From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e06smtp12.uk.ibm.com (e06smtp12.uk.ibm.com [195.75.94.108]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 1774B1A0736 for ; Thu, 26 Mar 2015 00:25:27 +1100 (AEDT) Received: from /spool/local by e06smtp12.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 25 Mar 2015 13:25:23 -0000 Received: from b06cxnps4074.portsmouth.uk.ibm.com (d06relay11.portsmouth.uk.ibm.com [9.149.109.196]) by d06dlp01.portsmouth.uk.ibm.com (Postfix) with ESMTP id C189D17D805F for ; Wed, 25 Mar 2015 13:25:49 +0000 (GMT) Received: from d06av12.portsmouth.uk.ibm.com (d06av12.portsmouth.uk.ibm.com [9.149.37.247]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t2PDPMr610813766 for ; Wed, 25 Mar 2015 13:25:22 GMT Received: from d06av12.portsmouth.uk.ibm.com (localhost [127.0.0.1]) by d06av12.portsmouth.uk.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t2PDPI7F004627 for ; Wed, 25 Mar 2015 07:25:21 -0600 Message-ID: <5512B73C.5050509@linux.vnet.ibm.com> Date: Wed, 25 Mar 2015 14:25:16 +0100 From: Laurent Dufour MIME-Version: 1.0 To: Ingo Molnar Subject: Re: [PATCH v2 2/2] powerpc/mm: Tracking vDSO remap References: <20150323085209.GA28965@gmail.com> <25152b76585716dc635945c3455ab9b49e645f6d.1427280806.git.ldufour@linux.vnet.ibm.com> <20150325121118.GA2542@gmail.com> In-Reply-To: <20150325121118.GA2542@gmail.com> Content-Type: text/plain; charset=windows-1252 Cc: linux-arch@vger.kernel.org, linux-s390@vger.kernel.org, x86@kernel.org, user-mode-linux-devel@lists.sourceforge.net, Arnd Bergmann , Jeff Dike , "H. Peter Anvin" , linux-kernel@vger.kernel.org, criu@openvz.org, linux-mm@kvack.org, Ingo Molnar , Paul Mackerras , user-mode-linux-user@lists.sourceforge.net, Richard Weinberger , Thomas Gleixner , Guan Xuetao , linuxppc-dev@lists.ozlabs.org, cov@codeaurora.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 25/03/2015 13:11, Ingo Molnar wrote: > > * 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? Sure you're right. I'll provide a v3 fixing that comment. Thanks, Laurent.