add posix_fadvise / posix_fadvise64 support

1 files changed, 57 insertions, 0 deletions

diff --git a/libc/sysdeps/linux/common/posix_fadvise64.c b/libc/sysdeps/linux/common/posix_fadvise64.c
new file mode 100644
index 000000000..93d56d6cb
--- /dev/null
+++ b/libc/sysdeps/linux/common/posix_fadvise64.c
@@ -0,0 +1,57 @@
+/* vi: set sw=4 ts=4: */
+/* 
+ * posix_fadvise64() for uClibc
+ * http://www.opengroup.org/onlinepubs/009695399/functions/posix_fadvise.html
+ *
+ * Copyright (C) 2000-2005 by Erik Andersen <andersen@codepoet.org>
+ *
+ * GNU Library General Public License (LGPL) version 2 or later.
+ */
+
+#include <features.h>
+#include <unistd.h>
+#include <errno.h>
+#include <endian.h>
+#include <stdint.h>
+#include <sys/types.h>
+#include <sys/syscall.h>
+#include <fcntl.h>
+
+#if defined __UCLIBC_HAS_LFS__ && defined __NR_fadvise64_64
+#define __NR___syscall_fadvise64_64 __NR_fadvise64_64
+
+/* 64 bit implementation is cake ... or more like pie ... */
+#if __WORDSIZE == 64
+_syscall4(int, __syscall_fadvise64_64, int, fd, __off64_t, offset, 
+          __off64_t, len, int, advice);
+int __libc_posix_fadvise64(int fd, __off64_t offset, __off64_t len, int advice)
+{
+	return (__syscall_fadvise64_64(fd, offset, len, advice));
+}
+weak_alias(__libc_posix_fadvise64, posix_fadvise64);
+
+/* 32 bit implementation is kind of a pita */
+#elif __WORDSIZE == 32
+
+#ifdef _syscall6 /* workaround until everyone has _syscall6() */
+_syscall6(int, __syscall_fadvise64_64, int, fd, 
+          unsigned long, high_offset, unsigned long, low_offset, 
+          unsigned long, high_len, unsigned long, low_len, 
+          int, advice);
+int __libc_posix_fadvise64(int fd, __off64_t offset, __off64_t len, int advice)
+{
+	return (__syscall_fadvise64_64(fd,
+	        __LONG_LONG_PAIR(offset >> 32, offset &  0xffffffff),
+	        __LONG_LONG_PAIR(len >> 32, len & 0xffffffff),
+	        advice));
+}
+weak_alias(__libc_posix_fadvise64, posix_fadvise64);
+#else
+#warning _syscall6 has not been defined for your machine :(
+#endif /* _syscall6 */
+
+#else
+#error your machine is neither 32 bit or 64 bit ... it must be magical
+#endif
+
+#endif