On 12/11/2013 05:59 PM, Vlastimil Babka wrote:
On 12/09/2013 09:26 PM, Sasha Levin wrote:
On 12/09/2013 12:12 PM, Vlastimil Babka wrote:
On 12/09/2013 06:05 PM, Sasha Levin wrote:
On 12/09/2013 04:34 AM, Vlastimil Babka wrote:
Hello, I will look at it, thanks.
Do you have specific reproduction instructions?
Not really, the fuzzer hit it once and I've been unable to trigger it again. Looking at
the piece of code involved it might have had something to do with hugetlbfs, so I'll crank
up testing on that part.
Thanks. Do you have trinity log and the .config file? I'm currently unable to even boot linux-next
with my config/setup due to a GPF.
Looking at code I wouldn't expect that it could encounter a tail page, without first encountering a
head page and skipping the whole huge page. At least in THP case, as TLB pages should be split when
a vma is split. As for hugetlbfs, it should be skipped for mlock/munlock operations completely. One
of these assumptions is probably failing here...
If it helps, I've added a dump_page() in case we hit a tail page there and got:
[ 980.172299] page:ffffea003e5e8040 count:0 mapcount:1 mapping: (null) index:0
x0
[ 980.173412] page flags: 0x2fffff80008000(tail)
I can also add anything else in there to get other debug output if you think of something else useful.
Please try the following. Thanks in advance.
[ 428.499889] page:ffffea003e5c0040 count:0 mapcount:4 mapping: (null) index:0x0
[ 428.499889] page flags: 0x2fffff80008000(tail)
[ 428.499889] start=140117131923456 pfn=16347137 orig_start=140117130543104 page_increm
=1 vm_start=140117130543104 vm_end=140117134688256 vm_flags=135266419
[ 428.499889] first_page pfn=16347136
[ 428.499889] page:ffffea003e5c0000 count:204 mapcount:44 mapping:ffff880fb5c466c1 inde
x:0x7f6f8fe00
[ 428.499889] page flags: 0x2fffff80084068(uptodate|lru|active|head|swapbacked)
[ 428.499889] pc:ffff880fcfb70000 pc->flags:2 pc->mem_cgroup:ffffc90006034000
[ 428.374171] 0000000000000000
[ 428.374171] 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ 428.374171] Call Trace:
[ 428.374171] [<ffffffff81283df9>] exit_mmap+0x59/0x170
[ 428.374171] [<ffffffff812b72d0>] ? __khugepaged_exit+0xe0/0x150
[ 428.374171] [<ffffffff812af89b>] ? kmem_cache_free+0x26b/0x370
[ 428.374171] [<ffffffff812b72d0>] ? __khugepaged_exit+0xe0/0x150
[ 428.374171] [<ffffffff8112e440>] mmput+0x70/0xe0
[ 428.374171] [<ffffffff8113246d>] exit_mm+0x18d/0x1a0
[ 428.374171] [<ffffffff811df625>] ? acct_collect+0x175/0x1b0
[ 428.374171] [<ffffffff811348df>] do_exit+0x26f/0x520
[ 428.374171] [<ffffffff81134c39>] do_group_exit+0xa9/0xe0
[ 428.374171] [<ffffffff81149d72>] get_signal_to_deliver+0x4e2/0x570
[ 428.374171] [<ffffffff8106cc3b>] do_signal+0x4b/0x120
[ 428.374171] [<ffffffff81176346>] ? vtime_account_user+0x96/0xb0
[ 428.374171] [<ffffffff843b0475>] ? _raw_spin_unlock+0x35/0x60
[ 428.374171] [<ffffffff81176346>] ? vtime_account_user+0x96/0xb0
[ 428.374171] [<ffffffff81249a58>] ? context_tracking_user_exit+0xb8/0x1d0
[ 428.374171] [<ffffffff8119376d>] ? trace_hardirqs_on+0xd/0x10
[ 428.374171] [<ffffffff8106cf9a>] do_notify_resume+0x5a/0xe0
[ 428.374171] [<ffffffff843b9d22>] int_signal+0x12/0x17
[ 428.374171] Code: 46 85 31 c0 e8 f9 60 12 03 48 8b 5b 30 48 c7 c7 b0 92 46 85 4a 8d 34 33 31 c0
48 c1 fe 06 e8 df 60 12 03 48 89 df e8 97 e1 fc ff <0f> 0b 0f 1f 44 00 00 eb fe 66 0f 1f 44 00 00 48
8b 03 66 85 c0
[ 428.374171] RIP [<ffffffff81282829>] munlock_vma_pages_range+0x109/0x240
[ 428.374171] RSP <ffff880f928edb38>
Thanks,
Sasha
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