Messages in this thread | | | Date | Fri, 11 Aug 2023 14:32:38 +0100 | Subject | Re: [RESEND PATCH 1/2] iommu/iova: Add check for cpu_rcache in free_iova_rcaches | From | Robin Murphy <> |
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On 2023-08-11 14:02, Zhang Zekun wrote: > free_iova_rcaches() needs to check if cpu_rcache->loaded and > cpu_rcache->prev is NULL before freeing them.
Why? iova_magazine_free() is just kfree(), and kfree(NULL) is perfectly valid, specifically to avoid having to make cleanup paths all fiddly and overcomplicated like this.
Thanks, Robin.
> Because > iova_domain_init_rcaches() may fail to alloc magazine for > cpu_rcache->loaded and cpu_rcache->prev, but they will be freed > for all cpus. > > Fixes: 32e92d9f6f87 ("iommu/iova: Separate out rcache init") > Signed-off-by: Zhang Zekun <zhangzekun11@huawei.com> > --- > drivers/iommu/iova.c | 10 +++++++++- > 1 file changed, 9 insertions(+), 1 deletion(-) > > diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c > index 10b964600948..3c784a28e9ed 100644 > --- a/drivers/iommu/iova.c > +++ b/drivers/iommu/iova.c > @@ -746,8 +746,12 @@ int iova_domain_init_rcaches(struct iova_domain *iovad) > > spin_lock_init(&cpu_rcache->lock); > cpu_rcache->loaded = iova_magazine_alloc(GFP_KERNEL); > + if (!cpu_rcache->loaded) { > + ret = -ENOMEM; > + goto out_err; > + } > cpu_rcache->prev = iova_magazine_alloc(GFP_KERNEL); > - if (!cpu_rcache->loaded || !cpu_rcache->prev) { > + if (!cpu_rcache->prev) { > ret = -ENOMEM; > goto out_err; > } > @@ -903,7 +907,11 @@ static void free_iova_rcaches(struct iova_domain *iovad) > break; > for_each_possible_cpu(cpu) { > cpu_rcache = per_cpu_ptr(rcache->cpu_rcaches, cpu); > + if (!cpu_rcache->loaded) > + break; > iova_magazine_free(cpu_rcache->loaded); > + if (!cpu_rcache->prev) > + break; > iova_magazine_free(cpu_rcache->prev); > } > free_percpu(rcache->cpu_rcaches);
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