| Message ID | 20241219115209.574065-1-linmiaohe@huawei.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] mm/memory-failure: fix VM_BUG_ON_PAGE(PagePoisoned(page)) when unpoison memory | expand |
On 19.12.24 12:52, Miaohe Lin wrote: > When I did memory failure tests recently, below panic occurs: > > page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) > kernel BUG at include/linux/page-flags.h:616! > Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI > CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 > RIP: 0010:unpoison_memory+0x2f3/0x590 > RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 > RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 > RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb > R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 > R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe > FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 > Call Trace: > <TASK> > unpoison_memory+0x2f3/0x590 > simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 > debugfs_attr_write+0x42/0x60 > full_proxy_write+0x5b/0x80 > vfs_write+0xd5/0x540 > ksys_write+0x64/0xe0 > do_syscall_64+0xb9/0x1d0 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > RIP: 0033:0x7f08f0314887 > RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 > RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 > RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 > RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 > R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 > </TASK> > Modules linked in: hwpoison_inject > ---[ end trace 0000000000000000 ]--- > RIP: 0010:unpoison_memory+0x2f3/0x590 > RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 > RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 > RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 > RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb > R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 > R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe > FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 > Kernel panic - not syncing: Fatal exception > Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) > ---[ end Kernel panic - not syncing: Fatal exception ]--- > > The root cause is that unpoison_memory() tries to check the PG_HWPoison > flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is > triggered. This can be reproduced by below steps: > 1.Offline memory block: > echo offline > /sys/devices/system/memory/memory12/state > 2.Get offlined memory pfn: > page-types -b n -rlN > 3.Write pfn to unpoison-pfn > echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn > > Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> > --- > v2: Use pfn_to_online_page per David. Thanks. > --- > mm/memory-failure.c | 14 +++++++++++--- > 1 file changed, 11 insertions(+), 3 deletions(-) > > diff --git a/mm/memory-failure.c b/mm/memory-failure.c > index a7b8ccd29b6f..02be0596ce67 100644 > --- a/mm/memory-failure.c > +++ b/mm/memory-failure.c > @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) > static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, > DEFAULT_RATELIMIT_BURST); > > - if (!pfn_valid(pfn)) > - return -ENXIO; > + p = pfn_to_online_page(pfn); > + if (!p) { > + struct dev_pagemap *pgmap; > > - p = pfn_to_page(pfn); > + if (!pfn_valid(pfn)) > + return -ENXIO; > + pgmap = get_dev_pagemap(pfn, NULL); > + if (!pgmap) > + return -ENXIO; > + put_dev_pagemap(pgmap); > + p = pfn_to_page(pfn); > + } Hm, I wonder if we can do anything reasonable with ZONE_DEVICE pages here? CCing Dan, maybe he knows if this interface used to do something reasonable with ZONE_DEVICE pages. Also, I'm not sure about using the page after doing the put_dev_pagemap(). Likely we would have to do that at the before exiting from this function.
On 2024/12/19 20:18, David Hildenbrand wrote: > On 19.12.24 12:52, Miaohe Lin wrote: >> When I did memory failure tests recently, below panic occurs: >> >> page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) >> kernel BUG at include/linux/page-flags.h:616! >> Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >> CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 >> RIP: 0010:unpoison_memory+0x2f3/0x590 >> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >> Call Trace: >> <TASK> >> unpoison_memory+0x2f3/0x590 >> simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 >> debugfs_attr_write+0x42/0x60 >> full_proxy_write+0x5b/0x80 >> vfs_write+0xd5/0x540 >> ksys_write+0x64/0xe0 >> do_syscall_64+0xb9/0x1d0 >> entry_SYSCALL_64_after_hwframe+0x77/0x7f >> RIP: 0033:0x7f08f0314887 >> RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >> RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 >> RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 >> RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff >> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 >> R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 >> </TASK> >> Modules linked in: hwpoison_inject >> ---[ end trace 0000000000000000 ]--- >> RIP: 0010:unpoison_memory+0x2f3/0x590 >> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >> Kernel panic - not syncing: Fatal exception >> Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) >> ---[ end Kernel panic - not syncing: Fatal exception ]--- >> >> The root cause is that unpoison_memory() tries to check the PG_HWPoison >> flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is >> triggered. This can be reproduced by below steps: >> 1.Offline memory block: >> echo offline > /sys/devices/system/memory/memory12/state >> 2.Get offlined memory pfn: >> page-types -b n -rlN >> 3.Write pfn to unpoison-pfn >> echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn >> >> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >> --- >> v2: Use pfn_to_online_page per David. Thanks. >> --- >> mm/memory-failure.c | 14 +++++++++++--- >> 1 file changed, 11 insertions(+), 3 deletions(-) >> >> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >> index a7b8ccd29b6f..02be0596ce67 100644 >> --- a/mm/memory-failure.c >> +++ b/mm/memory-failure.c >> @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) >> static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, >> DEFAULT_RATELIMIT_BURST); >> - if (!pfn_valid(pfn)) >> - return -ENXIO; >> + p = pfn_to_online_page(pfn); >> + if (!p) { >> + struct dev_pagemap *pgmap; >> - p = pfn_to_page(pfn); >> + if (!pfn_valid(pfn)) >> + return -ENXIO; >> + pgmap = get_dev_pagemap(pfn, NULL); >> + if (!pgmap) >> + return -ENXIO; >> + put_dev_pagemap(pgmap); >> + p = pfn_to_page(pfn); >> + } > > Hm, I wonder if we can do anything reasonable with ZONE_DEVICE pages here? All I can see in unpoison_memory() is folio_test_clear_hwpoison() for ZONE_DEVICE pages. > > CCing Dan, maybe he knows if this interface used to do something reasonable with ZONE_DEVICE pages. > > Also, I'm not sure about using the page after doing the put_dev_pagemap(). Likely we would have to do that at the before exiting from this function. IMHO, the page can be used after doing put_dev_pagemap(). The page should still be available while it has HWPoison set. Or are you worrying about memory offline? That might not be the scope of this problem. But I might be miss something. Thanks. .
On 20.12.24 03:35, Miaohe Lin wrote: > On 2024/12/19 20:18, David Hildenbrand wrote: >> On 19.12.24 12:52, Miaohe Lin wrote: >>> When I did memory failure tests recently, below panic occurs: >>> >>> page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) >>> kernel BUG at include/linux/page-flags.h:616! >>> Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >>> CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 >>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>> Call Trace: >>> <TASK> >>> unpoison_memory+0x2f3/0x590 >>> simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 >>> debugfs_attr_write+0x42/0x60 >>> full_proxy_write+0x5b/0x80 >>> vfs_write+0xd5/0x540 >>> ksys_write+0x64/0xe0 >>> do_syscall_64+0xb9/0x1d0 >>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>> RIP: 0033:0x7f08f0314887 >>> RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >>> RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 >>> RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 >>> RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff >>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 >>> R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 >>> </TASK> >>> Modules linked in: hwpoison_inject >>> ---[ end trace 0000000000000000 ]--- >>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>> Kernel panic - not syncing: Fatal exception >>> Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) >>> ---[ end Kernel panic - not syncing: Fatal exception ]--- >>> >>> The root cause is that unpoison_memory() tries to check the PG_HWPoison >>> flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is >>> triggered. This can be reproduced by below steps: >>> 1.Offline memory block: >>> echo offline > /sys/devices/system/memory/memory12/state >>> 2.Get offlined memory pfn: >>> page-types -b n -rlN >>> 3.Write pfn to unpoison-pfn >>> echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn >>> >>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>> --- >>> v2: Use pfn_to_online_page per David. Thanks. >>> --- >>> mm/memory-failure.c | 14 +++++++++++--- >>> 1 file changed, 11 insertions(+), 3 deletions(-) >>> >>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>> index a7b8ccd29b6f..02be0596ce67 100644 >>> --- a/mm/memory-failure.c >>> +++ b/mm/memory-failure.c >>> @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) >>> static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, >>> DEFAULT_RATELIMIT_BURST); >>> - if (!pfn_valid(pfn)) >>> - return -ENXIO; >>> + p = pfn_to_online_page(pfn); >>> + if (!p) { >>> + struct dev_pagemap *pgmap; >>> - p = pfn_to_page(pfn); >>> + if (!pfn_valid(pfn)) >>> + return -ENXIO; >>> + pgmap = get_dev_pagemap(pfn, NULL); >>> + if (!pgmap) >>> + return -ENXIO; >>> + put_dev_pagemap(pgmap); >>> + p = pfn_to_page(pfn); >>> + } >> >> Hm, I wonder if we can do anything reasonable with ZONE_DEVICE pages here? > > All I can see in unpoison_memory() is folio_test_clear_hwpoison() for ZONE_DEVICE pages. IIRC, it can only be triggered via debugfs in special kernel configs. So chances are this was never ever actually run against a ZONE_DEVICE page. > >> >> CCing Dan, maybe he knows if this interface used to do something reasonable with ZONE_DEVICE pages. >> >> Also, I'm not sure about using the page after doing the put_dev_pagemap(). Likely we would have to do that at the before exiting from this function. > > IMHO, the page can be used after doing put_dev_pagemap(). The page should still be > available while it has HWPoison set. 1) Why do you think it can be used afterwards? :) 2) At that point in time you don't even know yet if the page is HWPoisoned! That check is performed later 3) From GUP code, I recall that we must keep the pagemap referenced until we grabbed a page/folio reference. Or are you worrying about memory offline? That > might not be the scope of this problem. But I might be miss something. I suspect unpoison_memory() doesn't do with ZONE_DEVICE pages what it should be doing. Maybe I'm wrong, it would be great to get feedback from Dan.
