Messages in this thread | | | Date | Wed, 9 Aug 2017 11:13:41 +0100 | From | Catalin Marinas <> | Subject | Re: [PATCH] arm64/vdso: Support mremap() for vDSO |
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On Wed, Jul 26, 2017 at 08:07:37PM +0300, Dmitry Safonov wrote: > vDSO VMA address is saved in mm_context for the purpose of using > restorer from vDSO page to return to userspace after signal handling. > > In Checkpoint Restore in Userspace (CRIU) project we place vDSO VMA > on restore back to the place where it was on the dump. > With the exception for x86 (where there is API to map vDSO with > arch_prctl()), we move vDSO inherited from CRIU task to restoree > position by mremap(). > > CRIU does support arm64 architecture, but kernel doesn't update > context.vdso pointer after mremap(). Which results in translation > fault after signal handling on restored application: > https://github.com/xemul/criu/issues/288 > > Make vDSO code track the VMA address by supplying .mremap() fops > the same way it's done for x86 and arm32 by: > commit b059a453b1cf ("x86/vdso: Add mremap hook to vm_special_mapping") > commit 280e87e98c09 ("ARM: 8683/1: ARM32: Support mremap() for sigpage/vDSO"). > > Cc: Catalin Marinas <catalin.marinas@arm.com> > Cc: Will Deacon <will.deacon@arm.com> > Cc: Russell King <rmk+kernel@armlinux.org.uk> > Cc: linux-arm-kernel@lists.infradead.org > Cc: Cyrill Gorcunov <gorcunov@openvz.org> > Cc: Pavel Emelyanov <xemul@virtuozzo.com> > Cc: Christopher Covington <cov@codeaurora.org> > Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Queued for 4.14. Thanks.
-- Catalin
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