Hi Chris,
Le lundi 30 mars 2009, Chris Wright a écrit :
> * Jean Delvare (jdelvare@xxxxxxx) wrote:
> > --- linux-2.6.29-rc5.orig/drivers/scsi/libiscsi.c 2009-01-29 08:27:19.000000000 +0100
> > +++ linux-2.6.29-rc5/drivers/scsi/libiscsi.c 2009-02-16 21:19:14.000000000 +0100
> > @@ -1944,7 +1944,7 @@ iscsi_pool_init(struct iscsi_pool *q, in
> > num_arrays++;
> > q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
> > if (q->pool == NULL)
> > - goto enomem;
> > + return -ENOMEM;
> >
> > q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
> > GFP_KERNEL, NULL);
> > @@ -1979,8 +1979,7 @@ void iscsi_pool_free(struct iscsi_pool *
> >
> > for (i = 0; i < q->max; i++)
> > kfree(q->pool[i]);
> > - if (q->pool)
> > - kfree(q->pool);
> > + kfree(q->pool);
> > kfree(q->queue);
>
> AFAICT, This is still broken.
>
> thanks,
> -chris
> --
>
> Subject: [PATCH] libiscsi: fix error path on iscsi_pool_init
>
> From: Chris Wright <chrisw@xxxxxxxxxxxx>
>
> I'm not all that keen on kfifo_init returning ERR_PTR, but...
Ah, I had not noticed this. Good catch!
> q->queue could be ERR_PTR(-ENOMEM) which will break unwinding
> on error. Make iscsi_pool_free more defensive.
>
> Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
> ---
> diff --git a/drivers/scsi/libiscsi.c b/drivers/scsi/libiscsi.c
> index dfaa8ad..2f4df53 100644
> --- a/drivers/scsi/libiscsi.c
> +++ b/drivers/scsi/libiscsi.c
> @@ -1995,7 +1995,7 @@ iscsi_pool_init(struct iscsi_pool *q, int max, void ***items, int item_size)
> num_arrays++;
> q->pool = kzalloc(num_arrays * max * sizeof(void*), GFP_KERNEL);
> if (q->pool == NULL)
> - return -ENOMEM;
> + goto enomem;
>
> q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
> GFP_KERNEL, NULL);
> @@ -2028,10 +2028,13 @@ void iscsi_pool_free(struct iscsi_pool *q)
> {
> int i;
>
> - for (i = 0; i < q->max; i++)
> - kfree(q->pool[i]);
> - kfree(q->pool);
> - kfree(q->queue);
> + if (q->pool) {
> + for (i = 0; i < q->max; i++)
> + kfree(q->pool[i]);
> + kfree(q->pool);
> + if (!IS_ERR(q->queue))
> + kfree(q->queue);
> + }
> }
> EXPORT_SYMBOL_GPL(iscsi_pool_free);
Making the freeing of q->queue dependent on q->pool being set looks
really weird (although it is correct at the moment. But this seems
to be fixable in a much simpler way:
---
drivers/scsi/libiscsi.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
--- linux-2.6.30-rc0.orig/drivers/scsi/libiscsi.c 2009-03-30 09:27:48.000000000 +0200
+++ linux-2.6.30-rc0/drivers/scsi/libiscsi.c 2009-03-30 21:15:13.000000000 +0200
@@ -1999,8 +1999,10 @@ iscsi_pool_init(struct iscsi_pool *q, in
q->queue = kfifo_init((void*)q->pool, max * sizeof(void*),
GFP_KERNEL, NULL);
- if (q->queue == ERR_PTR(-ENOMEM))
+ if (q->queue == ERR_PTR(-ENOMEM)) {
+ q->queue = NULL;
goto enomem;
+ }
for (i = 0; i < max; i++) {
q->pool[i] = kzalloc(item_size, GFP_KERNEL);
With the benefit that only the error case is slowed down. In both
cases we have a problem if q->queue contains an error value but it's
not -ENOMEM. Apparently this can't happen today, but it doesn't feel
right to assume this will always be true. Maybe it's the right time
to fix this as well.
--
Jean Delvare
Suse L3
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