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CMS-TYPE: 201P X-CMS-RootMailID: 20240423075608eucas1p265e7c90f3efd6995cb240b3d2688b803 References: <20240423-sysctl-const-handler-v3-0-e0beccb836e2@weissschuh.net> <20240503090332.irkiwn73dgznjflz@joelS2.panther.com> <4cda5d2d-dd92-44ef-9e7b-7b780ec795ab@t-8ch.de> X-Rspamd-Server: rspam01 X-Stat-Signature: 49i3n3y9tzxf69q9q5k7r4i76yi4izkn X-Rspam-User: X-Rspamd-Queue-Id: 4D038100004 X-HE-Tag: 1715168448-914233 X-HE-Meta: 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 2I/Zhk/s 7jDsudqYpFgswChv9tDzKC0bd+qn84zwhD+n/AuqDv19KJTqUa6vSOMgTyLCoSokssYm/Q6QkdLyTWSgDW0IxwvWial3xu0gUaLXd3nd5Djx4sIvaYMbLqNGtG905Mdbrso0qHZGbybKGIon8w5X+s95Nb9qplqpC/FEO 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: List-Subscribe: List-Unsubscribe: --t6g7ogcm2uwc3jep Content-Type: text/plain; charset="iso-8859-1" Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, May 03, 2024 at 04:09:40PM +0200, Thomas Wei=DFschuh wrote: > Hey Joel, >=20 =2E.. > > # Motivation > > As I read it, the motivation for these constification efforts are: > > 1. It provides increased safety: Having things in .rodata section reduc= es the > > attack surface. This is especially relevant for structures that have= function > > pointers (like ctl_table); having these in .rodata means that these = pointers > > always point to the "intended" function and cannot be changed. > > 2. Compiler optimizations: This was just a comment in the patchsets tha= t I have > > mentioned ([3,4,5]). Do you know what optimizations specifically? Do= es it > > have to do with enhancing locality for the data in .rodata? Do you h= ave other > > specific optimizations in mind? >=20 > I don't know about anything that would make it faster. > It's more about safety and transmission of intent to API users, > especially callback implementers. Noted. =2E.. > > # Show the move > > I created [8] because there is no easy way to validate which objects ma= de it > > into .rodata. I ran [8] for your Dec 2nd patcheset [7] and there are le= ss in > > .rodata than I expected (the results are in [9]) Why is that? Is it som= ething > > that has not been posted to the lists yet?=20 >=20 > Constifying the APIs only *allows* the actual table to be constified > themselves. > Then each table definition will have to be touched and "const" added. That is what I thought. thx for clarifying. >=20 > See patches 17 and 18 in [7] for two examples. >=20 > Some tables in net/ are already "const" as the static definitions are > never registered themselves but only their copies are. >=20 =2E.. best --=20 Joel Granados --t6g7ogcm2uwc3jep Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQGzBAABCgAdFiEErkcJVyXmMSXOyyeQupfNUreWQU8FAmY7ZLUACgkQupfNUreW QU8gUgv+JUZin5OAF3NMj7s3DmErLOcek/iw2Q4tXtrCSrstF9AEp1KJR4h7cMPe Nh/NrY7roszof3ADLw9QcvijqtC2/YxQqtu+PqVfRYn15Tv7/eFIYRElCTK3Xdxj xMkZb9Afo5tMvUqCXLuy7hsa5GxNrpk5wLv3OEQnaOQPriuI0fAdMxQEFZXtRFst ZNvVqOVbGzH5fZhv6YS21SHWAIbki2fKfu9etPSftEhi5TQ60KT0GfnNLhonPMES 3q2s+Ox+m8zkKdpI8YZK/KYO7u7qM2aEGCcKQejM4cdJs8Ii0VVQT5lwyEipveYM 5d+sAYm/dF/FfZ6ocaC7REDrCC2P3+IxskN73CNRhwkkiUBSzXu52QdTzaAUF09Z azXiYxq/FpInFPHbBRWHRoeLkknyIlNmKUvVW+H6EHoMxgio7Pn2ERgGo4on6m8Z DX/ExB4ksH+M9m8Mw5niW9tzCilWV1c6EvwQ+9FlNY0szADvScD0Ocv3M0FVfvcx BVIXt1UD =UpYq -----END PGP SIGNATURE----- --t6g7ogcm2uwc3jep--