[PATCH 36/46] fstatfs: Add __libc_fstatfs wrapper

[Markos Chandras]

From: Markos Chandras <markos.chandras at imgtec.com>

New architectures don't have fstatfs anymore, so we use a wrapper for
__libc_fstatfs which will use fstatfs64 internally. The interface however
needs to remain the same (i.e accepting a struct statfs as a second
argument) for backwards compatibility

Signed-off-by: Markos Chandras <markos.chandras at imgtec.com>
---
 libc/sysdeps/linux/common/fstatfs.c |   43 ++++++++++++++++++++++++++++++++++-
 1 files changed, 42 insertions(+), 1 deletions(-)

diff --git a/libc/sysdeps/linux/common/fstatfs.c b/libc/sysdeps/linux/common/fstatfs.c
index fa0024a..82efdc9 100644
--- a/libc/sysdeps/linux/common/fstatfs.c
+++ b/libc/sysdeps/linux/common/fstatfs.c
@@ -9,8 +9,9 @@
 
 #include <sys/syscall.h>
 #include <sys/vfs.h>
+#include <string.h>
 
-#ifndef __USE_FILE_OFFSET64
+#if ! defined(__USE_FILE_OFFSET64)
 extern int fstatfs (int __fildes, struct statfs *__buf)
      __THROW __nonnull ((2));
 #else
@@ -23,8 +24,48 @@ extern int __REDIRECT_NTH (fstatfs, (int __fildes, struct statfs *__buf),
 #endif
 
 extern __typeof(fstatfs) __libc_fstatfs attribute_hidden;
+#ifdef __NR_fstatfs
 #define __NR___libc_fstatfs __NR_fstatfs
 _syscall2(int, __libc_fstatfs, int, fd, struct statfs *, buf)
+#else
+/* Backwards compatibility for __libc_fstatfs */
+int __libc_fstatfs (int __fildes, struct statfs *__buf)
+{
+	struct statfs64 b;
+	int err;
+
+	/*
+	 * Check if __buf has a sane value.
+	 * This does not prevent the user from passing
+	 * an artitrary possitive value that can lead to
+	 * segfault or other security problems
+	 */
+	if ( __buf == NULL || (int)__buf < 0) {
+		__set_errno(EFAULT);
+		return -1;
+	}
+
+	err = INLINE_SYSCALL(fstatfs64, 3, __fildes, sizeof(b), &b);
+
+	if (err < 0)
+		return -1;
+
+	memset(__buf, 0x00, sizeof(*__buf));
+	__buf->f_type = b.f_type;
+	__buf->f_bsize = b.f_bsize;
+	__buf->f_blocks = b.f_blocks;
+	__buf->f_bfree = b.f_bfree;
+	__buf->f_bavail = b.f_bavail;
+	__buf->f_files = b.f_files;
+	__buf->f_ffree = b.f_ffree;
+	__buf->f_namelen = b.f_namelen;
+	__buf->f_frsize = b.f_frsize;
+	__buf->f_fsid = b.f_fsid;
+	memcpy(__buf->f_spare, b.f_spare, sizeof(b.f_spare));
+	return err;
+};
+/* Redefined fstatfs because we need it for backwards compatibility */
+#endif /* __NR_fstatfs */
 
 #if defined __UCLIBC_LINUX_SPECIFIC__
 weak_alias(__libc_fstatfs,fstatfs)
-- 
1.7.1