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Prevent division by zero in aslod.

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rhead() and rsect() had assumed sizeof(long) == 4, but OpenBSD/amd64
has sizeof(long) == 8.  The problem revealed itself when sect->os_lign
became zero, and align() divided by zero.
This commit is contained in:
George Koehler 2012-09-21 22:51:12 -04:00
parent be234ea759
commit e7c79415b5
1 changed files with 23 additions and 31 deletions
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54
util/amisc/aslod.c
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@ -140,42 +140,29 @@ void emits(struct outsect* section)
} }
void iconvert(char* buf, char* str, char* fmt) /* Macros from modules/src/object/obj.h */
{ #define Xchar(ch) ((ch) & 0377)
register char *nf, *ni, *no ; #define uget2(c) (Xchar((c)[0]) | ((unsigned) Xchar((c)[1]) << 8))
int last, i ; #define get4(c) (uget2(c) | ((long) uget2((c)+2) << 16))
long value ;
ni=buf ; no=str ; nf=fmt ;
while ( last = *nf++ ) {
last -= '0' ;
if ( last<1 || last >9 ) fatal("illegal out.h format string\n");
value=0 ;
i=last ;
while ( i-- ) {
value = (value<<8) + (ni[i]&0xFF) ;
}
switch ( last ) {
case 0 : break ;
case 1 : *no= value ; break ;
case 2 : *(unsigned short *)no = value ; break ;
case 4 : *(long *)no = value ; break ;
default :
fatal("illegal out.h format string\n");
}
ni += last ; no += last ;
}
}
/* Read the ack.out file header. */ /* Read the ack.out file header. */
int rhead(FILE* f, struct outhead* head) int rhead(FILE* f, struct outhead* head)
{ {
char buf[sizeof(struct outhead)]; char buf[SZ_HEAD], *c;
if (fread(buf, sizeof(buf), 1, f) != 1) if (fread(buf, sizeof(buf), 1, f) != 1)
return 0; return 0;
iconvert(buf, (char*) head, SF_HEAD); c = buf;
head->oh_magic = uget2(c); c += 2;
head->oh_stamp = uget2(c); c += 2;
head->oh_flags = uget2(c); c += 2;
head->oh_nsect = uget2(c); c += 2;
head->oh_nrelo = uget2(c); c += 2;
head->oh_nname = uget2(c); c += 2;
head->oh_nemit = get4(c); c += 4;
head->oh_nchar = get4(c);
return 1; return 1;
} }
@ -183,12 +170,17 @@ int rhead(FILE* f, struct outhead* head)
int rsect(FILE* f, struct outsect* sect) int rsect(FILE* f, struct outsect* sect)
{ {
char buf[sizeof(struct outsect)]; char buf[SZ_SECT], *c;
if (fread(buf, sizeof(buf), 1, f) != 1) if (fread(buf, sizeof(buf), 1, f) != 1)
return 0; return 0;
iconvert(buf, (char*) sect, SF_SECT); c = buf;
sect->os_base = get4(c); c += 4;
sect->os_size = get4(c); c += 4;
sect->os_foff = get4(c); c += 4;
sect->os_flen = get4(c); c += 4;
sect->os_lign = get4(c);
return 1 ; return 1 ;
} }