[ltt-dev] sparc: sys32.S incorrect compat-layer splice() system call

[davem@davemloft.net (David Miller)]

From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Date: Tue, 18 Aug 2009 23:40:46 -0400

> * David Miller (davem at davemloft.net) wrote:
>> From: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
>> Date: Tue, 18 Aug 2009 22:56:23 -0400
>> 
>> > BTW, I can't figure out why we have %o5 in :
>> > 
>> > SIGN2(sys32_sync_file_range, compat_sync_file_range, %o0, %o5)
>> > 
>> > which takes only 4 arguments:
>> > 
>> >        int sync_file_range(int fd, off64_t offset, off64_t nbytes,
>> >                   unsigned int flags);
>> > 
>> > maybe it has something to do with the return value ? Anyway it should
>> > not hurt if it is unused.
>> 
>> It takes 4 arguments, but they are passed in 6 registers.  Each
>> off64_t is passed in two 32-bit register parts.
>> 
> 
> Thanks for the clarification. So the %o5 is there to sign-extend
> "unsigned int flags" ?

Yes, but it seems that might be inappropriate (albeit harmless) here.