Messages in this thread | | | From | David Laight <> | Subject | RE: [RFC][PATCH 01/22] x86 user stack frame reads: switch to explicit __get_user() | Date | Sun, 29 Mar 2020 18:03:49 +0000 |
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From: Linus Torvalds > Sent: 29 March 2020 18:57 > On Sun, Mar 29, 2020 at 10:41 AM David Laight <David.Laight@aculab.com> wrote: > > > > It may be worth implementing get_user() as an inline > > function that writes the result of access_ok() to a > > 'by reference' parameter and then returns the value > > from an 'real' __get_user() function. > > That's how get_user() already works. > > It is a polymorphic function (done using macros, sizeof() and ugly > compiler tricks) that generates a call, yes. But it's not a normal C > call. On x86-64, it returns the error code in %rax, and the value in > %rdx
I must be mis-remembering the object code from last time I looked at it.
David
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