[LTP] [PATCH] syscalls/getcpu: Add libc sched_getcpu() detection && fix compiler errors

[Cyril Hrubis]

Hi!
> 1)sched_getcpu() isn't defined on some old distros, so we can add dection and
> fix compiler error.
> 
> 2)If CPU_ALLOC isn't defined on some old distros, it will used "include/lapi/cpuset"
> CPU_ALLOC macro. But getcpu01.c has converted into new library, so it will report
> "cleanup" undefine error. We should ensure CPU_ALLOC can be used both new cases and
> old cases.
> 
> Signed-off-by: Yang Xu <xuyang2018.jy@cn.fujitsu.com>
> ---
>  configure.ac                                |  1 +
>  include/lapi/cpuset.h                       | 10 +++++++++-
>  testcases/kernel/syscalls/getcpu/getcpu01.c |  6 +++---
>  3 files changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/configure.ac b/configure.ac
> index de12499..3ac0f28 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -77,6 +77,7 @@ AC_CHECK_FUNCS([ \
>      readlinkat \
>      renameat \
>      renameat2 \
> +    sched_getcpu \
>      sigpending \
>      splice \
>      stime \
> diff --git a/include/lapi/cpuset.h b/include/lapi/cpuset.h
> index b946650..959462b 100644
> --- a/include/lapi/cpuset.h
> +++ b/include/lapi/cpuset.h
> @@ -33,11 +33,19 @@
>  #define LTP_CPUSET_H
>  
>  #ifndef CPU_ALLOC
> +#ifndef TST_TEST_H__
>  #define CPU_ALLOC(ncpus) malloc(sizeof(cpu_set_t)); \
>  if (ncpus > CPU_SETSIZE) { \
>  	tst_brkm(TCONF, cleanup, \
> -		"Your libc does not support masks with %ld cpus", ncpus); \
> +		"Your libc does not support masks with %d cpus", ncpus); \
>  }
> +#else
> +#define CPU_ALLOC(ncpus) malloc(sizeof(cpu_set_t)); \
> +if (ncpus > CPU_SETSIZE) { \
> +	tst_brk(TCONF, \
> +		"Your libc does not support masks with %d cpus", ncpus); \
> +}
> +#endif
>  #endif

Good catch.

I would be happier if we converted the sched_setaffinity01 to new
library then we could simply change the tst_brkm() to tst_brk(), but we
can always do that later on.

>  #ifndef CPU_FREE
> diff --git a/testcases/kernel/syscalls/getcpu/getcpu01.c b/testcases/kernel/syscalls/getcpu/getcpu01.c
> index eb6ded8..d033119 100644
> --- a/testcases/kernel/syscalls/getcpu/getcpu01.c
> +++ b/testcases/kernel/syscalls/getcpu/getcpu01.c
> @@ -16,15 +16,15 @@
>  #include <stdlib.h>
>  #include <sys/types.h>
>  #include "lapi/syscalls.h"
> -#include "lapi/cpuset.h"
>  #include "tst_test.h"
> +#include "lapi/cpuset.h"
>  
>  static inline int get_cpu(unsigned *cpu_id,
>  			  unsigned *node_id LTP_ATTRIBUTE_UNUSED,
>  			  void *cache_struct LTP_ATTRIBUTE_UNUSED)
>  {
> -#if defined(__i386__)
> -	return syscall(__NR_getcpu, cpu_id, node_id, cache_struct);
> +#ifndef HAVE_SCHED_GETCPU
> +	return tst_syscall(__NR_getcpu, cpu_id, node_id, cache_struct);
>  #else
>  	*cpu_id = sched_getcpu();
>  #endif

So when __NR_getcpu is not implemented we end up with tst_brk(TCONF,
...) called from the tst_syscall, right? Since AFAIK the getcpu syscall
is not implemented on all architectures...

-- 
Cyril Hrubis
chrubis@suse.cz