scc

commit aed49c6c0f2119764a1f905d01929cb294e0d228
parent 8540c69e9d7340ab9e702c57652f81f3d883694b
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Tue, 29 May 2018 21:21:47 +0100

[as/coff32] Calculate correct address for symbols

The address of every symbol depends of the relative address of
the section, and it means that we have to calculate the size
of the section before calculating the address of the symbol,
but we have to keep in mind tha the size was already increased.

Diffstat:
M
ld/coff32.c
 | 
42
++++++++++++++++++++++++++++--------------
M
ld/ld.h
 | 
8
+++++++-

2 files changed, 35 insertions(+), 15 deletions(-)
diff --git a/ld/coff32.c b/ld/coff32.c
@@ -95,21 +95,30 @@ readsects(Obj *obj, long off)
 	unsigned char buff[SCNHSZ];
 	SCNHDR *scn, *p;
 	FILHDR *hdr;
-	Symbol *sym;
+	Symbol *sym, **sec;
 
 	hdr = obj->filhdr;
 	nsec = hdr->f_nscns;
+
 	if (nsec > SIZE_MAX / sizeof(*scn))
 		return -1;
 
-	if ((scn = malloc(nsec * sizeof(*scn))) == NULL)
+	if (nsec > SIZE_MAX / sizeof(Symbol *))
 		return -1;
 
+	scn = malloc(nsec * sizeof(*scn));
+	sec = malloc(nsec * sizeof(Symbol *));
+	if (!scn || !sec)
+		outmem();
+	obj->sections = sec;
+	obj->scnhdr = scn;
+
 	if (fseek(obj->fp, off, SEEK_SET) == EOF)
 		return -1;
 
 	a = obj->align - 1;
-	for (p = scn; p < &scn[nsec]; ++p) {
+	for (i = 0; i < nsec; ++i) {
+		p = &scn[i];
 		if (fread(buff, SCNHSZ, 1, obj->fp) != 1)
 			return -1;
 		getscn(obj, buff, p);
@@ -123,8 +132,9 @@ readsects(Obj *obj, long off)
 			exit(EXIT_FAILURE);
 		}
 		sym->size += p->s_size;
+		obj->sections[i] = sym;
+		
 	}
-	obj->scnhdr = scn;
 
 	return 0;
 }
@@ -216,7 +226,9 @@ static TUINT
 getval(Obj *obj, SYMENT *ent)
 {
 	FILHDR *hdr = obj->filhdr;;
-	SCNHDR *scn = obj->scnhdr;
+	SCNHDR *scn;
+	Symbol *sym;
+	unsigned n;
 
 	if (ent->n_scnum > hdr->f_nscns) {
 		fprintf(stderr,
@@ -226,13 +238,13 @@ getval(Obj *obj, SYMENT *ent)
 		exit(EXIT_FAILURE);
 	}
 
-	scn = &scn[ent->n_scnum-1];
+	n = ent->n_scnum-1;
+	scn = obj->scnhdr;
+	scn = &scn[n];
+	sym = obj->sections[n];
+
 
-	/*
-	 * TODO: We have to add the composed size of the segment minus
-	 * the size of the fragment
-	 */
-	return ent->n_value - scn->s_size;
+	return ent->n_value + (sym->size - scn->s_size);
 }
 
 static int
@@ -276,10 +288,13 @@ readsyms(Obj *obj, long off)
 		type = typeof(obj, &ent);
 		sym = lookup(name);
 
+		if (ent.n_scnum <= 0)
+			continue;
+
 		switch (sym->type) {
 		case 'U':
 			sym->type = type;
-			sym->value = ent.n_value;
+			sym->value = getval(obj, &ent);
 			if (type == 'C')
 				sym->size = ent.n_value;
 			break;
@@ -292,7 +307,7 @@ readsyms(Obj *obj, long off)
 				break;
 			default:
 				sym->type = type;
-				sym->value = ent.n_value;
+				sym->value = getval(obj, &ent);
 				break;
 			}
 			break;
@@ -328,7 +343,6 @@ readobj(Obj *obj)
 	getfhdr(obj, buff, hdr);
 	obj->filhdr = hdr;
 
-	/* TODO: Check overflow */
 	stroff = pos + hdr->f_symptr + hdr->f_nsyms*SYMESZ;
 	symoff = pos + hdr->f_symptr;
 	secoff = pos + FILHSZ + hdr->f_opthdr;
diff --git a/ld/ld.h b/ld/ld.h
@@ -7,14 +7,20 @@ struct obj {
 	char *fname;
 	char *member;
 	FILE *fp;
+	Fmt *fmt;
+
 	void *filhdr;
 	void *scnhdr;
+
 	Symbol **symbols;
+	Symbol **sections;
+
 	char *strtbl;
 	size_t strsiz;
+
 	int (*unpack)(unsigned char *, char *, ...);
 	int align;
-	Fmt *fmt;
+
 	struct obj *next;
 };