@@ -2972,7 +2972,14 @@ static abi_long do_sendrecvmsg_locked(int fd, struct target_msghdr *msgp,
ret = target_to_host_sockaddr(fd, msg.msg_name,
tswapal(msgp->msg_name),
msg.msg_namelen);
- if (ret) {
+ if (ret == -TARGET_EFAULT) {
+ /* For connected sockets msg_name and msg_namelen must
+ * be ignored, so returning EFAULT immediately is wrong.
+ * Instead, pass a bad msg_name to the host kernel, and
+ * let it decide whether to return EFAULT or not.
+ */
+ msg.msg_name = (void *)-1;
+ } else if (ret) {
goto out2;
}
} else {
@@ -3025,7 +3032,7 @@ static abi_long do_sendrecvmsg_locked(int fd, struct target_msghdr *msgp,
}
if (!is_error(ret)) {
msgp->msg_namelen = tswap32(msg.msg_namelen);
- if (msg.msg_name != NULL) {
+ if (msg.msg_name != NULL && msg.msg_name != (void *)-1) {
ret = host_to_target_sockaddr(tswapal(msgp->msg_name),
msg.msg_name, msg.msg_namelen);
if (ret) {
The POSIX standard mandates that for a connected socket recvfrom() must ignore the msg_name and msg_namelen fields. This is awkward for QEMU because we will attempt to copy them from guest address space. Handle this by not immediately returning a TARGET_EFAULT if the copy failed, but instead passing a known-bad address to the host kernel, which can then return EFAULT or ignore the value appropriately. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> --- linux-user/syscall.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-)