Messages in this thread | | | From | Jani Nikula <> | Subject | Re: [PATCH v3 2/7] uaccess: Tell user_access_begin() if it's for a write or not | Date | Thu, 23 Jan 2020 15:11:05 +0200 |
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On Thu, 23 Jan 2020, Christophe Leroy <christophe.leroy@c-s.fr> wrote: > On 32 bits powerPC (book3s/32), only write accesses to user are > protected and there is no point spending time on unlocking for reads. > > On 64 bits powerpc (book3s/64 at least), access can be granted > read only, write only or read/write. > > Add an argument to user_access_begin() to tell when it's for write and > return an opaque key that will be used by user_access_end() to know > what was done by user_access_begin().
IMHO an opaque key is a prime example of a case where the use of an opaque typedef is warranted. Nobody needs to know or care it's specifically an unsigned long.
BR, Jani.
-- Jani Nikula, Intel Open Source Graphics Center
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