Vitaly Chikunov <vt@xxxxxxxxxxxx> writes:
> Adding netdev and PowerPC maintainers JFYI.
Thanks.
> On Sat, Oct 24, 2020 at 11:23:19AM +0300, Dmitry V. Levin wrote:
>> Hi,
>>
>> On Sat, Oct 24, 2020 at 02:06:41AM +0300, Vitaly Chikunov wrote:
>> > Hi,
>> >
>> > Commit f143c11bb7b9 ("tools: bpf: Use local copy of headers including
>> > uapi/linux/filter.h") introduces compilation issue on powerpc:
>> >
>> > builder@powerpc64le:~/linux$ make -C tools/bpf V=1
>> > make: Entering directory '/usr/src/linux/tools/bpf'
>> > gcc -Wall -O2 -D__EXPORTED_HEADERS__ -I/usr/src/linux/tools/include/uapi -I/usr/src/linux/tools/include -DDISASM_FOUR_ARGS_SIGNATURE -c -o bpf_dbg.o /usr/src/linux/tools/bpf/bpf_dbg.c
Defining __EXPORTED_HEADERS__ is a hack to circumvent the checks in the
uapi headers.
So first comment is to stop doing that, although it doesn't actually fix
this issue.
>> > In file included from /usr/include/asm/sigcontext.h:14,
>> > from /usr/include/bits/sigcontext.h:30,
>> > from /usr/include/signal.h:291,
>> > from /usr/src/linux/tools/bpf/bpf_dbg.c:51:
>> > /usr/include/asm/elf.h:160:9: error: unknown type name '__vector128'
>> > 160 | typedef __vector128 elf_vrreg_t;
>> > | ^~~~~~~~~~~
>> > make: *** [Makefile:67: bpf_dbg.o] Error 1
>> > make: Leaving directory '/usr/src/linux/tools/bpf'
>>
>> __vector128 is defined in arch/powerpc/include/uapi/asm/types.h;
>> while include/uapi/linux/types.h does #include <asm/types.h>,
>> tools/include/uapi/linux/types.h doesn't, resulting to this
>> compilation error.
>
> This is too puzzling to fix portably.
I don't really understand how this is expected to work.
We have tools/include/uapi/linux/types.h which is some sort of hand
hacked types.h, but doesn't match the real types.h from
include/uapi/linux.
In particular the tools/include types.h doesn't include asm/types.h,
which is why this breaks.
I can build bpf_dbg if I copy the properly exported header in:
$ make INSTALL_HDR_PATH=$PWD/headers headers_install
$ cp headers/include/linux/types.h tools/include/uapi/linux/
$ make -C tools/bpf bpf_dbg
make: Entering directory '/home/michael/linux/tools/bpf'
Auto-detecting system features:
... libbfd: [ on ]
... disassembler-four-args: [ on ]
CC bpf_dbg.o
LINK bpf_dbg
make: Leaving directory '/home/michael/linux/tools/bpf
I'm not sure what the proper fix is.
Maybe sync the tools/include types.h with the real one?
Or TBH I would have thought the best option is to not have
tools/include/uapi at all, but instead just run headers_install before
building and use the properly exported headers.
cheers
