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d=linuxfoundation.org; s=korg; t=1670344532; bh=xLPfb9uCpOGAMWazbtHia2mg57Cvx5Vy+jhdYipW07Q=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=PYt4F+B6zxS4blgAEKoWiYg7l3jca0OPluig0ko3yvCJEICgp9uHUMKVfQ+H1hrNu QP74wZEjlBTLdO6+wWL2tm28BVWMHF/mKUDSK6kQ2Q9xdQUcW/rGgavWKKU326bChP Tt9KveMsw9qXnuDJVTCGwTZ+vyRKDJV0X5STADsU= Date: Tue, 6 Dec 2022 17:35:29 +0100 From: Greg KH To: Jeff Xu Cc: jeffxu@chromium.org, skhan@linuxfoundation.org, keescook@chromium.org, akpm@linux-foundation.org, dmitry.torokhov@gmail.com, dverkamp@chromium.org, hughd@google.com, jorgelo@chromium.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org, jannh@google.com, linux-hardening@vger.kernel.org, kernel test robot Subject: Re: [PATCH v5 3/6] mm/memfd: add MFD_NOEXEC_SEAL and MFD_EXEC Message-ID: References: <20221206152358.1966099-1-jeffxu@google.com> <20221206152358.1966099-4-jeffxu@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 0C18440006 X-Stat-Signature: qf78ig4qsw6axumgpjnb4orsz6aicpbn X-Spamd-Result: default: False [3.84 / 9.00]; IRL_BL_25(2.00)[52.25.139.140:received]; SUSPICIOUS_RECIPS(1.50)[]; SUBJECT_HAS_UNDERSCORES(1.00)[]; BAYES_HAM(-0.76)[77.18%]; RCVD_NO_TLS_LAST(0.10)[]; MIME_GOOD(-0.10)[text/plain]; BAD_REP_POLICIES(0.10)[]; TAGGED_RCPT(0.00)[]; ARC_NA(0.00)[]; RCPT_COUNT_TWELVE(0.00)[15]; FROM_EQ_ENVFROM(0.00)[]; R_DKIM_ALLOW(0.00)[linuxfoundation.org:s=korg]; MIME_TRACE(0.00)[0:+]; R_SPF_ALLOW(0.00)[+ip4:145.40.68.75]; DMARC_POLICY_ALLOW(0.00)[linuxfoundation.org,none]; TO_MATCH_ENVRCPT_SOME(0.00)[]; TO_DN_SOME(0.00)[]; DKIM_TRACE(0.00)[linuxfoundation.org:+]; ARC_SIGNED(0.00)[hostedemail.com:s=arc-20220608:i=1]; RCVD_COUNT_THREE(0.00)[3]; FROM_HAS_DN(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[] X-Rspam-User: X-HE-Tag: 1670344535-974444 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: On Tue, Dec 06, 2022 at 08:26:30AM -0800, Jeff Xu wrote: > On Tue, Dec 6, 2022 at 8:04 AM Greg KH wrote: > > > > On Tue, Dec 06, 2022 at 03:23:55PM +0000, jeffxu@chromium.org wrote: > > > --- a/kernel/pid_namespace.c > > > +++ b/kernel/pid_namespace.c > > > @@ -110,6 +110,11 @@ static struct pid_namespace *create_pid_namespace(struct user_namespace *user_ns > > > ns->ucounts = ucounts; > > > ns->pid_allocated = PIDNS_ADDING; > > > > > > +#if defined(CONFIG_SYSCTL) && defined(CONFIG_MEMFD_CREATE) > > > + ns->memfd_noexec_scope = > > > + task_active_pid_ns(current)->memfd_noexec_scope; > > > +#endif > > > > .c files should never have #if in them. Can't you put this in a .h file > > properly so that this does not get really messy over time? > > > > > Thanks for reviewing. > It seems to me that checking for CONFIG_XXX is common in c code in > kernel/ path. Maybe, but please don't make it any worse if at all possible. It's tough to maintain code like that. > Do you have a sample code pattern (link/function) that I can follow? Any of the zillions of #if statements in .h files :) thanks, greg k-h