From: Wei Yang <[email protected]>
When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
doesn't work before sparse_init_one_section() is called. This leads to a
crash when hotplug memory:
[ 41.839170] BUG: unable to handle page fault for address: 0000000006400000
[ 41.840663] #PF: supervisor write access in kernel mode
[ 41.841822] #PF: error_code(0x0002) - not-present page
[ 41.842970] PGD 0 P4D 0
[ 41.843538] Oops: 0002 [#1] SMP PTI
[ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343
[ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
[ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
[ 41.847904] RIP: 0010:__memset+0x24/0x30
[ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3
[ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87
[ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000
[ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000
[ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000
[ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
[ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280
[ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000
[ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0
[ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 41.863628] Call Trace:
[ 41.863983] sparse_add_section+0x1c9/0x26a
[ 41.864570] __add_pages+0xbf/0x150
[ 41.865057] add_pages+0x12/0x60
[ 41.865489] add_memory_resource+0xc8/0x210
[ 41.866017] ? wake_up_q+0xa0/0xa0
[ 41.866416] __add_memory+0x62/0xb0
[ 41.866825] acpi_memory_device_add+0x13f/0x300
[ 41.867410] acpi_bus_attach+0xf6/0x200
[ 41.867890] acpi_bus_scan+0x43/0x90
[ 41.868448] acpi_device_hotplug+0x275/0x3d0
[ 41.868972] acpi_hotplug_work_fn+0x1a/0x30
[ 41.869473] process_one_work+0x1a7/0x370
[ 41.869953] worker_thread+0x30/0x380
[ 41.870396] ? flush_rcu_work+0x30/0x30
[ 41.870846] kthread+0x112/0x130
[ 41.871236] ? kthread_create_on_node+0x60/0x60
[ 41.871770] ret_from_fork+0x35/0x40
We should use memmap as it did.
Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
Signed-off-by: Wei Yang <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Reviewed-by: Baoquan He <[email protected]>
CC: Dan Williams <[email protected]>
---
v1->v2:
Add trace printed by triggered bug to log.
v1 can be found here:
http://lkml.kernel.org/r/[email protected]
mm/sparse.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/mm/sparse.c b/mm/sparse.c
index c184b69460b7..596b2a45b100 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -876,7 +876,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn,
* Poison uninitialized struct pages in order to catch invalid flags
* combinations.
*/
- page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages);
+ page_init_poison(memmap, sizeof(struct page) * nr_pages);
ms = __nr_to_section(section_nr);
set_section_nid(section_nr, nid);
--
2.17.2
On Tue, Feb 18, 2020 at 7:05 PM Baoquan He <[email protected]> wrote:
>
> From: Wei Yang <[email protected]>
>
> When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> doesn't work before sparse_init_one_section() is called. This leads to a
> crash when hotplug memory:
I'd also add:
"On x86 the impact is limited to x86_32 builds, or x86_64
configurations that override the default setting for
SPARSEMEM_VMEMMAP".
Other than that:
Reviewed-by: Dan Williams <[email protected]>
On 02/18/20 at 07:25pm, Dan Williams wrote:
> On Tue, Feb 18, 2020 at 7:05 PM Baoquan He <[email protected]> wrote:
> >
> > From: Wei Yang <[email protected]>
> >
> > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> > doesn't work before sparse_init_one_section() is called. This leads to a
> > crash when hotplug memory:
>
> I'd also add:
>
> "On x86 the impact is limited to x86_32 builds, or x86_64
> configurations that override the default setting for
> SPARSEMEM_VMEMMAP".
'When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP' in the current log
is a little duplicated with the overriding saying?
On Tue, Feb 18, 2020 at 07:25:15PM -0800, Dan Williams wrote:
> On Tue, Feb 18, 2020 at 7:05 PM Baoquan He <[email protected]> wrote:
> >
> > From: Wei Yang <[email protected]>
> >
> > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> > doesn't work before sparse_init_one_section() is called. This leads to a
> > crash when hotplug memory:
>
> I'd also add:
>
> "On x86 the impact is limited to x86_32 builds, or x86_64
> configurations that override the default setting for
> SPARSEMEM_VMEMMAP".
Do we also want to check how it affects, say, arm64, ia64 and ppc? ;-)
> Other than that:
>
> Reviewed-by: Dan Williams <[email protected]>
>
--
Sincerely yours,
Mike.
