.sect; sect!=nil; sect=sect->next)
+ elfrelocsect(sect, datap);
for(sect=segdata.sect; sect!=nil; sect=sect->next)
elfrelocsect(sect, datap);
}
@@ -1001,7 +1003,7 @@ doelf(void)
s = lookup(".plt", 0);
s->reachable = 1;
- s->type = SELFROSECT;
+ s->type = SELFRXSECT;
elfsetupplt();
@@ -1105,6 +1107,8 @@ asmbelfsetup(void)
for(sect=segtext.sect; sect!=nil; sect=sect->next)
elfshalloc(sect);
+ for(sect=segrodata.sect; sect!=nil; sect=sect->next)
+ elfshalloc(sect);
for(sect=segdata.sect; sect!=nil; sect=sect->next)
elfshalloc(sect);
}
@@ -1232,6 +1236,8 @@ asmbelf(vlong symo)
USED(resoff);
elfphload(&segtext);
+ if(segrodata.sect != nil)
+ elfphload(&segrodata);
elfphload(&segdata);
/* Dynamic linking sections */
@@ -1397,12 +1403,16 @@ elfobj:
for(sect=segtext.sect; sect!=nil; sect=sect->next)
elfshbits(sect);
+ for(sect=segrodata.sect; sect!=nil; sect=sect->next)
+ elfshbits(sect);
for(sect=segdata.sect; sect!=nil; sect=sect->next)
elfshbits(sect);
if(linkmode == LinkExternal) {
for(sect=segtext.sect; sect!=nil; sect=sect->next)
elfshreloc(sect);
+ for(sect=segrodata.sect; sect!=nil; sect=sect->next)
+ elfshreloc(sect);
for(sect=segdata.sect; sect!=nil; sect=sect->next)
elfshreloc(sect);
// add a .note.GNU-stack section to mark the stack as non-executable
diff --git a/src/cmd/ld/lib.c b/src/cmd/ld/lib.c
index d9e3af4c0..18943d5f3 100644
--- a/src/cmd/ld/lib.c
+++ b/src/cmd/ld/lib.c
@@ -36,6 +36,13 @@
#include <ar.h>
+enum
+{
+ // Whether to assume that the external linker is "gold"
+ // (http://sourceware.org/ml/binutils/2008-03/msg00162.html).
+ AssumeGoldLinker = 0,
+};
+
int iconv(Fmt*);
char symname[] = SYMDEF;
@@ -676,6 +683,10 @@ hostlink(void)
}
if(HEADTYPE == Hdarwin)
argv[argc++] = "-Wl,-no_pie,-pagezero_size,4000000";
+
+ if(iself && AssumeGoldLinker)
+ argv[argc++] = "-Wl,--rosegment";
+
argv[argc++] = "-o";
argv[argc++] = outfile;
diff --git a/src/cmd/ld/lib.h b/src/cmd/ld/lib.h
index 63775b5ff..d7998a6a5 100644
--- a/src/cmd/ld/lib.h
+++ b/src/cmd/ld/lib.h
@@ -33,7 +33,11 @@ enum
Sxxx,
/* order here is order in output file */
+ /* readonly, executable */
STEXT,
+ SELFRXSECT,
+
+ /* readonly, non-executable */
STYPE,
SSTRING,
SGOSTRING,
@@ -42,6 +46,8 @@ enum
SSYMTAB,
SPCLNTAB,
SELFROSECT,
+
+ /* writable, non-executable */
SMACHOPLT,
SELFSECT,
SMACHO, /* Mach-O __nl_symbol_ptr */
@@ -54,6 +60,7 @@ enum
SNOPTRBSS,
STLSBSS,
+ /* not mapped */
SXREF,
SMACHOSYMSTR,
SMACHOSYMTAB,
@@ -177,6 +184,7 @@ enum
};
EXTERN Segment segtext;
+EXTERN Segment segrodata;
EXTERN Segment segdata;
EXTERN Segment segdwarf;
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