* [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings
@ 2023-07-07 5:10 Mahesh Salgaonkar
2023-08-11 12:36 ` Joel Stanley
0 siblings, 1 reply; 5+ messages in thread
From: Mahesh Salgaonkar @ 2023-07-07 5:10 UTC (permalink / raw)
To: linuxppc-dev; +Cc: Aneesh Kumar K.V, Jordan Niethe
opal_prd_msg_notifier extracts the opal prd message size from the message
header and uses it for allocating opal_prd_msg_queue_item that includes
the correct message size to be copied. However, while running under
CONFIG_FORTIFY_SOURCE=y, it triggers following run-time warning:
[ 6458.234352] memcpy: detected field-spanning write (size 32) of single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size 4)
[ 6458.234390] WARNING: CPU: 9 PID: 660 at arch/powerpc/platforms/powernv/opal-prd.c:355 opal_prd_msg_notifier+0x174/0x188 [opal_prd]
[...]
[ 6458.234709] NIP [c00800000e0c0e6c] opal_prd_msg_notifier+0x174/0x188 [opal_prd]
[ 6458.234723] LR [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 [opal_prd]
[ 6458.234736] Call Trace:
[ 6458.234742] [c0000002acb23c10] [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable)
[ 6458.234759] [c0000002acb23ca0] [c00000000019ccc0] notifier_call_chain+0xc0/0x1b0
[ 6458.234774] [c0000002acb23d00] [c00000000019ceac] atomic_notifier_call_chain+0x2c/0x40
[ 6458.234788] [c0000002acb23d20] [c0000000000d69b4] opal_message_notify+0xf4/0x2c0
[...]
Split the copy to avoid false positive run-time warning.
Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
---
Change from v1:
- Rework the memcpy to copy message header and rest of the message
separately without adding flex array.
---
arch/powerpc/platforms/powernv/opal-prd.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/platforms/powernv/opal-prd.c b/arch/powerpc/platforms/powernv/opal-prd.c
index 113bdb151f687..a068cbc4d43c0 100644
--- a/arch/powerpc/platforms/powernv/opal-prd.c
+++ b/arch/powerpc/platforms/powernv/opal-prd.c
@@ -352,7 +352,9 @@ static int opal_prd_msg_notifier(struct notifier_block *nb,
if (!item)
return -ENOMEM;
- memcpy(&item->msg, msg->params, msg_size);
+ item->msg = *hdr;
+ hdr++;
+ memcpy((char *)&item->msg + sizeof(*hdr), hdr, msg_size - sizeof(*hdr));
spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
list_add_tail(&item->list, &opal_prd_msg_queue);
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings
2023-07-07 5:10 [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings Mahesh Salgaonkar
@ 2023-08-11 12:36 ` Joel Stanley
2023-08-15 10:47 ` Michael Ellerman
0 siblings, 1 reply; 5+ messages in thread
From: Joel Stanley @ 2023-08-11 12:36 UTC (permalink / raw)
To: Mahesh Salgaonkar, Michael Ellerman
Cc: linuxppc-dev, Jordan Niethe, Aneesh Kumar K.V
On Fri, 7 Jul 2023 at 05:11, Mahesh Salgaonkar <mahesh@linux.ibm.com> wrote:
>
> opal_prd_msg_notifier extracts the opal prd message size from the message
> header and uses it for allocating opal_prd_msg_queue_item that includes
> the correct message size to be copied. However, while running under
> CONFIG_FORTIFY_SOURCE=y, it triggers following run-time warning:
>
> [ 6458.234352] memcpy: detected field-spanning write (size 32) of single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size 4)
> [ 6458.234390] WARNING: CPU: 9 PID: 660 at arch/powerpc/platforms/powernv/opal-prd.c:355 opal_prd_msg_notifier+0x174/0x188 [opal_prd]
> [...]
> [ 6458.234709] NIP [c00800000e0c0e6c] opal_prd_msg_notifier+0x174/0x188 [opal_prd]
> [ 6458.234723] LR [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 [opal_prd]
> [ 6458.234736] Call Trace:
> [ 6458.234742] [c0000002acb23c10] [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable)
> [ 6458.234759] [c0000002acb23ca0] [c00000000019ccc0] notifier_call_chain+0xc0/0x1b0
> [ 6458.234774] [c0000002acb23d00] [c00000000019ceac] atomic_notifier_call_chain+0x2c/0x40
> [ 6458.234788] [c0000002acb23d20] [c0000000000d69b4] opal_message_notify+0xf4/0x2c0
> [...]
