From mboxrd@z Thu Jan 1 00:00:00 1970 From: Laura Abbott Subject: Re: [PATCH net-next 09/10] arm64: unexport set_memory_ro and set_memory_rw Date: Fri, 27 Feb 2015 10:51:57 -0800 Message-ID: <54F0BCCD.4000402@codeaurora.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: ast@plumgrid.com, netdev@vger.kernel.org, Will Deacon , linux-kernel@vger.kernel.org To: Daniel Borkmann , davem@davemloft.net Return-path: In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On 2/27/2015 6:55 AM, Daniel Borkmann wrote: > This effectively unexports set_memory_ro and set_memory_rw functions from > commit 11d91a770f1f ("arm64: Add CONFIG_DEBUG_SET_MODULE_RONX support"). > > No module user of those is in mainline kernel and we explicitly do not want > modules to use these functions, as they i.e. protect eBPF (interpreted and > JIT'ed) images from malicious modifications or bugs. > > Outside of eBPF scope, I believe also other set_memory_* functions should > be unexported on arm64 for modules. > > Signed-off-by: Daniel Borkmann > Cc: Laura Abbott > Cc: Will Deacon > Cc: linux-kernel@vger.kernel.org > Acked-by: Alexei Starovoitov > --- > arch/arm64/mm/pageattr.c | 2 -- > 1 file changed, 2 deletions(-) > We have some uses for modules doing set_memory_ro/rw but none that are in mainline. That can be dealt with if the features ever get mainlined which seems unlikely. Acked-by: Laura Abbott > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index bb0ea94..8659357 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -70,7 +70,6 @@ int set_memory_ro(unsigned long addr, int numpages) > __pgprot(PTE_RDONLY), > __pgprot(PTE_WRITE)); > } > -EXPORT_SYMBOL_GPL(set_memory_ro); > > int set_memory_rw(unsigned long addr, int numpages) > { > @@ -78,7 +77,6 @@ int set_memory_rw(unsigned long addr, int numpages) > __pgprot(PTE_WRITE), > __pgprot(PTE_RDONLY)); > } > -EXPORT_SYMBOL_GPL(set_memory_rw); > > int set_memory_nx(unsigned long addr, int numpages) > { > -- Qualcomm Innovation Center, Inc. Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project