From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from us-smtp-delivery-1.mimecast.com ([207.211.31.120] helo=us-smtp-1.mimecast.com) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jWlYI-0003n7-3U for kexec@lists.infradead.org; Thu, 07 May 2020 18:47:23 +0000 Date: Thu, 7 May 2020 14:47:05 -0400 From: Rafael Aquini Subject: Re: [PATCH v2] kernel: add panic_on_taint Message-ID: <20200507184705.GG205881@optiplex-lnx> References: <20200507180631.308441-1-aquini@redhat.com> <20200507182257.GX11244@42.do-not-panic.com> <20200507184307.GF205881@optiplex-lnx> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200507184307.GF205881@optiplex-lnx> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "kexec" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Luis Chamberlain Cc: rdunlap@infradead.org, keescook@chromium.org, bhe@redhat.com, linux-doc@vger.kernel.org, corbet@lwn.net, kexec@lists.infradead.org, linux-kernel@vger.kernel.org, cai@lca.pw, linux-fsdevel@vger.kernel.org, akpm@linux-foundation.org, dyoung@redhat.com On Thu, May 07, 2020 at 02:43:16PM -0400, Rafael Aquini wrote: > On Thu, May 07, 2020 at 06:22:57PM +0000, Luis Chamberlain wrote: > > On Thu, May 07, 2020 at 02:06:31PM -0400, Rafael Aquini wrote: > > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > > > index 8a176d8727a3..b80ab660d727 100644 > > > --- a/kernel/sysctl.c > > > +++ b/kernel/sysctl.c > > > @@ -1217,6 +1217,13 @@ static struct ctl_table kern_table[] = { > > > .extra1 = SYSCTL_ZERO, > > > .extra2 = SYSCTL_ONE, > > > }, > > > + { > > > + .procname = "panic_on_taint", > > > + .data = &panic_on_taint, > > > + .maxlen = sizeof(unsigned long), > > > + .mode = 0644, > > > + .proc_handler = proc_doulongvec_minmax, > > > + }, > > > > You sent this out before I could reply to the other thread on v1. > > My thoughts on the min / max values, or lack here: > > > > Valid range doesn't mean "currently allowed defined" masks. > > > > For example, if you expect to panic due to a taint, but a new taint type > > you want was not added on an older kernel you would be under a very > > *false* sense of security that your kernel may not have hit such a > > taint, but the reality of the situation was that the kernel didn't > > support that taint flag only added in future kernels. > > > > You may need to define a new flag (MAX_TAINT) which should be the last > > value + 1, the allowed max values would be > > > > (2^MAX_TAINT)-1 > > > > or > > > > (1< > > > Since this is to *PANIC* I think we do want to test ranges and ensure > > only valid ones are allowed. > > > > Ok. I'm thinking in: > > diff --git a/kernel/sysctl.c b/kernel/sysctl.c > index 8a176d8727a3..ee492431e7b0 100644 > --- a/kernel/sysctl.c > +++ b/kernel/sysctl.c > @@ -1217,6 +1217,15 @@ static struct ctl_table kern_table[] = { > .extra1 = SYSCTL_ZERO, > .extra2 = SYSCTL_ONE, > }, > + { > + .procname = "panic_on_taint", > + .data = &panic_on_taint, > + .maxlen = sizeof(unsigned long), > + .mode = 0644, > + .proc_handler = proc_doulongvec_minmax, > + .extra1 = SYSCTL_ZERO, > + .extra2 = (1 << TAINT_FLAGS_COUNT << 1) - 1, ^^^^^^^^ Without that crap, obviously. Sorry. That was a screw up on my side, when copyin' and pasting. -- Rafael > + }, > > > Would that address your concerns wrt this one? > > Cheers! > -- Rafael _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec