From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wg0-f51.google.com (mail-wg0-f51.google.com [74.125.82.51]) by kanga.kvack.org (Postfix) with ESMTP id 0B9F36B0038 for ; Wed, 25 Mar 2015 08:11:26 -0400 (EDT) Received: by wgdm6 with SMTP id m6so24965326wgd.2 for ; Wed, 25 Mar 2015 05:11:25 -0700 (PDT) Received: from mail-wi0-x232.google.com (mail-wi0-x232.google.com. [2a00:1450:400c:c05::232]) by mx.google.com with ESMTPS id fx9si4793584wib.15.2015.03.25.05.11.23 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 25 Mar 2015 05:11:24 -0700 (PDT) Received: by wibg7 with SMTP id g7so72886075wib.1 for ; Wed, 25 Mar 2015 05:11:23 -0700 (PDT) Date: Wed, 25 Mar 2015 13:11:19 +0100 From: Ingo Molnar Subject: Re: [PATCH v2 2/2] powerpc/mm: Tracking vDSO remap Message-ID: <20150325121118.GA2542@gmail.com> References: <20150323085209.GA28965@gmail.com> <25152b76585716dc635945c3455ab9b49e645f6d.1427280806.git.ldufour@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <25152b76585716dc635945c3455ab9b49e645f6d.1427280806.git.ldufour@linux.vnet.ibm.com> Sender: owner-linux-mm@kvack.org List-ID: To: Laurent Dufour Cc: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman , Jeff Dike , Richard Weinberger , Guan Xuetao , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org, Arnd Bergmann , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, user-mode-linux-devel@lists.sourceforge.net, user-mode-linux-user@lists.sourceforge.net, linux-arch@vger.kernel.org, linux-mm@kvack.org, cov@codeaurora.org, criu@openvz.org * Laurent Dufour wrote: > Some processes (CRIU) are moving the vDSO area using the mremap system > call. As a consequence the kernel reference to the vDSO base address is > no more valid and the signal return frame built once the vDSO has been > moved is not pointing to the new sigreturn address. > > This patch handles vDSO remapping and unmapping. > > Signed-off-by: Laurent Dufour > --- > arch/powerpc/include/asm/mmu_context.h | 36 +++++++++++++++++++++++++++++++++- > 1 file changed, 35 insertions(+), 1 deletion(-) > > diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h > index 73382eba02dc..be5dca3f7826 100644 > --- a/arch/powerpc/include/asm/mmu_context.h > +++ b/arch/powerpc/include/asm/mmu_context.h > @@ -8,7 +8,6 @@ > #include > #include > #include > -#include > #include > > /* > @@ -109,5 +108,40 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, > #endif > } > > +static inline void arch_dup_mmap(struct mm_struct *oldmm, > + struct mm_struct *mm) > +{ > +} > + > +static inline void arch_exit_mmap(struct mm_struct *mm) > +{ > +} > + > +static inline void arch_unmap(struct mm_struct *mm, > + struct vm_area_struct *vma, > + unsigned long start, unsigned long end) > +{ > + if (start <= mm->context.vdso_base && mm->context.vdso_base < end) > + mm->context.vdso_base = 0; > +} > + > +static inline void arch_bprm_mm_init(struct mm_struct *mm, > + struct vm_area_struct *vma) > +{ > +} > + > +#define __HAVE_ARCH_REMAP > +static inline void arch_remap(struct mm_struct *mm, > + unsigned long old_start, unsigned long old_end, > + unsigned long new_start, unsigned long new_end) > +{ > + /* > + * mremap don't allow moving multiple vma so we can limit the check > + * to old_start == vdso_base. s/mremap don't allow moving multiple vma mremap() doesn't allow moving multiple vmas right? Thanks, Ingo -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org