>
> Split the copy to avoid false positive run-time warning.
>
> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
I hit this on a box running the Ubuntu 6.2.0-27-generic kernel.
Do we plan on merging this fix?
> ---
> Change from v1:
> - Rework the memcpy to copy message header and rest of the message
> separately without adding flex array.
> ---
> arch/powerpc/platforms/powernv/opal-prd.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/platforms/powernv/opal-prd.c b/arch/powerpc/platforms/powernv/opal-prd.c
> index 113bdb151f687..a068cbc4d43c0 100644
> --- a/arch/powerpc/platforms/powernv/opal-prd.c
> +++ b/arch/powerpc/platforms/powernv/opal-prd.c
> @@ -352,7 +352,9 @@ static int opal_prd_msg_notifier(struct notifier_block *nb,
> if (!item)
> return -ENOMEM;
>
> - memcpy(&item->msg, msg->params, msg_size);
> + item->msg = *hdr;
> + hdr++;
> + memcpy((char *)&item->msg + sizeof(*hdr), hdr, msg_size - sizeof(*hdr));
>
> spin_lock_irqsave(&opal_prd_msg_queue_lock, flags);
> list_add_tail(&item->list, &opal_prd_msg_queue);
>
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings
2023-08-11 12:36 ` Joel Stanley
@ 2023-08-15 10:47 ` Michael Ellerman
2023-11-15 19:07 ` matoro
0 siblings, 1 reply; 5+ messages in thread
From: Michael Ellerman @ 2023-08-15 10:47 UTC (permalink / raw)
To: Joel Stanley, Mahesh Salgaonkar
Cc: linuxppc-dev, Jordan Niethe, Aneesh Kumar K.V
Joel Stanley <joel@jms.id.au> writes:
> On Fri, 7 Jul 2023 at 05:11, Mahesh Salgaonkar <mahesh@linux.ibm.com> wrote:
>>
>> opal_prd_msg_notifier extracts the opal prd message size from the message
>> header and uses it for allocating opal_prd_msg_queue_item that includes
>> the correct message size to be copied. However, while running under
>> CONFIG_FORTIFY_SOURCE=y, it triggers following run-time warning:
>>
>> [ 6458.234352] memcpy: detected field-spanning write (size 32) of single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size 4)
>> [ 6458.234390] WARNING: CPU: 9 PID: 660 at arch/powerpc/platforms/powernv/opal-prd.c:355 opal_prd_msg_notifier+0x174/0x188 [opal_prd]
>> [...]
>> [ 6458.234709] NIP [c00800000e0c0e6c] opal_prd_msg_notifier+0x174/0x188 [opal_prd]
>> [ 6458.234723] LR [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 [opal_prd]
>> [ 6458.234736] Call Trace:
>> [ 6458.234742] [c0000002acb23c10] [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable)
>> [ 6458.234759] [c0000002acb23ca0] [c00000000019ccc0] notifier_call_chain+0xc0/0x1b0
>> [ 6458.234774] [c0000002acb23d00] [c00000000019ceac] atomic_notifier_call_chain+0x2c/0x40
>> [ 6458.234788] [c0000002acb23d20] [c0000000000d69b4] opal_message_notify+0xf4/0x2c0
>> [...]
>>
>> Split the copy to avoid false positive run-time warning.
>>
>> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
>
> I hit this on a box running the Ubuntu 6.2.0-27-generic kernel.
>
> Do we plan on merging this fix?
I thought it was papering over the issue rather than fixing the root
cause.
I'll send a new version, as soon as I can work out how to trigger that
code path.
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings
2023-08-15 10:47 ` Michael Ellerman
@ 2023-11-15 19:07 ` matoro
2023-11-19 23:14 ` Michael Ellerman
0 siblings, 1 reply; 5+ messages in thread
From: matoro @ 2023-11-15 19:07 UTC (permalink / raw)
To: Michael Ellerman
Cc: linuxppc-dev, Aneesh Kumar K.V, Jordan Niethe, Joel Stanley,
Mahesh Salgaonkar
On 2023-08-15 06:47, Michael Ellerman wrote:
> Joel Stanley <joel@jms.id.au> writes:
>> On Fri, 7 Jul 2023 at 05:11, Mahesh Salgaonkar <mahesh@linux.ibm.com>
>> wrote:
>>>
>>> opal_prd_msg_notifier extracts the opal prd message size from the message
>>> header and uses it for allocating opal_prd_msg_queue_item that includes
>>> the correct message size to be copied. However, while running under
>>> CONFIG_FORTIFY_SOURCE=y, it triggers following run-time warning:
>>>
>>> [ 6458.234352] memcpy: detected field-spanning write (size 32) of single
>>> field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size
>>> 4)
>>> [ 6458.234390] WARNING: CPU: 9 PID: 660 at
>>> arch/powerpc/platforms/powernv/opal-prd.c:355
>>> opal_prd_msg_notifier+0x174/0x188 [opal_prd]
>>> [...]
