Messages in this thread |  | | Date | Tue, 15 Jan 2019 11:13:26 +0100 (CET) | From | Thomas Gleixner <> | Subject | Re:[PATCH] x86/mm/mem_encrypt_identity : fix error useage to sizeof |
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On Mon, 7 Jan 2019, peng.hao2@zte.com.cn wrote:
> >> Fix error usage to sizeof. It should not use sizeof to pointer. > > > >.... because? > > > >The commit message needs to explain what the potential issue could be > >and why it doesn't matter in this case. > I see the definition of pte_t may be more than sizeof(unsigned long). > So I think sizeof(pte_t) is safer.
What exactly is the difference between:
pte_t *p;
sizeof(*p)
and
sizeof(pte_t)
and what is safer about the latter?
Answer: No difference and nothing is safer because it's exactly the same.
In general we use sizeof(*p) simply because when the data type of p changes you don't have to update the code, it just works and stays correct.
Thanks,
tglx
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