* Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained access control [not found] ` <20220422212945.2227722-3-axelrasmussen@google.com> @ 2022-04-25 20:32 ` Dmitry V. Levin 2022-04-26 16:00 ` Axel Rasmussen 0 siblings, 1 reply; 3+ messages in thread From: Dmitry V. Levin @ 2022-04-25 20:32 UTC (permalink / raw) To: Axel Rasmussen Cc: Alexander Viro, Andrew Morton, Charan Teja Reddy, Dave Hansen, Gleb Fotengauer-Malinovskiy, Hugh Dickins, Jan Kara, Jonathan Corbet, Mel Gorman, Mike Kravetz, Mike Rapoport, Nadav Amit, Peter Xu, Shuah Khan, Suren Baghdasaryan, Vlastimil Babka, zhangyi, linux-api, linux-doc, linux-fsdevel, linux-kernel, linux-mm, linux-kselftest On Fri, Apr 22, 2022 at 02:29:41PM -0700, Axel Rasmussen wrote: [...] > --- a/include/uapi/linux/userfaultfd.h > +++ b/include/uapi/linux/userfaultfd.h > @@ -12,6 +12,10 @@ > > #include <linux/types.h> > > +/* ioctls for /dev/userfaultfd */ > +#define USERFAULTFD_IOC 0xAA > +#define USERFAULTFD_IOC_NEW _IOWR(USERFAULTFD_IOC, 0x00, int) Why this new ioctl is defined using _IOWR()? Since it neither reads from user memory nor writes into user memory, it should rather be defined using _IO(), shouldn't it? -- ldv ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained access control 2022-04-25 20:32 ` [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained access control Dmitry V. Levin @ 2022-04-26 16:00 ` Axel Rasmussen 2022-04-26 17:13 ` Arnd Bergmann 0 siblings, 1 reply; 3+ messages in thread From: Axel Rasmussen @ 2022-04-26 16:00 UTC (permalink / raw) To: Dmitry V. Levin Cc: Alexander Viro, Andrew Morton, Charan Teja Reddy, Dave Hansen, Gleb Fotengauer-Malinovskiy, Hugh Dickins, Jan Kara, Jonathan Corbet, Mel Gorman, Mike Kravetz, Mike Rapoport, Nadav Amit, Peter Xu, Shuah Khan, Suren Baghdasaryan, Vlastimil Babka, zhangyi, linux-api, linux-doc, linux-fsdevel, LKML, Linux MM, Linuxkselftest You're right, [1] says _IO is appropriate for ioctls which only take an integer argument. I'll send a v3 with this fix, although I might wait a bit for any other review comments before doing so. Thanks for taking a look! https://www.kernel.org/doc/html/latest/driver-api/ioctl.html On Mon, Apr 25, 2022 at 1:32 PM Dmitry V. Levin <ldv@altlinux.org> wrote: > > On Fri, Apr 22, 2022 at 02:29:41PM -0700, Axel Rasmussen wrote: > [...] > > --- a/include/uapi/linux/userfaultfd.h > > +++ b/include/uapi/linux/userfaultfd.h > > @@ -12,6 +12,10 @@ > > > > #include <linux/types.h> > > > > +/* ioctls for /dev/userfaultfd */ > > +#define USERFAULTFD_IOC 0xAA > > +#define USERFAULTFD_IOC_NEW _IOWR(USERFAULTFD_IOC, 0x00, int) > > Why this new ioctl is defined using _IOWR()? Since it neither reads from > user memory nor writes into user memory, it should rather be defined using > _IO(), shouldn't it? > > > -- > ldv ^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained access control 2022-04-26 16:00 ` Axel Rasmussen @ 2022-04-26 17:13 ` Arnd Bergmann 0 siblings, 0 replies; 3+ messages in thread From: Arnd Bergmann @ 2022-04-26 17:13 UTC (permalink / raw) To: Axel Rasmussen Cc: Dmitry V. Levin, Alexander Viro, Andrew Morton, Charan Teja Reddy, Dave Hansen, Gleb Fotengauer-Malinovskiy, Hugh Dickins, Jan Kara, Jonathan Corbet, Mel Gorman, Mike Kravetz, Mike Rapoport, Nadav Amit, Peter Xu, Shuah Khan, Suren Baghdasaryan, Vlastimil Babka, zhangyi, Linux API, open list:DOCUMENTATION, Linux FS-devel Mailing List, LKML, Linux MM, Linuxkselftest On Tue, Apr 26, 2022 at 6:00 PM Axel Rasmussen <axelrasmussen@google.com> wrote: > > You're right, [1] says _IO is appropriate for ioctls which only take > an integer argument. I'll send a v3 with this fix, although I might > wait a bit for any other review comments before doing so. Thanks for > taking a look! If there are no other command codes, you could also set .compat_ioctl to the same function pointer as .unlocked_ioctl, the compat_ptr_ioctl conversion is only needed when there are commands that take a pointer. Armd ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-04-26 17:19 UTC | newest]
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2022-04-25 20:32 ` [PATCH v2 2/6] userfaultfd: add /dev/userfaultfd for fine grained access control Dmitry V. Levin
2022-04-26 16:00 ` Axel Rasmussen
2022-04-26 17:13 ` Arnd Bergmann
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