sendfile: Use sendfile64 if arch does not have the sendfile syscall

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>

Signed-off-by: Bernhard Reutner-Fischer <rep.dot.nop@gmail.com>

include/sys/sendfile.h

@@ -44,6 +44,7 @@ extern ssize_t __REDIRECT_NTH (sendfile,
 #ifdef __USE_LARGEFILE64
 extern ssize_t sendfile64 (int __out_fd, int __in_fd, __off64_t *__offset,
 			   size_t __count) __THROW;
+libc_hidden_proto(sendfile64)
 #endif
 
 __END_DECLS

libc/sysdeps/linux/common/sendfile.c

@@ -9,12 +9,55 @@
 
 #include <sys/syscall.h>
 
-#ifdef __NR_sendfile
 # include <sys/sendfile.h>
 # include <bits/wordsize.h>
+
+#if defined __NR_sendfile
 _syscall4(ssize_t, sendfile, int, out_fd, int, in_fd, __off_t *, offset,
 	  size_t, count)
 # if defined __UCLIBC_HAS_LFS__ && (!defined __NR_sendfile64 || __WORDSIZE == 64)
 strong_alias_untyped(sendfile,sendfile64)
 # endif
+
+#elif defined __NR_sendfile64 && !defined __NR_sendfile
+# include <unistd.h>
+# include <stddef.h>
+
+ssize_t sendfile(int out_fd, int in_fd, __off_t *offset, size_t count)
+{
+	__off64_t off64, *off;
+	ssize_t res;
+
+	/*
+	 * Check if valid fds and valid pointers were passed
+	 * This does not prevent the user from passing
+	 * an arbitrary pointer causing a segfault or
+	 * other security issues
+	 */
+
+	if (in_fd < 0 || out_fd < 0) {
+		__set_errno(EBADF);
+		return -1;
+	}
+
+	if (offset == NULL || (int)offset < 0) {
+		__set_errno(EFAULT);
+		return -1;
+	}
+
+	if (offset) {
+		off = &off64;
+		off64 = *offset;
+	} else {
+		off = NULL;
+	}
+
+	res = INLINE_SYSCALL(sendfile64, 4, out_fd, in_fd, off, count);
+
+	if (res >= 0)
+		*offset = off64;
+
+	return res;
+}
+
 #endif

libc/sysdeps/linux/common/sendfile64.c

@@ -17,4 +17,5 @@
 #if defined __NR_sendfile64 && __WORDSIZE != 64
 # include <sys/sendfile.h>
 _syscall4(ssize_t,sendfile64, int, out_fd, int, in_fd, __off64_t *, offset, size_t, count)
+libc_hidden_def(sendfile64)
 #endif

libc/sysdeps/linux/common/stubs.c

@@ -320,7 +320,8 @@ make_stub(sched_setaffinity)
 make_stub(send)
 #endif
 
-#if !defined __NR_sendfile && defined __UCLIBC_LINUX_SPECIFIC__
+#if !defined __NR_sendfile && !defined __NR_sendfile64 \
+	&& defined __UCLIBC_LINUX_SPECIFIC__
 make_stub(sendfile)
 #endif