[CRIU] [PATCH 0/15] restorer: Sanitize sigreturn_restore()

[Pavel Emelyanov]

On 05/24/2016 11:59 PM, Andrew Vagin wrote:
> On Tue, May 24, 2016 at 02:32:15PM +0300, Pavel Emelyanov wrote:
>> This routine has grown too big and messy, since lots of
>> stuff require task_restore_args (and thread_restore_args)
>> to be at hands. Sometimes it's handled by keeping the
>> needed data somewhere and then copying it into restorer,
>> sometimes by patching talis of sigreturn_restore.
>>
>> This set makes first step towards making sigreturn_restore()
>> being small and doing one thing -- prepare restorer memory
>> layout and jumping into restorer blob. The step is -- make
>> task and thead args be ready as early as required.
> 
> [root at fc22-vm criu]# python test/zdtm.py run -t zdtm/static/futex
> === Run 1/1 ================
> 
> ========================== Run zdtm/static/futex in h ==========================
> Start test
> ./futex --pidfile=futex.pid --outfile=futex.out
> Run criu dump
> Run criu restore
> =[log]=> dump/zdtm/static/futex/24/1/restore.log
> ------------------------ grep Error ------------------------
> (00.386982) Error (cr-restore.c:995): 24 killed by signal 11: Segmentation fault

Ah :( The restorer memory can move, so static pointers do not work. I was
lucky to have mremap() just grow the mapping in my tests, thanks :)

I'll send fixes soon.

> (00.387039) Error (cr-restore.c:1872): Restoring FAILED.
> ------------------------ ERROR OVER ------------------------
> ################# Test zdtm/static/futex FAIL at CRIU restore ##################
> ##################################### FAIL #####################################
> 
> #0  0x000000000042aaca in prepare_aios (t=<optimized out>, ta=ta at entry=0x7f96d63b7000) at aio.c:135
> 135		ta->rings = (struct rst_aio_ring *)rst_mem_align_cpos(RM_PRIVATE);
> Missing separate debuginfos, use: dnf debuginfo-install glibc-2.23.1-5.fc24.x86_64 libnl3-3.2.27-3.fc24.x86_64 libselinux-2.5-3.fc24.x86_64 pcre-8.38-11.fc24.x86_64 protobuf-c-1.2.1-1.fc24.x86_64
> (gdb) bt
> #0  0x000000000042aaca in prepare_aios (t=<optimized out>, ta=ta at entry=0x7f96d63b7000) at aio.c:135
> #1  0x00000000004399d3 in restore_one_alive_task (core=0x11a6b60, pid=<optimized out>) at cr-restore.c:510
> #2  restore_one_task (core=0x11a6b60, pid=<optimized out>) at cr-restore.c:743
> #3  restore_task_with_children (_arg=<optimized out>) at cr-restore.c:1329
> #4  0x00007f96d52665cd in clone () from /lib64/libc.so.6
> 
> 
> 
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