From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Will Deacon <will@kernel.org>
Cc: linux-kernel@vger.kernel.org, kernel-team@android.com,
akpm@linux-foundation.org,
"K . Prasad" <prasad@linux.vnet.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Frederic Weisbecker <frederic@kernel.org>,
Christoph Hellwig <hch@lst.de>,
Quentin Perret <qperret@google.com>,
Alexei Starovoitov <ast@kernel.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
rostedt@goodmis.org
Subject: Re: [PATCH 0/3] Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol()
Date: Mon, 2 Mar 2020 14:28:11 -0500 [thread overview]
Message-ID: <20200302192811.n6o5645rsib44vco@localhost> (raw)
In-Reply-To: <20200221114404.14641-1-will@kernel.org>
On 21-Feb-2020 11:44:01 AM, Will Deacon wrote:
> Hi folks,
>
> Despite having just a single modular in-tree user that I could spot,
> kallsyms_lookup_name() is exported to modules and provides a mechanism
> for out-of-tree modules to access and invoke arbitrary, non-exported
> kernel symbols when kallsyms is enabled.
>
> This patch series fixes up that one user and unexports the symbol along
> with kallsyms_on_each_symbol(), since that could also be abused in a
> similar manner.
Hi,
I maintain a GPL kernel tracer (LTTng) since 2005 which happens to be
out-of-tree, even though we have made unsuccessful attempts to upstream
it in the past. It uses kallsyms_lookup_name() to fetch a few symbols. I
would be very glad to have them GPL-exported upstream rather than
relying on this work-around. Here is the list of symbols we would need
to GPL-export:
stack_trace_save
stack_trace_save_user
vmalloc_sync_all (CONFIG_X86)
get_pfnblock_flags_mask
disk_name
block_class
disk_type
global_wb_domain
task_prio
In order to provide address-to-symbol mapping at trace post-processing
(for which we have a prototype branch), we would also need the "_text"
symbol to be GPL-exported, as well as the list of currently loaded
modules (LIST_HEAD(modules) or a getter function).
The tricky part is justifying having those exported for a project
which is not upstream.
I welcome advice on this matter,
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2020-03-02 19:28 UTC|newest]
Thread overview: 26+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-21 11:44 [PATCH 0/3] Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() Will Deacon
2020-02-21 11:44 ` [PATCH 1/3] samples/hw_breakpoint: Drop HW_BREAKPOINT_R when reporting writes Will Deacon
2020-02-21 14:12 ` Christoph Hellwig
2020-02-21 11:44 ` [PATCH 2/3] samples/hw_breakpoint: Drop use of kallsyms_lookup_name() Will Deacon
2020-02-21 14:13 ` Christoph Hellwig
2020-02-21 14:20 ` Will Deacon
2020-02-21 11:44 ` [PATCH 3/3] kallsyms: Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() Will Deacon
2020-02-21 11:53 ` Greg Kroah-Hartman
2020-02-21 14:14 ` Christoph Hellwig
2020-02-21 15:11 ` Alexei Starovoitov
2020-02-21 14:27 ` [PATCH 0/3] " Masami Hiramatsu
2020-02-21 14:48 ` Will Deacon
2020-02-21 23:44 ` Masami Hiramatsu
2020-02-21 15:41 ` David Laight
2020-02-21 16:25 ` Quentin Perret
2020-02-25 10:05 ` Miroslav Benes
2020-02-25 12:11 ` Petr Mladek
2020-02-25 15:00 ` Joe Lawrence
2020-02-25 18:01 ` Miroslav Benes
2020-02-26 14:16 ` Joe Lawrence
2020-03-02 19:28 ` Mathieu Desnoyers [this message]
2020-03-02 19:36 ` Greg Kroah-Hartman
2020-03-02 19:39 ` Greg Kroah-Hartman
2020-03-02 20:17 ` Mathieu Desnoyers
2020-03-03 6:57 ` Greg Kroah-Hartman
2020-03-03 16:58 ` Mathieu Desnoyers
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