From owner-freebsd-virtualization@FreeBSD.ORG Tue Nov 12 11:33:47 2013 Return-Path: Delivered-To: freebsd-virtualization@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 526459D1; Tue, 12 Nov 2013 11:33:47 +0000 (UTC) Received: from mail-we0-x22c.google.com (mail-we0-x22c.google.com [IPv6:2a00:1450:400c:c03::22c]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (No client certificate requested) by mx1.freebsd.org (Postfix) with ESMTPS id BE446248E; Tue, 12 Nov 2013 11:33:46 +0000 (UTC) Received: by mail-we0-f172.google.com with SMTP id q58so5850867wes.31 for ; Tue, 12 Nov 2013 03:33:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type; bh=d54FOU0IlWdRdsKCe+8IiFJMdh9InBgW1cNrtalYqz0=; b=ILM6PnZynwCHcDrKW80b/9yFOGvNBSMwXX7uuOQz2KrG2iGsiHXq5xm5Ex4ZkwR0t0 ugTSe4/PwWxfqouO7LWCr3M5HGs6liJSWK9qba47CHoZ7q5fsZjmRbpjxthJLQuiqGUJ 7j235Jpsm8U6yHE0PFcISl8FRT0aOO7tMh70gA3p0UMS5oO0y5+kQjZn+ulCuSeIHza6 qPR9lJX8E7/stgBDVeyRVfI42uZXbBJN4205PYC16zp20Q3QyKu7L9X2pR6AwVFJhxxl Y5mpTIguJsWYKRNz/VtwK0IMeuotocnkd7dp/z3cKJqApUVJDKSXcjtgJjjqCM+cs/CA 0Xbw== MIME-Version: 1.0 X-Received: by 10.194.20.202 with SMTP id p10mr2151442wje.39.1384256025245; Tue, 12 Nov 2013 03:33:45 -0800 (PST) Received: by 10.216.203.195 with HTTP; Tue, 12 Nov 2013 03:33:45 -0800 (PST) In-Reply-To: <20131112030154.GA29757@dft-labs.eu> References: <52814D25.1050603@freebsd.org> <20131112030154.GA29757@dft-labs.eu> Date: Tue, 12 Nov 2013 15:33:45 +0400 Message-ID: Subject: Re: Running `sysctl -a` causes crash (Hyper-V) From: Sergey Kandaurov To: Mateusz Guzik Content-Type: text/plain; charset=ISO-8859-1 Cc: "freebsd-virtualization@freebsd.org" X-BeenThere: freebsd-virtualization@freebsd.org X-Mailman-Version: 2.1.16 Precedence: list List-Id: "Discussion of various virtualization techniques FreeBSD supports." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 12 Nov 2013 11:33:47 -0000 On 12 November 2013 07:01, Mateusz Guzik wrote: > On Mon, Nov 11, 2013 at 01:33:25PM -0800, Julian Elischer wrote: >> On 11/11/13, 7:49 AM, Pavel Timofeev wrote: >> >Great, it helped! Thanks a lot! >> >> the suggested change suggests fragile code. It should be able to >> handle unexpected input.. > > Indeed, I already suggested Sergey placing a compile time assertion to > make sure vm_guest range is covered. I have the following change for this. Btw, the last element in vm_guest_sysctl_names is NULL, is it really needed for something? Unlike vm_bnames/vm_pnames, it seems not. Add CTASSERT to handle enum VM_GUEST and vm_guest_sysctl_names cooperation. Index: sys/sys/systm.h =================================================================== --- sys/sys/systm.h (revision 258036) +++ sys/sys/systm.h (working copy) @@ -72,7 +72,8 @@ extern int vm_guest; /* Running as virtual machin * ever implemented (e.g. vendor-specific paravirtualization features). * Keep in sync with vm_guest_sysctl_names[]. */ -enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV }; +enum VM_GUEST { VM_GUEST_NO = 0, VM_GUEST_VM, VM_GUEST_XEN, VM_GUEST_HV, + VM_LAST }; #if defined(WITNESS) || defined(INVARIANTS) void kassert_panic(const char *fmt, ...) __printflike(1, 2); Index: sys/kern/subr_param.c =================================================================== --- sys/kern/subr_param.c (revision 258036) +++ sys/kern/subr_param.c (working copy) @@ -156,6 +156,7 @@ static const char *const vm_guest_sysctl_names[] = "hv", NULL }; +CTASSERT(nitems(vm_guest_sysctl_names) - 1 == VM_LAST); #ifndef XEN static const char *const vm_bnames[] = { -- wbr, pluknet