Hi,

On 2016/5/12 16:24, Yury Norov wrote:

On Thu, May 12, 2016 at 11:45:53AM +0800, Zhangjian (Bamvor) wrote:

[...]

quoted

quoted

Hmm, that is indeed tricky. I think COMPAT_SYSCALL_WRAP4 rightfully
refuses the loff_t argument here, as the common case is that this is
not possible.

It works if I apply the following patch, I defined the wrong `__TYPE_IS_xxx`
yesterday. Should we merge this into ILP32 series or send the compat.h
and syscalls.h individually? The current series of ILP32 is a little bit
long and hard to review.

diff --git a/include/linux/compat.h b/include/linux/compat.h
index ba6ebe0..22a9565 100644
--- a/include/linux/compat.h
+++ b/include/linux/compat.h

@@ -747,7 +747,8 @@ asmlinkage long compat_sys_fanotify_mark(int, unsigned int, __u32, __u32,
  #ifndef __SC_COMPAT_CAST
  #define __SC_COMPAT_CAST(t, a) ({                                      \
         BUILD_BUG_ON((sizeof(t) > 4) && !__TYPE_IS_L(t) &&              \
-                    !__TYPE_IS_UL(t) && !__TYPE_IS_PTR(t));            \
+                    !__TYPE_IS_UL(t) && !__TYPE_IS_PTR(t) &&           \
+                    !__TYPE_IS_LOFFT(t));                              \

I think it's wrong, as loff_t is 64-bit in 32-bit userspace, and this
will clear meaningful data in top halve.

Yes. It is my fault. The original thoughts is clear the up 32bit for size_t.
How should we skip the loff_t?

Regards

Bamvor