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Re: [PATCH 1/4] Add INTERNAL_SYSCALL_CALL
On 20/09/2016 18:36, Florian Weimer wrote:
> * Adhemerval Zanella:
>
>> +#define __INTERNAL_SYSCALL0(name, err) \
>> + INTERNAL_SYSCALL (name, err, 0)
>> +#define __INTERNAL_SYSCALL1(name, err, a1) \
>> + INTERNAL_SYSCALL (name, err, 1, a1)
>> +#define __INTERNAL_SYSCALL2(name, err, a1, a2) \
>> + INTERNAL_SYSCALL (name, err, 2, a1, a2)
>> +#define __INTERNAL_SYSCALL3(name, err, a1, a2, a3) \
>> + INTERNAL_SYSCALL (name, err, 3, a1, a2, a3)
>> +#define __INTERNAL_SYSCALL4(name, err, a1, a2, a3, a4) \
>> + INTERNAL_SYSCALL (name, err, 4, a1, a2, a3, a4)
>> +#define __INTERNAL_SYSCALL5(name, err, a1, a2, a3, a4, a5) \
>> + INTERNAL_SYSCALL (name, err, 5, a1, a2, a3, a4, a5)
>> +#define __INTERNAL_SYSCALL6(name, err, a1, a2, a3, a4, a5, a6) \
>> + INTERNAL_SYSCALL (name, err, 6, a1, a2, a3, a4, a5, a6)
>> +#define __INTERNAL_SYSCALL7(name, err, a1, a2, a3, a4, a5, a6, a7) \
>> + INTERNAL_SYSCALL (name, err, 7, a1, a2, a3, a4, a5, a6, a7)
>
> It's not immediately obvious why these definitions are needed.
I agree this is not obvious, but it follows the SYSCALL_CANCEL macro logic
where __INTERNAL_SYSCALL_DISP will select the correct __INTERNAL_SYSCALL
(based on number of arguments).
>
>> +#define __INTERNAL_SYSCALL_NARGS_X(a, b, c, d, e, f, g, h, n, ...) n
>> +#define __INTERNAL_SYSCALL_NARGS(...) \
>> + __INTERNAL_SYSCALL_NARGS_X (__VA_ARGS__, 7, 6, 5, 4, 3, 2, 1, 0, )
>> +#define __INTERNAL_SYSCALL_CONCAT_X(a, b) a##b
>> +#define __INTERNAL_SYSCALL_CONCAT(a, b) __SYSCALL_CONCAT_X (a, b)
>
> I think you can reuse the macros from sysdeps/unix/sysdep.h here.
Indeed this is just a duplicate macro logic with different name. I
think it is safe to remove.
>
>> +/* Issue a syscall defined by syscall number plus any other argument required.
>
> These comment lines are rather long.
Fixed.
>
>> + Any error will be handled using arch defined macros and errno will be se
>> + accordingly.
>
> “will be set”
>
Fixed.
