Add preadv/pwritev.
Bug: http://b/12612572
Change-Id: I38ff2684d69bd0fe3f21b1d371b88fa60d5421cb
diff --git a/libc/bionic/legacy_32_bit_support.cpp b/libc/bionic/legacy_32_bit_support.cpp
index a107664..20d258d 100644
--- a/libc/bionic/legacy_32_bit_support.cpp
+++ b/libc/bionic/legacy_32_bit_support.cpp
@@ -33,6 +33,7 @@
#include <stdarg.h>
#include <sys/resource.h>
#include <sys/types.h>
+#include <sys/uio.h>
#include <sys/vfs.h>
#include <unistd.h>
@@ -43,6 +44,8 @@
// System calls we need.
extern "C" int __fcntl64(int, int, void*);
extern "C" int __llseek(int, unsigned long, unsigned long, off64_t*, int);
+extern "C" int __preadv64(int, const struct iovec*, int, long, long);
+extern "C" int __pwritev64(int, const struct iovec*, int, long, long);
// For fcntl we use the fcntl64 system call to signal that we're using struct flock64.
int fcntl(int fd, int cmd, ...) {
@@ -77,6 +80,23 @@
return pwrite64(fd, buf, byte_count, static_cast<off64_t>(offset));
}
+// On LP32, there is no off_t preadv/pwritev, and even the 64-bit preadv/pwritev
+// don't use off64_t (see SYSCALLS.TXT for more). Here, this means that we need
+// to implement all four functions because the two system calls don't match any
+// of the userspace functions. Unlike llseek, the pair is split lo-hi, not hi-lo.
+ssize_t preadv(int fd, const struct iovec* ios, int count, off_t offset) {
+ return __preadv64(fd, ios, count, offset, 0);
+}
+ssize_t preadv64(int fd, const struct iovec* ios, int count, off64_t offset) {
+ return __preadv64(fd, ios, count, offset, offset >> 32);
+}
+ssize_t pwritev(int fd, const struct iovec* ios, int count, off_t offset) {
+ return __pwritev64(fd, ios, count, offset, 0);
+}
+ssize_t pwritev64(int fd, const struct iovec* ios, int count, off64_t offset) {
+ return __pwritev64(fd, ios, count, offset, offset >> 32);
+}
+
// There is no fallocate for 32-bit off_t, so we need to widen and call fallocate64.
int fallocate(int fd, int mode, off_t offset, off_t length) {
return fallocate64(fd, mode, static_cast<off64_t>(offset), static_cast<off64_t>(length));