One build issue comes up due to both mount.h included dev_in_maps.c

In file included from dev_in_maps.c:10: /usr/include/sys/mount.h:35:3: error: expected identifier before numeric constant 35 | MS_RDONLY = 1, /* Mount read-only. */ | ^~~~~~~~~ In file included from dev_in_maps.c:13:

Remove one of them to solve conflict, another error comes up:

dev_in_maps.c:170:6: error: implicit declaration of function ‘mount’ [-Werror=implicit-function-declaration] 170 | if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) == -1) { | ^~~~~ cc1: all warnings being treated as errors

and then , add sys_mount definition to solve it After both above, dev_in_maps.c can be built correctly on my mache(gcc 10.2,glibc-2.32,kernel-5.10)

Signed-off-by: Hu Yadi hu.yadi@h3c.com --- .../selftests/filesystems/overlayfs/dev_in_maps.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/tools/testing/selftests/filesystems/overlayfs/dev_in_maps.c b/tools/testing/selftests/filesystems/overlayfs/dev_in_maps.c index e19ab0e85709..759f86e7d263 100644 --- a/tools/testing/selftests/filesystems/overlayfs/dev_in_maps.c +++ b/tools/testing/selftests/filesystems/overlayfs/dev_in_maps.c @@ -10,7 +10,6 @@ #include <linux/mount.h> #include <sys/syscall.h> #include <sys/stat.h> -#include <sys/mount.h> #include <sys/mman.h> #include <sched.h> #include <fcntl.h> @@ -32,7 +31,11 @@ static int sys_fsmount(int fd, unsigned int flags, unsigned int attr_flags) { return syscall(__NR_fsmount, fd, flags, attr_flags); } - +static int sys_mount(const char *src, const char *tgt, const char *fst, + unsigned long flags, const void *data) +{ + return syscall(__NR_mount, src, tgt, fst, flags, data); +} static int sys_move_mount(int from_dfd, const char *from_pathname, int to_dfd, const char *to_pathname, unsigned int flags) @@ -166,8 +169,7 @@ int main(int argc, char **argv) ksft_test_result_skip("unable to create a new mount namespace\n"); return 1; } - - if (mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) == -1) { + if (sys_mount(NULL, "/", NULL, MS_SLAVE | MS_REC, NULL) == -1) { pr_perror("mount"); return 1; }