On 2024/12/20 16:50, David Hildenbrand wrote: > On 20.12.24 03:35, Miaohe Lin wrote: >> On 2024/12/19 20:18, David Hildenbrand wrote: >>> On 19.12.24 12:52, Miaohe Lin wrote: >>>> When I did memory failure tests recently, below panic occurs: >>>> >>>> page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) >>>> kernel BUG at include/linux/page-flags.h:616! >>>> Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >>>> CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 >>>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>>> Call Trace: >>>> <TASK> >>>> unpoison_memory+0x2f3/0x590 >>>> simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 >>>> debugfs_attr_write+0x42/0x60 >>>> full_proxy_write+0x5b/0x80 >>>> vfs_write+0xd5/0x540 >>>> ksys_write+0x64/0xe0 >>>> do_syscall_64+0xb9/0x1d0 >>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>>> RIP: 0033:0x7f08f0314887 >>>> RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >>>> RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 >>>> RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 >>>> RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff >>>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 >>>> R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 >>>> </TASK> >>>> Modules linked in: hwpoison_inject >>>> ---[ end trace 0000000000000000 ]--- >>>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>>> Kernel panic - not syncing: Fatal exception >>>> Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) >>>> ---[ end Kernel panic - not syncing: Fatal exception ]--- >>>> >>>> The root cause is that unpoison_memory() tries to check the PG_HWPoison >>>> flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is >>>> triggered. This can be reproduced by below steps: >>>> 1.Offline memory block: >>>> echo offline > /sys/devices/system/memory/memory12/state >>>> 2.Get offlined memory pfn: >>>> page-types -b n -rlN >>>> 3.Write pfn to unpoison-pfn >>>> echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn >>>> >>>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>>> --- >>>> v2: Use pfn_to_online_page per David. Thanks. >>>> --- >>>> mm/memory-failure.c | 14 +++++++++++--- >>>> 1 file changed, 11 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>>> index a7b8ccd29b6f..02be0596ce67 100644 >>>> --- a/mm/memory-failure.c >>>> +++ b/mm/memory-failure.c >>>> @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) >>>> static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, >>>> DEFAULT_RATELIMIT_BURST); >>>> - if (!pfn_valid(pfn)) >>>> - return -ENXIO; >>>> + p = pfn_to_online_page(pfn); >>>> + if (!p) { >>>> + struct dev_pagemap *pgmap; >>>> - p = pfn_to_page(pfn); >>>> + if (!pfn_valid(pfn)) >>>> + return -ENXIO; >>>> + pgmap = get_dev_pagemap(pfn, NULL); >>>> + if (!pgmap) >>>> + return -ENXIO; >>>> + put_dev_pagemap(pgmap); >>>> + p = pfn_to_page(pfn); >>>> + } >>> >>> Hm, I wonder if we can do anything reasonable with ZONE_DEVICE pages here? >> >> All I can see in unpoison_memory() is folio_test_clear_hwpoison() for ZONE_DEVICE pages. > > IIRC, it can only be triggered via debugfs in special kernel configs. So chances are this was never ever actually run against a ZONE_DEVICE page. If ZONE_DEVICE pages are never expected, we can simply filter them out. > >> >>> >>> CCing Dan, maybe he knows if this interface used to do something reasonable with ZONE_DEVICE pages. >>> >>> Also, I'm not sure about using the page after doing the put_dev_pagemap(). Likely we would have to do that at the before exiting from this function. >> >> IMHO, the page can be used after doing put_dev_pagemap(). The page should still be >> available while it has HWPoison set. > > 1) Why do you think it can be used afterwards? :) > > 2) At that point in time you don't even know yet if the page is > HWPoisoned! That check is performed later > > 3) From GUP code, I recall that we must keep the pagemap referenced > until we grabbed a page/folio reference. I think you're right, David. I missed this case. :) Thanks. . > > Or are you worrying about memory offline? That >> might not be the scope of this problem. But I might be miss something. > > I suspect unpoison_memory() doesn't do with ZONE_DEVICE pages what it should be doing. Maybe I'm wrong, it would be great to get feedback from Dan. > >
