[Qemu-devel] [PATCH] linux-user: fix convertion of flock/flock64 l_type field

[Laurent Vivier]

As l_type values (F_RDLCK, F_WRLCK, F_UNLCK, F_EXLCK, F_SHLCK)
are not bitmasks, we can't use target_to_host_bitmask() and
host_to_target_bitmask() to convert them.

Introduce target_to_host_flock() and host_to_target_flock()
to convert values between host and target.

Signed-off-by: Laurent Vivier <address@hidden>
---
 linux-user/syscall.c | 48 +++++++++++++++++++++++++++++++++---------------
 1 file changed, 33 insertions(+), 15 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index e4825747f9..fdf6766eca 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -6546,15 +6546,33 @@ static int target_to_host_fcntl_cmd(int cmd)
     return -TARGET_EINVAL;
 }
 
-#define TRANSTBL_CONVERT(a) { -1, TARGET_##a, -1, a }
-static const bitmask_transtbl flock_tbl[] = {
-    TRANSTBL_CONVERT(F_RDLCK),
-    TRANSTBL_CONVERT(F_WRLCK),
-    TRANSTBL_CONVERT(F_UNLCK),
-    TRANSTBL_CONVERT(F_EXLCK),
-    TRANSTBL_CONVERT(F_SHLCK),
-    { 0, 0, 0, 0 }
-};
+static unsigned int target_to_host_flock(unsigned int type)
+{
+    switch (type) {
+#define TRANSTBL_CONVERT(a) case TARGET_##a: return a;
+    TRANSTBL_CONVERT(F_RDLCK)
+    TRANSTBL_CONVERT(F_WRLCK)
+    TRANSTBL_CONVERT(F_UNLCK)
+    TRANSTBL_CONVERT(F_EXLCK)
+    TRANSTBL_CONVERT(F_SHLCK)
+#undef  TRANSTBL_CONVERT
+    }
+    return type;
+}
+
+static unsigned int host_to_target_flock(unsigned int type)
+{
+    switch (type) {
+#define TRANSTBL_CONVERT(a) case a: return TARGET_##a;
+    TRANSTBL_CONVERT(F_RDLCK)
+    TRANSTBL_CONVERT(F_WRLCK)
+    TRANSTBL_CONVERT(F_UNLCK)
+    TRANSTBL_CONVERT(F_EXLCK)
+    TRANSTBL_CONVERT(F_SHLCK)
+#undef  TRANSTBL_CONVERT
+    }
+    return type;
+}
 
 static inline abi_long copy_from_user_flock(struct flock64 *fl,
                                             abi_ulong target_flock_addr)
@@ -6567,7 +6585,7 @@ static inline abi_long copy_from_user_flock(struct 
flock64 *fl,
     }
 
     __get_user(l_type, &target_fl->l_type);
-    fl->l_type = target_to_host_bitmask(l_type, flock_tbl);
+    fl->l_type = target_to_host_flock(l_type);
     __get_user(fl->l_whence, &target_fl->l_whence);
     __get_user(fl->l_start, &target_fl->l_start);
     __get_user(fl->l_len, &target_fl->l_len);
@@ -6586,7 +6604,7 @@ static inline abi_long copy_to_user_flock(abi_ulong 
target_flock_addr,
         return -TARGET_EFAULT;
     }
 
-    l_type = host_to_target_bitmask(fl->l_type, flock_tbl);
+    l_type = host_to_target_flock(fl->l_type);
     __put_user(l_type, &target_fl->l_type);
     __put_user(fl->l_whence, &target_fl->l_whence);
     __put_user(fl->l_start, &target_fl->l_start);
@@ -6611,7 +6629,7 @@ static inline abi_long copy_from_user_oabi_flock64(struct 
flock64 *fl,
     }
 
     __get_user(l_type, &target_fl->l_type);
-    fl->l_type = target_to_host_bitmask(l_type, flock_tbl);
+    fl->l_type = target_to_host_flock(l_type);
     __get_user(fl->l_whence, &target_fl->l_whence);
     __get_user(fl->l_start, &target_fl->l_start);
     __get_user(fl->l_len, &target_fl->l_len);
@@ -6630,7 +6648,7 @@ static inline abi_long 
copy_to_user_oabi_flock64(abi_ulong target_flock_addr,
         return -TARGET_EFAULT;
     }
 
-    l_type = host_to_target_bitmask(fl->l_type, flock_tbl);
+    l_type = host_to_target_flock(fl->l_type);
     __put_user(l_type, &target_fl->l_type);
     __put_user(fl->l_whence, &target_fl->l_whence);
     __put_user(fl->l_start, &target_fl->l_start);
@@ -6652,7 +6670,7 @@ static inline abi_long copy_from_user_flock64(struct 
flock64 *fl,
     }
 
     __get_user(l_type, &target_fl->l_type);
-    fl->l_type = target_to_host_bitmask(l_type, flock_tbl);
+    fl->l_type = target_to_host_flock(l_type);
     __get_user(fl->l_whence, &target_fl->l_whence);
     __get_user(fl->l_start, &target_fl->l_start);
     __get_user(fl->l_len, &target_fl->l_len);
@@ -6671,7 +6689,7 @@ static inline abi_long copy_to_user_flock64(abi_ulong 
target_flock_addr,
         return -TARGET_EFAULT;
     }
 
-    l_type = host_to_target_bitmask(fl->l_type, flock_tbl);
+    l_type = host_to_target_flock(fl->l_type);
     __put_user(l_type, &target_fl->l_type);
     __put_user(fl->l_whence, &target_fl->l_whence);
     __put_user(fl->l_start, &target_fl->l_start);
-- 
2.14.3