Messages in this thread | | | Date | Sat, 12 Aug 2023 10:21:50 +0800 | Subject | Re: [RESEND PATCH 1/2] iommu/iova: Add check for cpu_rcache in free_iova_rcaches | From | "zhangzekun (A)" <> |
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在 2023/8/11 21:32, Robin Murphy 写道: > 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. > Hi, Robin Thanks for your review, I have missed that kfree() can handle NULL and it is safe to iterate through all cpus, because __alloc_percpu() will alloc a zero-filled area, and pointers passed to kfree() will be either NULL or a vaild one. There is no need to add check before these pointers.
Thanks, Zekun
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