On 23.12.24 03:55, Miaohe Lin wrote: > On 2024/12/20 16:50, David Hildenbrand wrote: >> On 20.12.24 03:35, Miaohe Lin wrote: >>> On 2024/12/19 20:18, David Hildenbrand wrote: >>>> On 19.12.24 12:52, Miaohe Lin wrote: >>>>> When I did memory failure tests recently, below panic occurs: >>>>> >>>>> page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) >>>>> kernel BUG at include/linux/page-flags.h:616! >>>>> Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >>>>> CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 >>>>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>>>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>>>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>>>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>>>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>>>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>>>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>>>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>>>> Call Trace: >>>>> <TASK> >>>>> unpoison_memory+0x2f3/0x590 >>>>> simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 >>>>> debugfs_attr_write+0x42/0x60 >>>>> full_proxy_write+0x5b/0x80 >>>>> vfs_write+0xd5/0x540 >>>>> ksys_write+0x64/0xe0 >>>>> do_syscall_64+0xb9/0x1d0 >>>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>>>> RIP: 0033:0x7f08f0314887 >>>>> RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >>>>> RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 >>>>> RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 >>>>> RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff >>>>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 >>>>> R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 >>>>> </TASK> >>>>> Modules linked in: hwpoison_inject >>>>> ---[ end trace 0000000000000000 ]--- >>>>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>>>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>>>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>>>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>>>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>>>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>>>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>>>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>>>> Kernel panic - not syncing: Fatal exception >>>>> Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) >>>>> ---[ end Kernel panic - not syncing: Fatal exception ]--- >>>>> >>>>> The root cause is that unpoison_memory() tries to check the PG_HWPoison >>>>> flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is >>>>> triggered. This can be reproduced by below steps: >>>>> 1.Offline memory block: >>>>> echo offline > /sys/devices/system/memory/memory12/state >>>>> 2.Get offlined memory pfn: >>>>> page-types -b n -rlN >>>>> 3.Write pfn to unpoison-pfn >>>>> echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn >>>>> >>>>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>>>> --- >>>>> v2: Use pfn_to_online_page per David. Thanks. >>>>> --- >>>>> mm/memory-failure.c | 14 +++++++++++--- >>>>> 1 file changed, 11 insertions(+), 3 deletions(-) >>>>> >>>>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>>>> index a7b8ccd29b6f..02be0596ce67 100644 >>>>> --- a/mm/memory-failure.c >>>>> +++ b/mm/memory-failure.c >>>>> @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) >>>>> static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, >>>>> DEFAULT_RATELIMIT_BURST); >>>>> - if (!pfn_valid(pfn)) >>>>> - return -ENXIO; >>>>> + p = pfn_to_online_page(pfn); >>>>> + if (!p) { >>>>> + struct dev_pagemap *pgmap; >>>>> - p = pfn_to_page(pfn); >>>>> + if (!pfn_valid(pfn)) >>>>> + return -ENXIO; >>>>> + pgmap = get_dev_pagemap(pfn, NULL); >>>>> + if (!pgmap) >>>>> + return -ENXIO; >>>>> + put_dev_pagemap(pgmap); >>>>> + p = pfn_to_page(pfn); >>>>> + } >>>> >>>> Hm, I wonder if we can do anything reasonable with ZONE_DEVICE pages here? >>> >>> All I can see in unpoison_memory() is folio_test_clear_hwpoison() for ZONE_DEVICE pages. >> >> IIRC, it can only be triggered via debugfs in special kernel configs. So chances are this was never ever actually run against a ZONE_DEVICE page. > > If ZONE_DEVICE pages are never expected, we can simply filter them out. Looking into some details, I think we should just ignore ZONE_DEVICE for now, I'm pretty sure that it's not handled correctly. So I suggest to fail if pfn_to_online_page() == NULL, just like soft_offline_page() would.
