Messages in this thread | | | Subject | Re: [PATCH v3 1/7] x86/sgx: Provide indication of life-cycle of EPC pages | From | Dave Hansen <> | Date | Wed, 28 Jul 2021 16:12:38 -0700 |
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On 7/28/21 3:57 PM, Luck, Tony wrote: >> Wouldn't it be safer to do something like: >> >> page->owner = owner ? owner : (void *)-1; >> >> -1 is non-NULL, but also invalid, which makes it harder for us to poke >> ourselves in the eye. > Does Linux have some #define INVALID_POINTER thing that > provides a guaranteed bad (e.g. non-canonical) value? > > (void *)-1 seems hacky.
ERR_PTR(-SOMETHING) wouldn't be too bad. I guess it could even be:
page->owner = ERR_PTR(SGX_EPC_PAGE_VA);
and then:
#define SGX_EPC_PAGE_VA 0xffff...something...greppable
I *thought* we had a file full of these magic values, but maybe I'm misremembering the uapi magic header.
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