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Prasad" , Thomas Gleixner , Greg Kroah-Hartman , Frederic Weisbecker , Christoph Hellwig , Quentin Perret , Alexei Starovoitov , Masami Hiramatsu Subject: Re: [PATCH 3/3] kallsyms: Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol() Message-ID: <20200221151109.gxrhyaybjwxqktul@ast-mbp> References: <20200221114404.14641-1-will@kernel.org> <20200221114404.14641-4-will@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200221114404.14641-4-will@kernel.org> User-Agent: NeoMutt/20180223 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 21, 2020 at 11:44:04AM +0000, Will Deacon wrote: > kallsyms_lookup_name() and kallsyms_on_each_symbol() are exported to > modules despite having no in-tree users and being wide open to abuse by > out-of-tree modules that can use them as a method to invoke arbitrary > non-exported kernel functions. > > Unexport kallsyms_lookup_name() and kallsyms_on_each_symbol(). > > Cc: Alexei Starovoitov > Cc: Masami Hiramatsu > Cc: Thomas Gleixner > Cc: Greg Kroah-Hartman > Cc: Christoph Hellwig > Cc: Quentin Perret > Signed-off-by: Will Deacon > --- > kernel/kallsyms.c | 2 -- > 1 file changed, 2 deletions(-) > > diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c > index a9b3f660dee7..16c8c605f4b0 100644 > --- a/kernel/kallsyms.c > +++ b/kernel/kallsyms.c > @@ -175,7 +175,6 @@ unsigned long kallsyms_lookup_name(const char *name) > } > return module_kallsyms_lookup_name(name); > } > -EXPORT_SYMBOL_GPL(kallsyms_lookup_name); > > int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, > unsigned long), > @@ -194,7 +193,6 @@ int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, > } > return module_kallsyms_on_each_symbol(fn, data); > } > -EXPORT_SYMBOL_GPL(kallsyms_on_each_symbol); Looking at commit 75a66614db21 ("Ksplice: Add functions for walking kallsyms symbols") this change will break ksplice. But I think it's the right call. live-patching needs to find a way to be better integrated with the core kernel. Acked-by: Alexei Starovoitov