On Wed, Feb 19, 2020 at 12:57 AM Mike Rapoport <[email protected]> wrote:
>
> On Tue, Feb 18, 2020 at 07:25:15PM -0800, Dan Williams wrote:
> > On Tue, Feb 18, 2020 at 7:05 PM Baoquan He <[email protected]> wrote:
> > >
> > > From: Wei Yang <[email protected]>
> > >
> > > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> > > doesn't work before sparse_init_one_section() is called. This leads to a
> > > crash when hotplug memory:
> >
> > I'd also add:
> >
> > "On x86 the impact is limited to x86_32 builds, or x86_64
> > configurations that override the default setting for
> > SPARSEMEM_VMEMMAP".
>
> Do we also want to check how it affects, say, arm64, ia64 and ppc? ;-)
Sure, I just did not take the time to look up their respective default
stances on SPARSEMEM_VMEMMAP. For a distro looking to backport this
commit I think it's helpful for them to understand if they are exposed
or not.
On Wed, Feb 19, 2020 at 08:37:25AM -0800, Dan Williams wrote:
> On Wed, Feb 19, 2020 at 12:57 AM Mike Rapoport <[email protected]> wrote:
> >
> > On Tue, Feb 18, 2020 at 07:25:15PM -0800, Dan Williams wrote:
> > > On Tue, Feb 18, 2020 at 7:05 PM Baoquan He <[email protected]> wrote:
> > > >
> > > > From: Wei Yang <[email protected]>
> > > >
> > > > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> > > > doesn't work before sparse_init_one_section() is called. This leads to a
> > > > crash when hotplug memory:
> > >
> > > I'd also add:
> > >
> > > "On x86 the impact is limited to x86_32 builds, or x86_64
> > > configurations that override the default setting for
> > > SPARSEMEM_VMEMMAP".
> >
> > Do we also want to check how it affects, say, arm64, ia64 and ppc? ;-)
>
> Sure, I just did not take the time to look up their respective default
> stances on SPARSEMEM_VMEMMAP. For a distro looking to backport this
> commit I think it's helpful for them to understand if they are exposed
> or not.
Looks like only i386_defconfig does not enable SPARSEMEM_VMEMMAP. All the
rest may have it disabled only with manual override.
--
Sincerely yours,
Mike.
On Wed, 19 Feb 2020 11:04:54 +0800 Baoquan He <[email protected]> wrote:
> From: Wei Yang <[email protected]>
>
> When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> doesn't work before sparse_init_one_section() is called. This leads to a
> crash when hotplug memory:
>
> [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000
> [ 41.840663] #PF: supervisor write access in kernel mode
> [ 41.841822] #PF: error_code(0x0002) - not-present page
> [ 41.842970] PGD 0 P4D 0
> [ 41.843538] Oops: 0002 [#1] SMP PTI
> [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343
> [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
> [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
> [ 41.847904] RIP: 0010:__memset+0x24/0x30
> [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3
> [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87
> [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000
> [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000
> [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000
> [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
> [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280
> [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000
> [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0
> [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [ 41.863628] Call Trace:
> [ 41.863983] sparse_add_section+0x1c9/0x26a
> [ 41.864570] __add_pages+0xbf/0x150
> [ 41.865057] add_pages+0x12/0x60
> [ 41.865489] add_memory_resource+0xc8/0x210
> [ 41.866017] ? wake_up_q+0xa0/0xa0
> [ 41.866416] __add_memory+0x62/0xb0
> [ 41.866825] acpi_memory_device_add+0x13f/0x300
> [ 41.867410] acpi_bus_attach+0xf6/0x200
> [ 41.867890] acpi_bus_scan+0x43/0x90
> [ 41.868448] acpi_device_hotplug+0x275/0x3d0
> [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30
> [ 41.869473] process_one_work+0x1a7/0x370
> [ 41.869953] worker_thread+0x30/0x380
> [ 41.870396] ? flush_rcu_work+0x30/0x30
> [ 41.870846] kthread+0x112/0x130
> [ 41.871236] ? kthread_create_on_node+0x60/0x60
> [ 41.871770] ret_from_fork+0x35/0x40
>
> We should use memmap as it did.
>
> Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
> Signed-off-by: Wei Yang <[email protected]>
> Acked-by: David Hildenbrand <[email protected]>
> Reviewed-by: Baoquan He <[email protected]>
> CC: Dan Williams <[email protected]>
This should have included your signed-off-by, as you were on the patch
delivery path. I have made that change to my copy of the patch - is
that OK?
I also added a cc:stable. Do we agree this is appropriate?
I added Dan's "On x86 the impact is limited to x86_32 builds, or x86_64
configurations that override the default setting for
SPARSEMEM_VMEMMAP." to the changelog.
