[CRIU] [PATCHv2] arm/pie/build: do not produce relocatable parasite object

[Christopher Covington]

On 04/22/2016 02:20 PM, Christopher Covington wrote:
> On 04/22/2016 02:12 PM, Christopher Covington wrote:
>> Hi Dmitry,
>>
>> On 04/21/2016 02:03 PM, Dmitry Safonov wrote:
>>> With `-r` option relocation to parasite_service
>>> was not made on ARM:
>>> 0x76dbc018:	bl	0x76dbc018		0xebfffffe
>>> (You may saw it with objdump also).
>>>
>>> This leaded to hang at "Putting tsock" message:
>>> (01.368297) ----------------------------------------
>>> (01.368321)
>>> (01.368339) Collecting fds (pid: 13503)
>>> (01.368360) ----------------------------------------
>>> (01.368535) Found 3 file descriptors
>>> (01.368564) ----------------------------------------
>>> (01.368648) Dump private signals of 13503
>>> (01.368708) Dump shared signals of 13503
>>> (01.368761) Parasite syscall_ip at 0x10000
>>> (01.369605) Set up parasite blob using memfd
>>> (01.369641) Putting parasite blob into 0x76cc5000->0x76e1f000
>>> (01.369755) Dumping GP/FPU registers for 13503
>>> (01.369818) Putting tsock into pid 13503
>>>
>>> Also link against native.lib.a
>>>
>>> Reported-by: alex vk <avankemp at gmail.com>
>>> Reported-by: long.wanglong <long.wanglong at huawei.com>
>>> Cc: Cyrill Gorcunov <gorcunov at gmail.com>
>>> Signed-off-by: Dmitry Safonov <dsafonov at virtuozzo.com>
>>> ---
>>> v2: drop partial linking only for arm/arm64
>>>
>>> P.S: please, do not apply, before it doesn't have
>>> Tested-by: Wang Long <long.wanglong at huawei.com>
>>> as I don't have arm64 board and can't tell if this is
>>> the same problem as on RPI2 (armv7) board.
>>
>> For what it's worth, I've done most of my AArch64 work on
>> qemu-system-aarch64. Example command line:
>>
>> qemu-system-aarch64 \
>> -nographic \
>> -monitor none \
>> -M virt \
>> -cpu cortex-a57 \
>> -m 4G \
>> -drive if=none,file=rootfs.img,cache=writeback,id=disk0 \
>> -device virtio-blk-device,drive=disk0 \
>> -serial stdio \
>> -kernel Image \
>> -append "root=/dev/vda rw console=ttyAMA0 maxcpus=1 norandmaps"
>> -fsdev local,id=r,security_model=none,path=/ \
>> -device virtio-9p-device,fsdev=r,mount_tag=passthrough \
>> -netdev user,id=mynet0,net=192.168.76.0/24,dhcpstart=192.168.76.9
>> -device virtio-net-device,netdev=mynet0
>>
>>>  criu/pie/Makefile | 13 +++++++++----
>>>  1 file changed, 9 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/criu/pie/Makefile b/criu/pie/Makefile
>>> index 3679e24438a4..4daf77338c85 100644
>>> --- a/criu/pie/Makefile
>>> +++ b/criu/pie/Makefile
>>> @@ -153,19 +153,24 @@ $(obj)/%-blob.h: $(obj)/%.built-in.bin.o $(SRC_DIR)/compel/compel
>>>  
>>>  else # !piegen-y
>>>  
>>> +# ld on arm doesn't like -pie and -r options together
>>> +ifeq ($(filter arm arm64,$(ARCH)),)
>>> +        LD_R := -r
>>
>> I think this is conventionally named LDFLAGS.
> 
> Although a user might expect to be able to set LDFLAGS on the command
> line. With that in mind, I think LD_R is fine. If you do want to go with
> LDFLAGS, consider using override (just for pie/Makefile, ideally letting
> the user play with LDFLAGS elsewhere).
> 
>>> +endif
>>> +
>>>  define gen-rule-built-in.bin.o
>>>  $(obj)/parasite-$(1).built-in.bin.o: $(obj)/$(1).built-in.o		\
>>> -				$(obj)/pie.lds-$(1).S
>>> +				$(obj)/pie.lds-$(1).S $(obj)/native.lib.a
>>>  	$$(call msg-gen, $$@)
>>> -	$(Q) $(LD) -r -T $(obj)/pie.lds-$(1).S -o $$@ $$<
>>> +	$(Q) $(LD) $(LD_R) -T $(obj)/pie.lds-$(1).S -o $$@ $$< $(obj)/native.lib.a
>>
>> Could you use "$$^" instead of "$$< $(obj)/native.lib.a"?

Oh, I now see the .S file should be skipped. Apologies for the oversight.

>>>  endef
>>>  
>>>  $(eval $(call map,gen-rule-built-in.bin.o,$(parasite_target)))
>>>  
>>>  $(obj)/restorer.built-in.bin.o: $(obj)/restorer.built-in.o		\
>>> -				$(obj)/pie.lds-native.S
>>> +				$(obj)/pie.lds-native.S $(obj)/native.lib.a
>>>  	$(call msg-gen, $@)
>>> -	$(Q) $(LD) -r -T $(obj)/pie.lds-native.S -o $@ $<
>>> +	$(Q) $(LD) $(LD_R) -T $(obj)/pie.lds-native.S -o $@ $< $(obj)/native.lib.a
>>>  
>>>  $(obj)/%.built-in.bin: $(obj)/%.built-in.bin.o
>>>  	$(call msg-gen, $@)

Having answered my own questions,

Reviewed-by: Christopher Covington <cov at codeaurora.org>


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