Messages in this thread | | | From | Justin Tee <> | Date | Wed, 1 Mar 2023 15:01:18 -0800 | Subject | Re: [PATCH] scsi: lpfc: avoid usage of list iterator variable after loop |
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On Wed, Mar 1, 2023 at 9:30 AM Jakob Koschel <jkl820.git@gmail.com> wrote: > > If the &epd_pool->list is empty when executing > lpfc_get_io_buf_from_expedite_pool() the function would return an > invalid pointer. Even in the case if the list is guaranteed to be > populated, the iterator variable should not be used after the loop to be > more robust for future changes. > > Linus proposed to avoid any use of the list iterator variable after the > loop, in the attempt to move the list iterator variable declaration into > the marcro to avoid any potential misuse after the loop [1]. > > Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] > Signed-off-by: Jakob Koschel <jkl820.git@gmail.com> > --- > drivers/scsi/lpfc/lpfc_sli.c | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c > index edbd81c3b643..5d06bf6d4f39 100644 > --- a/drivers/scsi/lpfc/lpfc_sli.c > +++ b/drivers/scsi/lpfc/lpfc_sli.c > @@ -21899,20 +21899,20 @@ lpfc_get_io_buf_from_private_pool(struct lpfc_hba *phba, > static struct lpfc_io_buf * > lpfc_get_io_buf_from_expedite_pool(struct lpfc_hba *phba) > { > - struct lpfc_io_buf *lpfc_ncmd; > + struct lpfc_io_buf *lpfc_ncmd = NULL, *iter; > struct lpfc_io_buf *lpfc_ncmd_next; > unsigned long iflag; > struct lpfc_epd_pool *epd_pool; > > epd_pool = &phba->epd_pool; > - lpfc_ncmd = NULL; > > spin_lock_irqsave(&epd_pool->lock, iflag); > if (epd_pool->count > 0) { > - list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next, > + list_for_each_entry_safe(iter, lpfc_ncmd_next, > &epd_pool->list, list) { > - list_del(&lpfc_ncmd->list); > + list_del(&iter->list); > epd_pool->count--; > + lpfc_ncmd = iter; > break; > } > } > > --- > base-commit: c0927a7a5391f7d8e593e5e50ead7505a23cadf9 > change-id: 20230301-scsi-lpfc-avoid-list-iterator-after-loop-7b7d5c3a8efc > > Best regards, > -- > Jakob Koschel <jkl820.git@gmail.com> >
Reviewed-by: Justin Tee <justin.tee@broadcom.com>
Thanks looks fine.
Regards, Justin
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