lstat/stat/fstat: Use 64bit version of syscall if available

This is needed for stat'ing loop devices > 255
since otherwise kernel returns EOVERFLOW becasue
it needs st_rdev/st_dev to be larger than 16bits but
in kernel it uses __old_kernel_stat for stat
syscall which has st_rdev/st_dev as unsigned short

Add a testcase

Signed-off-by: Khem Raj <raj.khem@gmail.com>

1 files changed, 14 insertions, 5 deletions

diff --git a/libc/sysdeps/linux/common/lstat.c b/libc/sysdeps/linux/common/lstat.c
index aa774473c..db72d1f60 100644
--- a/libc/sysdeps/linux/common/lstat.c
+++ b/libc/sysdeps/linux/common/lstat.c
@@ -12,19 +12,28 @@
 #include <sys/stat.h>
 #include "xstatconv.h"
 
-#define __NR___syscall_lstat __NR_lstat
-static __inline__ _syscall2(int, __syscall_lstat,
-		const char *, file_name, struct kernel_stat *, buf)
-
 int lstat(const char *file_name, struct stat *buf)
 {
 	int result;
+#ifdef __NR_lstat64
+	/* normal stat call has limited values for various stat elements
+	 * e.g. uid device major/minor etc.
+	 * so we use 64 variant if available
+	 * in order to get newer versions of stat elements
+	 */
+	struct kernel_stat64 kbuf;
+	result = INLINE_SYSCALL(lstat64, 2, file_name, &kbuf);
+	if (result == 0) {
+		__xstat32_conv(&kbuf, buf);
+	}
+#else
 	struct kernel_stat kbuf;
 
-	result = __syscall_lstat(file_name, &kbuf);
+	result = INLINE_SYSCALL(lstat, 2, file_name, &kbuf);
 	if (result == 0) {
 		__xstat_conv(&kbuf, buf);
 	}
+#endif
 	return result;
 }
 libc_hidden_def(lstat)