Re: [PATCH v4 0/9] add xenalyze to staging

[George Dunlap <george.dunlap@eu.citrix.com>]

On 06/03/2015 11:59 AM, Ian Campbell wrote:
> On Wed, 2015-06-03 at 11:33 +0100, George Dunlap wrote:
>> On 06/03/2015 11:10 AM, Ian Campbell wrote:
>>> On Sat, 2015-05-23 at 08:24 +0000, Olaf Hering wrote:
>>>> Having xenalyze in the source tree makes it much easier to keep private
>>>> debug code in hypervisor and xenalyze in sync. It helped alot while
>>>> debugging the root cause for commit 607e8494c42397fb249191904066cace6ac9a880.
>>>
>>> I'm afraid it doesn't build on arm64.
>>>
>>> Some of these actually look like non-arch specific failures (e.g.
>>> conflicts with register_t from system headers) or issues which should
>>> probably be addressed with xenalyze in tree (e.g. NR_CPUS ought to be
>>> available directly now?) or with some trivial #ifdef modifications.
>>>
>>> That said, I don't know that xentrace actually works on ARM nor that
>>> xenalyze could analyse such traces even with the build issues addressed,
>>> so I'd be equally happy if this was just made x86 only.
>>>
>>> In file included from /usr/aarch64-linux-gnu/include/linux/types.h:4:0,
>>>                  from /usr/aarch64-linux-gnu/include/asm/ptrace.h:22,
>>>                  from /usr/aarch64-linux-gnu/include/sys/user.h:25,
>>>                  from /usr/aarch64-linux-gnu/include/sys/procfs.h:34,
>>>                  from /usr/aarch64-linux-gnu/include/sys/ucontext.h:26,
>>>                  from /usr/aarch64-linux-gnu/include/signal.h:360,
>>>                  from /usr/aarch64-linux-gnu/include/sys/wait.h:30,
>>>                  from xenalyze.c:28:
>>> /local/scratch/ianc/devel/committer-arm64.git/tools/xentrace/../../xen/include/asm/types.h:54:13: error: conflicting types for 'register_t'
>>>  typedef u64 register_t;
>>>              ^
>>> In file included from /usr/aarch64-linux-gnu/include/stdlib.h:314:0,
>>>                  from xenalyze.c:24:
>>> /usr/aarch64-linux-gnu/include/sys/types.h:205:13: note: previous declaration of 'register_t' was here
>>>  typedef int register_t __attribute__ ((__mode__ (__word__)));
>>>              ^
>>
>> The weird thing about this one is that register_t isn't defined or used
>> by xenalyze at all.
>>
>> The include pedigree is a bit confusing, but it looks like
>> aarch64-linux-gnu/include/linux/types.h is including Xen files, and that
>> there's a type mismatch between Xen's xen/include/asm/types.h and the
>> system's include/sys/types.h.
>>
>> It looks like it will happen to any program which includes both #include
>> both stdlib.h and sys/wait.h.  If so, this is a general problem with Xen
>> on ARM64, not a bug in xenalyze.
>>
>> (But as I said, the #include chain is a bit confusing, so I feel free to
>> correct me if I got something wrong...)
> 
> Has tools/xentrace/../../xen/include/asm/types.h ended up shadowing an
> <asm/types.h> from one of these headers, which should have included 
> /usr/<arch>/include/asm/types.h?
> 
> IOW the bug is in CFLAGS using some -I... or other, and/or in the fact
> that our include directory somehow shadows the real ones?

Aha -- looks like here's the culprit:

xenalyze.o: CFLAGS += -I$(XEN_ROOT)/xen/include

That's not in my original Makefile, and I didn't notice it when doing
review.

Olaf?

 -George