>>> [ 6458.234709] NIP [c00800000e0c0e6c] opal_prd_msg_notifier+0x174/0x188
>>> [opal_prd]
>>> [ 6458.234723] LR [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188
>>> [opal_prd]
>>> [ 6458.234736] Call Trace:
>>> [ 6458.234742] [c0000002acb23c10] [c00800000e0c0e68]
>>> opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable)
>>> [ 6458.234759] [c0000002acb23ca0] [c00000000019ccc0]
>>> notifier_call_chain+0xc0/0x1b0
>>> [ 6458.234774] [c0000002acb23d00] [c00000000019ceac]
>>> atomic_notifier_call_chain+0x2c/0x40
>>> [ 6458.234788] [c0000002acb23d20] [c0000000000d69b4]
>>> opal_message_notify+0xf4/0x2c0
>>> [...]
>>>
>>> Split the copy to avoid false positive run-time warning.
>>>
>>> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
>>
>> I hit this on a box running the Ubuntu 6.2.0-27-generic kernel.
>>
>> Do we plan on merging this fix?
>
> I thought it was papering over the issue rather than fixing the root
> cause.
>
> I'll send a new version, as soon as I can work out how to trigger that
> code path.
>
> cheers
Hi, I see this was still not accepted. I was able to trigger this simply by
starting the opal-prd userspace daemon.
Restarting the service does not re-trigger the warning, however.
[Wed Nov 15 14:01:06 2023] i2c_dev: i2c /dev entries driver
[Wed Nov 15 14:01:07 2023] ------------[ cut here ]------------
[Wed Nov 15 14:01:07 2023] memcpy: detected field-spanning write (size 32) of
single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355
(size 4)
[Wed Nov 15 14:01:07 2023] WARNING: CPU: 5 PID: 379 at
arch/powerpc/platforms/powernv/opal-prd.c:355 0xc008000000640b1c
[Wed Nov 15 14:01:07 2023] Modules linked in: i2c_dev loop vhost_net vhost
vhost_iotlb tap kvm_hv kvm bridge rpcsec_gss_krb5 auth_rpcgss tun nfsv4
dns_resolver nfs lockd grace sunrpc fscache netfs cfg80211 rfkill 8021q garp
mrp stp llc nft_masq nft_chain_nat nft_reject_inet nf_reject_ipv4
nf_reject_ipv6 nft_reject nft_ct binfmt_misc nbd wireguard
libcurve25519_generic ip6_udp_tunnel udp_tunnel nft_nat nf_tables nfnetlink
nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 at24 ast i2c_algo_bit
drm_shmem_helper joydev ftdi_sio crct10dif_vpmsum onboard_usb_hub ofpart
drm_kms_helper ipmi_powernv rtc_opal ipmi_devintf powernv_flash
ipmi_msghandler mtd opal_prd i2c_opal vmx_crypto nvme crc32c_vpmsum tg3
nvme_core ixgbe nvme_common mdio
[Wed Nov 15 14:01:07 2023] CPU: 5 PID: 379 Comm: kopald Not tainted
6.5.9-gentoo-dist #1
[Wed Nov 15 14:01:07 2023] Hardware name: T2P9S01 REV 1.01 POWER9 0x4e1203
opal:skiboot-9858186 PowerNV
[Wed Nov 15 14:01:07 2023] NIP: c008000000640b1c LR: c008000000640b18 CTR:
0000000000000000
[Wed Nov 15 14:01:07 2023] REGS: c00000000e2339b0 TRAP: 0700 Not tainted
(6.5.9-gentoo-dist)
[Wed Nov 15 14:01:07 2023] MSR: 9000000000021033 <SF,HV,ME,IR,DR,RI,LE> CR:
44002222 XER: 00000000
[Wed Nov 15 14:01:07 2023] CFAR: c000000000152b10 IRQMASK: 1
GPR00: c008000000640b18 c00000000e233c50
c008000000668100 0000000000000086
GPR04: 00000000ffff7fff c00000000e233a10
c00000000e233a08 0000001ef74d0000
GPR08: 0000000000000027 c000001ef9626d10
0000000000000001 0000000044002222
