From: David Laight <David.Laight@ACULAB.COM> To: 'Mark Rutland' <mark.rutland@arm.com>, "Madhavan T. Venkataraman" <madvenka@linux.microsoft.com> Cc: Andy Lutomirski <luto@kernel.org>, Kernel Hardening <kernel-hardening@lists.openwall.com>, Linux API <linux-api@vger.kernel.org>, linux-arm-kernel <linux-arm-kernel@lists.infradead.org>, Linux FS Devel <linux-fsdevel@vger.kernel.org>, linux-integrity <linux-integrity@vger.kernel.org>, LKML <linux-kernel@vger.kernel.org>, "LSM List" <linux-security-module@vger.kernel.org>, Oleg Nesterov <oleg@redhat.com>, X86 ML <x86@kernel.org> Subject: RE: [PATCH v1 0/4] [RFC] Implement Trampoline File Descriptor Date: Mon, 3 Aug 2020 08:27:25 +0000 Message-ID: <a3068e3126a942c7a3e7ac115499deb1@AcuMS.aculab.com> (raw) In-Reply-To: <20200731183146.GD67415@C02TD0UTHF1T.local> From: Mark Rutland > Sent: 31 July 2020 19:32 ... > > It requires PC-relative data references. I have not worked on all architectures. > > So, I need to study this. But do all ISAs support PC-relative data references? > > Not all do, but pretty much any recent ISA will as it's a practical > necessity for fast position-independent code. i386 has neither PC-relative addressing nor moves from %pc. The cpu architecture knows that the sequence: call 1f 1: pop %reg is used to get the %pc value so is treated specially so that it doesn't 'trash' the return stack. So PIC code isn't too bad, but you have to use the correct sequence. David - Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK Registration No: 1397386 (Wales)
next prev parent reply index Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top [not found] <aefc85852ea518982e74b233e11e16d2e707bc32> 2020-07-28 13:10 ` madvenka 2020-07-28 13:10 ` [PATCH v1 1/4] [RFC] fs/trampfd: Implement the trampoline file descriptor API madvenka 2020-07-28 14:50 ` Oleg Nesterov 2020-07-28 14:58 ` Madhavan T. Venkataraman 2020-07-28 16:06 ` Oleg Nesterov 2020-07-28 13:10 ` [PATCH v1 2/4] [RFC] x86/trampfd: Provide support for the trampoline file descriptor madvenka 2020-07-30 9:06 ` Greg KH 2020-07-30 14:25 ` Madhavan T. Venkataraman 2020-07-28 13:10 ` [PATCH v1 3/4] [RFC] arm64/trampfd: " madvenka 2020-07-28 13:10 ` [PATCH v1 4/4] [RFC] arm/trampfd: " madvenka 2020-07-28 15:13 ` [PATCH v1 0/4] [RFC] Implement Trampoline File Descriptor David Laight 2020-07-28 16:32 ` Madhavan T. Venkataraman 2020-07-28 17:16 ` Andy Lutomirski 2020-07-28 18:52 ` Madhavan T. Venkataraman 2020-07-29 8:36 ` David Laight 2020-07-29 17:55 ` Madhavan T. Venkataraman [not found] ` <81d744c0-923e-35ad-6063-8b186f6a153c@linux.microsoft.com> 2020-07-29 5:16 ` Andy Lutomirski 2020-07-28 16:05 ` Casey Schaufler 2020-07-28 16:49 ` Madhavan T. Venkataraman 2020-07-28 17:05 ` James Morris 2020-07-28 17:08 ` Madhavan T. Venkataraman 2020-07-28 17:31 ` Andy Lutomirski 2020-07-28 19:01 ` Madhavan T. Venkataraman 2020-07-29 13:29 ` Florian Weimer 2020-07-30 13:09 ` David Laight 2020-08-02 11:56 ` Pavel Machek 2020-08-03 8:08 ` David Laight 2020-08-03 15:57 ` Madhavan T. Venkataraman 2020-07-30 14:42 ` Madhavan T. Venkataraman [not found] ` <6540b4b7-3f70-adbf-c922-43886599713a@linux.microsoft.com> 2020-07-30 20:54 ` Andy Lutomirski 2020-07-31 17:13 ` Madhavan T. Venkataraman 2020-07-31 18:31 ` Mark Rutland 2020-08-03 8:27 ` David Laight [this message] 2020-08-03 16:03 ` Madhavan T. Venkataraman 2020-08-03 16:57 ` David Laight 2020-08-03 17:00 ` Madhavan T. Venkataraman 2020-08-03 17:58 ` Madhavan T. Venkataraman 2020-08-04 13:55 ` Mark Rutland 2020-08-04 14:33 ` David Laight 2020-08-04 14:44 ` David Laight 2020-08-04 14:48 ` Madhavan T. Venkataraman 2020-08-04 15:46 ` Madhavan T. Venkataraman 2020-08-02 13:57 ` Florian Weimer 2020-08-02 18:54 ` Madhavan T. Venkataraman 2020-08-02 20:00 ` Andy Lutomirski 2020-08-02 22:58 ` Madhavan T. Venkataraman 2020-08-03 18:36 ` Madhavan T. Venkataraman 2020-08-10 17:34 ` Madhavan T. Venkataraman 2020-08-11 21:12 ` Madhavan T. Venkataraman 2020-08-03 8:23 ` David Laight 2020-08-03 15:59 ` Madhavan T. Venkataraman 2020-07-31 18:09 ` Mark Rutland 2020-07-31 20:08 ` Madhavan T. Venkataraman 2020-08-03 16:57 ` Madhavan T. Venkataraman 2020-08-04 14:30 ` Mark Rutland 2020-08-06 17:26 ` Madhavan T. Venkataraman 2020-08-08 22:17 ` Pavel Machek 2020-08-11 12:41 ` Madhavan T. Venkataraman 2020-08-11 13:08 ` Pavel Machek 2020-08-11 15:54 ` Madhavan T. Venkataraman 2020-08-12 10:06 ` Mark Rutland 2020-08-12 18:47 ` Madhavan T. Venkataraman 2020-08-19 18:53 ` Mickaël Salaün 2020-09-01 15:42 ` Mark Rutland
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=a3068e3126a942c7a3e7ac115499deb1@AcuMS.aculab.com \ --to=david.laight@aculab.com \ --cc=kernel-hardening@lists.openwall.com \ --cc=linux-api@vger.kernel.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-fsdevel@vger.kernel.org \ --cc=linux-integrity@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-security-module@vger.kernel.org \ --cc=luto@kernel.org \ --cc=madvenka@linux.microsoft.com \ --cc=mark.rutland@arm.com \ --cc=oleg@redhat.com \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
Linux-api Archive on lore.kernel.org Archives are clonable: git clone --mirror https://lore.kernel.org/linux-api/0 linux-api/git/0.git # If you have public-inbox 1.1+ installed, you may # initialize and index your mirror using the following commands: public-inbox-init -V2 linux-api linux-api/ https://lore.kernel.org/linux-api \ linux-api@vger.kernel.org public-inbox-index linux-api Example config snippet for mirrors Newsgroup available over NNTP: nntp://nntp.lore.kernel.org/org.kernel.vger.linux-api AGPL code for this site: git clone https://public-inbox.org/public-inbox.git