linux-user: Use ARRAY_SIZE with bitmask_transtbl

Rather than using a zero tuple to end the table, use a macro
to apply ARRAY_SIZE and pass that on to the convert functions.

This fixes two bugs in which the conversion functions required
that both the target and host masks be non-zero in order to
continue, rather than require both target and host masks be
zero in order to terminate.

This affected mmap_flags_tbl when the host does not support
all of the flags we wish to convert (e.g. MAP_UNINITIALIZED).
Mapping these flags to zero is good enough, and matches how
the kernel ignores bits that are unknown.

Fixes: 4b840f96 ("linux-user: Populate more bits in mmap_flags_tbl")
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

1 files changed, 11 insertions, 4 deletions

diff --git a/include/exec/user/thunk.h b/include/exec/user/thunk.h
index 300a840d58..6eedef48d8 100644
--- a/include/exec/user/thunk.h
+++ b/include/exec/user/thunk.h
@@ -193,10 +193,17 @@ static inline int thunk_type_align(const argtype *type_ptr, int is_host)
     }
 }
 
-unsigned int target_to_host_bitmask(unsigned int target_mask,
-                                    const bitmask_transtbl * trans_tbl);
-unsigned int host_to_target_bitmask(unsigned int host_mask,
-                                    const bitmask_transtbl * trans_tbl);
+unsigned int target_to_host_bitmask_len(unsigned int target_mask,
+                                        const bitmask_transtbl *trans_tbl,
+                                        size_t trans_len);
+unsigned int host_to_target_bitmask_len(unsigned int host_mask,
+                                        const bitmask_transtbl * trans_tbl,
+                                        size_t trans_len);
+
+#define target_to_host_bitmask(M, T) \
+    target_to_host_bitmask_len(M, T, ARRAY_SIZE(T))
+#define host_to_target_bitmask(M, T) \
+    host_to_target_bitmask_len(M, T, ARRAY_SIZE(T))
 
 void thunk_init(unsigned int max_structs);