On Wed, Feb 19, 2020 at 11:50 AM Andrew Morton
<[email protected]> wrote:
>
> On Wed, 19 Feb 2020 11:04:54 +0800 Baoquan He <[email protected]> wrote:
>
> > From: Wei Yang <[email protected]>
> >
> > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> > doesn't work before sparse_init_one_section() is called. This leads to a
> > crash when hotplug memory:
> >
> > [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000
> > [ 41.840663] #PF: supervisor write access in kernel mode
> > [ 41.841822] #PF: error_code(0x0002) - not-present page
> > [ 41.842970] PGD 0 P4D 0
> > [ 41.843538] Oops: 0002 [#1] SMP PTI
> > [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343
> > [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
> > [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
> > [ 41.847904] RIP: 0010:__memset+0x24/0x30
> > [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3
> > [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87
> > [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000
> > [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000
> > [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000
> > [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
> > [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280
> > [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000
> > [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0
> > [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > [ 41.863628] Call Trace:
> > [ 41.863983] sparse_add_section+0x1c9/0x26a
> > [ 41.864570] __add_pages+0xbf/0x150
> > [ 41.865057] add_pages+0x12/0x60
> > [ 41.865489] add_memory_resource+0xc8/0x210
> > [ 41.866017] ? wake_up_q+0xa0/0xa0
> > [ 41.866416] __add_memory+0x62/0xb0
> > [ 41.866825] acpi_memory_device_add+0x13f/0x300
> > [ 41.867410] acpi_bus_attach+0xf6/0x200
> > [ 41.867890] acpi_bus_scan+0x43/0x90
> > [ 41.868448] acpi_device_hotplug+0x275/0x3d0
> > [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30
> > [ 41.869473] process_one_work+0x1a7/0x370
> > [ 41.869953] worker_thread+0x30/0x380
> > [ 41.870396] ? flush_rcu_work+0x30/0x30
> > [ 41.870846] kthread+0x112/0x130
> > [ 41.871236] ? kthread_create_on_node+0x60/0x60
> > [ 41.871770] ret_from_fork+0x35/0x40
> >
> > We should use memmap as it did.
> >
> > Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
> > Signed-off-by: Wei Yang <[email protected]>
> > Acked-by: David Hildenbrand <[email protected]>
> > Reviewed-by: Baoquan He <[email protected]>
> > CC: Dan Williams <[email protected]>
>
> This should have included your signed-off-by, as you were on the patch
> delivery path. I have made that change to my copy of the patch - is
> that OK?
>
> I also added a cc:stable. Do we agree this is appropriate?
I see no harm.
> I added Dan's "On x86 the impact is limited to x86_32 builds, or x86_64
> configurations that override the default setting for
> SPARSEMEM_VMEMMAP." to the changelog.
Can also add with Mike's sleuthing. "Other memory hotplug archs
(arm64, ia64, and ppc) also default to SPARSEMEM_VMEMMAP=y."
On Wed, Feb 19, 2020 at 11:50:42AM -0800, Andrew Morton wrote:
>On Wed, 19 Feb 2020 11:04:54 +0800 Baoquan He <[email protected]> wrote:
>
>> From: Wei Yang <[email protected]>
>>
>> When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
>> doesn't work before sparse_init_one_section() is called. This leads to a
>> crash when hotplug memory:
>>
>> [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000
>> [ 41.840663] #PF: supervisor write access in kernel mode
>> [ 41.841822] #PF: error_code(0x0002) - not-present page
>> [ 41.842970] PGD 0 P4D 0
>> [ 41.843538] Oops: 0002 [#1] SMP PTI
>> [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343
>> [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
>> [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
>> [ 41.847904] RIP: 0010:__memset+0x24/0x30
>> [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3
>> [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87
>> [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000
>> [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000
>> [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000
>> [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
>> [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280
>> [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000
>> [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0
>> [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
>> [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
>> [ 41.863628] Call Trace:
>> [ 41.863983] sparse_add_section+0x1c9/0x26a
>> [ 41.864570] __add_pages+0xbf/0x150
>> [ 41.865057] add_pages+0x12/0x60
>> [ 41.865489] add_memory_resource+0xc8/0x210
>> [ 41.866017] ? wake_up_q+0xa0/0xa0
>> [ 41.866416] __add_memory+0x62/0xb0
>> [ 41.866825] acpi_memory_device_add+0x13f/0x300
>> [ 41.867410] acpi_bus_attach+0xf6/0x200
>> [ 41.867890] acpi_bus_scan+0x43/0x90
>> [ 41.868448] acpi_device_hotplug+0x275/0x3d0
>> [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30
>> [ 41.869473] process_one_work+0x1a7/0x370
>> [ 41.869953] worker_thread+0x30/0x380
>> [ 41.870396] ? flush_rcu_work+0x30/0x30
>> [ 41.870846] kthread+0x112/0x130
>> [ 41.871236] ? kthread_create_on_node+0x60/0x60
>> [ 41.871770] ret_from_fork+0x35/0x40
>>
>> We should use memmap as it did.
