selftests/nolibc: fix up failures when CONFIG_PROC_FS=n

For CONFIG_PROC_FS=n, the /proc is not mountable, but the /proc
directory has been created in the prepare() stage whenever /proc is
there or not.

so, the checking of /proc in the run_syscall() stage will be always true
and at last it will fail all of the procfs dependent test cases, which
deviates from the 'cond' check design of the EXPECT_xx macros, without
procfs, these test cases should be skipped instead of failed.

To solve this issue, one method is checking /proc/self instead of /proc,
another method is removing the /proc directory completely for
CONFIG_PROC_FS=n, we apply the second method to avoid misleading the
users.

Reviewed-by: Thomas Weißschuh <linux@weissschuh.net>
Signed-off-by: Zhangjin Wu <falcon@tinylab.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>

diff --git a/tools/testing/selftests/nolibc/nolibc-test.c b/tools/testing/selftests/nolibc/nolibc-test.c
index bb39a1e..55cc229 100644 (file)
--- a/tools/testing/selftests/nolibc/nolibc-test.c
+++ b/tools/testing/selftests/nolibc/nolibc-test.c
@@ -1057,8 +1057,11 @@ int prepare(void)
 
        /* try to mount /proc if not mounted. Silently fail otherwise */
        if (stat("/proc/.", &stat_buf) == 0 || mkdir("/proc", 0755) == 0) {
-               if (stat("/proc/self", &stat_buf) != 0)
-                       mount("/proc", "/proc", "proc", 0, 0);
+               if (stat("/proc/self", &stat_buf) != 0) {
+                       /* If not mountable, remove /proc completely to avoid misuse */
+                       if (mount("none", "/proc", "proc", 0, 0) != 0)
+                               rmdir("/proc");
+               }
        }
 
        return 0;