Date:   Sun, 5 Dec 2021 22:03:50 -0800
From:   Josh Poimboeuf <jpoimboe@redhat.com>
To:     Peter Zijlstra <peterz@infradead.org>
Cc:     Alexander Lobakin <alexandr.lobakin@intel.com>,
        linux-hardening@vger.kernel.org, x86@kernel.org,
        Jesse Brandeburg <jesse.brandeburg@intel.com>,
        Kristen Carlson Accardi <kristen@linux.intel.com>,
        Kees Cook <keescook@chromium.org>,
        Miklos Szeredi <miklos@szeredi.hu>,
        Ard Biesheuvel <ardb@kernel.org>,
        Tony Luck <tony.luck@intel.com>,
        Bruce Schlobohm <bruce.schlobohm@intel.com>,
        Jessica Yu <jeyu@kernel.org>,
        kernel test robot <lkp@intel.com>,
        Miroslav Benes <mbenes@suse.cz>,
        Evgenii Shatokhin <eshatokhin@virtuozzo.com>,
        Jonathan Corbet <corbet@lwn.net>,
        Masahiro Yamada <masahiroy@kernel.org>,
        Michal Marek <michal.lkml@markovi.net>,
        Nick Desaulniers <ndesaulniers@google.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>,
        Thomas Gleixner <tglx@linutronix.de>,
        Will Deacon <will@kernel.org>, Ingo Molnar <mingo@redhat.com>,
        Borislav Petkov <bp@alien8.de>,
        Dave Hansen <dave.hansen@linux.intel.com>,
        "H. Peter Anvin" <hpa@zytor.com>,
        Andy Lutomirski <luto@kernel.org>,
        Arnd Bergmann <arnd@arndb.de>,
        Nathan Chancellor <nathan@kernel.org>,
        Masami Hiramatsu <mhiramat@kernel.org>,
        Marios Pomonis <pomonis@google.com>,
        Sami Tolvanen <samitolvanen@google.com>,
        linux-kernel@vger.kernel.org, linux-kbuild@vger.kernel.org,
        linux-arch@vger.kernel.org, live-patching@vger.kernel.org,
        llvm@lists.linux.dev
Subject: Re: [PATCH v8 08/14] livepatch: only match unique symbols when using
 FG-KASLR
Message-ID: <20211206060350.f4hqug2jhgjlaw3c@treble>
References: <20211202223214.72888-1-alexandr.lobakin@intel.com>
 <20211202223214.72888-9-alexandr.lobakin@intel.com>
 <YansAlTr0/MfNxWc@hirez.programming.kicks-ass.net>
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On Fri, Dec 03, 2021 at 11:05:54AM +0100, Peter Zijlstra wrote:
> On Thu, Dec 02, 2021 at 11:32:08PM +0100, Alexander Lobakin wrote:
> > If any type of function granular randomization is enabled, the sympos
> > algorithm will fail, as it will be impossible to resolve symbols when
> > there are duplicates using the previous symbol position.
> > 
> > We could override sympos to 0, but make it more clear to the user
> > and bail out if the symbol is not unique.
> 
> Since we're going lots of horrendous things already, why can't we fix
> this duplicate nonsense too?

I assume you mean using this new linker flag: "-z unique-symbol"

https://sourceware.org/bugzilla/show_bug.cgi?id=26391

-- 
Josh