[PATCH 3/3] tools/nolibc: validate directory with O_DIRECTORY in opendir()

[Thomas Weißschuh]

fdopendir() requires a call to fstat() to determine if the opened file
is a directory. Currently opendir() inherits this extra syscall.

Switch to O_DIRECTORY and remove the call to fdopendir() in opendir()
to make the directory type check cheaper.

Signed-off-by: Thomas Weißschuh <linux@xxxxxxxxxxxxxx>
---
 tools/include/nolibc/dirent.h | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tools/include/nolibc/dirent.h b/tools/include/nolibc/dirent.h
index 25fbff208998..2dbf4052b85a 100644
--- a/tools/include/nolibc/dirent.h
+++ b/tools/include/nolibc/dirent.h
@@ -55,10 +55,11 @@ DIR *opendir(const char *name)
 {
 	int fd;
 
-	fd = open(name, O_RDONLY);
+	fd = open(name, O_RDONLY | O_DIRECTORY);
 	if (fd == -1)
 		return NULL;
-	return fdopendir(fd);
+
+	return (DIR *)(intptr_t)~fd;
 }
 
 static __attribute__((unused))

-- 
2.55.0