scc

commit f73976bc3b2384aae0124998f5746eb8f84677dd
parent 42a7e083ac9e2c901944975a21bf3b1f0d5674d6
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sat, 18 Jan 2025 14:03:35 +0100

libmach/coff32: Fix reading line info

This part of the code was not tested ever, and there were
many wrong things, like the definition of the own structure
for lines.

Diffstat:
M
include/bits/scc/coff32/linenum.h
 | 
6
++++--
M
src/libmach/coff32/coff32read.c
 | 
21
++++++++++++---------
M
src/libmach/coff32/coff32write.c
 | 
3
+--

3 files changed, 17 insertions(+), 13 deletions(-)
diff --git a/include/bits/scc/coff32/linenum.h b/include/bits/scc/coff32/linenum.h
@@ -1,8 +1,10 @@
 /* This file is inspired in the book "Understanding and using COFF" */
 
 struct lineno {
-	long l_symndx;         /* index in table symbol if l_lnno == 0 */
-	long l_paddr;          /* Break pointable address if l_lnno > 0 */
+	union {
+		long l_symndx;         /* index in table symbol if l_lnno == 0 */
+		long l_paddr;          /* Break pointable address if l_lnno > 0 */
+	} l_addr;
 	unsigned short l_lnno; /* Line number */
 };
 
diff --git a/src/libmach/coff32/coff32read.c b/src/libmach/coff32/coff32read.c
@@ -35,9 +35,8 @@ unpack_line(int order, unsigned char *buf, LINENO *lp)
 
 	n = unpack(order,
 	           buf,
-	           "lls",
-	           &lp->l_symndx,
-	           &lp->l_paddr,
+	           "ls",
+	           &lp->l_addr.l_symndx,
 	           &lp->l_lnno);
 	assert(n == LINESZ);
 }
@@ -448,7 +447,7 @@ static int
 readlines(Obj *obj, FILE *fp)
 {
 	int i,j;
-	LINENO **lines, *lp;
+	LINENO **lines, *lp, *p;
 	FILHDR *hdr;
 	SCNHDR *scn;
 	struct coff32 *coff;
@@ -475,14 +474,18 @@ readlines(Obj *obj, FILE *fp)
 			return 0;
 		lines[i] = lp;
 
+		if (!objpos(obj, fp, scn->s_lnnoptr))
+			return 0;
+
 		for (j = 0; j < scn->s_nlnno; j++) {
-			if (!objpos(obj, fp, scn->s_lnnoptr))
-				return 0;
-			if (fread(buf, LINESZ, 1, fp) == 1)
+			if (fread(buf, LINESZ, 1, fp) != 1)
 				return 0;
-			unpack_line(ORDER(obj->type), buf, &lp[j]);
-			if (lp[i].l_symndx >= hdr->f_nsyms)
+			unpack_line(ORDER(obj->type), buf, lp);
+			if (lp->l_lnno != 0			
+			&&  lp->l_addr.l_symndx >= hdr->f_nsyms) {
 				return 0;
+			}
+			++lp;
 		}
 	}
 
diff --git a/src/libmach/coff32/coff32write.c b/src/libmach/coff32/coff32write.c
@@ -204,8 +204,7 @@ pack_line(int order, unsigned char *buf, LINENO *lp)
 	n = pack(order,
 	         buf,
 	         "lls",
-	         lp->l_symndx,
-	         lp->l_paddr,
+	         lp->l_addr.l_symndx,
 	         lp->l_lnno);
 	assert(n == LINESZ);
 }