sms@wlv.imsd.contel.com (Steven M. Schultz) (08/02/89)
Subject: ld symboltable length is wrong
Index: bin/ld.c 2.10BSD
Description:
ld produces incorrect length for the size of the symbol
table, the symbols ARE in the file, just the length is
wrong. this causes (in the case of the kernel) approximately
19 symbols to be inaccessible by 'adb'. 'nm' WILL show
the symbols however. Somewhere in 'ld' the cumulative size
is being calculated incorrectly, but the amount of information
written is right.
Repeat-By:
I noticed the problem when 'adb' refused to admit that there
was a symbol in the kernel called "netdata":
nm -g /unix|egrep netdata
note 1) that the symbol is found, 2) the value of it.
adb -k /unix /dev/mem
netdata/o
symbol not found
Fix:
Apply the following patch to ld.c. The comments (yes, comments!;-))
should make clear what is going on - essentially the size of the
symbol table is calculated just before being written out.
*** ld.c.old Wed Apr 19 14:29:09 1989
--- ld.c Sun Jul 30 01:13:20 1989
***************
*** 1091,1097 ****
{
register u_int n, *p;
register SYMBOL *sp, *symp;
!
if (numov) {
/* int aovno = adrof("__ovno"); XXX KB */
int aovhndlr[NOVL+1];
--- 1091,1098 ----
{
register u_int n, *p;
register SYMBOL *sp, *symp;
! long before, after;
!
if (numov) {
/* int aovno = adrof("__ovno"); XXX KB */
int aovhndlr[NOVL+1];
***************
*** 1127,1132 ****
--- 1128,1136 ----
copy(&troutb);
copy(&droutb);
}
+
+ flush(&toutb);
+ before = lseek(toutb.fildes , 0L, 1);
if (sflag==0) {
if (xflag==0)
copy(&soutb);
***************
*** 1146,1152 ****
--- 1150,1176 ----
p++;
}
}
+ /*
+ * the following is a workaround ("kludge") to insure that the
+ * correct size of the symbol table is written to the header. this
+ * was occasioned by noticing that the value of a_syms for /unix showed
+ * 0115200 (39552) instead of 0115544 (39780). somewhere 19 symbols were
+ * not being counted - (oh where oh where have the symbols gone...?;-))
+ * but they were being written out! Granted, it is not proper to
+ * treat the symptom instead of the problem, but this works, and if you
+ * fix it for real i'd like a copy of ld.c - Steven M. Schultz
+ *
+ * I really think this should be calculated anyhow, makes as much sense
+ * as trying to maintain counts everywhere else.
+ */
+
flush(&toutb);
+ after = lseek(toutb.fildes, 0L, 1);
+ lseek(toutb.fildes, 0L, 0);
+ read(toutb.fildes, &filhdr, sizeof (filhdr));
+ filhdr.a_syms = after - before;
+ lseek(toutb.fildes, 0L, 0);
+ write(toutb.fildes, &filhdr, sizeof (filhdr));
close(toutb.fildes);
if (!ofilfnd) {
unlink("a.out");
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