tools/testing/selftests/kcmp/kcmp_test.c: add KCMP_EPOLL_TFD testing

KCMP's KCMP_EPOLL_TFD mode merged in commit 0791e3644e5ef2 ("kcmp: add
KCMP_EPOLL_TFD mode to compare epoll target files") we've had no selftest
for it yet (except in criu development list).  Thus add it.

Link: http://lkml.kernel.org/r/20170901151620.GK1898@uranus.lan
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Andrey Vagin <avagin@openvz.org>
Cc: Pavel Emelyanov <xemul@virtuozzo.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/tools/testing/selftests/kcmp/kcmp_test.c b/tools/testing/selftests/kcmp/kcmp_test.c
index a5a4da856dfedd7178fcaccd2f859c7bf3eb10b8..73684c4a1ed6929ddf5482119c009cd0c9ce1694 100644 (file)
--- a/tools/testing/selftests/kcmp/kcmp_test.c
+++ b/tools/testing/selftests/kcmp/kcmp_test.c
@@ -8,7 +8,6 @@
 #include <errno.h>
 #include <string.h>
 #include <fcntl.h>
-
 #include <linux/unistd.h>
 #include <linux/kcmp.h>
 
@@ -16,20 +15,28 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/wait.h>
+#include <sys/epoll.h>
 
 #include "../kselftest.h"
 
-static long sys_kcmp(int pid1, int pid2, int type, int fd1, int fd2)
+static long sys_kcmp(int pid1, int pid2, int type, unsigned long fd1, unsigned long fd2)
 {
        return syscall(__NR_kcmp, pid1, pid2, type, fd1, fd2);
 }
 
+static const unsigned int duped_num = 64;
+
 int main(int argc, char **argv)
 {
        const char kpath[] = "kcmp-test-file";
+       struct kcmp_epoll_slot epoll_slot;
+       struct epoll_event ev;
        int pid1, pid2;
+       int pipefd[2];
        int fd1, fd2;
+       int epollfd;
        int status;
+       int fddup;
 
        fd1 = open(kpath, O_RDWR | O_CREAT | O_TRUNC, 0644);
        pid1 = getpid();
@@ -39,6 +46,37 @@ int main(int argc, char **argv)
                ksft_exit_fail();
        }
 
+       if (pipe(pipefd)) {
+               perror("Can't create pipe");
+               ksft_exit_fail();
+       }
+
+       epollfd = epoll_create1(0);
+       if (epollfd < 0) {
+               perror("epoll_create1 failed");
+               ksft_exit_fail();
+       }
+
+       memset(&ev, 0xff, sizeof(ev));
+       ev.events = EPOLLIN | EPOLLOUT;
+
+       if (epoll_ctl(epollfd, EPOLL_CTL_ADD, pipefd[0], &ev)) {
+               perror("epoll_ctl failed");
+               ksft_exit_fail();
+       }
+
+       fddup = dup2(pipefd[1], duped_num);
+       if (fddup < 0) {
+               perror("dup2 failed");
+               ksft_exit_fail();
+       }
+
+       if (epoll_ctl(epollfd, EPOLL_CTL_ADD, fddup, &ev)) {
+               perror("epoll_ctl failed");
+               ksft_exit_fail();
+       }
+       close(fddup);
+
        pid2 = fork();
        if (pid2 < 0) {
                perror("fork failed");
@@ -95,6 +133,24 @@ int main(int argc, char **argv)
                        ksft_inc_pass_cnt();
                }
 
+               /* Compare epoll target */
+               epoll_slot = (struct kcmp_epoll_slot) {
+                       .efd    = epollfd,
+                       .tfd    = duped_num,
+                       .toff   = 0,
+               };
+               ret = sys_kcmp(pid1, pid1, KCMP_EPOLL_TFD, pipefd[1],
+                              (unsigned long)(void *)&epoll_slot);
+               if (ret) {
+                       printf("FAIL: 0 expected but %d returned (%s)\n",
+                               ret, strerror(errno));
+                       ksft_inc_fail_cnt();
+                       ret = -1;
+               } else {
+                       printf("PASS: 0 returned as expected\n");
+                       ksft_inc_pass_cnt();
+               }
+
                ksft_print_cnts();
 
                if (ret)