[PULL 1/4] linux-user: add preadv2/preadv2

[Helge Deller <deller@kernel.org>]

From: Dominique Martinet <dominique.martinet@atmark-techno.com>

Some programs apparently use these, like the python test suite.

The flags argument (rwf_t) is an int, with values shared on all arches
and does not need translating.

This was tested manually with the following python script:
```
import os
fd = os.open('test', os.O_RDWR|os.O_CREAT)
os.pwritev(fd, [b'test', b'ok'], 0, os.RWF_HIPRI)
buf = [bytearray(3), bytearray(10)]
os.preadv(fd, buf, 0, os.RWF_HIPRI)
print(buf[0])
print(buf[1])
```

Signed-off-by: Dominique Martinet <dominique.martinet@atmark-techno.com>
Reviewed-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
---
 linux-user/syscall.c | 38 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 38 insertions(+)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 37ede95510..fbe357b7e0 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -741,6 +741,11 @@ safe_syscall5(ssize_t, preadv, int, fd, const struct iovec *, iov, int, iovcnt,
               unsigned long, pos_l, unsigned long, pos_h)
 safe_syscall5(ssize_t, pwritev, int, fd, const struct iovec *, iov, int, iovcnt,
               unsigned long, pos_l, unsigned long, pos_h)
+safe_syscall6(ssize_t, preadv2, int, fd, const struct iovec *, iov, int, iovcnt,
+              unsigned long, pos_l, unsigned long, pos_h, __kernel_rwf_t, flags)
+safe_syscall6(ssize_t, pwritev2, int, fd, const struct iovec *, iov,
+              int, iovcnt, unsigned long, pos_l, unsigned long, pos_h,
+              __kernel_rwf_t, flags)
 safe_syscall3(int, connect, int, fd, const struct sockaddr *, addr,
               socklen_t, addrlen)
 safe_syscall6(ssize_t, sendto, int, fd, const void *, buf, size_t, len,
@@ -11907,6 +11912,39 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
            }
         }
         return ret;
+#endif
+#if defined(TARGET_NR_preadv2)
+    case TARGET_NR_preadv2:
+        {
+            struct iovec *vec = lock_iovec(VERIFY_WRITE, arg2, arg3, 0);
+            if (vec != NULL) {
+                unsigned long low, high;
+
+                target_to_host_low_high(arg4, arg5, &low, &high);
+                ret = get_errno(safe_preadv2(arg1, vec, arg3, low, high, arg6));
+                unlock_iovec(vec, arg2, arg3, 1);
+            } else {
+                ret = -host_to_target_errno(errno);
+           }
+        }
+        return ret;
+#endif
+#if defined(TARGET_NR_pwritev2)
+    case TARGET_NR_pwritev2:
+        {
+            struct iovec *vec = lock_iovec(VERIFY_READ, arg2, arg3, 1);
+            if (vec != NULL) {
+                unsigned long low, high;
+
+                target_to_host_low_high(arg4, arg5, &low, &high);
+                ret = get_errno(safe_pwritev2(arg1, vec, arg3, low, high,
+                                              arg6));
+                unlock_iovec(vec, arg2, arg3, 0);
+            } else {
+                ret = -host_to_target_errno(errno);
+           }
+        }
+        return ret;
 #endif
     case TARGET_NR_getsid:
         return get_errno(getsid(arg1));
-- 
2.54.0