On 2024/12/23 18:42, David Hildenbrand wrote: > On 23.12.24 03:55, Miaohe Lin wrote: >> On 2024/12/20 16:50, David Hildenbrand wrote: >>> On 20.12.24 03:35, Miaohe Lin wrote: >>>> On 2024/12/19 20:18, David Hildenbrand wrote: >>>>> On 19.12.24 12:52, Miaohe Lin wrote: >>>>>> When I did memory failure tests recently, below panic occurs: >>>>>> >>>>>> page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) >>>>>> kernel BUG at include/linux/page-flags.h:616! >>>>>> Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI >>>>>> CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 >>>>>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>>>>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>>>>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>>>>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>>>>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>>>>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>>>>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>>>>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>>>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>>>>> Call Trace: >>>>>> <TASK> >>>>>> unpoison_memory+0x2f3/0x590 >>>>>> simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 >>>>>> debugfs_attr_write+0x42/0x60 >>>>>> full_proxy_write+0x5b/0x80 >>>>>> vfs_write+0xd5/0x540 >>>>>> ksys_write+0x64/0xe0 >>>>>> do_syscall_64+0xb9/0x1d0 >>>>>> entry_SYSCALL_64_after_hwframe+0x77/0x7f >>>>>> RIP: 0033:0x7f08f0314887 >>>>>> RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 >>>>>> RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 >>>>>> RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 >>>>>> RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff >>>>>> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 >>>>>> R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 >>>>>> </TASK> >>>>>> Modules linked in: hwpoison_inject >>>>>> ---[ end trace 0000000000000000 ]--- >>>>>> RIP: 0010:unpoison_memory+0x2f3/0x590 >>>>>> RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 >>>>>> RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 >>>>>> RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 >>>>>> RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb >>>>>> R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 >>>>>> R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe >>>>>> FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 >>>>>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>>>>> CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 >>>>>> Kernel panic - not syncing: Fatal exception >>>>>> Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) >>>>>> ---[ end Kernel panic - not syncing: Fatal exception ]--- >>>>>> >>>>>> The root cause is that unpoison_memory() tries to check the PG_HWPoison >>>>>> flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is >>>>>> triggered. This can be reproduced by below steps: >>>>>> 1.Offline memory block: >>>>>> echo offline > /sys/devices/system/memory/memory12/state >>>>>> 2.Get offlined memory pfn: >>>>>> page-types -b n -rlN >>>>>> 3.Write pfn to unpoison-pfn >>>>>> echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn >>>>>> >>>>>> Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> >>>>>> --- >>>>>> v2: Use pfn_to_online_page per David. Thanks. >>>>>> --- >>>>>> mm/memory-failure.c | 14 +++++++++++--- >>>>>> 1 file changed, 11 insertions(+), 3 deletions(-) >>>>>> >>>>>> diff --git a/mm/memory-failure.c b/mm/memory-failure.c >>>>>> index a7b8ccd29b6f..02be0596ce67 100644 >>>>>> --- a/mm/memory-failure.c >>>>>> +++ b/mm/memory-failure.c >>>>>> @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) >>>>>> static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, >>>>>> DEFAULT_RATELIMIT_BURST); >>>>>> - if (!pfn_valid(pfn)) >>>>>> - return -ENXIO; >>>>>> + p = pfn_to_online_page(pfn); >>>>>> + if (!p) { >>>>>> + struct dev_pagemap *pgmap; >>>>>> - p = pfn_to_page(pfn); >>>>>> + if (!pfn_valid(pfn)) >>>>>> + return -ENXIO; >>>>>> + pgmap = get_dev_pagemap(pfn, NULL); >>>>>> + if (!pgmap) >>>>>> + return -ENXIO; >>>>>> + put_dev_pagemap(pgmap); >>>>>> + p = pfn_to_page(pfn); >>>>>> + } >>>>> >>>>> Hm, I wonder if we can do anything reasonable with ZONE_DEVICE pages here? >>>> >>>> All I can see in unpoison_memory() is folio_test_clear_hwpoison() for ZONE_DEVICE pages. >>> >>> IIRC, it can only be triggered via debugfs in special kernel configs. So chances are this was never ever actually run against a ZONE_DEVICE page. >> >> If ZONE_DEVICE pages are never expected, we can simply filter them out. > > Looking into some details, I think we should just ignore ZONE_DEVICE for now, I'm pretty sure that it's not handled correctly. > > So I suggest to fail if pfn_to_online_page() == NULL, just like soft_offline_page() would. I think current code doesn't take ZONE_DEVICE pages into account. So I tend to ignore them too. But let's wait some time for input from Dan. Thanks. .
