From: Laurent Dufour <ldufour@linux.vnet.ibm.com>
To: Ingo Molnar <mingo@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
Jeff Dike <jdike@addtoit.com>,
Richard Weinberger <richard@nod.at>,
Guan Xuetao <gxt@mprc.pku.edu.cn>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Arnd Bergmann <arnd@arndb.de>,
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
Subject: Re: [PATCH v2 2/2] powerpc/mm: Tracking vDSO remap
Date: Wed, 25 Mar 2015 14:25:16 +0100 [thread overview]
Message-ID: <5512B73C.5050509@linux.vnet.ibm.com> (raw)
In-Reply-To: <20150325121118.GA2542@gmail.com>
On 25/03/2015 13:11, Ingo Molnar wrote:
>
> * Laurent Dufour <ldufour@linux.vnet.ibm.com> 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 <ldufour@linux.vnet.ibm.com>
>> ---
>> 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 <linux/spinlock.h>
>> #include <asm/mmu.h>
>> #include <asm/cputable.h>
>> -#include <asm-generic/mm_hooks.h>
>> #include <asm/cputhreads.h>
>>
>> /*
>> @@ -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.
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next prev parent reply other threads:[~2015-03-25 13:25 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-03-20 15:53 [PATCH 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-20 15:53 ` [PATCH 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-20 23:19 ` Richard Weinberger
2015-03-23 8:52 ` Ingo Molnar
2015-03-23 9:11 ` Laurent Dufour
2015-03-25 11:06 ` [PATCH v2 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-25 11:06 ` [PATCH v2 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-25 11:06 ` [PATCH v2 2/2] powerpc/mm: Tracking vDSO remap Laurent Dufour
2015-03-25 12:11 ` Ingo Molnar
2015-03-25 13:25 ` Laurent Dufour [this message]
2015-03-25 13:53 ` [PATCH v3 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-25 13:53 ` [PATCH v3 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-25 13:53 ` [PATCH v3 2/2] powerpc/mm: Tracking vDSO remap Laurent Dufour
2015-03-25 18:33 ` Ingo Molnar
2015-03-25 18:36 ` Ingo Molnar
2015-03-25 21:11 ` Benjamin Herrenschmidt
2015-03-26 9:43 ` Ingo Molnar
2015-03-26 10:37 ` Laurent Dufour
2015-03-26 14:17 ` Ingo Molnar
2015-03-26 14:32 ` Laurent Dufour
2015-03-26 17:37 ` [PATCH v4 0/2] Tracking user space vDSO remaping Laurent Dufour
2015-03-26 17:37 ` [PATCH v4 1/2] mm: Introducing arch_remap hook Laurent Dufour
2015-03-26 17:37 ` [PATCH v4 2/2] powerpc/mm: Tracking vDSO remap Laurent Dufour
2015-03-26 18:55 ` Ingo Molnar
2015-03-27 11:02 ` Laurent Dufour
2015-03-26 23:23 ` [PATCH v3 " Benjamin Herrenschmidt
2015-03-25 21:09 ` Benjamin Herrenschmidt
2015-03-26 9:48 ` Ingo Molnar
2015-03-26 10:13 ` Laurent Dufour
2015-03-20 15:53 ` [PATCH " Laurent Dufour
2016-03-02 12:13 ` [PATCH 0/2] Tracking user space vDSO remaping Christopher Covington
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