From mboxrd@z Thu Jan 1 00:00:00 1970 From: oleg@redhat.com (Oleg Nesterov) Date: Fri, 2 Jan 2015 18:51:15 +0100 Subject: [RFC 5/8] ARM64: Re-factor flush_ptrace_access In-Reply-To: References: Message-ID: <20150102175115.GB6761@redhat.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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. Oleg. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752138AbbABRwi (ORCPT ); Fri, 2 Jan 2015 12:52:38 -0500 Received: from mx1.redhat.com ([209.132.183.28]:49074 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750736AbbABRwh (ORCPT ); Fri, 2 Jan 2015 12:52:37 -0500 Date: Fri, 2 Jan 2015 18:51:15 +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: <20150102175115.GB6761@redhat.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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 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. Oleg.