[msan][test] Use a large cpusetsize for pthread_getaffinity_np

[MaskRay]

Summary

pthread_getaffinity_np (Linux kernel/sched/core.c:sched_getaffinity) fails
with EINVAL if 8*cpusetsize (constant in glibc: 1024) is smaller than
nr_cpu_ids (CONFIG_NR_CPUS, which is 2048 for several arch/powerpc/configs
configurations).

The build bot clang-ppc64le-linux-lnt seems to have a larger nr_cpu_ids.

[MaskRay]

I'll push this, hopefully we can avoid UNSUPPORTED: powerpc

[vitalybuka]

Thanks for the fix!

compiler-rt/test/sanitizer_common/TestCases/Linux/pthread_getaffinity_np.cpp

 // RUN: %clangxx -O0 %s -o %t && %run %t
 
 // Android does not implement pthread_getaffinity_np.
 // (Note: libresolv is integrated with libc, but apparently only
 // sched_getaffinity).
 // UNSUPPORTED: android
 
 #ifndef _GNU_SOURCE
 #  define _GNU_SOURCE
 #endif
 
 #include <assert.h>
 #include <pthread.h>
-#include <stdio.h>
 #include <sys/sysinfo.h>
 
 #include <sanitizer/msan_interface.h>
 
 int main() {
-  cpu_set_t set_x;
+  cpu_set_t set_x[4];
   pthread_t tid = pthread_self();
-  int res = pthread_getaffinity_np(tid, sizeof(set_x), &set_x);
-  if (res != 0) {
-    fprintf(stderr, "tid: %lu\n", tid);
-    fprintf(stderr, "sizeof(set_x): %d\n", sizeof(set_x));
-    fprintf(stderr, "res: %d\n", res);
-  }
+  int res = pthread_getaffinity_np(tid, sizeof(set_x), set_x);
   assert(res == 0);
-  assert(CPU_COUNT_S(sizeof(set_x), &set_x) == get_nprocs());
+  assert(CPU_COUNT_S(sizeof(set_x), set_x) == get_nprocs());
 
   return 0;
 }