linux-kernel - Re: [PATCH v6 15/27] compiler: Option to default to hidden symbols

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: <3a2bdc07-e8c4-c340-dde7-516ab0de66f2@intel.com>
Date:   Fri, 1 Feb 2019 10:22:22 +0200
From:   Adrian Hunter <adrian.hunter@...el.com>
To:     Thomas Garnier <thgarnie@...omium.org>,
        kernel-hardening@...ts.openwall.com
Cc:     kristen@...ux.intel.com, Thomas Gleixner <tglx@...utronix.de>,
        Ingo Molnar <mingo@...hat.com>, Borislav Petkov <bp@...en8.de>,
        "H. Peter Anvin" <hpa@...or.com>, x86@...nel.org,
        Luis Chamberlain <mcgrof@...nel.org>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Arnd Bergmann <arnd@...db.de>,
        Luc Van Oostenryck <luc.vanoostenryck@...il.com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Jason Baron <jbaron@...mai.com>,
        Thomas Garnier <thgarnie@...gle.com>,
        Jordan Borgner <mail@...dan-borgner.de>,
        Masami Hiramatsu <mhiramat@...nel.org>,
        Masahiro Yamada <yamada.masahiro@...ionext.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Kees Cook <keescook@...omium.org>,
        Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
        Arnaldo Carvalho de Melo <acme@...hat.com>,
        Andi Kleen <ak@...ux.intel.com>,
        Jan Beulich <JBeulich@...e.com>,
        Song Liu <songliubraving@...com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        linux-kernel@...r.kernel.org, linux-arch@...r.kernel.org,
        linux-sparse@...r.kernel.org
Subject: Re: [PATCH v6 15/27] compiler: Option to default to hidden symbols

On 31/01/19 9:24 PM, Thomas Garnier wrote:
> Provide an option to default visibility to hidden except for key
> symbols. This option is disabled by default and will be used by x86_64
> PIE support to remove errors between compilation units.
> 
> The default visibility is also enabled for external symbols that are
> compared as they maybe equals (start/end of sections). In this case,
> older versions of GCC will remove the comparison if the symbols are
> hidden. This issue exists at least on gcc 4.9 and before.

What does this mean, if anything, for what/how symbols appear in /proc/kallsyms?