From: Adrian Hunter <adrian.hunter@intel.com>
To: Thomas Garnier <thgarnie@chromium.org>,
kernel-hardening@lists.openwall.com
Cc: kristen@linux.intel.com, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Luis Chamberlain <mcgrof@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Jason Baron <jbaron@akamai.com>,
Thomas Garnier <thgarnie@google.com>,
Jordan Borgner <mail@jordan-borgner.de>,
Masami Hiramatsu <mhiramat@kernel.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
Mathieu
Subject: Re: [PATCH v6 15/27] compiler: Option to default to hidden symbols
Date: Fri, 1 Feb 2019 10:22:22 +0200 [thread overview]
Message-ID: <3a2bdc07-e8c4-c340-dde7-516ab0de66f2@intel.com> (raw)
In-Reply-To: <20190131192533.34130-16-thgarnie@chromium.org>
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?
WARNING: multiple messages have this Message-ID (diff)
From: Adrian Hunter <adrian.hunter@intel.com>
To: Thomas Garnier <thgarnie@chromium.org>,
kernel-hardening@lists.openwall.com
Cc: kristen@linux.intel.com, Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Luis Chamberlain <mcgrof@kernel.org>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
"Rafael J. Wysocki" <rafael@kernel.org>,
Arnd Bergmann <arnd@arndb.de>,
Luc Van Oostenryck <luc.vanoostenryck@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Jason Baron <jbaron@akamai.com>,
Thomas Garnier <thgarnie@google.com>,
Jordan Borgner <mail@jordan-borgner.de>,
Masami Hiramatsu <mhiramat@kernel.org>,
Masahiro Yamada <yamada.masahiro@socionext.com>,
"Peter Zijlstra (Intel)" <peterz@infradead.org>,
Andrew Morton <akpm@linux-foundation.org>,
Kees Cook <keescook@chromium.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
Arnaldo Carvalho de Melo <acme@redhat.com>,
Andi Kleen <ak@linux.intel.com>, Jan Beulich <JBeulich@suse.com>,
Song Liu <songliubraving@fb.com>,
Alexander Shishkin <alexander.shishkin@linux.intel.com>,
linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org,
linux-sparse@vger.kernel.org
Subject: Re: [PATCH v6 15/27] compiler: Option to default to hidden symbols
Date: Fri, 1 Feb 2019 10:22:22 +0200 [thread overview]
Message-ID: <3a2bdc07-e8c4-c340-dde7-516ab0de66f2@intel.com> (raw)
Message-ID: <20190201082222.2kNAU4tWb1_rVryZvMkz_VBCB5b2UVKFVmK09GMS7ik@z> (raw)
In-Reply-To: <20190131192533.34130-16-thgarnie@chromium.org>
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?
next prev parent reply other threads:[~2019-02-01 8:22 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-31 19:24 [PATCH v6 00/27] x86: PIE support and option to extend KASLR randomization Thomas Garnier
2019-01-31 19:24 ` [PATCH v6 15/27] compiler: Option to default to hidden symbols Thomas Garnier
2019-01-31 19:24 ` Thomas Garnier
2019-02-01 7:12 ` Dan Carpenter
2019-02-01 7:12 ` Dan Carpenter
2019-02-01 17:00 ` Thomas Garnier
2019-02-01 17:00 ` Thomas Garnier
2019-02-01 8:22 ` Adrian Hunter [this message]
2019-02-01 8:22 ` Adrian Hunter
2019-02-01 17:35 ` Thomas Garnier
2019-02-01 17:35 ` Thomas Garnier
2019-01-31 19:24 ` [PATCH v6 24/27] x86/mm: Make the x86 GOT read-only Thomas Garnier
2019-01-31 19:24 ` Thomas Garnier
2019-01-31 19:59 ` [PATCH v6 00/27] x86: PIE support and option to extend KASLR randomization Kees Cook
2019-01-31 21:40 ` Konrad Rzeszutek Wilk
2019-01-31 22:42 ` Thomas Garnier
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