bsd-user: Implement open, openat and close

Add the open, openat and close system calls. We need to lock paths, so
implmenent that as well.

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Jung-uk Kim <jkim@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Warner Losh <imp@bsdimp.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>

bsd-user/bsd-file.h

@@ -22,11 +22,25 @@
 
 #include "qemu/path.h"
 
+#define LOCK_PATH(p, arg)                   \
+do {                                        \
+    (p) = lock_user_string(arg);            \
+    if ((p) == NULL) {                      \
+        return -TARGET_EFAULT;              \
+    }                                       \
+} while (0)
+
+#define UNLOCK_PATH(p, arg)     unlock_user(p, arg, 0)
+
+
 extern struct iovec *lock_iovec(int type, abi_ulong target_addr, int count,
         int copy);
 extern void unlock_iovec(struct iovec *vec, abi_ulong target_addr, int count,
         int copy);
 
+int safe_open(const char *path, int flags, mode_t mode);
+int safe_openat(int fd, const char *path, int flags, mode_t mode);
+
 ssize_t safe_read(int fd, void *buf, size_t nbytes);
 ssize_t safe_pread(int fd, void *buf, size_t nbytes, off_t offset);
 ssize_t safe_readv(int fd, const struct iovec *iov, int iovcnt);
@@ -190,4 +204,39 @@ static abi_long do_bsd_pwritev(void *cpu_env, abi_long arg1,
     return ret;
 }
 
+/* open(2) */
+static abi_long do_bsd_open(abi_long arg1, abi_long arg2, abi_long arg3)
+{
+    abi_long ret;
+    void *p;
+
+    LOCK_PATH(p, arg1);
+    ret = get_errno(safe_open(path(p), target_to_host_bitmask(arg2,
+                fcntl_flags_tbl), arg3));
+    UNLOCK_PATH(p, arg1);
+
+    return ret;
+}
+
+/* openat(2) */
+static abi_long do_bsd_openat(abi_long arg1, abi_long arg2,
+        abi_long arg3, abi_long arg4)
+{
+    abi_long ret;
+    void *p;
+
+    LOCK_PATH(p, arg2);
+    ret = get_errno(safe_openat(arg1, path(p),
+                target_to_host_bitmask(arg3, fcntl_flags_tbl), arg4));
+    UNLOCK_PATH(p, arg2);
+
+    return ret;
+}
+
+/* close(2) */
+static inline abi_long do_bsd_close(abi_long arg1)
+{
+    return get_errno(close(arg1));
+}
+
 #endif /* BSD_FILE_H */

bsd-user/freebsd/os-syscall.c

@@ -44,6 +44,10 @@
 #include "bsd-proc.h"
 
 /* I/O */
+safe_syscall3(int, open, const char *, path, int, flags, mode_t, mode);
+safe_syscall4(int, openat, int, fd, const char *, path, int, flags, mode_t,
+    mode);
+
 safe_syscall3(ssize_t, read, int, fd, void *, buf, size_t, nbytes);
 safe_syscall4(ssize_t, pread, int, fd, void *, buf, size_t, nbytes, off_t,
     offset);
@@ -257,6 +261,18 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
         ret = do_bsd_pwritev(cpu_env, arg1, arg2, arg3, arg4, arg5, arg6);
         break;
 
+    case TARGET_FREEBSD_NR_open: /* open(2) */
+        ret = do_bsd_open(arg1, arg2, arg3);
+        break;
+
+    case TARGET_FREEBSD_NR_openat: /* openat(2) */
+        ret = do_bsd_openat(arg1, arg2, arg3, arg4);
+        break;
+
+    case TARGET_FREEBSD_NR_close: /* close(2) */
+        ret = do_bsd_close(arg1);
+        break;
+
     default:
         qemu_log_mask(LOG_UNIMP, "Unsupported syscall: %d\n", num);
         ret = -TARGET_ENOSYS;

bsd-user/syscall_defs.h

@@ -226,4 +226,8 @@ type safe_##name(type1 arg1, type2 arg2, type3 arg3, type4 arg4, \
     return safe_syscall(SYS_##name, arg1, arg2, arg3, arg4, arg5, arg6); \
 }
 
+/* So far all target and host bitmasks are the same */
+#define target_to_host_bitmask(x, tbl) (x)
+#define host_to_target_bitmask(x, tbl) (x)
+
 #endif /* SYSCALL_DEFS_H */