With this change, userfaultfd fails to build with undefined reference swap() error:

userfaultfd.c: In function ‘userfaultfd_stress’: userfaultfd.c:1530:17: warning: implicit declaration of function ‘swap’; did you mean ‘swab’? [-Wimplicit-function-declaration] 1530 | swap(area_src, area_dst); | ^~~~ | swab /usr/bin/ld: /tmp/ccDGOAdV.o: in function `userfaultfd_stress': userfaultfd.c:(.text+0x549e): undefined reference to `swap' /usr/bin/ld: userfaultfd.c:(.text+0x54bc): undefined reference to `swap' collect2: error: ld returned 1 exit status

Revert the commit to fix the problem.

Fixes: 2c769ed7137a ("tools/testing/selftests/vm/userfaultfd.c: use swap() to make code cleaner") Signed-off-by: Shuah Khan skhan@linuxfoundation.org --- tools/testing/selftests/vm/userfaultfd.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c index d3fd24f9fae8..2f49c9af1b58 100644 --- a/tools/testing/selftests/vm/userfaultfd.c +++ b/tools/testing/selftests/vm/userfaultfd.c @@ -1417,6 +1417,7 @@ static void userfaultfd_pagemap_test(unsigned int test_pgsize) static int userfaultfd_stress(void) { void *area; + char *tmp_area; unsigned long nr; struct uffdio_register uffdio_register; struct uffd_stats uffd_stats[nr_cpus]; @@ -1527,9 +1528,13 @@ static int userfaultfd_stress(void) count_verify[nr], nr);

/* prepare next bounce */ - swap(area_src, area_dst); + tmp_area = area_src; + area_src = area_dst; + area_dst = tmp_area;

- swap(area_src_alias, area_dst_alias); + tmp_area = area_src_alias; + area_src_alias = area_dst_alias; + area_dst_alias = tmp_area;

uffd_stats_report(uffd_stats, nr_cpus); }