Cc'ing more people.
On Thu, Aug 18, 2011 at 09:19:11PM +0100, Ralf Baechle wrote:
> > But really I think this patch fixes things at the wrong level. Each
> > architecture potentially needs a similar patch. What would happen if
> > we did something like:
>
> > +++ b/kernel/futex_compat.c
> > @@ -180,9 +180,9 @@ err_unlock:
> > return ret;
> > }
> >
> > -asmlinkage long compat_sys_futex(u32 __user *uaddr, int op, u32 val,
> > - struct compat_timespec __user *utime, u32 __user *uaddr2,
> > - u32 val3)
> > +SYSCALL_DEFINE6(compat_sys_futex, u32 __user *, uaddr, int , op, u32, val,
> > + struct compat_timespec __user *, utime, u32 __user *, uaddr2,
> > + u32, val3)
> > {
> > struct timespec ts;
> > ktime_t t, *tp = NULL;
> >
> > Obviously the function name is wrong, but a varient of
> > SYSCALL_DEFINE*() could be created so the proper function names are
> > produced.
>
> Right now none of the the generic compat_ functions is wrapped in
> SYSCALL_DEFINE* because for some architectures a further wrapper function
> is needed. It seems some architectures call compat_ calls directly
> without SYSCALL_DEFINE* which with CONFIG_FTRACE_SYSCALLS is a bug ...
Just checked some archs which have HAVE_SYSCALL_TRACEPOINTS=y and could
call compat_* syscalls when run 32bit process on 64bit kernel, I don't
find any special code against FTRACE_SYSCALLS. So that means we could
not trace compat syscalls even if we want to(Am I missing something?).
So I think if we want to trace it, the easy way is just like what we have
done on normal syscalls, IOW, we could SYSCALL_DEFINE all of the compat
syscalls.
Thought?
BTW, I have make a trival patch to introduce COMPAT_SYSCALL_DEFINE, it's just
for calling of inspiration(no test no build, and I leave SYSCALL_METADATA
etc untouched.)
Thanks,
Yong
---
diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h
index 8c03b98..e79027f 100644
--- a/include/linux/syscalls.h
+++ b/include/linux/syscalls.h
@@ -221,26 +221,38 @@ extern struct trace_event_functions exit_syscall_print_funcs;
__SC_STR_ADECL##x(__VA_ARGS__) \
}; \
SYSCALL_METADATA(sname, x); \
- __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+ __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
+
+#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
+ static const char *types_compat_##sname[] = { \
+ __SC_STR_TDECL##x(__VA_ARGS__) \
+ }; \
+ static const char *args_compat_##sname[] = { \
+ __SC_STR_ADECL##x(__VA_ARGS__) \
+ }; \
+ SYSCALL_METADATA(compat, sname, x); \
+ __SYSCALL_DEFINEx(cmopat_, x, sname, __VA_ARGS__)
#else
#define SYSCALL_DEFINEx(x, sname, ...) \
- __SYSCALL_DEFINEx(x, sname, __VA_ARGS__)
+ __SYSCALL_DEFINEx(, x, sname, __VA_ARGS__)
+#define COMPAT_SYSCALL_DEFINEx(x, sname, ...) \
+ __SYSCALL_DEFINEx(compat_, x, sname, __VA_ARGS__)
#endif
#ifdef CONFIG_HAVE_SYSCALL_WRAPPERS
-#define SYSCALL_DEFINE(name) static inline long SYSC_##name
+#define SYSCALL_DEFINE(compat, name) static inline long compat##SYSC_##name
-#define __SYSCALL_DEFINEx(x, name, ...) \
- asmlinkage long sys##name(__SC_DECL##x(__VA_ARGS__)); \
- static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__)); \
- asmlinkage long SyS##name(__SC_LONG##x(__VA_ARGS__)) \
+#define __SYSCALL_DEFINEx(compat, x, name, ...) \
+ asmlinkage long compat##sys##name(__SC_DECL##x(__VA_ARGS__)); \
+ static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__));\
+ asmlinkage long compat##SyS##name(__SC_LONG##x(__VA_ARGS__)) \
{ \
__SC_TEST##x(__VA_ARGS__); \
- return (long) SYSC##name(__SC_CAST##x(__VA_ARGS__)); \
+ return (long) compat##SYSC##name(__SC_CAST##x(__VA_ARGS__));\
} \
- SYSCALL_ALIAS(sys##name, SyS##name); \
- static inline long SYSC##name(__SC_DECL##x(__VA_ARGS__))
+ SYSCALL_ALIAS(compat##sys##name, compat##SyS##name); \
+ static inline long compat##SYSC##name(__SC_DECL##x(__VA_ARGS__))
#else /* CONFIG_HAVE_SYSCALL_WRAPPERS */
