Messages in this thread Patch in this message | | | Date | Sun, 27 Jan 2008 21:07:01 +0100 | From | "Vegard Nossum" <> | Subject | lib/idr.c: initialize struct idr_layer |
| |
Hi,
I am testing my kmemcheck patches, and it has come up with a couple of uses of uninitialized memory in lib/idr.c. These are (the line numbers may differ slightly):
line 135 (sub_alloc): bm = ~p->bitmap; p->bitmap is uninitialized
line 171 (sub_alloc): if (!p->ary[m]) { p->ary is uninitialized
line 249 (idr_get_new_above_int): pa[0]->count++; pa[0]->count is uninitialized
I cannot guarantee that these are truly errors, but I would be grateful if you could help me confirm/deny the validity of the reports. Personally, I can get rid of the errors using this patch:
diff --git a/lib/idr.c b/lib/idr.c index afbb0b1..dd28ee5 100644 --- a/lib/idr.c +++ b/lib/idr.c @@ -39,12 +39,16 @@ static struct idr_layer *alloc_layer(struct idr *idp) { struct idr_layer *p; unsigned long flags; + int i;
spin_lock_irqsave(&idp->lock, flags); if ((p = idp->id_free)) { idp->id_free = p->ary[0]; idp->id_free_cnt--; - p->ary[0] = NULL; + p->bitmap = 0; + for(i = 0; i < ARRAY_SIZE(p->ary); ++i) + p->ary[i] = NULL; + p->count = 0; } spin_unlock_irqrestore(&idp->lock, flags); return(p);
Thanks a lot.
Vegard
| |