From: Christoffer Dall <christoffer.dall@linaro.org>
To: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>,
kvmarm@lists.cs.columbia.edu,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] KVM: arm/arm64: Stop leaking vcpu pid references
Date: Mon, 27 Jun 2016 13:08:39 +0200 [thread overview]
Message-ID: <20160627110839.GD26498@cbox> (raw)
In-Reply-To: <1465403085-2358-1-git-send-email-james.morse@arm.com>
On Wed, Jun 08, 2016 at 05:24:45PM +0100, James Morse wrote:
> kvm provides kvm_vcpu_uninit(), which amongst other things, releases the
> last reference to the struct pid of the task that was last running the vcpu.
>
> On arm64 built with CONFIG_DEBUG_KMEMLEAK, starting a guest with kvmtool,
> then killing it with SIGKILL results (after some considerable time) in:
> > cat /sys/kernel/debug/kmemleak
> > unreferenced object 0xffff80007d5ea080 (size 128):
> > comm "lkvm", pid 2025, jiffies 4294942645 (age 1107.776s)
> > hex dump (first 32 bytes):
> > 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > backtrace:
> > [<ffff8000001b30ec>] create_object+0xfc/0x278
> > [<ffff80000071da34>] kmemleak_alloc+0x34/0x70
> > [<ffff80000019fa2c>] kmem_cache_alloc+0x16c/0x1d8
> > [<ffff8000000d0474>] alloc_pid+0x34/0x4d0
> > [<ffff8000000b5674>] copy_process.isra.6+0x79c/0x1338
> > [<ffff8000000b633c>] _do_fork+0x74/0x320
> > [<ffff8000000b66b0>] SyS_clone+0x18/0x20
> > [<ffff800000085cb0>] el0_svc_naked+0x24/0x28
> > [<ffffffffffffffff>] 0xffffffffffffffff
>
> On x86 kvm_vcpu_uninit() is called on the path from kvm_arch_destroy_vm(),
> on arm no equivalent call is made. Add the call to kvm_arch_vcpu_free().
>
> Signed-off-by: James Morse <james.morse@arm.com>
> Fixes: 749cf76c5a36 ("KVM: ARM: Initial skeleton to compile KVM support")
> Cc: <stable@vger.kernel.org> # 3.10+
> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Applied, thanks.
-Christoffer
WARNING: multiple messages have this Message-ID (diff)
From: christoffer.dall@linaro.org (Christoffer Dall)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] KVM: arm/arm64: Stop leaking vcpu pid references
Date: Mon, 27 Jun 2016 13:08:39 +0200 [thread overview]
Message-ID: <20160627110839.GD26498@cbox> (raw)
In-Reply-To: <1465403085-2358-1-git-send-email-james.morse@arm.com>
On Wed, Jun 08, 2016 at 05:24:45PM +0100, James Morse wrote:
> kvm provides kvm_vcpu_uninit(), which amongst other things, releases the
> last reference to the struct pid of the task that was last running the vcpu.
>
> On arm64 built with CONFIG_DEBUG_KMEMLEAK, starting a guest with kvmtool,
> then killing it with SIGKILL results (after some considerable time) in:
> > cat /sys/kernel/debug/kmemleak
> > unreferenced object 0xffff80007d5ea080 (size 128):
> > comm "lkvm", pid 2025, jiffies 4294942645 (age 1107.776s)
> > hex dump (first 32 bytes):
> > 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > backtrace:
> > [<ffff8000001b30ec>] create_object+0xfc/0x278
> > [<ffff80000071da34>] kmemleak_alloc+0x34/0x70
> > [<ffff80000019fa2c>] kmem_cache_alloc+0x16c/0x1d8
> > [<ffff8000000d0474>] alloc_pid+0x34/0x4d0
> > [<ffff8000000b5674>] copy_process.isra.6+0x79c/0x1338
> > [<ffff8000000b633c>] _do_fork+0x74/0x320
> > [<ffff8000000b66b0>] SyS_clone+0x18/0x20
> > [<ffff800000085cb0>] el0_svc_naked+0x24/0x28
> > [<ffffffffffffffff>] 0xffffffffffffffff
>
> On x86 kvm_vcpu_uninit() is called on the path from kvm_arch_destroy_vm(),
> on arm no equivalent call is made. Add the call to kvm_arch_vcpu_free().
>
> Signed-off-by: James Morse <james.morse@arm.com>
> Fixes: 749cf76c5a36 ("KVM: ARM: Initial skeleton to compile KVM support")
> Cc: <stable@vger.kernel.org> # 3.10+
> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Applied, thanks.
-Christoffer
next prev parent reply other threads:[~2016-06-27 11:02 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-08 16:24 [PATCH] KVM: arm/arm64: Stop leaking vcpu pid references James Morse
2016-06-08 16:24 ` James Morse
2016-06-27 11:08 ` Christoffer Dall [this message]
2016-06-27 11:08 ` Christoffer Dall
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