From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.cvg.de (mail.cvg.de [193.158.56.148]) by mail.openembedded.org (Postfix) with ESMTP id 798916011B for ; Sat, 24 Mar 2018 00:22:56 +0000 (UTC) Received: from mail-mta-0.intern.sigma-chemnitz.de (mail-mta-0.intern.sigma-chemnitz.de [192.168.12.76]) by mailout-1.intern.sigma-chemnitz.de (8.14.7/8.14.7) with ESMTP id w2O0Mv6S017564 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Sat, 24 Mar 2018 01:22:57 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sigma-chemnitz.de; s=v2012061000; t=1521850977; bh=PVZtlmXMd+bDLcbVr6T1Osh5l+0dKTj8UjCaB9IAZzY=; h=From:To:Cc:Subject:References:Date:In-Reply-To:Message-ID: MIME-Version:Content-Type:Sender; b=LTvkzHDN+RSq87C0Kmaq1sWcYNRbO+erImyf6zJL8+T/7p97zBjrM+RrRMoIDPsSG ZoN7POUPThysNskFitl40VYVcrXQu137DoFh6NH624NLj9S+NypuVLe7PnhgkeVVhr h7qYmO+S0iM6hN6Y8oDW2fAZpl4NmOapBEZaYFVw= Received: from reddoxx.intern.sigma-chemnitz.de (reddoxx.intern.sigma-chemnitz.de [192.168.0.193]) by mail-mta-0.intern.sigma-chemnitz.de (8.14.7/8.14.7) with ESMTP id w2O0MoHl011471 for from enrico.scholz@sigma-chemnitz.de; Sat, 24 Mar 2018 01:22:51 +0100 Received: from mail-msa-0.intern.sigma-chemnitz.de ( [192.168.12.77]) by reddoxx.intern.sigma-chemnitz.de (Reddoxx engine) with SMTP id 8691EB2114; Sat, 24 Mar 2018 01:13:21 +0100 Received: from ensc-virt.intern.sigma-chemnitz.de (ensc-virt.intern.sigma-chemnitz.de [192.168.3.24]) by mail-msa-0.intern.sigma-chemnitz.de (8.14.7/8.14.7) with ESMTP id w2O0MZrB011446 (version=TLSv1/SSLv3 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Sat, 24 Mar 2018 01:22:35 +0100 Received: from ensc by ensc-virt.intern.sigma-chemnitz.de with local (Exim 4.90_1) (envelope-from ) id 1ezWx9-0001Hr-Iu; Sat, 24 Mar 2018 01:22:35 +0100 From: Enrico Scholz To: Seebs References: <20180323112820.12bc94a4@seebsdell> <20180323114939.218c0607@seebsdell> <1521848850.11431.36.camel@linuxfoundation.org> <20180323185655.51d96c05@seebsdell> Date: Sat, 24 Mar 2018 01:22:35 +0100 In-Reply-To: <20180323185655.51d96c05@seebsdell> (seebs@seebs.net's message of "Fri, 23 Mar 2018 18:56:55 -0500") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.3 (gnu/linux) MIME-Version: 1.0 Sender: Enrico Scholz X-DSPAM-Result: Innocent X-DSPAM-Probability: 0 X-DSPAM-Confidence: 0.74 X-Spam-Score: -4.6 X-Spam-Level: ---- X-Spam-Tests: AWL, BAYES_00, DKIM_ADSP_ALL, SPF_NEUTRAL, T_RP_MATCHES_RCVD, DSPAM_INNOCENT X-Scanned-By: MIMEDefang 2.83 Cc: OE-core Subject: Re: pseudo: host user contamination X-BeenThere: openembedded-core@lists.openembedded.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Patches and discussions about the oe-core layer List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 24 Mar 2018 00:22:59 -0000 Content-Type: text/plain Seebs writes: >> > I... am really unsure whether it's possible to catch that, because >> > I really, really, don't want to try to intercept raw syscall() >> > calls. I don't think that ends well. > > Potentially. We rely pretty heavily on the assumption that an *actual* > syscall can go through. I think, this would end in implementing architecture dependening assembly code. E.g. for ARM you can write ---- syscall: cmp r0, #__NR_renameat2 beq renameat2 ldr r12, _orig_syscall_addr mov pc, [r9, r12] _orig_syscall_addr: .word orig_syscall_addr ---- (Untested; the last three lines are probably wrong and try to get the address of the variable where the original syscall() address has been stored into). > Although... Actually, I don't even know if this is an actual syscall. > This could be an actual glibc wrapper around the syscall interface, > just like all the others, which is not the *actual* raw syscall or > whatever, and... I have no idea how often that is or isn't hit. 'ltrace' catches it. Enrico