lists.openwall.net   lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
 
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <YxiqjKU9xGma3Bnt@hirez.programming.kicks-ass.net>
Date:   Wed, 7 Sep 2022 16:28:28 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Masami Hiramatsu <mhiramat@...nel.org>
Cc:     Steven Rostedt <rostedt@...dmis.org>,
        Ingo Molnar <mingo@...nel.org>,
        Suleiman Souhlal <suleiman@...gle.com>,
        bpf <bpf@...r.kernel.org>, linux-kernel@...r.kernel.org,
        Borislav Petkov <bp@...e.de>,
        Josh Poimboeuf <jpoimboe@...nel.org>, x86@...nel.org
Subject: Re: [PATCH 1/2] x86/kprobes: Fix kprobes instruction boudary check
 with CONFIG_RETHUNK

On Wed, Sep 07, 2022 at 10:49:13PM +0900, Masami Hiramatsu wrote:
> On Wed, 7 Sep 2022 14:56:52 +0200
> Peter Zijlstra <peterz@...radead.org> wrote:
> 
> > On Wed, Sep 07, 2022 at 09:55:21AM +0900, Masami Hiramatsu (Google) wrote:
> > 
> > >  	if (!kallsyms_lookup_size_offset(paddr, NULL, &offset))
> > >  		return 0;
> > >  
> > 
> > One more thing:
> > 
> >   https://lkml.kernel.org/r/20220902130951.853460809@infradead.org
> > 
> > can result in negative offsets. The expression:
> > 
> > 	'paddr - offset'
> > 
> > will still get you to +0, but I might not have fully considered things
> > when I wrote that patch.
> 
> Hmm, isn't 'offset' unsigned? If 'paddr - offset' is still available
> to find the function entry address, it is OK to me.

Yeah, but the magic of 2s complement means it doesn't matter ;-)

Powered by blists - more mailing lists

Powered by Openwall GNU/*/Linux Powered by OpenVZ