Re: [PATCH bpf-next v2] samples/bpf: Set flag __SANE_USERSPACE_TYPES__ for MIPS to fix build warnings

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to bpf/bpf-next.git (refs/heads/master):

On Mon, 25 Jan 2021 13:05:46 +0800 you wrote:
> There exists many build warnings when make M=samples/bpf on the Loongson
> platform, this issue is MIPS related, x86 compiles just fine.
> 
> Here are some warnings:
> 
>   CC  samples/bpf/ibumad_user.o
> samples/bpf/ibumad_user.c: In function ‘dump_counts’:
> samples/bpf/ibumad_user.c:46:24: warning: format ‘%llu’ expects argument of 
> type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long 
> unsigned int’} [-Wformat=]
> printf("0x%02x : %llu\n", key, value);
>  ~~~^  ~
>  %lu
>   CC  samples/bpf/offwaketime_user.o
> samples/bpf/offwaketime_user.c: In function ‘print_ksym’:
> samples/bpf/offwaketime_user.c:34:17: warning: format ‘%llx’ expects argument 
> of type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long 
> unsigned int’} [-Wformat=]
>printf("%s/%llx;", sym->name, addr);
>   ~~~^   
>   %lx
> samples/bpf/offwaketime_user.c: In function ‘print_stack’:
> samples/bpf/offwaketime_user.c:68:17: warning: format ‘%lld’ expects argument 
> of type ‘long long int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned 
> int’} [-Wformat=]
>   printf(";%s %lld\n", key->waker, count);
>   ~~~^ ~
>   %ld
> 
> [...]

Here is the summary with links:
  - [bpf-next,v2] samples/bpf: Set flag __SANE_USERSPACE_TYPES__ for MIPS to 
fix build warnings
https://git.kernel.org/bpf/bpf-next/c/190d1c921ad0

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Re: [PATCH bpf-next v2] samples/bpf: Set flag __SANE_USERSPACE_TYPES__ for MIPS to fix build warnings

[Yonghong Song]

On 1/24/21 9:05 PM, Tiezhu Yang wrote:

There exists many build warnings when make M=samples/bpf on the Loongson
platform, this issue is MIPS related, x86 compiles just fine.

Here are some warnings:

   CC  samples/bpf/ibumad_user.o
samples/bpf/ibumad_user.c: In function ‘dump_counts’:
samples/bpf/ibumad_user.c:46:24: warning: format ‘%llu’ expects argument of 
type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long 
unsigned int’} [-Wformat=]
 printf("0x%02x : %llu\n", key, value);
  ~~~^  ~
  %lu
   CC  samples/bpf/offwaketime_user.o
samples/bpf/offwaketime_user.c: In function ‘print_ksym’:
samples/bpf/offwaketime_user.c:34:17: warning: format ‘%llx’ expects argument 
of type ‘long long unsigned int’, but argument 3 has type ‘__u64’ {aka ‘long 
unsigned int’} [-Wformat=]
printf("%s/%llx;", sym->name, addr);
   ~~~^   
   %lx
samples/bpf/offwaketime_user.c: In function ‘print_stack’:
samples/bpf/offwaketime_user.c:68:17: warning: format ‘%lld’ expects argument 
of type ‘long long int’, but argument 3 has type ‘__u64’ {aka ‘long unsigned 
int’} [-Wformat=]
   printf(";%s %lld\n", key->waker, count);
   ~~~^ ~
   %ld

MIPS needs __SANE_USERSPACE_TYPES__ before  to select
'int-ll64.h' in arch/mips/include/uapi/asm/types.h, then it can avoid
build warnings when printing __u64 with %llu, %llx or %lld.

The header tools/include/linux/types.h defines __SANE_USERSPACE_TYPES__,
it seems that we can include  in the source files which
have build warnings, but it has no effect due to actually it includes
usr/include/linux/types.h instead of tools/include/linux/types.h, the
problem is that "usr/include" is preferred first than "tools/include"
in samples/bpf/Makefile, that sounds like a ugly hack to -Itools/include
before -Iusr/include.

So define __SANE_USERSPACE_TYPES__ for MIPS in samples/bpf/Makefile
is proper, if add "TPROGS_CFLAGS += -D__SANE_USERSPACE_TYPES__" in
samples/bpf/Makefile, it appears the following error:

Auto-detecting system features:
...libelf: [ on  ]
...  zlib: [ on  ]
...   bpf: [ OFF ]

BPF API too old
make[3]: *** [Makefile:293: bpfdep] Error 1
make[2]: *** [Makefile:156: all] Error 2

With #ifndef __SANE_USERSPACE_TYPES__  in tools/include/linux/types.h,
the above error has gone and this ifndef change does not hurt other
compilations.

Signed-off-by: Tiezhu Yang 


Acked-by: Yonghong Song