bsd-user: Implement shm_open(2)

Co-authored-by: Kyle Evans <kevans@FreeBSD.org>

Signed-off-by: Stacey Son <sson@FreeBSD.org>
Signed-off-by: Kyle Evans <kevans@FreeBSD.org>
Signed-off-by: Karim Taha <kariem.taha2.7@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230925182709.4834-20-kariem.taha2.7@gmail.com>

bsd-user/bsd-mem.h

@@ -257,4 +257,29 @@ static inline abi_long do_obreak(abi_ulong brk_val)
     return target_brk;
 }
 
+/* shm_open(2) */
+static inline abi_long do_bsd_shm_open(abi_ulong arg1, abi_long arg2,
+        abi_long arg3)
+{
+    int ret;
+    void *p;
+
+    if (arg1 == (uintptr_t)SHM_ANON) {
+        p = SHM_ANON;
+    } else {
+        p = lock_user_string(arg1);
+        if (p == NULL) {
+            return -TARGET_EFAULT;
+        }
+    }
+    ret = get_errno(shm_open(p, target_to_host_bitmask(arg2, fcntl_flags_tbl),
+                             arg3));
+
+    if (p != SHM_ANON) {
+        unlock_user(p, arg1, 0);
+    }
+
+    return ret;
+}
+
 #endif /* BSD_USER_BSD_MEM_H */

bsd-user/freebsd/os-syscall.c

@@ -843,6 +843,10 @@ static abi_long freebsd_syscall(void *cpu_env, int num, abi_long arg1,
         ret = do_bsd_mincore(arg1, arg2, arg3);
         break;
 
+    case TARGET_FREEBSD_NR_freebsd12_shm_open: /* shm_open(2) */
+        ret = do_bsd_shm_open(arg1, arg2, arg3);
+        break;
+
 #if defined(__FreeBSD_version) && __FreeBSD_version >= 1300048
     case TARGET_FREEBSD_NR_shm_open2: /* shm_open2(2) */
         ret = do_freebsd_shm_open2(arg1, arg2, arg3, arg4, arg5);