Re: [PATCH] selftests: net: fix warning when compiling selftest/net

From: Guo Zhengkui
Date: Thu Mar 17 2022 - 02:52:10 EST


On 2022/3/17 11:22, Jakub Kicinski wrote:
On Wed, 16 Mar 2022 19:50:40 +0800 Guo Zhengkui wrote:
When I compile tools/testing/selftests/net/ by
`make -C tools/testing/selftests/net` with gcc (Debian 8.3.0-6) 8.3.0,
it reports the following warnings:

txtimestamp.c: In function 'validate_timestamp':
txtimestamp.c:164:29: warning: format '%lu' expects argument of type
'long unsigned int', but argument 3 has type 'int64_t'
{aka 'long long int'} [-Wformat=]
fprintf(stderr, "ERROR: %lu us expected between %d and %d\n",
~~^
%llu
cur64 - start64, min_delay, max_delay);
~~~~~~~~~~~~~~~
txtimestamp.c: In function '__print_ts_delta_formatted':
txtimestamp.c:173:22: warning: format '%lu' expects argument of type
'long unsigned int', but argument 3 has type 'int64_t'
{aka 'long long int'} [-Wformat=]
fprintf(stderr, "%lu ns", ts_delta);
~~^ ~~~~~~~~
%llu
txtimestamp.c:175:22: warning: format '%lu' expects argument of type
'long unsigned int', but argument 3 has type 'int64_t'
{aka 'long long int'} [-Wformat=]
fprintf(stderr, "%lu us", ts_delta / NSEC_PER_USEC);
~~^
%llu

`int64_t` is the alias for `long long int`. '%lld' is more suitable.

That's on 32bit machines, I think what you need to use is PRId64.
Or just cast the result / change variable types to long long.

But it should be '%ld' instead of '%lu', right?

Zhengkui