GPR12: 20646c6569662065 c000001fff7fb400
c0000000001900e8 c00000000e919540
GPR16: 0000000000000000 0000000000000000
0000000000000000 0000000000000000
GPR20: 0000000000000000 0000000000000000
0000000000000000 0000000000000000
GPR24: c00000000e959de0 0000000000000006
0000000000000000 c008000000660290
GPR28: c000000007498410 0000000000000020
c00000000e959de8 c000000007498400
[Wed Nov 15 14:01:07 2023] NIP [c008000000640b1c] 0xc008000000640b1c
[Wed Nov 15 14:01:07 2023] LR [c008000000640b18] 0xc008000000640b18
[Wed Nov 15 14:01:07 2023] Call Trace:
[Wed Nov 15 14:01:07 2023] [c00000000e233c50] [c008000000640b18]
0xc008000000640b18 (unreliable)
[Wed Nov 15 14:01:07 2023] [c00000000e233cd0] [c000000000192dd0]
notifier_call_chain+0xc0/0x1b0
[Wed Nov 15 14:01:07 2023] [c00000000e233d30] [c000000000192eec]
atomic_notifier_call_chain+0x2c/0x40
[Wed Nov 15 14:01:07 2023] [c00000000e233d50] [c0000000000cec44]
opal_message_notify+0xf4/0x2a0
[Wed Nov 15 14:01:07 2023] [c00000000e233de0] [c000000000206d58]
__handle_irq_event_percpu+0x78/0x240
[Wed Nov 15 14:01:07 2023] [c00000000e233e70] [c000000000207034]
handle_irq_event+0x74/0x140
[Wed Nov 15 14:01:07 2023] [c00000000e233ea0] [c00000000020e9bc]
handle_level_irq+0xdc/0x270
[Wed Nov 15 14:01:07 2023] [c00000000e233ed0] [c000000000204fb8]
generic_handle_domain_irq+0x48/0x70
[Wed Nov 15 14:01:07 2023] [c00000000e233ef0] [c0000000000d6f38]
opal_handle_events+0xb8/0x140
[Wed Nov 15 14:01:07 2023] [c00000000e233f50] [c0000000000ce514]
kopald+0x84/0x110
[Wed Nov 15 14:01:07 2023] [c00000000e233f90] [c000000000190218]
kthread+0x138/0x140
[Wed Nov 15 14:01:07 2023] [c00000000e233fe0] [c00000000000ded8]
start_kernel_thread+0x14/0x18
[Wed Nov 15 14:01:07 2023] Code: 2c0a0000 4082ff48 3ca20000 e8a58050 3c620000
e8638058 39400001 38c00004 7fa4eb78 99490000 480004c5 e8410018 <0fe00000>
4bffff18 3860fff4 4bffff8c
[Wed Nov 15 14:01:07 2023] ---[ end trace 0000000000000000 ]---
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings
2023-11-15 19:07 ` matoro
@ 2023-11-19 23:14 ` Michael Ellerman
0 siblings, 0 replies; 5+ messages in thread
From: Michael Ellerman @ 2023-11-19 23:14 UTC (permalink / raw)
To: matoro
Cc: linuxppc-dev, Aneesh Kumar K.V, Jordan Niethe, Joel Stanley,
Mahesh Salgaonkar
matoro <matoro_mailinglist_kernel@matoro.tk> writes:
> On 2023-08-15 06:47, Michael Ellerman wrote:
>> Joel Stanley <joel@jms.id.au> writes:
>>> On Fri, 7 Jul 2023 at 05:11, Mahesh Salgaonkar <mahesh@linux.ibm.com>
>>> wrote:
>>>>
>>>> opal_prd_msg_notifier extracts the opal prd message size from the message
>>>> header and uses it for allocating opal_prd_msg_queue_item that includes
>>>> the correct message size to be copied. However, while running under
>>>> CONFIG_FORTIFY_SOURCE=y, it triggers following run-time warning:
>>>>
>>>> [ 6458.234352] memcpy: detected field-spanning write (size 32) of single
>>>> field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355 (size
>>>> 4)
>>>> [ 6458.234390] WARNING: CPU: 9 PID: 660 at
>>>> arch/powerpc/platforms/powernv/opal-prd.c:355
>>>> opal_prd_msg_notifier+0x174/0x188 [opal_prd]
>>>> [...]
