From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752436AbbABSU3 (ORCPT ); Fri, 2 Jan 2015 13:20:29 -0500 Received: from mx1.redhat.com ([209.132.183.28]:36647 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750745AbbABSU2 (ORCPT ); Fri, 2 Jan 2015 13:20:28 -0500 Date: Fri, 2 Jan 2015 19:19:08 +0100 From: Oleg Nesterov To: Pratyush Anand Cc: linux-arm-kernel@lists.infradead.org, linux@arm.linux.org.uk, tixy@linaro.org, ananth@in.ibm.com, sandeepa.prabhu@linaro.org, catalin.marinas@arm.com, will.deacon@arm.com, linux-kernel@vger.kernel.org, anil.s.keshavamurthy@intel.com, masami.hiramatsu.pt@hitachi.com, wcohen@redhat.com Subject: Re: [RFC 5/8] ARM64: Re-factor flush_ptrace_access Message-ID: <20150102181908.GA8466@redhat.com> References: <20150102175115.GB6761@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150102175115.GB6761@redhat.com> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/02, Oleg Nesterov wrote: > > On 12/31, Pratyush Anand wrote: > > > > Re-factor flush_ptrace_access to reuse vma independent part. > > But for what? The changelog should explain this. > > > Signed-off-by: Pratyush Anand > > --- > > arch/arm64/mm/flush.c | 24 +++++++++++++++--------- > > 1 file changed, 15 insertions(+), 9 deletions(-) > > > > diff --git a/arch/arm64/mm/flush.c b/arch/arm64/mm/flush.c > > index b6f14e8d2121..9a4dd6f39cfb 100644 > > --- a/arch/arm64/mm/flush.c > > +++ b/arch/arm64/mm/flush.c > > @@ -34,19 +34,25 @@ void flush_cache_range(struct vm_area_struct *vma, unsigned long start, > > __flush_icache_all(); > > } > > > > +static void __flush_ptrace_access(struct page *page, unsigned long uaddr, > > + void *kaddr, unsigned long len) > > +{ > > + unsigned long addr = (unsigned long)kaddr; > > + > > + if (icache_is_aliasing()) { > > + __flush_dcache_area(kaddr, len); > > + __flush_icache_all(); > > + } else { > > + flush_icache_range(addr, addr + len); > > + } > > +} > > + > > static void flush_ptrace_access(struct vm_area_struct *vma, struct page *page, > > unsigned long uaddr, void *kaddr, > > unsigned long len) > > { > > - if (vma->vm_flags & VM_EXEC) { > > - unsigned long addr = (unsigned long)kaddr; > > - if (icache_is_aliasing()) { > > - __flush_dcache_area(kaddr, len); > > - __flush_icache_all(); > > - } else { > > - flush_icache_range(addr, addr + len); > > - } > > - } > > + if (vma->vm_flags & VM_EXEC) > > + __flush_ptrace_access(page, uaddr, kaddr, len); > > } > > So why uprobes can't use flush_ptrace_access() ? flush_uprobe_xol_access() is > called by arch_uprobe_copy_ixol(), and xol vma has VM_EXEC bit set. Ah, sorry, I forgot that arch_uprobe_copy_ixol() doesn't have "vma" so it can't use flush_ptrace_access()... perhaps you can update the changelog. Oleg.