Messages in this thread | | | Subject | Re: [PATCH] powerpc/pseries/iommu: Add of_node_put() before break | From | Leonardo Brás <> | Date | Thu, 14 Oct 2021 14:32:43 -0300 |
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Hello Wan, thank you for this patch.
On Thu, 2021-10-14 at 03:56 -0400, Wan Jiabing wrote: > Fix following coccicheck warning: > > ./arch/powerpc/platforms/pseries/iommu.c:924:1-28: WARNING: Function > for_each_node_with_property should have of_node_put() before break > > Early exits from for_each_node_with_property should decrement the > node reference counter.
Yeah, it makes sense to me.
for_each_node_with_property calls of_find_node_with_property() at each step, which ends up calling of_node_put() after using each node.
Introducing this break caused this of_node_put not to happen to the last node, so IIUC this patch fixes a possible issue if kzalloc() fails in ddw_list_new_entry().
Another option would be s/break/continue here, but it does not make sense to keep trying next nodes if there is no memory to allocate for a struct dma_win (4 pointers).
On the other hard, failing on allocating such small space should not happen often (if it will ever happen), so a 'continue' here makes code simpler.
Anyway, FWIW: Reviewed-by: Leonardo Bras <leobras.c@gmail.com>
Best regards, Leo
> > Signed-off-by: Wan Jiabing <wanjiabing@vivo.com> > --- > arch/powerpc/platforms/pseries/iommu.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/platforms/pseries/iommu.c > b/arch/powerpc/platforms/pseries/iommu.c > index 269f61d519c2..c140aa683f66 100644 > --- a/arch/powerpc/platforms/pseries/iommu.c > +++ b/arch/powerpc/platforms/pseries/iommu.c > @@ -929,8 +929,10 @@ static void find_existing_ddw_windows_named(const > char *name) > } > > window = ddw_list_new_entry(pdn, dma64); > - if (!window) > + if (!window) { > + of_node_put(pdn); > break; > + } > > spin_lock(&dma_win_list_lock); > list_add(&window->list, &dma_win_list);
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