Use a reliable reference for calculating progs offsets.

Now that pr->zone can be null, it cannot be used as a reference. Fixes
random crashes when using qfprogs (random due to heap randomization).
This commit is contained in:
Bill Currie 2018-10-13 23:23:45 +09:00
parent aaab18c9a7
commit 0f5f2a125a

View file

@ -116,6 +116,7 @@ PR_LoadProgsFile (progs_t *pr, QFile *file, int size)
int offset_tweak;
dprograms_t progs;
byte *base;
byte *heap;
if (!pr->file_error)
pr->file_error = file_error;
@ -199,6 +200,7 @@ PR_LoadProgsFile (progs_t *pr, QFile *file, int size)
Qread (file, base, size - sizeof (progs));
CRC_ProcessBlock (base, &pr->crc, size - sizeof (progs));
base -= sizeof (progs); // offsets are from file start
heap = ((byte *) pr->progs + pr->progs_size + pr->pr_edictareasize);
if (pr->edicts) {
*pr->edicts = (edict_t *)((byte *) pr->progs + pr->progs_size);
@ -207,20 +209,19 @@ PR_LoadProgsFile (progs_t *pr, QFile *file, int size)
if (pr->zone_size) {
//FIXME zone_size needs to be at least as big as memzone_t, but
//memzone_t is opaque so its size is unknown
pr->zone = (memzone_t *)((byte *) pr->progs + pr->progs_size
+ pr->pr_edictareasize);
pr->zone = (memzone_t *) heap;
}
pr->pr_functions =
(dfunction_t *) (base + pr->progs->ofs_functions);
pr->pr_strings = (char *) base + pr->progs->ofs_strings;
pr->pr_stringsize = (char *) pr->zone + pr->zone_size - (char *) base;
pr->pr_stringsize = (char *) heap + pr->zone_size - (char *) base;
pr->pr_globaldefs = (ddef_t *) (base + pr->progs->ofs_globaldefs);
pr->pr_fielddefs = (ddef_t *) (base + pr->progs->ofs_fielddefs);
pr->pr_statements = (dstatement_t *) (base + pr->progs->ofs_statements);
pr->pr_globals = (pr_type_t *) (base + pr->progs->ofs_globals);
pr->stack = (pr_type_t *) ((byte *) pr->zone + pr->zone_size);
pr->stack = (pr_type_t *) ((byte *) heap + pr->zone_size);
pr->stack_bottom = pr->stack - pr->pr_globals;
pr->globals_size = (pr_type_t *) ((byte *) pr->stack + pr->stack_size)
- pr->pr_globals;