>>
>> Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
>> Signed-off-by: Wei Yang <[email protected]>
>> Acked-by: David Hildenbrand <[email protected]>
>> Reviewed-by: Baoquan He <[email protected]>
>> CC: Dan Williams <[email protected]>
>
>This should have included your signed-off-by, as you were on the patch
>delivery path. I have made that change to my copy of the patch - is
>that OK?
>
>I also added a cc:stable. Do we agree this is appropriate?
Agree with this.
>
>I added Dan's "On x86 the impact is limited to x86_32 builds, or x86_64
>configurations that override the default setting for
>SPARSEMEM_VMEMMAP." to the changelog.
--
Wei Yang
Help you, Help me
On 02/19/20 at 11:50am, Andrew Morton wrote:
> On Wed, 19 Feb 2020 11:04:54 +0800 Baoquan He <[email protected]> wrote:
>
> > From: Wei Yang <[email protected]>
> >
> > When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> > doesn't work before sparse_init_one_section() is called. This leads to a
> > crash when hotplug memory:
> >
> > [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000
> > [ 41.840663] #PF: supervisor write access in kernel mode
> > [ 41.841822] #PF: error_code(0x0002) - not-present page
> > [ 41.842970] PGD 0 P4D 0
> > [ 41.843538] Oops: 0002 [#1] SMP PTI
> > [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343
> > [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
> > [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
> > [ 41.847904] RIP: 0010:__memset+0x24/0x30
> > [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3
> > [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87
> > [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000
> > [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000
> > [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000
> > [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
> > [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280
> > [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000
> > [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> > [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0
> > [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> > [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> > [ 41.863628] Call Trace:
> > [ 41.863983] sparse_add_section+0x1c9/0x26a
> > [ 41.864570] __add_pages+0xbf/0x150
> > [ 41.865057] add_pages+0x12/0x60
> > [ 41.865489] add_memory_resource+0xc8/0x210
> > [ 41.866017] ? wake_up_q+0xa0/0xa0
> > [ 41.866416] __add_memory+0x62/0xb0
> > [ 41.866825] acpi_memory_device_add+0x13f/0x300
> > [ 41.867410] acpi_bus_attach+0xf6/0x200
> > [ 41.867890] acpi_bus_scan+0x43/0x90
> > [ 41.868448] acpi_device_hotplug+0x275/0x3d0
> > [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30
> > [ 41.869473] process_one_work+0x1a7/0x370
> > [ 41.869953] worker_thread+0x30/0x380
> > [ 41.870396] ? flush_rcu_work+0x30/0x30
> > [ 41.870846] kthread+0x112/0x130
> > [ 41.871236] ? kthread_create_on_node+0x60/0x60
> > [ 41.871770] ret_from_fork+0x35/0x40
> >
> > We should use memmap as it did.
> >
> > Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
> > Signed-off-by: Wei Yang <[email protected]>
> > Acked-by: David Hildenbrand <[email protected]>
> > Reviewed-by: Baoquan He <[email protected]>
> > CC: Dan Williams <[email protected]>
>
> This should have included your signed-off-by, as you were on the patch
> delivery path. I have made that change to my copy of the patch - is
> that OK?
OK, thanks.
>
> I also added a cc:stable. Do we agree this is appropriate?
Agree, this breakage happened since subsection hotplug.
>
> I added Dan's "On x86 the impact is limited to x86_32 builds, or x86_64
> configurations that override the default setting for
> SPARSEMEM_VMEMMAP." to the changelog.
Looks good, thanks.
