[CRIU] Error (pie-util-vdso.c:190): vdso: Not all dynamic entries are present
Dmitry Safonov
dsafonov at virtuozzo.com
Tue Jun 7 08:13:21 PDT 2016
On 06/07/2016 05:43 PM, Tycho Andersen wrote:
> Hi Dmitry,
>
> On Tue, Jun 07, 2016 at 03:53:47PM +0300, Dmitry Safonov wrote:
>> On 06/07/2016 03:40 PM, Dmitry Safonov wrote:
>>> On 06/07/2016 03:24 PM, Dmitry Safonov wrote:
>>>> On 06/07/2016 01:29 AM, Tycho Andersen wrote:
>>>>> Hi guys,
>>>>>
>>>>> With kernel 4.6 (and maybe earlier, although not with 4.4), I'm
>>>>> getting the error in the subject line. The full restore log is,
>>>>>
>>>>> (00.000044) File tty[8800:e] will be restored from inherit fd 5
>>>>> (00.004389) Pagemap is fully functional
>>>>> (00.004422) Found task size of 7ffffffff000
>>>>> (00.004489) cpu: fpu:1 fxsr:1 xsave:0
>>>>> (00.004590) vdso: Parsing at 7ffcc11ca000 7ffcc11cb000
>>>>> (00.004597) vdso: PT_LOAD p_vaddr: 0
>>>>> (00.004601) Error (pie-util-vdso.c:190): vdso: Not all dynamic entries
>>>>> are present
>>>>>
>>>>> The symptom is that the phdr we get for PT_DYNAMIC has p_filesz == 0,
>>>>> so the loop in parse_elf_dynamic() never executes.
>>>>>
>>>>> Any ideas?
>>>>>
>>>>
>>>> Hi Tycho!
>>>>
>>>> Could you try with the following diff?
>>>
>>> Oh, I guess, it will not work, according to docs:
>>>
>>> If p_memsz is greater than p_filesz, the memory range from
>>> (p_vaddr + p_filesz) to (p_vaddr + p_memsz) is zero-filled
>>> when the segment is loaded.
>>>
>>> Well, let me think.
>>>
>>
>> Oh, it would be nice, if you gave it a shot anyway -
>> this zero-padding is valid for loadable segments, not
>> dynamic.
>
> Sure,
>
> (00.000127) Probing sock diag modules
> (00.000198) Done probing
> (00.003191) ========================================
> (00.003233) Dumping processes (pid: 6554)
> (00.003243) ========================================
> (00.003276) Running pre-dump scripts
> (00.003351) Pagemap is fully functional
> (00.003392) Found anon-shmem device at 5
> (00.003410) Reset 14739's dirty tracking
> (00.003447) ... done
> (00.003480) Dirty track supported on kernel
> (00.003538) Found task size of 7ffffffff000
> (00.003579) irmap: Searching irmap cache in work dir
> (00.003609) No irmap-cache image
> (00.003627) irmap: Searching irmap cache in parent
> (00.003640) irmap: No irmap cache
> (00.003657) cpu: fpu:1 fxsr:1 xsave:0
> (00.003730) vdso: Parsing at 7fff6cdc7000 7fff6cdc8000
> (00.003742) vdso: PT_LOAD p_vaddr: 0
> (00.003750) vdso: Dynamic segment's file size 0, memory size 0
> (00.003757) Error (pie-util-vdso.c:194): vdso: Not all dynamic entries
> are present
> (00.003770) Unlock network
> (00.003783) Error (cr-dump.c:1600): Dumping FAILED.
Thanks.
>> And could you gave `uname -a` - so I could reproduce it in VM maybe?
>
> Sure, it's:
>
> Linux dev 4.6.0-8-generic #9 SMP Mon Jun 6 14:21:30 MDT 2016 x86_64 x86_64 x86_64 GNU/Linux
>
> which is really 66b7a6c3fa35ea617c60d938bd2028eb6141c2f0 from
> git://kernel.ubuntu.com/ubuntu/unstable.git
>
> I put the debs I built here:
>
> http://files.tycho.ws/tmp/vdso/
>
> if you want to just download those. Let me know if you want me to try
> something else.
Ok, I fetched your kernel.
Here is it:
[ubuntu-unstable]$ git checkout 66b7a6c3fa35ea617c60d938bd2028eb6141c2f0
[ubuntu-unstable]$ make clean
...
[ubuntu-unstable]$ make -j5 arch/x86/entry/vdso/
...
[ubuntu-unstable]$ readelf --program-headers arch/x86/entry/vdso/vdso64.so
Elf file type is EXEC (Executable file)
Entry point 0x5c0
There are 4 program headers, starting at offset 64
Program Headers:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000979 0x0000000000000979 R E 1000
DYNAMIC 0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000000 0x0000000000000000 R 8
readelf: Error: no .dynamic section in the dynamic segment
NOTE 0x0000000000000460 0x0000000000000460 0x0000000000000460
0x000000000000003c 0x000000000000003c R 4
GNU_EH_FRAME 0x000000000000049c 0x000000000000049c 0x000000000000049c
0x0000000000000034 0x0000000000000034 R 4
Section to Segment mapping:
Segment Sections...
00 .rodata .note .eh_frame_hdr .eh_frame .text .altinstructions
.altinstr_replacement
01
02 .note
03 .eh_frame_hdr
See? There is no .dynamic section :)
Ok, lets find, what broke it...
[ubuntu-unstable]$ git checkout f8830b2956a3~1
[ubuntu-unstable]$ make clean
...
[ubuntu-unstable]$ make -j5 arch/x86/entry/vdso/
...
[ubuntu-unstable]$ readelf --program-headers arch/x86/entry/vdso/vdso64.so
Elf file type is DYN (Shared object file)
Entry point 0x910
There are 4 program headers, starting at offset 64
Program Headers:
Type Offset VirtAddr PhysAddr
FileSiz MemSiz Flags Align
LOAD 0x0000000000000000 0x0000000000000000 0x0000000000000000
0x0000000000000cb9 0x0000000000000cb9 R E 1000
DYNAMIC 0x0000000000000360 0x0000000000000360 0x0000000000000360
0x0000000000000110 0x0000000000000110 R 8
NOTE 0x00000000000007b0 0x00000000000007b0 0x00000000000007b0
0x000000000000003c 0x000000000000003c R 4
GNU_EH_FRAME 0x00000000000007ec 0x00000000000007ec 0x00000000000007ec
0x0000000000000034 0x0000000000000034 R 4
Section to Segment mapping:
Segment Sections...
00 .hash .gnu.hash .dynsym .dynstr .gnu.version .gnu.version_d
.dynamic .rodata .note .eh_frame_hdr .eh_frame .text .altinstructions
.altinstr_replacement
01 .dynamic
02 .note
03 .eh_frame_hdr
And here it is. Not sure that this commit f8830b2956a3 ("disable -pie
when gcc has it enabled by default") has broke it, but it looks quite
suspicious.
Anyway, I'm not sure, maybe we could re-arrange vdso code in CRIU
that it wouldn't need .dynamic? I'm not sure, maybe I'll check it
when I'll have some more time :)
--
Regards,
Dmitry Safonov
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