2022-04-07 21:13:15

by Guo Zhengkui

Subject: [PATCH] userfaultfd/selftests: use swap() instead of open coding it

Address the following coccicheck warning:

tools/testing/selftests/vm/userfaultfd.c:1536:21-22: WARNING opportunity
for swap().
tools/testing/selftests/vm/userfaultfd.c:1540:33-34: WARNING opportunity
for swap().

by using swap() for the swapping of variable values and drop
`tmp_area` that is not needed any more.

`swap()` macro in userfaultfd.c is introduced in commit 681696862bc18
("selftests: vm: remove dependecy from internal kernel macros")

It has been tested with gcc (Debian 8.3.0-6) 8.3.0.

Signed-off-by: Guo Zhengkui <[email protected]>
---
tools/testing/selftests/vm/userfaultfd.c | 9 ++-------
1 file changed, 2 insertions(+), 7 deletions(-)

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 92a4516f8f0d..7aba3ced7545 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -1422,7 +1422,6 @@ 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];
@@ -1533,13 +1532,9 @@ static int userfaultfd_stress(void)
count_verify[nr], nr);

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

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

uffd_stats_report(uffd_stats, nr_cpus);
}
--
2.20.1

2022-04-07 21:18:06

by Muchun Song

Subject: Re: [PATCH] userfaultfd/selftests: use swap() instead of open coding it

On Thu, Apr 07, 2022 at 08:31:41PM +0800, Guo Zhengkui wrote:
> Address the following coccicheck warning:
>
> tools/testing/selftests/vm/userfaultfd.c:1536:21-22: WARNING opportunity
> for swap().
> tools/testing/selftests/vm/userfaultfd.c:1540:33-34: WARNING opportunity
> for swap().
>
> by using swap() for the swapping of variable values and drop
> `tmp_area` that is not needed any more.
>
> `swap()` macro in userfaultfd.c is introduced in commit 681696862bc18
> ("selftests: vm: remove dependecy from internal kernel macros")
>
> It has been tested with gcc (Debian 8.3.0-6) 8.3.0.
>
> Signed-off-by: Guo Zhengkui <[email protected]>

Reviewed-by: Muchun Song <[email protected]>

Thanks.