>>>> [ 6458.234709] NIP [c00800000e0c0e6c] opal_prd_msg_notifier+0x174/0x188
>>>> [opal_prd]
>>>> [ 6458.234723] LR [c00800000e0c0e68] opal_prd_msg_notifier+0x170/0x188
>>>> [opal_prd]
>>>> [ 6458.234736] Call Trace:
>>>> [ 6458.234742] [c0000002acb23c10] [c00800000e0c0e68]
>>>> opal_prd_msg_notifier+0x170/0x188 [opal_prd] (unreliable)
>>>> [ 6458.234759] [c0000002acb23ca0] [c00000000019ccc0]
>>>> notifier_call_chain+0xc0/0x1b0
>>>> [ 6458.234774] [c0000002acb23d00] [c00000000019ceac]
>>>> atomic_notifier_call_chain+0x2c/0x40
>>>> [ 6458.234788] [c0000002acb23d20] [c0000000000d69b4]
>>>> opal_message_notify+0xf4/0x2c0
>>>> [...]
>>>>
>>>> Split the copy to avoid false positive run-time warning.
>>>>
>>>> Reported-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
>>>> Signed-off-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
>>>
>>> I hit this on a box running the Ubuntu 6.2.0-27-generic kernel.
>>>
>>> Do we plan on merging this fix?
>>
>> I thought it was papering over the issue rather than fixing the root
>> cause.
>>
>> I'll send a new version, as soon as I can work out how to trigger that
>> code path.
>>
>> cheers
>
> Hi, I see this was still not accepted. I was able to trigger this simply by
> starting the opal-prd userspace daemon.
> Restarting the service does not re-trigger the warning, however.
It should be fixed by:
https://git.kernel.org/torvalds/c/feea65a338e52297b68ceb688eaf0ffc50310a83
Which went into v6.6.
> [Wed Nov 15 14:01:06 2023] i2c_dev: i2c /dev entries driver
> [Wed Nov 15 14:01:07 2023] ------------[ cut here ]------------
> [Wed Nov 15 14:01:07 2023] memcpy: detected field-spanning write (size 32) of
> single field "&item->msg" at arch/powerpc/platforms/powernv/opal-prd.c:355
> (size 4)
> [Wed Nov 15 14:01:07 2023] WARNING: CPU: 5 PID: 379 at
> arch/powerpc/platforms/powernv/opal-prd.c:355 0xc008000000640b1c
> [Wed Nov 15 14:01:07 2023] Modules linked in: i2c_dev loop vhost_net vhost
> vhost_iotlb tap kvm_hv kvm bridge rpcsec_gss_krb5 auth_rpcgss tun nfsv4
> dns_resolver nfs lockd grace sunrpc fscache netfs cfg80211 rfkill 8021q garp
> mrp stp llc nft_masq nft_chain_nat nft_reject_inet nf_reject_ipv4
> nf_reject_ipv6 nft_reject nft_ct binfmt_misc nbd wireguard
> libcurve25519_generic ip6_udp_tunnel udp_tunnel nft_nat nf_tables nfnetlink
> nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 at24 ast i2c_algo_bit
> drm_shmem_helper joydev ftdi_sio crct10dif_vpmsum onboard_usb_hub ofpart
> drm_kms_helper ipmi_powernv rtc_opal ipmi_devintf powernv_flash
> ipmi_msghandler mtd opal_prd i2c_opal vmx_crypto nvme crc32c_vpmsum tg3
> nvme_core ixgbe nvme_common mdio
> [Wed Nov 15 14:01:07 2023] CPU: 5 PID: 379 Comm: kopald Not tainted
> 6.5.9-gentoo-dist #1
I'll request a back port of the fix to 6.5 stable.
cheers
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2023-11-19 23:15 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz follow: Atom feed
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2023-07-07 5:10 [PATCH v2] powernv/opal-prd: Silence memcpy() run-time false positive warnings Mahesh Salgaonkar
2023-08-11 12:36 ` Joel Stanley
2023-08-15 10:47 ` Michael Ellerman
2023-11-15 19:07 ` matoro
2023-11-19 23:14 ` Michael Ellerman
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