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b=ENn3siKcf22oNZBRFZiFRGe/3kDZ1cRe9VhX5fs/gkJBge9tHAM1fZopaBsx5kzOa UYnUkWT+oamvExA76HoT8LZYfjQvRxOVqYytGdap9IBp7BMCAltVUfFKNKbX2s1up3 ZuHYMD4E9NWowqb2LDIPZD5HvYRajIsGtJRRKoRqeUki3hXSJCExTHQ6N90cYlBQ2h uHUb0SuYEcye3oxNG9zxY5ImyODNCCsUQkBvae9v6eMO8cOs9bjvI1HS76NZnZnVio 1FqQZflt18eeAqblAD3uPi9Er1noWnfu+1XpEeAG7DsSRpvxXb+UlYsibskoT83aOb Wt7gIbWKNfexA== Date: Tue, 26 Sep 2023 01:26:12 +0200 From: Alejandro Colomar To: Axel Rasmussen Cc: Peter Xu , linux-man@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 01/10] userfaultfd.2: briefly mention two-step feature handshake process Message-ID: References: <20230919190206.388896-1-axelrasmussen@google.com> <20230919190206.388896-2-axelrasmussen@google.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha512; protocol="application/pgp-signature"; boundary="tgqgkjx42vy67lq3" Content-Disposition: inline In-Reply-To: <20230919190206.388896-2-axelrasmussen@google.com> X-Rspamd-Queue-Id: 22D35C0016 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: oa3cu6eeibgzhsspbznjczmkm588fozy X-HE-Tag: 1695684376-890293 X-HE-Meta: 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 Vo3BoKFk xbOlzBE3WYpstoy5sHbXNntEWDO6MXsOpuKrMpucH1YgOt8jsTkKYisRJfysNX1Mqe86AXE+Uu7McrzBjKjE+CeXMDI0c2E8WpdYfcslnOpmkjkkjLwaGtgQQgdpNizHVkjrxsbJdY+DnKfny9qblpnkIAGCz7nntW2xdJxyxSHyEQ4gIi09HQ9miQXeE8FIVA10+XerMVItsfU8CBXleHnEixRXkXoqYOZvW0RP9AZO174VaegbEGXFEV8jrCFUQar5lJM0VFq7QXTx8ZT5OzkGvFwgSaughSKhvOOoe0wga3QiLxVJl2HSXeQ== X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: --tgqgkjx42vy67lq3 Content-Type: text/plain; protected-headers=v1; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Subject: Re: [PATCH 01/10] userfaultfd.2: briefly mention two-step feature handshake process MIME-Version: 1.0 On Tue, Sep 19, 2023 at 12:01:57PM -0700, Axel Rasmussen wrote: > This process is critical for programs which depend on extra features, so > it's worth mentioning here. >=20 > Future commits will much more fully describe it in ioctl_userfaultfd.2. >=20 > Signed-off-by: Axel Rasmussen Patch applied. Thanks, Alex > --- > man2/userfaultfd.2 | 5 +++-- > 1 file changed, 3 insertions(+), 2 deletions(-) >=20 > diff --git a/man2/userfaultfd.2 b/man2/userfaultfd.2 > index 40354065c..1b2af22f9 100644 > --- a/man2/userfaultfd.2 > +++ b/man2/userfaultfd.2 > @@ -200,8 +200,9 @@ the application must enable it using the > .B UFFDIO_API > .BR ioctl (2) > operation. > -This operation allows a handshake between the kernel and user space > -to determine the API version and supported features. > +This operation allows a two-step handshake between the kernel and user s= pace > +to determine what API version and features the kernel supports, > +and then to enable those features user space wants. > This operation must be performed before any of the other > .BR ioctl (2) > operations described below (or those operations fail with the > --=20 > 2.42.0.459.ge4e396fd5e-goog >=20 --tgqgkjx42vy67lq3 Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCgAdFiEE6jqH8KTroDDkXfJAnowa+77/2zIFAmUSFxQACgkQnowa+77/ 2zJzhQ//fs/V8Tpm5+m/k8G4xl6w0oXrzif8flzrufdNp4if/Z5VGlrNmo8xPh7G YsRjHzLKAXQrn79h8vRvC459DSkMixazhRhmxcnPi45kkMJX53LNMNyzugY/20Vc CSya5HdMV5/5m43RITW+PCQsnSmgByKP+KuPn3cuANpSF1Hyvwz1E3OXmTJN+qL2 8KPz+fRrC25+eMGmM4K/+pIwPGctelcXAx13icBj50ae+4VDsmNR9tXKuq5m0tNo Z34PEQp2rt+PW3XnyGSsZ2k2RQV2F1utm8Jm9G7gRkb7Ub5sab9xxdt4kUDM4Faj WawMXG/x7PfB37cU440t7eytXOhBCpHAA5SwIdPcI/V453pQs+hRYwXCwVR6UgpZ vV6BUf/2NcHLwEp3L3dUHfgSslaoK2o+/bsZZkj/JrpdJ3PpV4DhWNCz3y4XerEu M4huVEtzmbXFoKWHzLz2hZVZxSxNnfFY2AbZnnfi1tZVhFXeXXvNqWO98Uhyk6bE MRqi8pEWB0fWRyya7gG7/THkrejuNtlGcxCbNH9ucqe55eZZBiDYWDopWS56P7iy LLS2NgOsXXmBM3I/TVKmu3NvlDMt9VOzCQ4rPk6kU4i03eOPloqKqe/phCYZbBDa Kx2cT2wxyr1TzPd/Z3iZno58u7KDTYkJhgGt+BRCkCZCL3VqBoI= =2ZdH -----END PGP SIGNATURE----- --tgqgkjx42vy67lq3--