diff --git a/mm/memory-failure.c b/mm/memory-failure.c index a7b8ccd29b6f..02be0596ce67 100644 --- a/mm/memory-failure.c +++ b/mm/memory-failure.c @@ -2556,10 +2556,18 @@ int unpoison_memory(unsigned long pfn) static DEFINE_RATELIMIT_STATE(unpoison_rs, DEFAULT_RATELIMIT_INTERVAL, DEFAULT_RATELIMIT_BURST); - if (!pfn_valid(pfn)) - return -ENXIO; + p = pfn_to_online_page(pfn); + if (!p) { + struct dev_pagemap *pgmap; - p = pfn_to_page(pfn); + if (!pfn_valid(pfn)) + return -ENXIO; + pgmap = get_dev_pagemap(pfn, NULL); + if (!pgmap) + return -ENXIO; + put_dev_pagemap(pgmap); + p = pfn_to_page(pfn); + } folio = page_folio(p); mutex_lock(&mf_mutex);
When I did memory failure tests recently, below panic occurs: page dumped because: VM_BUG_ON_PAGE(PagePoisoned(page)) kernel BUG at include/linux/page-flags.h:616! Oops: invalid opcode: 0000 [#1] PREEMPT SMP NOPTI CPU: 3 PID: 720 Comm: bash Not tainted 6.10.0-rc1-00195-g148743902568 #40 RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Call Trace: <TASK> unpoison_memory+0x2f3/0x590 simple_attr_write_xsigned.constprop.0.isra.0+0xb3/0x110 debugfs_attr_write+0x42/0x60 full_proxy_write+0x5b/0x80 vfs_write+0xd5/0x540 ksys_write+0x64/0xe0 do_syscall_64+0xb9/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f08f0314887 RSP: 002b:00007ffece710078 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000009 RCX: 00007f08f0314887 RDX: 0000000000000009 RSI: 0000564787a30410 RDI: 0000000000000001 RBP: 0000564787a30410 R08: 000000000000fefe R09: 000000007fffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000009 R13: 00007f08f041b780 R14: 00007f08f0417600 R15: 00007f08f0416a00 </TASK> Modules linked in: hwpoison_inject ---[ end trace 0000000000000000 ]--- RIP: 0010:unpoison_memory+0x2f3/0x590 RSP: 0018:ffffa57fc8787d60 EFLAGS: 00000246 RAX: 0000000000000037 RBX: 0000000000000009 RCX: ffff9be25fcdc9c8 RDX: 0000000000000000 RSI: 0000000000000027 RDI: ffff9be25fcdc9c0 RBP: 0000000000300000 R08: ffffffffb4956f88 R09: 0000000000009ffb R10: 0000000000000284 R11: ffffffffb4926fa0 R12: ffffe6b00c000000 R13: ffff9bdb453dfd00 R14: 0000000000000000 R15: fffffffffffffffe FS: 00007f08f04e4740(0000) GS:ffff9be25fcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000564787a30410 CR3: 000000010d4e2000 CR4: 00000000000006f0 Kernel panic - not syncing: Fatal exception Kernel Offset: 0x31c00000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) ---[ end Kernel panic - not syncing: Fatal exception ]--- The root cause is that unpoison_memory() tries to check the PG_HWPoison flags of an uninitialized page. So VM_BUG_ON_PAGE(PagePoisoned(page)) is triggered. This can be reproduced by below steps: 1.Offline memory block: echo offline > /sys/devices/system/memory/memory12/state 2.Get offlined memory pfn: page-types -b n -rlN 3.Write pfn to unpoison-pfn echo <pfn> > /sys/kernel/debug/hwpoison/unpoison-pfn Signed-off-by: Miaohe Lin <linmiaohe@huawei.com> --- v2: Use pfn_to_online_page per David. Thanks. --- mm/memory-failure.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)