On Wed 19-02-20 11:04:54, Baoquan He wrote:
> From: Wei Yang <[email protected]>
>
> When we use SPARSEMEM instead of SPARSEMEM_VMEMMAP, pfn_to_page()
> doesn't work before sparse_init_one_section() is called. This leads to a
> crash when hotplug memory:
>
> [ 41.839170] BUG: unable to handle page fault for address: 0000000006400000
> [ 41.840663] #PF: supervisor write access in kernel mode
> [ 41.841822] #PF: error_code(0x0002) - not-present page
> [ 41.842970] PGD 0 P4D 0
> [ 41.843538] Oops: 0002 [#1] SMP PTI
> [ 41.844125] CPU: 3 PID: 221 Comm: kworker/u16:1 Tainted: G W 5.5.0-next-20200205+ #343
> [ 41.845659] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.0.0 02/06/2015
> [ 41.846977] Workqueue: kacpi_hotplug acpi_hotplug_work_fn
> [ 41.847904] RIP: 0010:__memset+0x24/0x30
> [ 41.848660] Code: cc cc cc cc cc cc 0f 1f 44 00 00 49 89 f9 48 89 d1 83 e2 07 48 c1 e9 03 40 0f b6 f6 48 b8 01 01 01 01 01 01 01 01 48 0f af c6 <f3> 48 ab 89 d1 f3 aa 4c 89 c8 c3 90 49 89 f9 40 88 f0 48 89 d1 f3
> [ 41.851836] RSP: 0018:ffffb43ac0373c80 EFLAGS: 00010a87
> [ 41.852686] RAX: ffffffffffffffff RBX: ffff8a1518800000 RCX: 0000000000050000
> [ 41.853824] RDX: 0000000000000000 RSI: 00000000000000ff RDI: 0000000006400000
> [ 41.854967] RBP: 0000000000140000 R08: 0000000000100000 R09: 0000000006400000
> [ 41.856107] R10: 0000000000000000 R11: 0000000000000002 R12: 0000000000000000
> [ 41.857255] R13: 0000000000000028 R14: 0000000000000000 R15: ffff8a153ffd9280
> [ 41.858414] FS: 0000000000000000(0000) GS:ffff8a153ab00000(0000) knlGS:0000000000000000
> [ 41.859703] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> [ 41.860627] CR2: 0000000006400000 CR3: 0000000136fca000 CR4: 00000000000006e0
> [ 41.861716] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> [ 41.862680] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> [ 41.863628] Call Trace:
> [ 41.863983] sparse_add_section+0x1c9/0x26a
> [ 41.864570] __add_pages+0xbf/0x150
> [ 41.865057] add_pages+0x12/0x60
> [ 41.865489] add_memory_resource+0xc8/0x210
> [ 41.866017] ? wake_up_q+0xa0/0xa0
> [ 41.866416] __add_memory+0x62/0xb0
> [ 41.866825] acpi_memory_device_add+0x13f/0x300
> [ 41.867410] acpi_bus_attach+0xf6/0x200
> [ 41.867890] acpi_bus_scan+0x43/0x90
> [ 41.868448] acpi_device_hotplug+0x275/0x3d0
> [ 41.868972] acpi_hotplug_work_fn+0x1a/0x30
> [ 41.869473] process_one_work+0x1a7/0x370
> [ 41.869953] worker_thread+0x30/0x380
> [ 41.870396] ? flush_rcu_work+0x30/0x30
> [ 41.870846] kthread+0x112/0x130
> [ 41.871236] ? kthread_create_on_node+0x60/0x60
> [ 41.871770] ret_from_fork+0x35/0x40
>
> We should use memmap as it did.
>
> Fixes: ba72b4c8cf60 ("mm/sparsemem: support sub-section hotplug")
> Signed-off-by: Wei Yang <[email protected]>
> Acked-by: David Hildenbrand <[email protected]>
> Reviewed-by: Baoquan He <[email protected]>
> CC: Dan Williams <[email protected]>
Acked-by: Michal Hocko <[email protected]>
> ---
> v1->v2:
> Add trace printed by triggered bug to log.
>
> v1 can be found here:
> http://lkml.kernel.org/r/[email protected]
>
> mm/sparse.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/sparse.c b/mm/sparse.c
> index c184b69460b7..596b2a45b100 100644
> --- a/mm/sparse.c
> +++ b/mm/sparse.c
> @@ -876,7 +876,7 @@ int __meminit sparse_add_section(int nid, unsigned long start_pfn,
> * Poison uninitialized struct pages in order to catch invalid flags
> * combinations.
> */
> - page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages);
> + page_init_poison(memmap, sizeof(struct page) * nr_pages);
>
> ms = __nr_to_section(section_nr);
> set_section_nid(section_nr, nid);
> --
> 2.17.2
>
--
Michal Hocko
SUSE Labs