Re: [BUG] User process tainting in linux-next tree

[Jeshwanth Kumar N K]

On Mon, Jun 30, 2014 at 2:12 AM, Borislav Petkov <bp@xxxxxxxxx> wrote:
> Hi,
>
> first of all, please do not top-post. Here's why:
>
> A: Because it messes up the order in which people normally read text.
> Q: Why is top-posting such a bad thing?
> A: Top-posting.
> Q: What is the most annoying thing in e-mail?

Looks bottom posting is better :). Thanks
>
>> Yes booted by increase the buffer length, but the ignore_loglevel is
>> running continously for 5 minutes.
>
> Huh, what? I can't parse that sentence above.

I will explain:
1. I have compiled kernel with LOG level 7.
2. You have mentioned to run with "log_buf_len=10M ignore_loglevel".
When I ran, the Error messages started splashing continuously, I
waited for 5 mins and tried to switch modes using Ctrl+alt+F1, no use.
3. The one I attached dmesg is only log_buf_len=500M (no ignore_loglevel).

>
> ignore_loglevel is another kernel cmdline parameter:
>
>         ignore_loglevel [KNL]
>                         Ignore loglevel setting - this will print /all/
>                         kernel messages to the console. Useful for debugging.
>                         We also add it as printk module parameter, so users
>                         could change it dynamically, usually by
>                         /sys/module/printk/parameters/ignore_loglevel.
>
>
>> So I ignored that and ran with
>> log_buf_len=500M ( because 10M also filled) only.
>>
>> When I copied the dmesg, the size was 76M, so I attached only first
>> 1500 lines. Please find in below link.
>>
>> https://bugzilla.kernel.org/show_bug.cgi?id=79171
>
> Ok, that's better. The warnings start spewing pretty early with the one
> below. Let's CC linux-mm.
>
> [    1.062658] registered taskstats version 1
> [    1.063400] ------------[ cut here ]------------
> [    1.063455] WARNING: CPU: 0 PID: 55 at kernel/res_counter.c:28 res_counter_uncharge_until+0x84/0x110()
> [    1.063513] Modules linked in:
> [    1.063516] CPU: 0 PID: 55 Comm: modprobe Not tainted 3.16.0-rc1-next-20140620+ #4
> [    1.063518] Hardware name: Dell Inc. Studio 1555/0C234M, BIOS A11 03/29/2010
> [    1.063520]  00000000 00000000 d34d7de4 c1648de3 00000000 d34d7e14 c105b74e c1822e40
> [    1.063524]  00000000 00000037 c183384f 0000001c c10dab24 c10dab24 d3c048c8 ffffffff
> [    1.063529]  00000000 d34d7e24 c105b812 00000009 00000000 d34d7e58 c10dab24 00000282
> [    1.063534] Call Trace:
> [    1.063538]  [<c1648de3>] dump_stack+0x41/0x52
> [    1.063541]  [<c105b74e>] warn_slowpath_common+0x7e/0xa0
> [    1.063543]  [<c10dab24>] ? res_counter_uncharge_until+0x84/0x110
> [    1.063546]  [<c10dab24>] ? res_counter_uncharge_until+0x84/0x110
> [    1.063548]  [<c105b812>] warn_slowpath_null+0x22/0x30
> [    1.063551]  [<c10dab24>] res_counter_uncharge_until+0x84/0x110
> [    1.063553]  [<c10dabc1>] res_counter_uncharge+0x11/0x20
> [    1.063557]  [<c117e975>] mem_cgroup_uncharge_end+0x85/0xa0
> [    1.063560]  [<c113acb1>] release_pages+0x71/0x1c0
> [    1.063563]  [<c1164072>] free_pages_and_swap_cache+0x92/0xb0
> [    1.063567]  [<c1151b63>] tlb_flush_mmu_free+0x23/0x40
> [    1.063570]  [<c11523cd>] tlb_flush_mmu+0x1d/0x30
> [    1.063572]  [<c11523f1>] tlb_finish_mmu+0x11/0x40
> [    1.063575]  [<c11588c7>] unmap_region+0x97/0xc0
> [    1.063577]  [<c1158c22>] ? vma_rb_erase+0xe2/0x1b0
> [    1.063580]  [<c115a8e3>] do_munmap+0x1c3/0x2d0
> [    1.063582]  [<c115aa27>] vm_munmap+0x37/0x50
> [    1.063584]  [<c115b710>] SyS_munmap+0x20/0x30
> [    1.063588]  [<c1650318>] sysenter_do_call+0x12/0x28
> [    1.063590] ---[ end trace 812035dd9a004e6c ]---
>
> --
> Regards/Gruss,
>     Boris.
>
> Sent from a fat crate under my desk. Formatting is fine.
> --



-- 
Regards
Jeshwanth Kumar N K
Bangalore, India
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