I think patch below simplify the macro code and address your comments:
--
diff --git a/sysdeps/unix/sysdep.h b/sysdeps/unix/sysdep.h
index 94a2ce0..7816b6a 100644
--- a/sysdeps/unix/sysdep.h
+++ b/sysdeps/unix/sysdep.h
@@ -24,6 +24,40 @@
#define SYSCALL__(name, args) PSEUDO (__##name, name, args)
#define SYSCALL(name, args) PSEUDO (name, name, args)
+/* Glue macros to select the correct {INTERNAL,INLINE}_SYSCALL variant based
+ on number of arguments used. */
+#define __SYSCALL_NARGS_X(a,b,c,d,e,f,g,h,n,...) n
+#define __SYSCALL_NARGS(...) \
+ __SYSCALL_NARGS_X (__VA_ARGS__,7,6,5,4,3,2,1,0,)
+#define __SYSCALL_CONCAT_X(a,b) a##b
+#define __SYSCALL_CONCAT(a,b) __SYSCALL_CONCAT_X (a, b)
+#define __SYSCALL_DISP(b,...) \
+ __SYSCALL_CONCAT (b,__SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
+
+
+#define __INTERNAL_SYSCALL0(name, err) \
+ INTERNAL_SYSCALL (name, err, 0)
+#define __INTERNAL_SYSCALL1(name, err, a1) \
+ INTERNAL_SYSCALL (name, err, 1, a1)
+#define __INTERNAL_SYSCALL2(name, err, a1, a2) \
+ INTERNAL_SYSCALL (name, err, 2, a1, a2)
+#define __INTERNAL_SYSCALL3(name, err, a1, a2, a3) \
+ INTERNAL_SYSCALL (name, err, 3, a1, a2, a3)
+#define __INTERNAL_SYSCALL4(name, err, a1, a2, a3, a4) \
+ INTERNAL_SYSCALL (name, err, 4, a1, a2, a3, a4)
+#define __INTERNAL_SYSCALL5(name, err, a1, a2, a3, a4, a5) \
+ INTERNAL_SYSCALL (name, err, 5, a1, a2, a3, a4, a5)
+#define __INTERNAL_SYSCALL6(name, err, a1, a2, a3, a4, a5, a6) \
+ INTERNAL_SYSCALL (name, err, 6, a1, a2, a3, a4, a5, a6)
+#define __INTERNAL_SYSCALL7(name, err, a1, a2, a3, a4, a5, a6, a7) \
+ INTERNAL_SYSCALL (name, err, 7, a1, a2, a3, a4, a5, a6, a7)
+
+/* Issue a syscall defined by syscall number plus any other argument required.
+ It is similar to INTERNAL_SYSCALL macro, but without the need to pass the
+ expected argument number as second parameter. */
+#define INTERNAL_SYSCALL_CALL(nr, err, ...) \
+ __SYSCALL_DISP (__INTERNAL_SYSCALL, nr, err, __VA_ARGS__)
+
#define __SYSCALL0(name) \
INLINE_SYSCALL (name, 0)
#define __SYSCALL1(name, a1) \
@@ -41,25 +75,22 @@
#define __SYSCALL7(name, a1, a2, a3, a4, a5, a6, a7) \
INLINE_SYSCALL (name, 7, a1, a2, a3, a4, a5, a6, a7)
-#define __SYSCALL_NARGS_X(a,b,c,d,e,f,g,h,n,...) n
-#define __SYSCALL_NARGS(...) \
- __SYSCALL_NARGS_X (__VA_ARGS__,7,6,5,4,3,2,1,0,)
-#define __SYSCALL_CONCAT_X(a,b) a##b
-#define __SYSCALL_CONCAT(a,b) __SYSCALL_CONCAT_X (a, b)
-#define __SYSCALL_DISP(b,...) \
- __SYSCALL_CONCAT (b,__SYSCALL_NARGS(__VA_ARGS__))(__VA_ARGS__)
-
-#define __SYSCALL_CALL(...) __SYSCALL_DISP (__SYSCALL, __VA_ARGS__)
+/* Issue a syscall defined by syscall number plus any other argument
+ required. Any error will be handled using arch defined macros and errno
+ will be set accordingly.
+ It is similar to INLINE_SYSCALL macro, but without the need to pass the
+ expected argument number as second parameter. */
+#define INLINE_SYSCALL_CALL(...) __SYSCALL_DISP (__SYSCALL, __VA_ARGS__)
#define SYSCALL_CANCEL(...) \
({ \
long int sc_ret; \
if (SINGLE_THREAD_P) \
- sc_ret = __SYSCALL_CALL (__VA_ARGS__); \
+ sc_ret = INLINE_SYSCALL_CALL (__VA_ARGS__); \
else \
{ \
int sc_cancel_oldtype = LIBC_CANCEL_ASYNC (); \
- sc_ret = __SYSCALL_CALL (__VA_ARGS__); \
+ sc_ret = INLINE_SYSCALL_CALL (__VA_ARGS__); \
LIBC_CANCEL_RESET (sc_cancel_oldtype); \
} \
sc_ret; \